236 results on '"WALLABIES"'
Search Results
2. An improved Tully–Fisher estimate of H0.
- Author
-
Boubel, Paula, Colless, Matthew, Said, Khaled, and Staveley-Smith, Lister
- Subjects
- *
COSMOLOGICAL distances , *TYPE I supernovae , *RED giants , *GALAXIES , *WALLABIES - Abstract
We propose an improved comprehensive method for determining the Hubble constant (|$H_0$|) using the Tully–Fisher relation. By fitting a peculiar velocity model in conjunction with the Tully–Fisher relation, all available data can be used to derive self-consistent Tully–Fisher parameters. In comparison to previous approaches, our method offers several improvements: it can be readily generalized to different forms of the Tully–Fisher relation and its intrinsic scatter; it uses a peculiar velocity model to predict distances more accurately; it can account for all selection effects; it uses the entire data set to fit the Tully–Fisher relation; and it is fully self-consistent. The Tully–Fisher relation zero-point is calibrated using the subset of galaxies with distances from absolute distance indicators. We demonstrate this method on the Cosmicflows-4 catalogue i -band and |$W1$| -band Tully–Fisher samples and show that the uncertainties from fitting the Tully–Fisher relation amount to only 0.2 km s |$^{-1}$| Mpc |$^{-1}$|. Using all available absolute distance calibrators, we obtain |$H_0=73.3$| |$\pm$| 2.1 (stat) |$\pm$| 3.5 (sys) km s |$^{-1}$| Mpc |$^{-1}$| , where the statistical uncertainty is dominated by the small number of galaxies with absolute distance estimates. The substantial systematic uncertainty reflects inconsistencies between various zero-point calibrations of the Cepheid period–luminosity relation, the tip of the red giant branch standard candle, and the Type Ia supernova standard candle. However, given a reliable set of absolute distance calibrators, our method promises enhanced precision in |$H_0$| measurements from large new Tully–Fisher samples such as the WALLABY survey. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
3. Imprinted X chromosome inactivation in marsupials: The paternal X arrives at the egg with a silent DNA methylation profile.
- Author
-
Milton, Ashley M., Marín-Gual, Laia, Lister, Nicholas C., McIntyre, Kim L., Grady, Patrick G. S., Laird, Melanie K., Bond, Donna M., Hore, Timothy A., O'Neill, Rachel J., Pask, Andrew J., Renfree, Marilyn B., Ruiz-Herrera, Aurora, and Waters, Paul D.
- Subjects
- *
X chromosome , *DNA methylation , *SOMATIC cells , *GENETIC transcription , *WALLABIES - Abstract
X chromosome inactivation (XCI) is an epigenetic process that results in the transcriptional silencing of one X chromosome in the somatic cells of females. This phenomenon is common to both eutherian and marsupial mammals, but there are fundamental differences. In eutherians, the X chosen for silencing is random. DNA methylation on the eutherian inactive X is high at transcription start sites (TSSs) and their flanking regions, resulting in universally high DNA methylation. This contrasts XCI in marsupials where the paternally derived X is always silenced, and in which DNA methylation is low at TSSs and flanking regions. Here, we examined the DNA methylation status of the tammar wallaby X chromosome during spermatogenesis to determine the DNA methylation profile of the paternal X prior to and at fertilization. Whole genome enzymatic methylation sequencing was carried out on enriched flow-sorted populations of premeiotic, meiotic, and postmeiotic cells. We observed that the X displayed a pattern of DNA methylation from spermatogonia to mature sperm that reflected the inactive X in female somatic tissue. Therefore, the paternal X chromosome arrives at the egg with a DNA methylation profile that reflects the transcriptionally silent X in adult female somatic tissue. We present this epigenetic signature as a candidate for the long sought-after imprint for paternal XCI in marsupials. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
4. WALLABY pilot survey: the Tully–Fisher relation in the NGC 4808, Vela, and NGC 5044 fields.
- Author
-
Mould, Jeremy, Jarrett, T H, Courtois, Hélène, Bosma, Albert, Deg, Nathan, Dupuy, Alexandra, Staveley-Smith, Lister, Taylor, E N, English, Jayanne, Rajohnson, S H A, Kraan-Korteweg, Renée, Forbes, Duncan, Dénes, Helga, Lee-Waddell, Karen, Shen, Austin, Wong, O I, Holwerda, Benne, Koribalski, Bärbel, Leahy, Denis, and Piña, Pavel Mancera
- Subjects
- *
PHASED array antennas , *SPIRAL galaxies , *DARK energy , *WALLABIES , *DATA release - Abstract
The Tully–Fisher Relation (TFR) is a well-known empirical relationship between the luminosity of a spiral galaxy and its circular velocity, allowing us to estimate redshift independent distances. Here we use high signal-to-noise H i 21-cm integrated spectra from the second pilot data release (PDR2, 180 deg2) of the Widefield ASKAP L -band Legacy All-sky Blind surveY (WALLABY). In order to prepare for the full WALLABY survey, we have investigated the TFR in phase 2 of the pilot survey with a further three fields. The data were obtained with wide-field Phased Array Feeds on the Australian Square Kilometre Array Pathfinder (ASKAP) and have an angular resolution of 30 arcsec and a velocity resolution of |$\sim$| 4 km s−1. Galaxy luminosities have been measured from the Wide-field Infrared Survey Explorer , and optical galaxy inclinations from the Dark Energy Camera Legacy Survey. We present TFRs for wavelengths from 0.8 to 3.4 μ m. We examine sources of galaxy inclination data and investigate magnitudes from the DECam Local Volume Exploration Survey and DENIS catalogues and the 4HS target catalogue based on the VISTA Hemisphere Survey. We consider the baryonic TFR. These are all of interest for TFR using the full WALLABY survey of 200 000 galaxies. We demonstrate that WALLABY TFR distances can take their place among state-of-the-art studies of the local velocity field. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
5. WALLABY pilot survey: an 'almost' dark cloud near the Hydra cluster.
- Author
-
O'Beirne, T, Staveley-Smith, L, Wong, O I, Westmeier, T, Batten, G, Kilborn, V A, Lee-Waddell, K, Mancera Piña, P E, Román, J, Verdes-Montenegro, L, Catinella, B, Cortese, L, Deg, N, Dénes, H, For, B Q, Kamphuis, P, Koribalski, B S, Murugeshan, C, Rhee, J, and Spekkens, K
- Subjects
- *
WALLABIES , *DARK energy , *OPTICAL limiting , *DATA release , *GALACTIC evolution - Abstract
We explore the properties of an 'almost' dark cloud of neutral hydrogen (H i) using data from the Widefield ASKAP L-band Legacy All-sky Survey (WALLABY). Until recently, WALLABY J103508 − 283427 (also known as H1032 − 2819 or LEDA 2793457) was not known to have an optical counterpart, but we have identified an extremely faint optical counterpart in the Dark Energy Spectroscopic Instrument (DESI) Legacy Imaging Survey Data Release 10. We measured the mean g -band surface brightness to be 27.0 ± 0.3 mag arcsec−2. The WALLABY data revealed the cloud to be closely associated with the interacting group Klemola 13 (also known as HIPASS J1034 − 28 and the Tol 9 group), which itself is associated with the Hydra cluster. In addition to WALLABY J103508 − 283427/H1032 − 2819, Klemola 13 contains 10 known significant galaxies and almost half of the total H i gas is beyond the optical limits of the galaxies. By combining the new WALLABY data with archival data from the Australia Telescope Compact Array, we investigate the H i distribution and kinematics of the system. We discuss the relative role of tidal interactions and ram pressure stripping in the formation of the cloud and the evolution of the system. The ease of detection of this cloud and intragroup gas is due to the sensitivity, resolution, and wide field of view of WALLABY, and showcases the potential of the full WALLABY survey to detect many more examples. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
6. WALLABY pilot survey: the potential polar ring galaxies NGC 4632 and NGC 6156.
- Author
-
Deg, N, Palleske, R, Spekkens, K, Wang, J, Jarrett, T, English, J, Lin, X, Yeung, J, Mould, J R, Catinella, B, Dénes, H, Elagali, A, For, B -Q, Kamphuis, P, Koribalski, B S, Lee-Waddell, K, Murugeshan, C, Oh, S, Rhee, J, and Serra, P
- Subjects
- *
WALLABIES , *GALAXIES , *DATA release , *VIRTUAL reality software - Abstract
We report on the discovery of two potential polar ring galaxies (PRGs) in the WALLABY Pilot Data Release 1 (PDR1). These untargeted detections, cross-matched to NGC 4632 and NGC 6156, are some of the first galaxies where the H i observations show two distinct components. We used the iDaVIE virtual reality software to separate the anomalous gas from the galactic gas and found that the anomalous gas comprises ∼50 per cent of the total H i content of both systems. We have generated plausible 3D kinematic models for each galaxy, assuming that the rings are circular and inclined at 90° to the galaxy bodies. These models show that the data are consistent with PRGs but do not definitively prove that the galaxies are PRGs. By projecting these models at different combinations of main disc inclinations, ring orientations, and angular resolutions in mock data cubes, we have further investigated the detectability of similar PRGs in WALLABY. Assuming that these galaxies are indeed PRGs, the detectability fraction, combined with the size distribution of WALLABY PDR1 galaxies, implies an incidence rate of ∼1–3 per cent. If this rate holds true, the WALLABY survey will detect hundreds of new polar ring galaxies. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
