Search

There are few scientific reports on the histology of the phallus of ratite birds. The aim of this study was to conduct a histochemical analysis to determine the distribution of smooth muscle cells and the volumetric density (Vv) of the fibres of the elastic system in the ostrich phallus. Adult ostriches, 14 months old, were used. The phalluses were fixed in Bouin's solution and then transferred to a buffered formalin solution. They were then processed using standard histological stains for paraffin and slices were obtained. The following techniques were performed: HE, Picrosirius red, Alcian Blue at pH 1.0 and 2.5. The Periodic acid‐Schiff reagent and Weigert's Resorcin‐Fuchsin with previous oxidation were performed. The M42 test system was used to quantify the elastic system fibres. For immunohistochemical analysis, an anti alpha smooth muscle actin monoclonal antibody was used. The surface of the phallus is covered by a non‐keratinized stratified squamous epithelium, which becomes stratified cylindrical in the region of the spermatic sulcus. No glands associated with the connective tissue were observed. The Vv of the elastic system fibres was 4.75%. Smooth muscle cells were visualized only in the walls of blood vessels through immunostaining, with an absence in the lymphatic sinuses. Despite similarities with other birds, such as the presence of a fibrous external axis, a lymphatic core, and a spermatic groove, the ostrich phallus shows marked differences, including the absence of an elastic core, a non‐keratinized lining epithelium, and the absence of glands throughout its extension. [ABSTRACT FROM AUTHOR]

The analysis of haematological parameters is of great importance from a diagnostic point of view and is important on a global scale as well. The study aimed to evaluate the effects of the month, farm, bird age, and sex on blood haematology values and to make a reference range for diagnostic purposes for ostriches. Blood samples were taken during the slaughter of the birds in October and November, 2021 and in May and June, 2022. In total, 22 females and 33 males aged between 8 and 60 months from three farms in eastern Hungary were included in the evaluation. Temperature and humidity data were also collected in the indicated months. The month, farm, and age of birds strongly influenced the haematology values. The white blood cell count (WBC) was the highest in June and the mean corpuscular haemoglobin (MCH) was the lowest in May. Farm "B" differed from the two other farms in the mean cell volume (MCV), expressing the lowest mean cell value. For the 8-10- and 15-17-monthold birds, the red blood cell count (RBC), haemoglobin (HGB), and haematocrit (HCT) showed lower values compared to the 11-13- and 48-60-month-old birds. The white blood cell count (WBC), mid-cell count (MID#), and granulocyte count (GRAN#) were the highest for the 8-10- and 11-13-month old age groups; the mean cell volume (MCV) was the highest for the 48-60-month-olds. Differences could not be explained by the weather conditions. Contrary to the literature, birds on farms using probiotics did not always show higher haematological values. To draw more precise conclusions, diagnostic and serum chemical analyses should also be performed in the future. [ABSTRACT FROM AUTHOR]

Few studies describe the sequence of morphological events that characterize spermiogenesis in birds. In this paper, the clearly observable steps of spermiogenesis are described and illustrated for the first time in a commercially important ratite, the ostrich, based on light microscopy of toluidine blue-stained plastic sections. Findings were supplemented and supported by ultrastructural observations, PNA labeling of acrosome development, and immunocytochemical labeling of isolated spermatogenic cells. Spermiogenesis in the ostrich followed the general pattern described in non-passerine birds. Eight steps were identified based on changes in nuclear shape and contents, positioning of the centriolar complex, and acrosome development. Only two steps could be recognized with certainty during development of the round spermatid which contributed to the fewer steps recorded for the ostrich compared to that described in some other bird species. The only lectin that displayed acrosome reactivity was PNA and only for the first three steps of spermiogenesis. This suggests that organizational and/or compositional changes may occur in the acrosome during development and merits further investigation. Immunological labeling provided additional evidence to support the finding of previous studies that the tip of the nucleus in the ostrich is shaped by the forming acrosome and not by the microtubular manchette. To our knowledge, this is the first complete description of spermiogenesis in ostrich and one of few in any avian species. In addition to comparative reproduction and animal science, this work has implications for evolutionary biology as the reported germ cell features provide a bridge between reptile and ratite-avian spermatogenesis. [ABSTRACT FROM AUTHOR]

The greater rhea, Rhea americana, is a wild ratite of high scientific importance and significant and zootechnical value, especially considering the current development state of Brazilian poultry production, where research aimed at increasing the productivity of these animals has become extremely relevant. Studies concerning fetal attachments and embryonic development are paramount, as they can provide essential information concerning reproductive and nutritional animal management. However, a lack of information on greater rhea fetal morphology is noted. Therefore, the aim of the present study was to establish a standard model for fetal attachments in this species. Greater rhea eggs were incubated from 0 to 36 days, and macroscopic and microscopic embryonic attachment characterizations were performed. Histologically, all embryonic annexes exhibit germ layers, namely the ectoderm (outer layer), mesoderm (middle layer) and endoderm (inner layer). The findings indicate that greater rhea development patterns are similar to other birds. [ABSTRACT FROM AUTHOR]

Simple Summary: The rhea (Rhea americana) is nearly threatened in nature, while playing important ecological and economic roles. Therefore, the study of its reproductive biology is necessary to provide information that will serve as a basis for its conservation through natural breeding and reproductive biotechnologies. We characterized rhea spermatozoa and analyzed changes that occur in the cells during the transit between the epididymis to the vas deferens (based on sperm motility, morphology, morphometry, and ultrastructure). We reveal, for the first time, that rhea spermatozoa undergo an increase in size and motility throughout their transit in the spermatic pathways. The objective was to characterize morphological, morphometric, and ultrastructural changes in rhea spermatozoa between the epididymis and the vas deferens. Sperm samples were collected from the reproductive tracts of seven adult individuals and evaluated for sperm characteristics using brightfield microscopy as well as ultrastructural features using scanning electron microscopy (SM). Mean sperm count tended to increase in the vas deferens (378.0 ± 135.0 × 106) compared to the epididymis (201.0 ± 77.4 × 106). Percentages of motile sperm grew from 37.0 ± 4.9% in the epididymis to 58.5 ± 7.7% in the vas deferens. The proportion of normal spermatozoa was 75.6 ± 1.8% and most common defects were bent tails (9.7 ± 0.9%). However, these proportions were not different between epididymis and vas deferens. SM analysis revealed further features of rhea spermatozoa. Normal rhea spermatozoa were threadlike with an acrosome (0.95 ± 0.0 µm), head (7.53 ± 0.01 µm), midpiece (2.08 ± 0.01 µm), and tail (30.7 ± 0.06 µm). Lengths of sperm acrosome, head, midpiece, and tail were longer in the vas deferens compared to the epididymis. Our findings suggest that rhea spermatozoa undergo a maturation process during the passage from the epididymis to the vas deferens. [ABSTRACT FROM AUTHOR]

To investigate the cardiac anatomy of North Island brown kiwi (Apteryx mantelli) through heart morphometric parameters measured at post-mortem examination. Morphometric cardiac parameters were established at post-mortem examination of 20 North Island brown kiwi. Birds were classified by gender and age (chicks vs. adults). Measurements included: body mass, heart mass, sternal length, midpoint thickness of left ventricular free wall, midpoint thickness of right ventricular free wall and ratios of heart mass to body mass, left ventricular length to sternal length, right ventricular length to sternal length, length of left ventricle to right ventricle, interventricular septal thickness relative to the sternal length and interventricular septal thickness relative to the left ventricular length. Unadjusted estimates of the median difference and their 95% CI were then reported at each age and sex for all the cardiac morphometric parameters and their ratios. The small sample size led to wide 95% CI for the median difference between gender and age for the cardiac morphometric measurements. Nevertheless, between adult female and male kiwi, the estimated population median differences for heart mass (2.2 (95% CI = −2.9–5.6) g), length (1.2 (95% CI = −2.2–5.6) mm), width (6.1 (95% CI = −1.0–8.2) mm), left ventricular free wall length (5.5 (95% CI = −0.5–8.8) mm) and right ventricular free wall length (2.6 (95% CI = −3.7–6.9) mm) were established. In adult North Island brown kiwi, the heart mass is 0.8 (95% CI = 0.7–0.8)% of the body mass. The precision of the differences noted in heart measurements recorded between male and female kiwi at each age was limited by the low sample size available for this study. This led to wide CI and an inability to adjust differences observed for gender by differences in other confounders such as body size. With this caveat, there is weak evidence that adult female kiwi have a larger heart size and mass than the adult males. These results can be used to improve the diagnosis of cardiac disease in kiwi at post-mortem examination and aid in interpretation of the results of echocardiography in live birds for the antemortem diagnosis of cardiac disorders. [ABSTRACT FROM AUTHOR]

Objetivo. Los resultados de la inclusión de heno de alfalfa en la dieta del emú fueron determinados, como un ensayo sencillo para analizar la práctica de campo de su uso como fuente de forraje similar a dietas de otras ratitas. Materiales y métodos. Los tratamientos consistieron en dos dietas, sin (dieta 1) o con (dieta 2) inclusión de heno de alfalfa. Veinte emús, con edad promedio de 38.4 semanas fueron distribuídas en los tratamientos y alojadas en sistema semi-intensivo con alimento y agua ad libitum. El peso corporal se evaluó semanalmente durante 13 semanas. Después de 91 días, los emús fueron sacrificados y se midió el rendimiento de la canal y la alometría gastrointestinal. Resultados. La ganancia de peso acumulada fue menor (p0.05). Conclusiones. El heno de alfalfa puede comprometer negativamente el crecimiento, la deposición de grasa de los emús y altera la alometría del tracto gastrointestinal, cuando se agrega al alimento final.