7. To eat, or not to eat: a phantom decoy affects information-gathering behavior by a free-ranging mammalian herbivore.
- Author
-
Orlando, Cristian Gabriel, Banks, Peter B, Latty, Tanya, and McArthur, Clare
- Subjects
- *
HERBIVORES , *ABSOLUTE value , *WALLABIES , *SWAMPS , *FOOD animals - Abstract
When foraging, making appropriate food choices is crucial to an animal's fitness. Classic foraging ecology theories assume animals choose food of greatest benefit based on their absolute value across multiple dimensions. Consequently, poorer options are considered irrelevant alternatives that should not influence decision-making among better options. But heuristic studies demonstrate that irrelevant alternatives (termed decoys) can influence the decisions of some animals, indicating they use a relative rather than absolute evaluation system. Our aim was to test whether a decoy influenced the decision-making process—that is, information-gathering and food choice—of a free-ranging mammalian herbivore. We tested swamp wallabies, Wallabia bicolor, comparing their behavior toward, and choice of, two available food options over time in the absence or presence of the decoy. We used a phantom decoy—unavailable option—and ran two trials in different locations and seasons. Binary preferences (decoy absent) for the two available food options differed between trials. Irrespective of this difference, across both trials the presence of the decoy resulted in animals more likely to overtly investigate available food options. But, the decoy only shifted food choice, weakly, in one trial. Our results indicate that the decoy influenced the information-gathering behavior during decision-making, providing the first evidence that decoys can affect decision-making process of free-ranging mammalian herbivores in an ecologically realistic context. It is premature to say these findings confirm the use of relative evaluation systems. Whether the foraging outcome is more strongly affected by other decoys, food dimensions, or ecological contexts, is yet to be determined. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
8. Development of the ethmoid in a wallaby and implications for the homology of turbinal elements in marsupials.
- Author
-
Macrini, Thomas E., Hopwood, Jenna, Herbert, Catherine A., and Weisbecker, Vera
- Subjects
- *
WALLABIES , *MARSUPIALS , *COMPUTED tomography , *SYSTEMS development - Abstract
The homologies of the turbinals (scroll bones) of the ethmoid are not well understood, including the potential implication for understanding mammalian phylogeny. Here we examine the postnatal development of this anatomical system in a marsupial mammal because previous work has shown that the adult pattern of five endoturbinals (ethmoturbinals) and two ectoturbinals (frontoturbinals) is conserved. Furthermore, marsupial phylogeny is fairly well resolved and provides a solid evolutionary framework for examining turbinal homologies. In this study, we documented the development of the ethmoid of the tammar wallaby, Notamacropus eugenii, using histology and computed tomography imagery of a growth series of pouch young. The pattern of development of the turbinal elements in the wallaby was compared to that in didelphids, as described in previous work. We found that four ethmoturbinals initially develop, followed later in development by an interturbinal; these five elements then develop into the bony endoturbinals found in adults. These data support the idea that endoturbinal III, derived from an interturbinal, has a distinctive development pattern from the other endoturbinals. This is consistent with what is seen in the didelphid marsupials, Caluromys philander and Monodelphis domestica, suggesting this is a common developmental pattern for marsupials. This article is part of the theme issue 'The mammalian skull: development, structure and function'. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
9. WALLABY pre-pilot and pilot survey: The Tully Fisher relation in Eridanus, Hydra, Norma, and NGC4636 fields.
- Author
-
Courtois, Hélène M, Said, Khaled, Mould, Jeremy, Jarrett, T H, Pomarède, Daniel, Westmeier, Tobias, Staveley-Smith, Lister, Dupuy, Alexandra, Hong, Tao, Guinet, Daniel, Howlett, Cullan, Deg, Nathan, For, Bi-Qing, Kleiner, Dane, Koribalski, Bärbel, Lee-Waddell, Karen, Rhee, Jonghwan, Spekkens, Kristine, Wang, Jing, and Wong, O I
- Subjects
- *
WALLABIES , *FISHING surveys , *GALAXY spectra , *LARGE scale structure (Astronomy) , *GALACTIC redshift , *GAMMA ray bursts - Abstract
The WALLABY pilot survey has been conducted using the Australian SKA Pathfinder (ASKAP). The integrated 21-cm H i line spectra are formed in a very different manner compared to usual single-dish spectra Tully–Fisher measurements. It is thus extremely important to ensure that slight differences (e.g. biases due to missing flux) are quantified and understood in order to maximise the use of the large amount of data becoming available soon. This article is based on four fields for which the data are scientifically interesting by themselves. The pilot data discussed here consist of 614 galaxy spectra at a rest wavelength of 21 cm. Of these spectra, 472 are of high enough quality to be used to potentially derive distances using the Tully–Fisher relation. We further restrict the sample to the 251 galaxies whose inclination is sufficiently close to edge-on. For these, we derive Tully–Fisher distances using the deprojected WALLABY velocity widths combined with infrared (WISE W 1) magnitudes. The resulting Tully–Fisher distances for the Eridanus, Hydra, Norma, and NGC4636 clusters are 21.5, 53.5, 69.4, and 23.0 Mpc, respectively, with uncertainties of 5–10 per cent, which are better or equivalent to the ones obtained in studies using data obtained with giant single dish telescopes. The pilot survey data show the benefits of WALLABY over previous giant single-dish telescope surveys. WALLABY is expected to detect around half a million galaxies with a mean redshift of |$z = 0.05 (200\, \mathrm{Mpc})$|. This study suggests that about 200 000 Tully–Fisher distances might result from the survey. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
10. Marsupial genome analysis suggests that satellite DNA formation from walb endogenous retrovirus is an event specific to the red‐necked wallaby.
- Author
-
Koga, Akihiko, Hashimoto, Kenji, Honda, Yusuke, and Nishihara, Hidenori
- Subjects
- *
SATELLITE DNA , *WALLABIES , *MARSUPIALS , *NUMBERS of species , *TANDEM repeats - Abstract
We recently identified walbRep, a satellite DNA residing in the genome of the red‐necked wallaby Notamacropus rufogriseus. It originates from the walb endogenous retrovirus and is organized in a manner in which the provirus structure is retained. The walbRep repeat units feature an average pairwise nucleotide identity as high as 99.5%, raising the possibility of a recent origin. The tammar wallaby N. eugenii is a species estimated to have diverged from the red‐necked wallaby 2–3 million years ago. In PCR analyses of these two and other related species, walbRep‐specific fragment amplification was observed only in the red‐necked wallaby. Sequence database searches for the tammar wallaby resulted in sequence alignment lists that were sufficiently powerful to exclude the possibility of walbRep existence. These results suggested that the walbRep formation occurred in the red‐necked wallaby lineage after its divergence from the tammar wallaby lineage, thus in a time span of maximum 3 million years. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
11. Paternal imprinting and X chromosome inactivation.
- Author
-
T. J.
- Subjects
- *
X chromosome , *DNA methylation , *GENETIC transcription , *WALLABIES , *MARSUPIALS - Published
- 2024
- Full Text
- View/download PDF
12. Rustrela virus infection – An emerging neuropathogen of red‐necked wallabies (Macropus rufogriseus).
- Author
-
Voss, Anne, Schlieben, Patricia, Gerst, Sascha, Wylezich, Claudia, Pfaff, Florian, Langner, Christoph, Niesler, Michael, Schad, Petra, Beer, Martin, Rubbenstroth, Dennis, Breithaupt, Angele, and Mundhenk, Lars
- Subjects
- *
VIRUS diseases , *WALLABIES , *MICROTUS , *NUCLEIC acid hybridization , *ZOO animals , *PLANT viruses - Abstract
Summary: The rustrela virus (RusV) was recently described as a novel pathogen in a circumscribed area of northern Germany close to the Baltic Sea. Up to now, the virus has been detected in cases of fatal non‐suppurative meningoencephalitis in zoo animals of different species and a single wild carnivore as well as in apparently healthy yellow‐necked field mice (Apodemus flavicollis). Data regarding the background of this previously undiscovered pathogen, including clinical presentation of the disease, host range and distribution of the virus, are still limited. Here, three euthanized red‐necked wallabies (Macropus rufogriseus) from zoos of different areas in northeastern Germany were submitted for necropsy after presenting with apathy and therapeutically unresponsive neurological signs. A moderate to severe, non‐suppurative meningoencephalitis was diagnosed in all three cases. RusV was consistently detected via RT‐qPCR and RNA in situ hybridization in the brains of all wallabies. Other commonly known neuropathogens could not be detected. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
13. Arterial Circle of the Brain of the Red-Necked Wallaby (Notamacropus rufogriseus).
- Author
-
Zdun, Maciej, Ruszkowski, Jakub J., Gogulski, Maciej, Józefiak, Agata, and Hetman, Mateusz
- Subjects
- *
WALLABIES , *CARDIOVASCULAR system , *MARSUPIALS , *MAMMALS , *CIRCLE of Willis - Abstract
Simple Summary: The red-necked wallaby is a small, herbivorous mammal that is native to Australia. In the study, the anatomy of arterial vessels that transport blood to the brain in this species was described and compared with that of other groups of mammals. The results of this research can contribute to further physiological and pathophysiological studies. This is the first description of this anatomical area that has been carried out in a marsupial species. The red-necked wallaby is a medium-sized marsupial species, which have increasingly been kept as pets around the world. In the study, the arterial blood supply for the brain in this species was described. The study was conducted on 50 specimens with two preparation methods. The main artery supplying the brain was the internal carotid artery. The arterial circle of the brain was closed from the caudal side. The anatomy of the arteries of the described region was compared with other groups of mammals. This is the first description of this anatomical area that has been carried out in a marsupial species. Understanding the anatomy of the circulatory system in the wallaby can be valuable for further physiological and pathophysiological studies. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
14. From Embryo to Adult: The Complete Development and Unusual Replacement of the Dentition of the Tammar Wallaby (Macropus eugenii).
- Author
-
Nasrullah, Qamariya, Renfree, Marilyn, and Evans, Alistair R.