Pathoanatomical studies of diseases that affect wild animals are extremely important as appropriate measures can then be taken for the prevention and control of such diseases. We report here the case of death of a greater rhea (Rhea americana) by intestinal intussusception secondary to the ingestion of a large amount of sand. The animal was bred at the Center for Multiplication of Wild Animals of the Federal Rural University of the Semi-Arid. The animal died after presenting clinical signs of apathy, weakness, prostration, and inability to move, drink water, or eat. After death, the carcass was immediately sent for necropsy. During necropsy, intussusception was found involving the jejunum, ileum, and colon. The duodenum contained large amounts of coarse sand. The invaginated intestinal segments were reddish in color, with necrotic spots, and covered by a fibrinous exudate. Histopathological examination of the invaginated segments showed necrosis of the enterocytes, detachment of the intestinal epithelium, and the presence of inflammatory cells. The ingestion of a large amount of sand may have resulted in altered intestinal transit, contributing to the occurrence of intussusception, which resulted in ischemic alterations, intestinal necrosis, and consequent death of the animal.

The lesser rhea (family Rheidae) is a flightless large bird of South America, threatened due to habitat loss, hunting and egg collecting, with special concern in Northern Patagonia. Diet and food availability were estimated throughout the year by micro-histological analysis and point-quadrat transects in a landscape inside and another outside the Payunia Reserve, the northernmost part of the Rhea pennata pennata distribution. Significant differences were detected by Kruskall-Wallis ANOVA, food selection by Chi-square test and Bailey’s confidence interval. A strong food selection characterized the diet of lesser rheas, dominated by leaves of shrubs and forbs, complemented by dicot seeds and a few insects. This agrees with the documented low dietary overlap with other herbivores in Payunia. Dietary changes agree with the expected from the selective quality hypothesis. Food availability was better inside than outside the protected area, with probable conservation effects for lesser rheas. Seeds, forbs and soft grasses could be for lesser rheas some key food resources to survive during unfavorable seasons in arid environments without "mallines", as Payunia. Shrubby patches, with high availability of preferred food items (tall shrubs and forbs), stood out as key habitats. Therefore, avoiding fire and woody plant removal is crucial for the conservation of lesser rheas in the northern of its range.

Yearly the ostrich industry loses up to 40% of newly-hatched chicks, partly due to insufficient feed intake. This study was conducted to determine whether the inclusion of various feed flavourants would improve feed intake in ostrich chicks (Trial 1). Ninety-six dayold ostrich chicks were raised in groups of 12 at a Western Cape research farm until 28 days of age. These chicks were provided with free-choice access to a variety of flavoured diets, namely sweet, sour, bitter, salt or an unflavoured control diet. Chicks were found to prefer salty feed, as the salt-flavoured diet had the highest daily feed intake (34% of total) throughout the trial. Subsequently Trial 2 was conducted to determine the preferred level of dietary salt (Experiment 1) as well as the influence dietary salt had on various production parameters (Experiment 2). In Experiment 1, three groups of seven chicks each were offered ad libitum access to diets containing 4 g/kg, 14 g/kg, 24 g/kg, and 34 g/kg of salt respectively. Experiment 1 found that chicks preferred the diet containing 14 g salt/kg (36.4% of total daily feed consumed). For Experiment 2, 56 birds were divided into eight groups of seven. Conversely to the current conventional inclusion of 4 g salt/kg, Experiment 2 showed that chicks reared on a diet containing 14 g salt/kg had a 41.7% higher average daily gain than the group consuming 4 g salt/kg. It can therefore be concluded that ostriches prefer diets with a higher dietary salt level than current conventional diets provide (14 g/kg vs 4 g/kg). [ABSTRACT FROM AUTHOR]

The objective was to characterize morphological, morphometric, and ultrastructural changes in rhea spermatozoa between the epididymis and the vas deferens. Sperm samples were collected from the reproductive tracts of seven adult individuals and evaluated for sperm characteristics using brightfield microscopy as well as ultrastructural features using scanning electron microscopy (SM). Mean sperm count tended to increase in the vas deferens (378.0 ± 135.0 × 106) compared to the epididymis (201.0 ± 77.4 × 106). Percentages of motile sperm grew from 37.0 ± 4.9% in the epididymis to 58.5 ± 7.7% in the vas deferens. The proportion of normal spermatozoa was 75.6 ± 1.8% and most common defects were bent tails (9.7 ± 0.9%). However, these proportions were not different between epididymis and vas deferens. SM analysis revealed further features of rhea spermatozoa. Normal rhea spermatozoa were threadlike with an acrosome (0.95 ± 0.0 µm), head (7.53 ± 0.01 µm), midpiece (2.08 ± 0.01 µm), and tail (30.7 ± 0.06 µm). Lengths of sperm acrosome, head, midpiece, and tail were longer in the vas deferens compared to the epididymis. Our findings suggest that rhea spermatozoa undergo a maturation process during the passage from the epididymis to the vas deferens.

Japanese names are a useful tool for Japanese speakers to communicate scientifically about birds. However, over 30 years have already passed since the most influential book treating Japanese names for all modern birds(Yamashina 1986)was published. During that time, the classification of birds has undergone major changes. Here we provide a revised list of Japanese names for species of ratites and tinamous(Paleognathae), which adopts the latest classification system(Gill et al. 2021). [ABSTRACT FROM AUTHOR]

There is a dearth of scientific information about the physicochemical characteristics of eggs from ratite birds including emus. Thus, an experiment was carried out with 19 laying emu ((Dromaius novaehollandiae) hens, maintained in cages, and divided into two groups according to age, to record morphometric and physicochemical characteristics of the eggs. The width, length, average weight, form index, Haugh unit, yolk index, percentage of egg components, yolk pigmentation, pH of yolk and albumen, and eggshell weight and thickness were recorded. This morphometric characterization was influenced by the age of the hen. Neither the yolk nor albumen pH was influenced by the age of the bird. The eggs from emus that were raised in captivity presented physical and morphometric characteristics that varied with age, although they remained within the ranges of observations that were previously observed for ratite species, but were different from those of domestic chickens. The high fragility and easy rupture of the vitelline membrane in the emu eggs may limit the use of this product in industrial applications. Further studies of emu eggs are needed to improve their suitability for consumption and for the food industry. [ABSTRACT FROM AUTHOR]

ABSTRACT The objective of this study was to describe emus’ breeding performance in Brazil at different ages, grouped in couples or colonies. The duration of the breeding season and the production of eggs per female housed were recorded, and the productivity and breeding variables were associated with the variation of the photoperiod. The total production of the flock was 180 eggs, and the breeding season lasted 167 days (April-September), a period with an average of 11 h and 11min of daylight. The breeding season lasted 113, 133 and 82 days, the numbers of eggs produced per female were 7.29, 25.67 and 17.3, and productivity values were 31.6, 38.6, and 45.4% in the groups of birds with ages of two, four and seven years, respectively. The breeding season in 2016 occurred between April and August in Brazil. Older birds tended to start breeding later. The production rate observations indicated that earlier peak production was associated with lower egg production potential. Finally, there was a tendency for better breeding performance of birds housed in couples than in groups with more birds.

How early human foragers impacted insular forests is a topic with implications across multiple disciplines, including resource management. Paradoxically, terminal Pleistocene and Early Holocene impacts of foraging communities have been characterized as both extreme—as in debates over human-driven faunal extinctions—and minimal compared to later landscape transformations by farmers and herders. We investigated how rainforest hunter-gatherers managed resources in montane New Guinea and present some of the earliest documentation of Late Pleistocene through mid-Holocene exploitation of cassowaries (Aves: Casuariidae). Worldwide, most insular ratites were extirpated by the Late Holocene, following human arrivals, including elephant birds of Madagascar (Aepyornithidae) and moa of Aotearoa/New Zealand (Dinornithiformes)—icons of anthropogenic island devastation. Cassowaries are exceptional, however, with populations persisting in New Guinea and Australia. Little is known of past human exploitation and what factors contributed to their survival. We present a method for inferring past human interaction with mega-avifauna via analysis of microstructural features of archaeological eggshell. We then contextualize cassowary hunting and egg harvesting by montane foragers and discuss the implications of human exploitation. Our data suggest cassowary egg harvesting may have been more common than the harvesting of adults. Furthermore, our analysis of cassowary eggshell microstructural variation reveals a distinct pattern of harvesting eggs in late ontogenetic stages. Harvesting eggs in later stages of embryonic growth may reflect human dietary preferences and foraging seasonality, but the observed pattern also supports the possibility that—as early as the Late Pleistocene—people were collecting eggs in order to hatch and rear cassowary chicks. [ABSTRACT FROM AUTHOR]

Greater rheas have been the subject of scientific studies in the various areas of veterinary and biology in order to obtain essential information for their captivity management. The aim of this study was to describe the morphology of the greater rhea heart. The 20 animals were incised in sagittal plane, then fixed in 3.7% formaldehyde and dissected after 72 h. In addition, samples from the cardiovascular system were collected, processed for hematoxylin-eosin and Gomori Trichrome Staining. The heart is conical in shape, dark red when fresh and is located between the hepatic lobes. It has two atria and two ventricles, and four valves (left and right atrioventricular, aortic and pulmonary). The aorta and pulmonary trunk emerge at the heart base, while the ostia of the cranial and caudal vena cava emerged from the right atrium and the right and left pulmonary veins and the left coronary vein from the left atrium. From the aorta artery, the right and left coronary arteries arose, which originated, respectively, the superficial and conal branches and the profuse, left ventricular and superficial branches, being responsible for the irrigation of the heart. Microscopically the heart was constituted by simple pavement epithelium, rich in loose connective tissue. The aorta and pulmonary arteries were composed of the intima, middle and adventitial tunics. Thus, it is concluded that the morphological findings of greater rhea resemble those described for other birds such as ostrich and Gallus gallus domesticus.