- Subjects
- *
ADULT development , *DENTITION , *WALLABIES , *DECIDUOUS teeth , *INCISORS - Abstract
Unlike their reptile-like ancestors with continuous tooth replacement, mammals have evolved to replace each tooth either only once, or not at all. In previous large-scale comparative studies, it has been suggested that this tooth replacement only occurs from a successional dental lamina produced lingually to the primary tooth. This study aims to document the complete tooth development and replacement pattern of the tammar wallaby (Macropus eugenii). The tammar wallaby is a diprotodont marsupial, a group defined by their two procumbent lower incisors. To provide a comprehensive documentation of the spatio-temporal pattern of tooth development, we used Lugol's Iodine staining and microCT scanning (diceCT) of embryos and pouch young into adulthood, resulting in high resolution 3D models for both soft and mineralised stages of development for all tooth positions. Our results reveal that the eponymous lower incisors are the successional generation at the third incisor locus, where the primary dentition initiates but never erupts. Furthermore, we track the development of the only replacement tooth, the permanent third premolar (P3), from initiation to eruption, and found it develops from the primary dental lamina, mesial to the dP3. This is contrary to the conventional view of lingual replacement from successional lamina in mammals. Our findings indicate that no functional tooth replacement occurs in the tammar wallaby, and expands the diversity of tooth replacement patterns found in mammals. We also conclude that since almost all marsupial and placental mammals produce replacement teeth from the distalmost deciduous premolar, this tooth should be considered homologous in these two groups. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
15. The impact of headstarting on the survival and naiveté of an endangered terrestrial mammal after return to the wild.
- Author
-
Ross, A. K., Lawes, J. C., and Letnic, M.
- Subjects
- *
RARE mammals , *PREDATION , *WALLABIES , *PREDATORY animals , *MAMMALS , *SPECIES - Abstract
Complete separation of endangered prey from introduced predators improves prey survival at the cost of reduced predator recognition and antipredator behaviours, termed 'prey naiveté'. Headstarting is a conservation strategy that has been used to improve the survival of juveniles for numerous species, whereby prey is separated from predators only in their vulnerable early life stage before release to the wild. However, by isolating prey from predators headstarting could compromise prey individuals' antipredator behaviour. Here, we evaluate the effects that headstarting has on the survival, dispersal, body condition and flight initiation distance (FID) of a terrestrial mammal, the bridled nailtail wallaby Onychogalea fraenata. Young bridled nailtail wallabies were isolated from predators in a 9.2 ha predator‐free fenced exclosure and were released into the wild once their body mass exceeded 3 kg. There was no difference in dispersal, body condition or survival of headstarted wallabies compared to wild‐raised wallabies. FID of headstarted wallabies assessed using night‐vision goggles was lower than wild‐raised wallabies in the week following release, but converged with that of wild‐raised wallabies within 4 weeks post‐release. Our results show that headstarting can be an effective conservation strategy for terrestrial mammals whose early life stages are vulnerable to introduced predators. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
16. An endogenous retrovirus presumed to have been endogenized or relocated recently in a marsupial, the red-necked wallaby.
- Author
-
Hayashi, Sakura, Shimizu, Konami, Honda, Yusuke, Katsura, Yukako, and Koga, Akihiko
- Subjects
- *
WALLABIES , *MARSUPIALS , *AMINO acid sequence , *MELANINS , *INVOLUNTARY relocation , *VIRUS diseases - Abstract
An albino infant wallaby was born to a mother with wild-type body color. PCR and sequencing analyses of TYR (encoding tyrosinase, which is essential for melanin biosynthesis) of this albino wallaby revealed a 7.1-kb-long DNA fragment inserted in the first exon. Since the fragment carried long terminal repeats, we assumed it to be a copy of an endogenous retrovirus, which we named walb. We cloned other walb copies residing in the genomes of this species and of another wallaby species. The copies exhibited length variation, and the longest copy (>8.0 kb) contained open reading frames whose deduced amino acid sequences were well aligned with those of gag, pol, and env of retroviruses. It is unknown through which of the following likely processes the walb copy was inserted into TYR: endogenization (infection of a germline cell by an exogenous virus), reinfection (infection by a virus produced from a previously endogenized provirus), or retrotransposition (intracellular relocation of a provirus). In any case, the insertion into TYR is considered to have been a recent event on an evolutionary timescale because albino mutant alleles generally do not persist for long because of their deleterious effects in wild circumstances. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
17. Morphological pattern of the pes tendons in Bennett's Wallaby (Macropus rufogriseus).
- Author
-
Yunus, Hasen Awel, Ekim, Okan, Bakıcı, Caner, Bakıcı, Merve, and Batur, Barış
- Subjects
- *
TENDONS , *WALLABIES , *PHALANGES , *FLEXOR tendons , *HINDLIMB , *METATARSUS - Abstract
Wallabies are small‐ to medium‐sized hopping marsupials and have large and flexible tendons in their hind limbs that act like springs. This study aimed to show the morphological pattern of the pes tendons in Bennett's wallaby. Two Bennett's Wallabies (Macropus rufogriseus) that died of natural causes have been used for this study. The pes was dissected using standard dissection techniques to expose the tendons around metatarsals and digits. The crural musculature of the hind limb was also dissected to identify the origin of the tendons. Tendons of m. extensor digitorum longus, m. extensor digitorum lateralis, m. extensor digiti II et III longus, m. flexor digitorum superficialis, m. flexor digitorum profundus and mm. interossei were the main identified tendons. Tendons of m. extensor digitorum longus attached to the distal phalanx of the fourth digit. The tendon of m. extensor digitorum lateralis had two insertion points, on the fourth and the fifth digits. The tendon of m. flexor digitorum superficialis bifurcates at the level proximal one‐third of the metatarsus. The relatively thinner branch inserted into the phalanx of the fifth digit, while the thicker splits and inserted to the medial and lateral surface of the distal end of the proximal phalanx of the fourth digit. Tendon of m. flexor digitorum profundus was the thickest tendon on the plantar surface, and it had four insertion points, which were the distal phalanges of the second, third, fourth and fifth digits. This study provides detailed information for future studies on the biomechanical and functional morphology of tendons in marsupials. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
18. Activity patterns and temporal niche partitioning in sympatric red‐legged and red‐necked pademelons.
- Author
-
Smith, Lucy E. V., Andrew, Nigel R., and Vernes, Karl
- Subjects
- *
WALLABIES , *CIRCADIAN rhythms - Abstract
Temporal partitioning between ecologically similar species facilitates co‐occurrence and can influence the structure of mammalian assemblages. We studied diel activity patterns of two sympatric forest‐dwelling wallabies, the red‐legged pademelon (Thylogale stigmatica) and red‐necked pademelon (Thylogale thetis) in eastern Australia to better understand spatiotemporal partitioning between these closely related macropods. Temporally, both species displayed strongly crepuscular activity patterns typical of many macropod species; however, compared with T. thetis, T. stigmatica was less active during evening twilight and more active in the period prior to dawn. Spatially, T. stigmatica used dense forest cover exclusively throughout the 24‐hour cycle, while T. thetis divided its habitat spatiotemporally, spending the diurnal period under forest cover and the nocturnal period on pasture beyond the forest edge. In practical terms, this meant that T. stigmatica and T. thetis were fully spatially segregated at night, during the period they would be likely to do most of their foraging. We propose that the spatiotemporal partitioning observed is niche partitioning, and provides a mechanism for the co‐occurrence of these closely related species. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
19. Time since fire influences macropod occurrence in a fire‐prone coastal ecosystem.
- Author
-
Chard, Matthew, Foster, Claire N., Lindenmayer, David B., Cary, Geoffrey J., MacGregor, Christopher I., and Blanchard, Wade
- Subjects
- *
FIRE management , *ECOSYSTEM management , *WILDLIFE management , *PREDATION , *FIRE ecology , *ECOSYSTEMS , *WALLABIES , *NATIONAL parks & reserves - Abstract
Knowledge of animal responses to fire is fundamental to wildlife management in fire‐prone ecosystems. Fire can influence the occurrence of large herbivores by altering the structure and composition of vegetation. However, how fire affects herbivore occurrence in many ecosystems is poorly understood. Large herbivores may be attracted to burnt areas due to higher foraging quality. Conversely, herbivores may avoid burnt areas due to heightened predation risk. We tested the influence of vegetation type and fire history variables on the occurrence of macropods at Booderee National Park in south‐eastern Australia. We documented macropod occurrence at 107 long‐term monitoring sites using spotlighting surveys conducted between 2003 and 2019. We modelled relationships between the occurrence of the eastern grey kangaroo (Macropus giganteus) and the swamp wallaby (Wallabia bicolor) with three fire history variables; time since fire, fire frequency and burn context (the proportion of the area surrounding each site that was recently burnt), as well as their interaction with vegetation type. We found both macropod species selected recently burnt sites, likely due to a higher abundance of preferred plants at these sites. Increasing fire frequency was associated with a reduced occurrence of the eastern grey kangaroo. The occurrence of both macropod species was significantly higher in forest sites, possibly reflecting higher foraging quality of grass and shrub species compared to woodland, heathland and shrubland sites. We suggest that if fire is used as a management tool, it is important to recognise potential feedbacks from increased foraging pressure from large herbivores. Future fire management will need to avoid burning areas of sensitive vegetation if local herbivores display pyric herbivory responses, and/or avoid small‐scale burns, which may concentrate foraging pressure. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
20. Utilising power analyses and occupancy modelling to inform population monitoring of the regionally endangered black‐striped wallaby (Macropus dorsalis) in New South Wales.
- Author
-
McHugh, Darren and Goldingay, Ross L.
- Subjects
- *
WALLABIES , *RARE mammals , *ENDANGERED species , *LANDSCAPE changes , *ORIENTAL fruit fly , *DINGO - Abstract
Small macropodoid marsupials are well represented among Australia's extinct and threatened mammals. Population monitoring is central to understanding how remaining species respond to on‐going landscape change and threatening processes on private land and within managed conservation reserves. Camera trapping and occupancy modelling provide a reliable approach to monitor these often cryptic species. However, understanding the survey effort required to detect population declines of a given magnitude with high statistical certainty is often overlooked. We use empirical data from camera trapping and occupancy modelling to determine an optimal survey design for a regionally endangered population of the black‐striped wallaby. We established a 1200 ha grid of 60 cameras and sampled in three 30‐day intervals over a 1‐year period. We investigated factors that may influence occupancy and detection followed by power analyses with our broad objective being to devise a monitoring program that would be robust enough to detect a 50% decline with at least 80% power. This species was not detected at rainforest sites. Naïve occupancy within eucalypt forest was 0.42. The detection probability (using 5‐day detection occasions) varied with season (from 0.17 ± 0.04 in autumn to 0.34 ± 0.05 in spring). Occupancy was negatively influenced by shrub cover and negatively influenced by elevation. We found no apparent influence of dingo detection on occupancy or detection of the black‐striped wallaby. We explored different configurations of detection sites and number of survey occasions to satisfy our 50:80 criteria when initial occupancy was 0.40. Sampling 60 sites for a minimum of 30 days would satisfy these criteria. Power analyses can inform optimal designs for threatened species monitoring and similar investigations should be conducted for other threatened small macropods to assist their conservation. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
21. Takotsubo-like Cardiomyopathy Associated with Capture Myopathy in a Zoo-Kept, Red-Necked Wallaby (Macropus Rufogriseus).