Pathoanatomical studies of diseases that affect wild animals are extremely important as appropriate measures can then be taken for the prevention and control of such diseases. We report here the case of death of a greater rhea (Rhea americana) by intestinal intussusception secondary to the ingestion of a large amount of sand. The animal was bred at the Center for Multiplication of Wild Animals of the Federal Rural University of the Semi-Arid. The animal died after presenting clinical signs of apathy, weakness, prostration, and inability to move, drink water, or eat. After death, the carcass was immediately sent for necropsy. During necropsy, intussusception was found involving the jejunum, ileum, and colon. The duodenum contained large amounts of coarse sand. The invaginated intestinal segments were reddish in color, with necrotic spots, and covered by a fibrinous exudate. Histopathological examination of the invaginated segments showed necrosis of the enterocytes, detachment of the intestinal epithelium, and the presence of inflammatory cells. The ingestion of a large amount of sand may have resulted in altered intestinal transit, contributing to the occurrence of intussusception, which resulted in ischemic alterations, intestinal necrosis, and consequent death of the animal. [ABSTRACT FROM AUTHOR]

The purpose of this research was to study the histology and describe the microscopy findings of the epididymis epithelium of greater Rhea americana at three time periods: November 2005 (n=14), December 2006 (n= 20), and May 2007 (n= 20), to observe and compare the differences that occurred. We studied the epididymis from 54 rheas, bred in Santa Maria, Rio Grande do Sul, Brazil. The epididymis were collected during commercial slaughter and fixed in bouin. Optical microscopy was used to measure the cellular structure, types of cells, tubules, and stereological values like the epididymis epithelium diameters, lumen, thickness, and relative volume of the tissue structure. Additionally, electron microscopy was studied. In December 2006 and May 2007, the means of the epididymis tubular diameter were: 79.1 and 58.1 µm, epithelium thickness: 24.0 and 52.2 µm, and lumen diameter: 55.0 and 5.8 µm, respectively. Regarding the volumetric proportion, we reported the following values: epithelium volume 36.2 and 80.4%, lumen without spermatozoon 19.6 and 3.0%, lumen with spermatozoon 5.4 and 0.0%, interstitium 35.4 and 12.0%, blood vessels 3.5 and 4.6%, structures in cellular superficies 1.4 and 0%, lamina 1.4 and 3.2%, and artifacts 0.3 and 1.3%, respectively. The epididymis ducts had a circular form in transverse sections with spermatozoon only in November 2005 and December 2006. The Rhea's epididymis morphology was found to be similar to ostriches, roosters, and Japanese quail. Here, we present data from stereological microscopy (tubular diameter, epithelium thickness, and lumen diameter), volumetric proportion (epithelium, lumen without spermatozoon, lumen with spermatozoon, interstitium, blood vessels, structures in cellular superficies; cilium, estereocilium, and lamina) in this species during the repose and sexual activity period (reproductive season). [ABSTRACT FROM AUTHOR]

Palaeognathae includes ratite and tinamou species that are important for understanding early avian evolution. Here, we analyzed the whole-genome sequences of 15 paleognathous species to infer their demographic histories, which are presently unknown. We found that most species showed a reduction of population size since the beginning of the last glacial period, except for those species distributed in Australasia and in the far south of South America. Different degrees of contraction and expansion of transposable elements (TE) have shaped the paleognathous genome architecture, with a higher transposon removal rate in tinamous than in ratites. One repeat family, AviRTE, likely underwent horizontal transfer from tropical parasites to the ancestor of little and undulated tinamous about 30 million years ago. Our analysis of gene families identified rapid turnover of immune and reproductionrelated genes but found no evidence of gene family changes underlying the convergent evolution of flightlessness among ratites. We also found that mitochondrial genes have experienced a faster evolutionary rate in tinamous than in ratites, with the former also showing more degenerated W chromosomes. This result can be explained by the Hill-Robertson interference affecting genetically linked W chromosomes and mitochondria. Overall, we reconstructed the evolutionary history of the Palaeognathae populations, genes, and TEs. Our findings of co-evolution between mitochondria and W chromosomes highlight the key difference in genome evolution between species with ZW sex chromosomes and those with XY sex chromosomes. [ABSTRACT FROM AUTHOR]

Maternal corticosterone in avian egg yolks may signal and prepare offspring for the prevailing conditions. However, this adjustment requires flexible mechanisms of regulation that lead to the absence of a correlation between hormone levels in the mother and the yolk. In this study, we examined whether yolk immunoreactive corticosterone and maternal glucocorticoid levels are related in the Greater Rhea (Rhea americana), a ratite species with a communal nesting system. During the intermediate laying period of the season, we carried out daily nest-observations to collect those eggs in which the laying female was identified. We also collected fresh fecal samples from the identified laying females to quantify their fecal glucocorticoid metabolite (FGM) levels during the yolk formation period (7 days before egg-laying). Yolk immunoreactive corticosterone and FGM levels were measured using a corticosterone125 radioimmunoassay kit, previously validated for the species. No significant relationships were found between female FGM and yolk immunoreactive corticosterone. Although futures studies are needed to elucidate the underlying mechanisms, our results suggest that Greater Rhea female may be able to control the distribution of corticosterone into their yolks, supporting the idea that this hormone may be mediating an adaptive maternal effect. [ABSTRACT FROM AUTHOR]

Copyright of Revista Brasileira de Reprodução Animal is the property of Revista Brasileira de Reproducao Animal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Finite element analysis (FEA) was used to conduct mechanical analyses on eggshells of giant birds, and relate this to the evolution and reproductive behavior of avian species. We aim to (1) investigate mechanical characteristics of eggshell structures of various ratite species, enabling comparisons between species with or without reversed sexual size dimorphism (RSSD); (2) quantify the safety margin provided by RSSD; (3) determine whether the Williams’ egg can have been incubated by an extinct giant bird Genyornis newtoni; (4) determine the theoretical maximum body mass for contact incubation. We use a dimensionless number C to quantify relative shell stiffness with respect to the egg size, allowing for comparison across wide body masses. We find that RSSD in moas significantly increases the safety margin of contact incubation by the lighter males. However, their safety margins are still smaller than those of the moa species without RSSD. Two different strategies were adopted by giant birds—one is RSSD and thinner shells, represented by some moa species; the other is no RSSD and regular shells, represented by the giant elephant bird. Finally, we predicted that the upper limit of body mass for contact incubation was 2000 kg.

Los avestruces poseen características productivas que la hacen una especie atractiva para el mercado de carne y huevos, además de otros subproductos como plumas, grasas, y piel. En diferentes países del mundo, incluyendo a Colombia, la producción de esta especie está aumentando y para mantener su población en cautiverio se están tomando medidas preventivas contra enfermedades virales, bacterianas y parasitarias. El objetivo de este trabajo fueidentificar parásitos gastrointestinales en un criadero de avestruces del departamento del Cauca. Para el estudio, se colectó material coprológico de 38 animales, 19 adultos (> 7 años de edad), 9 Juveniles (1 año), 10 polluelos (1 mes), siendo enviado a 4 °C a un laboratorio donde fue procesado y examinado. Se identificaron quistes compatibles con Eimeria sp. (15,7%), Balantidium sp. (13,2%) y huevos compatibles con Libyostrongylus sp. (10,5%), no hubo correlación entre las edades y la carga parasitaria, así como, el sexo y la carga parasitaria. A pesar de que los animales muestreados no presentaron signos clínicos de enfermedad parasitaria, es necesario realizar más estudios para comprender ciclo biológico de estos parásitos en los avestruces de la región, en el presente trabajo se sugiere la presencia de Libyostrongylus sp., el cual ya ha sido reportado una vez en Colombia.

The objectives of the study were to (1) describe the kinematic parameters of spermatozoa (2) compare methods of evaluating sperm viability (3) validate assays of functionality and integrity of the sperm membrane and (4) evaluate possible changes between spermatozoa from the epididymis and the vas deferens of the greater rhea. Semen samples were recovered from 7 adult individuals. Sperm motility was characterized by adjusting the set-up for Computer-assisted semen analysis (CASA) to that new species. For sperm viability evaluation, smears of bromophenol blue and eosin-nigrosine dyes were used. Five solutions of different osmolarities were then tested for the hypoosmotic swelling test (HOST). The combination of fluorescent probes (propidium iodide - IP and Hoechst 33342) was also used to assess plasma membrane integrity. Data were presented as mean ± SEM. Rhea spermatozoa from the vas deferens had an overall motility of 14.6 ± 2.5%. The bromophenol blue staining technique revealed that 64.6 ± 5.2% sperm were viable, while that proportion was 72.1 ± 2.5% using eosin-nigrosine. An average of 77.6 ± 4.8% of spermatozoa reacted to the HOST with distilled water at 0 mOsm/l. Fluorescent probes indicated that 65.3 ± 2.6% of spermatozoa had intact membranes. Interestingly, no statistical differences were observed between the parameters analyzed in the epididymal spermatozoa and the vas deferens. These new assays set reference values that can now be used to further exploration of sperm handling conditions and freezing protocols in rheas., Competing Interests: Conflict of interest: The authors have no conflict of interest to declare.