- Author
-
C., Tanner M., D., Thomason J., T., Rooney, M., Schneider S., R., Lynn C., and D., Eshar
- Subjects
- *
CARDIOMYOPATHIES , *WALLABIES , *MALIGNANT hyperthermia , *TAKOTSUBO cardiomyopathy , *MUSCLE diseases , *DIASTOLE (Cardiac cycle) , *NEMALINE myopathy - Published
- 2022
22. WALLABY pilot survey: H i gas disc truncation and star formation of galaxies falling into the Hydra I cluster.
- Author
-
Reynolds, T N, Catinella, B, Cortese, L, Westmeier, T, Meurer, G R, Shao, L, Obreschkow, D, Román, J, Verdes-Montenegro, L, Deg, N, Dénes, H, For, B-Q, Kleiner, D, Koribalski, B S, Lee-Waddell, K, Murugeshan, C, Oh, S-H, Rhee, J, Spekkens, K, and Staveley-Smith, L
- Subjects
- *
GALAXY formation , *STAR formation , *WALLABIES , *GALAXY clusters , *GAS reservoirs , *ATOMIC hydrogen - Abstract
We present results from our analysis of the Hydra I cluster observed in neutral atomic hydrogen (H i) as part of the Widefield ASKAP L-band Legacy All-sky Blind Survey (WALLABY). These WALLABY observations cover a 60-square-degree field of view with uniform sensitivity and a spatial resolution of 30 arcsec. We use these wide-field observations to investigate the effect of galaxy environment on H i gas removal and star formation quenching by comparing the properties of cluster, infall, and field galaxies extending up to ∼5 R 200 from the cluster centre. We find a sharp decrease in the H i -detected fraction of infalling galaxies at a projected distance of ∼1.5 R 200 from the cluster centre from |$\sim 85{{\ \rm per\ cent}}$| to |$\sim 35{{\ \rm per\ cent}}$|. We see evidence for the environment removing gas from the outskirts of H i -detected cluster and infall galaxies through the decrease in the H i to r -band optical disc diameter ratio. These galaxies lie on the star-forming main sequence, indicating that gas removal is not yet affecting the inner star-forming discs and is limited to the galaxy outskirts. Although we do not detect galaxies undergoing galaxy-wide quenching, we do observe a reduction in recent star formation in the outer disc of cluster galaxies, which is likely due to the smaller gas reservoirs present beyond the optical radius in these galaxies. Stacking of H i non-detections with H i masses below |$M_{\rm {HI}}\lesssim 10^{8.4}\, \rm {M}_{\odot }$| will be required to probe the H i of galaxies undergoing quenching at distances ≳60 Mpc with WALLABY. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
23. Successful bilateral phacoemulsification and vitrectomy in a Bennett's wallaby (Macropus rufogriseus).
- Author
-
Sailler, Anaïs, Prieto, Morgane, and Goulle, Frédéric
- Subjects
- *
WALLABIES , *VITRECTOMY , *PHACOEMULSIFICATION , *VITREOUS humor , *SURGICAL complications - Abstract
CASE DESCRIPTION: A 7 - month - old hand - reared female Bennett's wallaby (Macropus rufogriseus) was evaluated for bilateral ocular opacity of 3 months' duration. CLINICALFINDINGS: On physical examination, the wallaby was in good overall condition. An ophthalmic examination revealed mature cataracts in both eyes (OU). The cataracts were suspected to have a nutritional origin as it has been described in hand-reared macropods. Results of tonometry were normal OU. Results of CBC and serum biochemistry were unremarkable. The wallaby was premedicated with medetomidine and ketamine hydrochloride. Ocular ultrasonography performed while the wallaby was anesthetized revealed a thickened and opaque lens, mildly heterogeneous vitreous humor, and no sign of retinal detachment OU. An electroretinogram confirmed functional retinae OU. TREATMENTANDOUTCOME: Surgery was considered necessary for welfare reasons. Phacoemulsification and vitrectomy were performed without intraoperative complication. The wallaby recovered uneventfully, and systemic NSAID, topical corticosteroid, and systemic and topical antimicrobial therapy were prescribed. One year later, the animal had vision OU. Physical examination did not show any vision-threatening postoperative complications. CLINICALRELEVANCE: The etiology of nutritional cataracts is not fully understood in macropods, but this condition is rather common in these species. To our knowledge, this is the first detailed report of a successful bilateral phacoemulsification and vitrectomy in a Bennett's wallaby. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
24. Cross‐cultural collaboration leads to greater understanding of the rare Spectacled Hare‐wallaby in the west Kimberley, Western Australia.
- Author
-
Wysong, Michael L., Gregory, Pius, Watson, Alexander W. T., Woolley, Leigh‐Ann, Parker, Christopher W., Country Managers, Yawuru, Rangers, Karajarri, and Mangala Rangers, Nyikina
- Subjects
- *
DINGO , *FERAL cats , *CATS , *CATTLE , *WALLABIES , *FELIDAE - Abstract
Summary: Cross‐cultural collaboration between Yawuru Country Managers (Rangers) and WWF‐Australia ecologists led to new detections of the Spectacled Hare‐wallaby (SHW), (Lagorchestes conspicillatus) in the west Kimberley region of Western Australia where it was presumed to be locally extirpated. This collaboration relied on the expertise of the Yawuru Country Managers to select specific locations for targeted field surveys and resulted in the confirmation of SHW on the Yawuru IPA for the first time in a decade. Subsequent remote camera trap surveys over a larger area included collaboration with two additional neighbouring Indigenous ranger groups, Karrajarri and Nyikina Mangala. These surveys investigated the spatial and temporal relationship between SHW and other mammals which may threaten (e.g., feral Cat [Felis catus], Dingo [Canis familiaris dingo]) or compete (e.g., Agile Wallaby [Macropus agilis]; Cattle [Bos taurus]) with them. We found a negative relationship between SHW and cat activity, suggesting that cats may limit the activity or abundance of SHW. Temporal portioning was evident between SHW and both Cattle and Agile Wallaby suggesting that SHW may avoid times when these species are most active. Further, we found a negative relationship between SHW occurrence and distance to fire scar edge burnt in current or previous fire season. This edge habitat is likely important to SHW because they may require recently burnt areas to forage and dense unburnt areas to shelter. This project highlights the benefits of cross‐cultural research and monitoring partnerships with Indigenous rangers as active observers and managers of their traditional lands. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
25. Evaluating methods for controlling feral cats that minimise non‐target impacts at Taunton National Park (Scientific).
- Author
-
Augusteyn, John and Nolan, Barry
- Subjects
- *
FERAL cats , *CATS , *NATIONAL parks & reserves , *FELIDAE , *SAWLOGS , *WALLABIES - Abstract
Summary: Feral Cat (Felis catus) (cat) is a predator of the Bridled Nail‐Tailed Wallaby (BNTW) (Onychogalea frenata) living at Taunton National Park (Scientific) (Taunton). The aim of this study was to determine if traps and poison baits could be used to control feral cats without impacting non‐target species at Taunton. The techniques trialled included poison fresh meat baits and several types of traps presented in different ways and with various lures. Thirty‐one percent of fresh meat baits was taken during bait uptake trials; corvids removed 40% of these and dogs removed 16%. Cats were not detected, on camera traps, taking a bait. The elevated soft‐jaw traps (81 trap nights/cat) and single‐entry cage traps (98 trap nights/cat) were found to be the most successful of all the trap types trialled and had low amounts of by‐catch. Other trap types trialled took more than 166 trap nights to catch a cat. The elevated soft‐jaw trap configurations had the lowest amount of by‐catch (avg. 0.33%), and the log trap had the highest amount of by‐catch (1%). Ground‐set traps successfully trapped cats (305 trap nights/cat) but caught more by‐catch (0.9%) compared to the elevated soft‐jaw trap types and most wallabies caught in these traps had to be euthanised. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
26. Harvesting Agile Wallabies for human consumption in the Northern Territory of Australia.
- Author
-
Hunt, Warren, Bedoya‐Perez, Miguel, Geesink, Geert, Van Den Heuvel, Aaron, Mullen, John, and Frost, David
- Subjects
- *
CONSUMPTION (Economics) , *WALLABIES , *RIPARIAN areas , *SOCIAL enterprises - Abstract
Summary: Agile Wallaby (Notamacropus agilis) has been in the diet of Aboriginal inhabitants of northern Australia for millennia. The species inhabits riparian zones and savannah woodlands, has a high rate of natural increase and can become pests in modified agricultural or plantation systems. Although the profitability of market‐based game harvesting appears marginal, local consumption could be incorporated into existing employment programmes on Aboriginal lands as a social enterprise. The legal environment is discussed, and further investigation and a trial as a pilot enterprise are recommended. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
27. How many macropods? A manager's guide to small‐scale population surveys of kangaroos and wallabies.
- Author
-
Coulson, Graeme, Snape, Melissa A., and Cripps, Jemma K.
- Subjects
- *
DEMOGRAPHIC surveys , *WALLABIES , *KANGAROOS , *EXECUTIVES , *HABITATS - Abstract
Summary: Every macropod population is unique in terms of the combination of species, site and management goals, so there is no universal 'best' method for surveying populations. We distinguish between different measures of abundance and the confidence a manager can place in them. We examine the separate components of survey methods: the survey platform, mode of detection and form of sampling. We also review the range of current methods available and highlight new developments, including their assumptions and limitations. To guide managers in choosing a method for their management context, we provide a decision matrix based on the behavioural ecology of the target species, the structure of habitat at the site and the porosity of the site boundary. To promote current best practice, we describe in detail four standard counting methods: direct count, sweep count, faecal accumulation rate and distance sampling. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
28. Growth of the Black Wallaby (Wallabia bicolor) population at the Cranbourne Gardens (Royal Botanic Gardens Victoria), after the implementation of fox control.