Copyright of Revista Colombiana de Ciencia Animal - RECIA is the property of Revista Colombiana de Ciencia Animal - RECIA and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The recently extinct Malagasy elephant birds (Palaeognathae, Aepyornithiformes) included the largest birds that ever lived. Elephant bird neuroanatomy is understudied but can shed light on the lifestyle of these enigmatic birds. Palaeoneurological studies can provide clues to the ecologies and behaviours of extinct birds because avian brain shape is correlated with neurological function. We digitally reconstruct endocasts of two elephant bird species, Aepyornis maximus and A. hildebrandti, and compare them with representatives of all major extant and recently extinct palaeognath lineages. Among palaeognaths, we find large olfactory bulbs in taxa generally occupying forested environments where visual cues used in foraging are likely to be limited. We detected variation in olfactory bulb size among elephant bird species, possibly indicating interspecific variation in habitat. Elephant birds exhibited extremely reduced optic lobes, a condition also observed in the nocturnal kiwi. Kiwi, the sister taxon of elephant birds, have effectively replaced their visual systems with hyperdeveloped olfactory, somatosensory and auditory systems useful for foraging. We interpret these results as evidence for nocturnality among elephant birds. Vision was likely deemphasized in the ancestor of elephant birds and kiwi. These results show a previously unreported trend towards decreased visual capacity apparently exclusive to flightless, nocturnal taxa endemic to predator-depauperate islands. [ABSTRACT FROM AUTHOR]

The functional anatomies of avian finger joints have never been compared with those of the basal avian Archaeopteryx lithographica or maniraptoran theropod dinosaurs. These startling oversights are due to unfamiliarity of the joints outside of highly specialised studies of bird-wing biomechanics. Here fleshed to skeletonised repeated-measures analyses of finger-joint ranges of motion (ROMs) in a basal palaeognath, the Ostrich Struthio camelus, were utilised as a model to begin filling in these knowledge gaps. Results verified that all of the flight-adapted, avian-specific finger joints are retained in the flightless, yet large and well-differentiated fingers of the Ostrich. Moreover, Ostrich finger joints still possess flight-restricted ROMs within the semi-pronated plane of the manus. The osteological markers of these highly conserved flight-adapted characters in Ostrich show that prior descriptions have unknowingly demonstrated that the main avian finger-joint complex began evolving at the base of Pennaraptora (Oviraptorosauria + Paraves). This detailed functional analysis provides non-embryological support for the hypothesis that maniraptoran theropods shared digital homologies with birds, and supports recent pronation studies indicating that pennaraptoran theropods had evolved avian distal wing joints stiffened for aerial locomotion. [ABSTRACT FROM AUTHOR]

Background: The Rhea americana americana is a wild bird belonging to the group of Ratites, and is important from the scientific point of view given their adaptability to captivity. Considering that information about its morphology is important for the viability of domesticating the species, the aim of this study was to macroscopically identify the brain regions, as well as the cerebral arteries and the cerebral arterial circuit in order to establish the cerebral vascular pattern and systematization. Materials, Methods & Results: Twenty one brains from young and adult Greater Rheas of both sexes were used from animals that had died due to natural causes and were then kept in a freezer. The specimens were thawed and incised in the cervical region to allow exposure of the left common carotid artery, which was cannulated. The vascular system was rinsed with 0.9% saline solution, then perfused with latex Neoprene 650 stained with red pigment. The animals were subsequently fixed in 3.7% aqueous formaldehyde solution for 72 h, and then they were dissected by removing the bones from the skull cap. The brains were analyzed, and the structures were identified, photographed, schematized and denominated. Morphometric measurements were performed on the basilar and cerebellar ventral caudal arteries, recording the values of length and width in millimeters with the aid of a digital caliper. The brain was divided into: telencephalon, diencephalon, brainstem and cerebellum; while externally, the observed structures are: olfactory bulbs, optical lobes, optic nerves, optic chiasm, pituitary and pineal glands. Vascularization was performed by the following arteries: ventral spinal artery, basilar artery, ventricular cerebellar arteries, medium ventricular cerebellar arteries, caudal branches of the carotid arteries of the brain, ventral mesencephalic artery, cerebral caudal arteries, rostral branches of the carotid arteries of the brain, middle cerebral arteries, cerebroethmoidal arteries, rostral intercerebral anastomosis, rostral cerebral arteries, ethmoidal arteries, internal ophthalmic arteries, inter-hemispheric artery, pituitary arteries, dorsal mesencephalic tectal arteries, dorsal cerebellar arteries, occipital, pineal and dorsal hemispherical branches. The cerebral arterial circuit was both caudally and rostrally closed in 100.0% of the samples, being composed of the arteries: basilar artery, caudal branches of the carotid brain, rostral branches of the brain carotid, cerebroethmoidal arteries and rostral intercerebral anastomosis. Discussion: Encephalon classification regarding the presence or absence of gyri is a characteristic associated to evolutionary aspects among vertebrates, being respectively considered as lisencephalon or girencecephalus when it presents or does not present convolutions. In Greater Rheas, the telencephalon was quite developed, with a relatively rounded shape and the absence of sulci and convolutions in the cortex, which allowed it to be classified as a lisencephalon. Such findings resemble those described for the ostrich and in a comparative study involving kiwis, emus, owls and pigeons, although different sizes and forms of telencephalon development were observed in the latter. Regarding the cerebral arterial circuit, this structure in Rheas was complete and both caudally and rostrally closed in 100.0% of the specimens. Our findings differ from those observed for ostriches, in which a rostrally open behavior has been described, while it is caudally closed in 20.0% of cases and opened in 80.0%. Regarding the vascular type of the brain, in the Rhea it was observed that there was only contribution of the carotid system, similar to that found for birds such as ostriches and turkeys which confer a type I encephalic vascularization. [ABSTRACT FROM AUTHOR]