- Subjects
- *
BOTANICAL gardens , *WALLABIES , *MAMMAL communities , *FERTILITY decline , *GARDENS - Abstract
Summary: Coincident with a decade of introduced predator suppression, there was an increase in populations of a range of native mammals at the Royal Botanic Gardens Victoria (Cranbourne). A small, regionally significant population of the Black Wallaby (Wallabia bicolor) grew exponentially from an estimated 0.6 individuals km−2 in 2001 to more than 70 km−2 in 2013. The measured mean annual instantaneous rate of increase derived from a regular spotlight survey was ˜0.37 and extrapolates to a doubling of the population approximately every 2 years. There was little indication that growth was abating as the population increased. Modelling predicted that in the absence of a decline in fertility or natural increase in mortality one third of the population would need to be shed annually to moderate or reverse growth and allow vegetation communities and small mammal habitats to recover. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
29. Respiratory characteristics of the tammar wallaby pouch young and functional limitations in a newborn with skin gas exchange.
- Author
-
MacFarlane, P. M., Frappell, P. B., and Haase, T.
- Subjects
- *
NEWBORN infants , *LOW birth weight , *WALLABIES , *FUNCTIONAL status , *PULMONARY gas exchange - Abstract
A short gestation, low birth weight and presence of cutaneous exchange of O2 and CO2 comprise altricial features of newborn marsupials and that collectively implies a highly immature respiratory system. In the present study, we investigated various respiratory characteristics of the neonatal/postnatal tammar wallaby, a species of marsupial in which > 30% of the newborn's total O2 demands are supported by cutaneous rather than pulmonary gas exchange. The ventilatory response (HVR) to acute hypoxia (10% inspired O2) was absent in the newborn (1 day old) pouch young; a hypoxic hypometabolism contributed entirely to the hyperventilation (increased pulmonary convection requirement). A high (compared to older animals) resting metabolic cost to breathe and an inefficient respiratory system suggest the lack of a HVR might be due to an energetic constraint that impinges on their ability to sustain an increase in ventilation. The latter was supported by the inability of the newborn to tolerate metabolic-ventilatory stimulation following administration of the metabolic uncoupler, 2,4-dinitrophenol (2,4-DNP). At 1 week of age, the cost of breathing was reduced, which coincided with the expression of a significant ventilatory response to hypoxia, a more energetically efficient respiratory system, and tolerance to 2,4-DNP. These data suggest this species of marsupial is born with major respiratory insufficiency, and that their pronounced dependence on the skin for metabolic gas exchange is of critical importance for survival. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
30. WALLABY Pre-Pilot Survey: the effects of angular momentum and environment on the H i gas and star formation properties of galaxies in the Eridanus supergroup.
- Author
-
Murugeshan, C, Kilborn, V A, For, B-Q, Wong, O I, Wang, J, Westmeier, T, Stevens, A R H, Spekkens, K, Kamphuis, P, Staveley-Smith, L, Lee-Waddell, K, Kleiner, D, Koribalski, B S, Cluver, M E, Oh, S-H, Rhee, J, Catinella, B, Reynolds, T N, Dénes, H, and Elagali, A
- Subjects
- *
STAR formation , *ANGULAR momentum (Mechanics) , *WALLABIES , *GALAXY formation , *GALACTIC evolution , *GALAXIES - Abstract
We use high-resolution ASKAP observations of galaxies in the Eridanus supergroup to study their H i , angular momentum, and star formation properties, as part of the WALLABY pre-pilot survey efforts. The Eridanus supergroup is composed of three sub-groups in the process of merging to form a cluster. The main focus of this study is the Eridanus (or NGC 1395) sub-group. The baryonic specific angular momentum – baryonic mass (j b− M b) relation for the Eridanus galaxies is observed to be an unbroken power law of the form |$j_{\mathrm{b}} \propto M_{\mathrm{b}}^{0.57 \pm 0.05}$| , with a scatter of ∼0.10 ± 0.01 dex, consistent with previous works. We examine the relation between the atomic gas fraction, f atm, and the integrated atomic disc stability parameter q (the f atm− q relation), and find that the Eridanus galaxies deviate significantly from the relation owing to environmental processes such as tidal interactions and ram pressure affecting their H i gas. We find that a majority of the Eridanus galaxies are H i deficient compared to normal star-forming galaxies in the field. We also find that the star formation among the Eridanus galaxies may be suppressed owing to their environment, thus hinting at significant levels of pre-processing within the Eridanus sub-group, even before the galaxies have entered a cluster-like environment. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
31. WALLABY pre-pilot survey: two dark clouds in the vicinity of NGC 1395.
- Author
-
Wong, O I, Stevens, A R H, For, B-Q, Westmeier, T, Dixon, M, Oh, S-H, Józsa, G I G, Reynolds, T N, Lee-Waddell, K, Román, J, Verdes-Montenegro, L, Courtois, H M, Pomarède, D, Murugeshan, C, Whiting, M T, Bekki, K, Bigiel, F, Bosma, A, Catinella, B, and Dénes, H
- Subjects
- *
GALAXY clusters , *GALACTIC magnitudes , *WALLABIES , *DARK matter , *GALACTIC evolution , *SURFACE brightness (Astronomy) - Abstract
We present the Australian Square Kilometre Array Pathfinder (ASKAP) WALLABY pre-pilot observations of two 'dark' H i sources (with H i masses of a few times 108 |$\rm {M}_\odot$| and no known stellar counterpart) that reside within 363 kpc of NGC 1395, the most massive early-type galaxy in the Eridanus group of galaxies. We investigate whether these 'dark' H i sources have resulted from past tidal interactions or whether they are an extreme class of low surface brightness galaxies. Our results suggest that both scenarios are possible, and not mutually exclusive. The two 'dark' H i sources are compact, reside in relative isolation, and are more than 159 kpc away from their nearest H i -rich galaxy neighbour. Regardless of origin, the H i sizes and masses of both 'dark' H i sources are consistent with the H i size–mass relationship that is found in nearby low-mass galaxies, supporting the possibility that these H i sources are an extreme class of low surface brightness galaxies. We identified three analogues of candidate primordial 'dark' H i galaxies within the TNG100 cosmological, hydrodynamic simulation. All three model analogues are dark matter dominated, have assembled most of their mass 12–13 Gyr ago, and have not experienced much evolution until cluster infall 1–2 Gyr ago. Our WALLABY pre-pilot science results suggest that the upcoming large-area H i surveys will have a significant impact on our understanding of low surface brightness galaxies and the physical processes that shape them. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
32. WALLABY pre-pilot survey: H i content of the Eridanus supergroup.
- Author
-
For, B-Q, Wang, J, Westmeier, T, Wong, O I, Murugeshan, C, Staveley-Smith, L, Courtois, H M, Pomarède, D, Spekkens, K, Catinella, B, McQuinn, K B W, Elagali, A, Koribalski, B S, Lee-Waddell, K, Madrid, J P, Popping, A, Reynolds, T N, Rhee, J, Bekki, K, and Dènes, H
- Subjects
- *
SPIRAL galaxies , *WALLABIES , *GALAXY clusters , *STELLAR mass , *ALGORITHMS , *GALAXIES - Abstract
We present observations of the Eridanus supergroup obtained with the Australian Square Kilometre Array Pathfinder (ASKAP) as part of the pre-pilot survey for the Widefield ASKAP L-band Legacy All-sky Blind surveY (WALLABY). The total number of detected H i sources is 55, of which 12 are background galaxies not associated with the Eridanus supergroup. Two massive H i clouds are identified and large H i debris fields are seen in the NGC 1359 interacting galaxy pair, and the face-on spiral galaxy NGC 1385. We describe the data products from the source finding algorithm and present the basic parameters. The presence of distorted H i morphology in all detected galaxies suggests ongoing tidal interactions within the subgroups. The Eridanus group has a large fraction of H i -deficient galaxies as compared to previously studied galaxy groups. These H i -deficient galaxies are not found at the centre of the group. We find that galaxies in the Eridanus supergroup do not follow the general trend of the atomic gas fraction versus stellar mass scaling relation, which indicates that the scaling relation changes with environmental density. In general, the majority of these galaxies are actively forming stars. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
33. sofia 2 – an automated, parallel H i source finding pipeline for the WALLABY survey.
- Author
-
Westmeier, T, Kitaeff, S, Pallot, D, Serra, P, van der Hulst, J M, Jurek, R J, Elagali, A, For, B-Q, Kleiner, D, Koribalski, B S, Lee-Waddell, K, Mould, J R, Reynolds, T N, Rhee, J, and Staveley-Smith, L
- Subjects
- *
WALLABIES , *PROGRAMMING languages , *SIGNAL-to-noise ratio , *NOISE measurement , *ACTINIC flux - Abstract
We present sofia 2, the fully automated 3D source finding pipeline for the WALLABY extragalactic H i survey with the Australian SKA Pathfinder (ASKAP). sofia 2 is a reimplementation of parts of the original sofia pipeline in the c programming language and makes use of OpenMP for multithreading of the most time-critical algorithms. In addition, we have developed a parallel framework called sofia -X that allows the processing of large data cubes to be split across multiple computing nodes. As a result of these efforts, sofia 2 is substantially faster and comes with a much reduced memory footprint compared to its predecessor, thus allowing the large WALLABY data volumes of hundreds of gigabytes of imaging data per epoch to be processed in real time. The source code has been made publicly available to the entire community under an open-source licence. Performance tests using mock galaxies injected into genuine ASKAP data suggest that in the absence of significant imaging artefacts sofia 2 is capable of achieving near-100 per cent completeness and reliability above an integrated signal-to-noise ratio (SNR) of about 5–6. We also demonstrate that sofia 2 generally recovers the location, integrated flux, and w 20 line width of galaxies with high accuracy. Other parameters, including the peak flux density and w 50 line width, are more strongly biased due to the influence of the noise on the measurement. In addition, very faint galaxies below an integrated SNR of about 10 may get broken up into multiple components, thus requiring a strategy to identify fragmented sources and ensure that they do not affect the integrity of any scientific analysis based on the sofia 2 output. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
34. The Effect of Visitor Number on the Behavior of Zoo-Housed Macropods.
- Author
-
Meade, Jessica, Melfi, Vicky A., Keith, Melanie, and Burns, Alicia L.
- Subjects
- *
ANIMAL behavior , *FORAGING behavior , *EMPATHY , *WALLABIES , *ZOOS - Abstract
Free-range exhibits are used by zoos to allow visitors to experience or interact with animals in a semi-natural setting; close interactions with animals have been shown to increase empathy and contribute to conservation outcomes, and as such zoos are increasingly implementing free-range style exhibits to facilitate this goal. We aimed to investigate whether this close proximity to zoo visitors impacted upon four species of macropod (red kangaroo Macropus rufus, red-necked wallaby Macropus rufogriseus, swamp wallaby Wallabia bicolor, and quokka Setonix brachyurus) in a free-range exhibit in an Australian zoo. Specifically, we used instantaneous scan sampling to assess animal behavior and examined whether visitor number affected the proportion of individuals that exhibited four target behaviors; visitor-directed vigilance, retreat, resting, and foraging behavior. We found that the proportion of individuals exhibiting visitor-directed vigilance significantly increased as pedestrian visitor number increased for three of the four species, and the proportion of individuals that were resting was significantly negatively related to visitor number for both wallaby species. The proportion of individuals of each species foraging or retreating was unrelated to visitor number. These data suggest that a visitor effect exists in a walk-through exhibit of macropods, and once visitor numbers go beyond a threshold, the behavior of more animals is impacted, likely compromising welfare. Interestingly, quokka do not appear to be affected by zoo visitors; which may be due to visitor pressure being perceived differently due to evolutionary differences, or that housing and husbandry ameliorate the visitor effect for this species but not others. Like many studies before, taking a species-specific approach to understanding zoo visitor–animal interactions has determined how the visitor effect likely impacts macropods differently. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
35. WALLABY Pilot Survey: The Diversity of Ram Pressure Stripping of the Galactic H i Gas in the Hydra Cluster.
- Author
-
Wang, Jing, Staveley-Smith, Lister, Westmeier, Tobias, Catinella, Barbara, Shao, Li, Reynolds, T. N., For, Bi-Qing, Lee, Bumhyun, Liang, Ze-zhong, Wang, Shun, Elagali, A., Dénes, H., Kleiner, D., Koribalski, Bärbel S., Lee-Waddell, K., Oh, S-H., Rhee, J., Serra, P., Spekkens, K., and Wong, O. I.
- Subjects
- *
WALLABIES , *STAR formation , *GALAXY clusters , *GALAXIES , *GASES - Abstract
This study uses H i image data from the Widefield ASKAP L-band Legacy All-sky Blind surveY (WALLABY) pilot survey with the Australian Square Kilometre Array Pathfinder (ASKAP) telescope, covering the Hydra cluster out to 2.5r200. We present the projected phase–space distribution of H i -detected galaxies in Hydra, and identify that nearly two-thirds of the galaxies within may be in the early stages of ram pressure stripping. More than half of these may be only weakly stripped, with the ratio of strippable H i (i.e., where the galactic restoring force is lower than the ram pressure in the disk) mass fraction (over total H i mass) distributed uniformly below 90%. Consequently, the H i mass is expected to decrease by only a few 0.1 dex after the currently strippable portion of H i in these systems has been stripped. A more detailed look at the subset of galaxies that are spatially resolved by WALLABY observations shows that, while it typically takes less than 200 Myr for ram pressure stripping to remove the currently strippable portion of H i , it may take more than 600 Myr to significantly change the total H i mass. Our results provide new clues to understanding the different rates of H i depletion and star formation quenching in cluster galaxies. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
36. Is relative growth by the mammalian heart biphasic or monophasic?
- Author
-
Packard, Gary C.
- Subjects
- *
NONLINEAR regression , *HEART , *STATISTICAL models , *WALLABIES , *KANGAROOS , *PARTURITION - Abstract
I re‐examined data for relative growth by the heart in four species of mammal to reconcile divergent reports that appear in the literature. Raw data for heart and body mass for Horro sheep, humans, gray kangaroos, and tammar wallabies were studied by linear and nonlinear regression, thereby enabling me to avoid the confounding effects of logarithmic transformation and to evaluate multiple statistical models for describing pattern in each set of observations. My analyses indicate that relative growth by the heart is monophasic in all four species and either isometric or near isometric on the arithmetic scale. The heart in these mammals consequently grows in mass in approximate proportion to growth in mass by the body. The appearance of biphasic allometric growth in prior studies was an artifact resulting from logarithmic transformation. Although parturition in sheep and humans is accompanied by a change in the distribution of blood out of the heart and into pulmonary and systemic circuits, the challenge is met without marked increases in absolute or relative size of the heart. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
37. Camera trap detection of mycophagy among co‐occurring vertebrates.
- Author
-
Elliott, Todd F. and Vernes, Karl
- Subjects
- *
CAMERAS , *ECTOMYCORRHIZAL fungi , *VERTEBRATES , *WALLABIES - Abstract
Thirty camera traps were deployed for a total of 4179 trap‐nights between January and June 2020 as part of a project assessing post‐fire recovery of pademelons (Thylogale spp.) in northern New South Wales. By chance, one camera documented a site that was highly productive for the ectomycorrhizal fungal genus Amanita. This camera provided a rare opportunity to document a diversity of co‐habitating vertebrates that utilise these ectomycorrhizal fungi for food and in turn perform an important ecosystem function through the dispersal of their spores. Our camera recorded eleven vertebrate species; of these, we captured photographic evidence of Australian brush‐turkeys (Alectura lathami), a parma wallaby (Notamacropus parma), long‐nosed bandicoots (Perameles nasuta), red‐legged pademelons (Thylogale stigmatica) and red‐necked pademelons (T. thetis) feeding on fungal fruiting bodies. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
38. Spatial and temporal responses of swamp wallabies to roads in a human-modified landscape.
- Author
-
Fischer, Manuela, Stillfried, Milena, Coulson, Graeme, Sutherland, Duncan R., Kramer-Schadt, Stephanie, and Di Stefano, Julian
- Subjects
- *
WALLABIES , *HOME range (Animal geography) , *SWAMPS , *ANIMAL populations , *SPEED limits - Abstract
Roads can have significant impacts on wildlife populations by impeding movement, restricting access to resources and causing wildlife-vehicle collisions. In particular, wildlife-vehicle collisions represent a substantial conservation and social problem, and although mitigation measures are available, an increased understanding of the temporal and spatial patterns of animal movement around roads will enhance their effectiveness. We analysed GPS telemetry data from 47 swamp wallabies Wallabia bicolor on Phillip Island, south-east Australia, within patches of native vegetation dissected by roads. Our aims were to determine if (a) road crossing frequency was influenced by time period (day, night) or sex, (b) wallabies avoided roads, and if avoidance was influenced by time period or sex and (c) road crossing locations were associated with dense vegetation, and other habitat characteristics. We found that males crossed roads more often at night than during the day while females showed the opposite pattern. Further, wallabies avoided roads, with some evidence that avoidance increased at night (p = 0.07). The chance of a wallaby crossing roads with high speed limits (80-100 km h-1) increased with vegetation density during the day but not at night. In contrast, vegetation density had no influence on crossing locations along roads with lower (50-70 km h-1) speed limits during the day or night. Both vegetation density and vehicle speed may influence wallaby-vehicle collisions and suggest management strategies targeting these factors. Partial fencing guiding wallabies towards safer crossing locations, combined with other measures such as reduced speed limits and signage, could reduce collisions between vehicles and swamp wallabies on Phillip Island. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
39. Primordial germ cell expression of SSEA1 and DDX4 (VASA) in female Trichosurus vulpecula (Marsupialia) reveals conserved and unique molecular patterns during marsupial germ cell development.
- Author
-
Laird, Melanie K. and Hore, Timothy A.
- Subjects
- *
GERM cells , *MARSUPIALS , *SEX differentiation (Embryology) , *WALLABIES , *MOLECULAR dynamics , *GONADS , *MEIOSIS - Abstract
Development of primordial germ cells (PGCs: precursors to adult gametes) is a key process in vertebrate sexual differentiation. Marsupials are ideal to investigate this phenomenon because much of PGC migration and development unusually occurs postnatally in pouch young. However, investigation of the molecular dynamics underpinning PGC development is restricted to one marsupial model species: the tammar wallaby (Macropus eugenii). Given the reproductive diversity among clades, marsupial PGCs likely exhibit diversity in molecular patterns that could help uncover their developmental dynamics. Here we characterise PGC marker expression (SSEA1 and DDX4) in developing ovaries of the brushtail possum, Trichosurus vulpecula. Female germ cells expressed DDX4 from 6 days postpartum (dpp) and almost all germ cells expressed DDX4 by meiosis (40 dpp), consistent with M. eugenii and eutherian mammals. In contrast, PGCs and oogonia expressed SSEA1 from 12 dpp, throughout proliferation and until entry into meiosis (40–63 dpp). SSEA1 expression was temporally distinct from that of M. eugenii , in which SSEA1 expression persists only until 14 dpp, indicating differential expression between marsupial species at equivalent stages of germ cell development. Hence, the molecular characteristics of M. eugenii germ cells cannot be assumed for all marsupials, as at least one key molecule exhibits species-specific expression. Molecular changes during sex-cell development are essential to understanding how marsupial gonads develop after birth, yet have been investigated in only one species – the tammar wallaby. We found that immature brushtail possum ovaries show the same fluorescence pattern for sex-cell marker DDX4 as tammar ovaries, suggesting a conserved role in marsupial development, but a different species-specific pattern for SSEA1. We conclude that the molecular characteristics of marsupial sex-cell development are diverse and cannot be assumed from one species alone. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
40. Spatial and temporal responses of swamp wallabies to roads in a human-modified landscape.
- Author
-
Fischer, Manuela, Stillfried, Milena, Coulson, Graeme, Sutherland, Duncan R., Kramer-Schadt, Stephanie, and Stefano, Julian Di
- Subjects
- *
WALLABIES , *HOME range (Animal geography) , *SWAMPS , *ANIMAL populations , *SPEED limits - Abstract
Roads can have significant impacts on wildlife populations by impeding movement, restricting access to resources and causing wildlife–vehicle collisions. In particular, wildlife–vehicle collisions represent a substantial conservation and social problem, and although mitigation measures are available, an increased understanding of the temporal and spatial patterns of animal movement around roads will enhance their effectiveness. We analysed GPS telemetry data from 47 swamp wallabies Wallabia bicolor on Phillip Island, south-east Australia, within patches of native vegetation dissected by roads. Our aims were to determine if (a) road crossing frequency was influenced by time period (day, night) or sex, (b) wallabies avoided roads, and if avoidance was influenced by time period or sex and (c) road crossing locations were associated with dense vegetation, and other habitat characteristics. We found that males crossed roads more often at night than during the day while females showed the opposite pattern. Further, wallabies avoided roads, with some evidence that avoidance increased at night (p = 0.07). The chance of a wallaby crossing roads with high speed limits (80–100 km h-1) increased with vegetation density during the day but not at night. In contrast, vegetation density had no influence on crossing locations along roads with lower (50–70 km h-1) speed limits during the day or night. Both vegetation density and vehicle speed may influence wallaby–vehicle collisions and suggest management strategies targeting these factors. Partial fencing guiding wallabies towards safer crossing locations, combined with other measures such as reduced speed limits and signage, could reduce collisions between vehicles and swamp wallabies on Phillip Island. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
41. Long-term maternal exposure to atrazine in the drinking water reduces penis length in the tammar wallaby Macropus eugenii.
- Author
-
Cook, Laura E., Chen, Yu, Renfree, Marilyn B., and Pask, Andrew J.
- Subjects
- *
ATRAZINE , *MATERNAL exposure , *DRINKING water , *WALLABIES , *ENDOCRINE disruptors , *PENIS - Abstract
Marsupials are experiencing devastating population declines across Australia. Exposure to environmental endocrine disruptors, through ingestion of contaminated resources in the environment, could be contributing to this decline. Atrazine (ATZ), a widely used herbicide in Australia, is an endocrine disruptor with the ability to cause reproductive abnormalities in a diverse range of vertebrates. We exposed adult female wallabies (Macropus eugenii) to drinking water containing ATZ (450 p.p.m) throughout pregnancy, parturition and lactation. We assessed the outcome of this exposure to the reproductive development of their young by assessing gonad and phallus development. Both these organs are especially sensitive to perturbations in the hormonal environment during development. Although no gross abnormalities were seen in gonad structure, exposure to ATZ did alter the expression of genes required for normal testis function. Furthermore, long-term exposure to ATZ resulted in a significant reduction in penis length. These results demonstrate that ATZ exposure during gestation and lactation can significantly affect the development of male young by affecting virilisation. Given the known vulnerability of macropodid marsupials to endocrine disruption, as well as their overlapping distribution with agricultural areas, these data raise major concerns for the use of pesticides in areas with fragile marsupial populations. Marsupials are experiencing devastating population declines across Australia. Exposure to environmental endocrine disruptors could be contributing to this decline. We exposed marsupials to atrazine (ATZ), an endocrine disrupting herbicide widely used in Australia. ATZ affected male development, reducing penis size and altering gene expression in the testis. Together, these data raise major concerns for the use of pesticides in areas with fragile marsupial populations. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
42. Modeling mycorrhizal fungi dispersal by the mycophagous swamp wallaby (Wallabia bicolor).
- Author
-
Danks, Melissa A., Simpson, Natalie, Elliott, Todd F., Paine, C. E. Timothy, and Vernes, Karl
- Subjects
- *
MYCORRHIZAL fungi , *WALLABIES , *SWAMPS , *ANIMAL dispersal , *FUNGAL spores - Abstract
Despite the importance of mammal‐fungal interactions, tools to estimate the mammal‐assisted dispersal distances of fungi are lacking. Many mammals actively consume fungal fruiting bodies, the spores of which remain viable after passage through their digestive tract. Many of these fungi form symbiotic relationships with trees and provide an array of other key ecosystem functions. We present a flexible, general model to predict the distance a mycophagous mammal would disperse fungal spores. We modeled the probability of spore dispersal by combining animal movement data from GPS telemetry with data on spore gut‐retention time. We test this model using an exemplar generalist mycophagist, the swamp wallaby (Wallabia bicolor). We show that swamp wallabies disperse fungal spores hundreds of meters—and occasionally up to 1,265 m—from the point of consumption, distances that are ecologically significant for many mycorrhizal fungi. In addition to highlighting the ecological importance of swamp wallabies as dispersers of mycorrhizal fungi in eastern Australia, our simple modeling approach provides a novel and effective way of empirically describing spore dispersal by a mycophagous animal. This approach is applicable to the study of other animal‐fungi interactions in other ecosystems. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
43. Where's wallaby? Using public records and media reports to describe the status of red‐necked wallabies in Britain.
- Author
-
English, Holly M. and Caravaggi, Anthony
- Subjects
- *
WALLABIES , *PUBLIC records , *HISTORICAL maps , *INTRODUCED species , *BIOTIC communities - Abstract
Investigating the range and population dynamics of introduced species provides insight into species behavior, habitat preferences, and potential of becoming established. Here, we show the current population status of the red‐necked wallaby (Notamacropus rufogriseus) in Britain based on records from an eleven‐year period (2008–2018). Records were obtained from Local Environmental Records Centres (LERCs), the National Biodiversity Network (NBN), and popular media. All records were mapped and compared to a historical distribution map (1940–2007), derived from published data. A total of 95 confirmed wallaby sightings were recorded between 2008 and 2018, of which 64 came from media sources, 18 from Local Environmental Records Centres (LERCs), seven from the National Biodiversity Network (NBN), and six from the published literature (Yalden, Br. Wildl., 24, 2013, 169). The greatest density of wallaby sightings was in southern England, with the Chiltern Hills Area of Outstanding Natural Beauty a particular hot spot (n = 11). More sightings were recorded in August than in any other month. Much of the species' ecology and responses to British biota and anthropogenic pressures are unknown, and therefore, further research is warranted. The methods used here are widely applicable to other non‐native species, particularly those that the public are more likely to report and could be an important supplement to existing studies of conservation and management relevance. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
44. Distribution and abundance of large herbivores in a northern Australian tropical savanna: A multi‐scale approach.
- Author
-
Reid, Angela M., Murphy, Brett P., Vigilante, Tom, and Bowman, David M. J. S.
- Subjects
- *
SAVANNAS , *HERBIVORES , *AERIAL surveys , *LANDSCAPE changes , *WALLABIES , *DINGO - Abstract
Australian mammals have exhibited exceptionally high rates of decline since European settlement 230 years ago with much focus on small mammals in northern tropical savannas. In these systems, little scientific attention has been given to the suite of grazing macropods, family Macropodidae, (common wallaroo (Osphranter robustus), antilopine wallaroo (O. antilopinus) and agile wallaby (Notamacropus agilis)). These species may be impacted by feral herbivores and contemporary fire regimes, two threats linked to small mammal declines. A multi‐scale approach using aerial surveys, road surveys and camera trapping was utilised to determine the effects of feral cattle and fire on the distribution and abundance of large macropods in the North Kimberley bioregion. Feral cattle density and biomass exceeded that of macropods regardless of survey technique. Density estimates for cattle were up to 125 times higher (0.3–10.0 km−2) than estimates for macropods (0.08–0.49 km−2). Cattle biomass, based on the aerial survey estimates (corrected for perception bias), were 15 and 95 times higher than macropods for infertile (279 vs. 19 kg km−2) and fertile savannas (518 vs. 5 kg km−2), respectively. Proximity to the nearest pastoral station was a significant predictor of the aerial sightings of feral cattle (P ≤ 0.05). Abundance and foraging activity of cattle were positively associated (P ≤ 0.05) with recently burnt areas. In contrast, camera trapping showed agile wallaby and wallaroo occurrence and foraging were associated with longer unburnt areas (P ≤ 0.05). Agile wallaby and wallaroo were negatively associated with cattle (P ≤ 0.05) and showed substantial diurnal and seasonal separation consistent with an antagonistic interspecific interaction. Results also suggest that the agile wallaby is the primary prey of the dingo, not wallaroo. Collectively, this study suggests that recent landscape changes such as altered fire regimes and introduced herbivores have negatively impacted large grazing macropod species. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
45. Molecular identification of Eimeria hestermani and Eimeria prionotemni from a red-necked wallaby (Macropodidae; Macropus rufogriseus) in Japan.
- Author
-
Ekawasti, Fitrine, Kitagawa, Kazuya, Domae, Hiroshi, Wardhana, April Hari, Shibahara, Tomoyuki, Uni, Shigehiko, Tokoro, Masaharu, Sasai, Kazumi, and Matsubayashi, Makoto
- Subjects
- *
EIMERIA , *WALLABIES , *ANIMAL mortality , *GASTROINTESTINAL contents , *ANIMAL species - Abstract
To date, more than 50 Eimeria spp. have been isolated from marsupials of the family Macropodidae. Although 18 species of Eimeria have been previously detected from multiple animal species belonging to the genus Macropus of the family, limited genetic analyses of the parasites are available, and their pathogenicity remains unclear. Here, we report the isolation of Eimeria spp. from a zoo specimen of red-necked wallaby (Macropodidae; Macropus rufogriseus). Specifically, two distinct types of Eimeria oocysts were recovered, one from the feces before treatment with an anthelmintic and the second from the intestinal contents after death of the animal. The oocysts obtained from the two sources were morphologically identified as E. hestermani and E. prionotemni, respectively. We successfully determined partial gene sequences from the two isolates, including segments of the 18S rRNA genes, and for the first time have used phylogenetic analyses of these sequences to assign the species to distinct clades. In combination with further genetic data, these results are expected to help elucidate the pathogenicity and host ranges of Eimeria spp. within the respective family and genus. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
46. Unique reproductive strategy in the swamp wallaby.
- Author
-
Menzies, Brandon R., Hildebrandt, Thomas B., and Renfree, Marilyn B.
- Subjects
- *
DURATION of pregnancy , *WALLABIES , *ESTRUS , *SWAMPS , *OVULATION - Abstract
Reproduction in mammals requires distinct cycles of ovulation, fertilization, pregnancy, and lactation often interspersed with periods of anoestrus when breeding does not occur. Macropodids, the largest extant species of marsupials, the kangaroos and wallabies, have a very different reproductive strategy to most eutherian mammals whereby young are born at a highly altricial stage of development with the majority of development occurring over a lengthy lactation period. Furthermore, the timings of ovulation and birth in some species occurs within a very short interval of each other (sometimes hours). Female swamp wallabies have an oestrous cycle shorter than their pregnancy length and were, therefore, speculated to mate and form a new embryo before birth thereby supporting two conceptuses at different stages of pregnancy. To confirm this, we used high-resolution ultrasound to monitor reproduction in swamp wallabies during pregnancy. Here, we show that females ovulate,mate, and form a new embryo prepartumwhile still carrying a full-term fetus in the contralateral uterus. This embryo enters embryonic diapause until the newborn leaves the pouch 9 mo later. Thus, combined with embryonic diapause, females are continuously pregnant and lactating at the same time throughout their reproductive life, a unique reproductive strategy that completely blurs the normal staged system of reproduction in mammals. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
47. Induction of synchronous oestrus but not ovulation after pre-treatment with the GnRH agonist, Lucrin® Depot, in the tammar wallaby.
- Author
-
Witt, Ryan R., Hinds, Lyn A., and Rodger, John C.
- Subjects
- *
GENITALIA , *CORPUS luteum , *OVULATION , *ESTRUS , *WALLABIES , *CHORIONIC gonadotropins , *OVARIES - Abstract
We investigated the capacity for pregnant mare serum gonadotrophin (PMSG) and human chorionic gonadotrophin (hCG) to induce synchronous oestrus and ovulation in the tammar wallaby (Notamacropus eugenii) after follicular suppression with Lucrin® Depot, a one-month GnRH agonist. On Day 0 pouch young were removed (RPY) to reactivate a normal oestrous cycle and then two groups were treated with vehicle (Control; n = 5 and Superovulation (SOvn); n = 5) and two groups were treated with 7.5 mg of Lucrin Depot (Lucrin; n = 6; Lucrin+SOvn, n = 6). On Day 20 RPY the SOvn and Lucrin+SOvn Group received 20 IU of PMSG, which was followed on Day 23 RPY with 500 IU of hCG. The Lucrin+SOvn females underwent a more synchronous oestrus with 5 of 6 mating on Day 26 RPY while the SOvn (n = 5/5) and Control (n = 5/5) Groups copulated over two days, between Day 25–27 RPY and Day 27–29 RPY respectively. Mating plugs were not detected in any of the females in the Lucrin Group by Day 31 RPY. Autopsy on Day 31 RPY confirmed all females in each treatment group had undergone a reactivated cycle as evidenced by the presence of a large corpus luteum (CL) in one ovary. At autopsy the females in the Lucrin+SOvn Group had highly stimulated reproductive tracts, and their ovaries contained many follicles >3 mm; 14 ± 2.1 and 15.3 ± 2.1 follicles >3 mm in the CL-bearing ovary and contralateral ovary respectively. Similarly, females in the SOvn Group had 11.4 ± 2.4 and 17.4 ± 1.9 follicles >3 mm in each respective ovary. Uterine flushing and ovarian histology confirmed that females in Lucrin+SOvn and SOvn Groups had not ovulated, but normal oocytes were present in the follicles. By comparison, the Control Group had ovulated with a single embryo being recovered from the uterus of 4 of 5 females. In contrast to all groups, females in the Lucrin Group showed follicular suppression (all follicles <1.5 mm) and an unstimulated reproductive tract. We conclude that a suppression plus stimulation regimen using Lucrin Depot followed by PMSG and hCG has the capacity to synchronise oestrus, and that 20 IU of PMSG stimulates the development of antral follicles >3 mm in both ovaries. However, a single 500 IU treatment of hCG on Day 23 RPY was not able to induce ovulation in the tammar wallaby. • Single-shot GnRH agonist inhibits oestrus and follicular development in wallabies. • GnRH agonist pretreatment prior to PSMG and hCG treatment synchronised oestrus. • Hormone regimen, GnRH agonist + PMSG + hCG and PMSG + hCG, did not induce ovulation. • 20 IU of PMSG stimulates the development of pre-ovulatory follicles in both ovaries. • 500 IU treatment of hCG on Day 23 RPY was not sufficient to induce ovulation. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
48. A wallaby homecoming.
- Author
-
WILLIS, BRON
- Subjects
- *
WALLABIES - Abstract
FEATURES THE HEALTHY, NOT QUITE fully grown, female southern brush-tailed rock-wallaby is unusually calm in the heavy hessian sack resting on the lap of Annette Rypalski, biodiversity director at the Mt Rothwell Biodiversity Interpretation Centre. The multiple pens central to the breeding programs at Mt Rothwell allowed Annette and her team to separate particular individuals from the Tidbinbilla colony and keep the carefully engineered social groups intact. The Mulligans Flat evacuation never eventuated, but Mt Rothwell was by then in emergency mode and in preparation to receive two species of endangered animals from Tidbinbilla, eastern bettongs and the southern brush-tailed rock-wallabies. Annette, two wildlife officers and about 20 volunteers have been caring for wallabies from the southern group at the centre since 2015, when 20 were introduced here as part of a breeding program by the species' recovery team. [Extracted from the article]
- Published
- 2021
49. WALLABY early science − V. ASKAP H i imaging of the Lyon Group of Galaxies 351.
- Author
-
For, B-Q, Staveley-Smith, L, Westmeier, T, Whiting, M, Oh, S-H, Koribalski, B, Wang, J, Wong, O I, Bekiaris, G, Cortese, L, Elagali, A, Kleiner, D, Lee-Waddell, K, Madrid, J P, Popping, A, Rhee, J, Reynolds, T N, Collier, J D, Phillips, C J, and Voronkov, M A
- Subjects
- *
GALAXY clusters , *WALLABIES , *DWARF galaxies , *STAR formation , *GROUP velocity , *DATA reduction - Abstract
We present an H i study of the galaxy group LGG 351 using Widefield ASKAP L -band Legacy All-sky Blind Survey (WALLABY) early science data observed with the Australian Square Kilometre Array Pathfinder (ASKAP). LGG 351 resides behind the M 83 group at a velocity range (cz) of ∼3500–4800 km s−1 within the rich Hydra-Centaurus overdensity region. We detect 40 sources with the discovery of a tidally interacting galaxy pair and two new H i sources that are not presented in previous optical catalogues. 23 out of 40 sources have new redshifts derived from the new H i data. This study is the largest WALLABY sub-sample to date and also allows us to further validate the performance of ASKAP and the data reduction pipeline askapsoft. Extended H i emission is seen in six galaxies indicating interaction within the group, although no H i debris is found. We also detect H i in a known ultra-faint dwarf galaxy (dw 1328−29), which demonstrates that it is not a satellite of the M 83 group as previously thought. In conjunction with multiwavelength data, we find that our galaxies follow the atomic gas fraction and baryonic Tully–Fisher scaling relations derived from the GALEX Arecibo SDSS Survey. In addition, majority of our galaxies fall within the star formation main sequence indicating inefficiency of gas removal processes in this loose galaxy group. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
50. WALLABY Early Science – IV. ASKAP H i imaging of the nearby galaxy IC 5201.
- Author
-
Kleiner, D, Koribalski, B S, Serra, P, Whiting, M T, Westmeier, T, Wong, O I, Kamphuis, P, Popping, A, Bekiaris, G, Elagali, A, For, B-Q, Lee-Waddell, K, Madrid, J P, Reynolds, T N, Rhee, J, Shao, L, Staveley-Smith, L, Wang, J, Anderson, C S, and Collier, J
- Subjects
- *
WALLABIES , *GALAXIES , *STELLAR mass , *STAR formation , *RADIO galaxies , *SPIRAL galaxies , *DWARF galaxies - Abstract
We present a Wide-field ASKAP L-Band Legacy All-sky Blind surveY (WALLABY) study of the nearby (v sys = 915 km s−1) spiral galaxy IC 5201 using the Australian Square Kilometre Array Pathfinder (ASKAP). IC 5201 is a blue, barred spiral galaxy that follows the known scaling relations between stellar mass, SFR, H i mass, and diameter. We create a four-beam mosaicked H i image cube from 175 h of observations made with a 12-antenna sub-array. The root mean square noise level of the cube is 1.7 mJy beam−1 per channel, equivalent to a column density of |$N_{\rm H\, \small {I}}$| = 1.4 × 1020 cm−2 over 25 km s−1. We report nine extragalactic H i detections – five new H i detections including the first velocity measurements for two galaxies. These sources are IC 5201, three dwarf satellite galaxies, two galaxies, and a tidal feature belonging to the NGC 7232/3 triplet and two potential infalling galaxies to the triplet. There is evidence of a previous tidal interaction between IC 5201 and the irregular satellite AM 2220−460. A close fly-by is likely responsible for the asymmetric optical morphology of IC 5201 and warping its disc, resulting in the irregular morphology of AM 2220−460. We quantify the H i kinematics of IC 5201, presenting its rotation curve as well as showing that the warp starts at 14 kpc along the major axis, increasing as a function of radius with a maximum difference in position angle of 20°. There is no evidence of stripped H i , triggered or quenched star formation in the system as measured using DECam optical and GALEX UV photometry. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.