The greater rhea (Rhea americana americana) is a bird of the Rheidae family, and is known as a ratite for being a flightless bird. This animal has great reproductive and productive potential, according to the products and by-products that it can provide such as meat, leather, feathers and fat which are very popular in the world market. Given its economic importance and lack of information in the literature on its morphology, especially in regard to its cardiovascular apparatus, this study aimed to describe the collateral arteries of the aortic arch, in order to establish the origin and distribution of arteries and thus contribute information to the biology of the species. The bodies of 20 young and adult rheas of both sexes which had died from natural causes and were being stored in a freezer at CEMAS / UFERSA were used. The study was approved by CEUA /UFERSA (Opinion No. 09/2015, process No. 23091.004968 / 2015-23). The animals were thawed and had the cannulated thoracic aorta artery and the vascular system perfused with Neoprene 450 latex colored with yellow pigment. Subsequently, the animals were fixed in 3.7% aqueous solution of formaldehyde, and after 72 hours dissections were carried out, images were obtained and schematic drawings were prepared. The right and left brachiocephalic trunks emerged from the aortic arch in 100% of the specimens from the right brachiocephalic trunk origined a common trunk the thyroid arteries, syringotracheal trunk, vertebral artery, superficial lateral cervical artery, basecervical artery, and ascending esophageal artery. The left brachiocephalic trunk collaterally stemmed in the left common carotid artery, which in turn led to the left internal carotid and a common trunk which stemmed the thyroid arteries, the syringotracheal trunk, vertebral artery, superficial lateral cervical artery, basecervical artery and descending esophageal artery. At the end of its trajectory, the right and left brachiocephalic trunks give rise to the right and left subclavian arteries, which in turn, stem the sternoclavicular, axillary, and intercostal arteries, pectoral trunk, cranial pectoral arteries, pectoral caudal artery and collateral branches of the pectoral trunk. Based on the results, it was concluded that the aortic arch in rheas issued right and left brachycephalic trunks.

Birds have genomic and chromosomal features that make them an attractive group to analyze the evolution of recombination rate and the distribution of crossing over. Yet, analyses are biased towards certain species, especially domestic poultry and passerines. Here we analyze for the first time the recombination rate and crossover distribution in the primitive ratite bird, Rhea americana (Rheiformes, Palaeognathae). Using a cytogenetic approach for in situ mapping of crossovers we found that the total genetic map is 3050 cM with a global recombination rate of 2.1 cM/Mb for female rheas. In the five largest macrobivalents there were 3 or more crossovers in most bivalents. Recombination rates for macrobivalents ranges between 1.8–2.1 cM/Mb and the physical length of their synaptonemal complexes is highly predictive of their genetic lengths. The crossover rate at the pseudoautosomal region is 2.1 cM/Mb, similar to those of autosomal pairs 5 and 6 and only slightly higher compared to other macroautosomes. It is suggested that the presence of multiple crossovers on the largest macrobivalents is a feature common to many avian groups, irrespective of their position throughout phylogeny. These data provide new insights to analyze the heterogeneous recombination landscape of birds. [ABSTRACT FROM AUTHOR]

Ostrich-like birds (Palaeognathae) show very little taxonomic diversity while their sister taxon (Neognathae) contains roughly 10,000 species. The main anatomical differences between the two taxa are in the crania. Palaeognaths lack an element in the bill called the lateral bar that is present in both ancestral theropods and modern neognaths, and have thin zones in the bones of the bill, and robust bony elements on the ventral surface of their crania. Here we use a combination of modeling and developmental experiments to investigate the processes that might have led to these differences. Engineering-based finite element analyses indicate that removing the lateral bars from a neognath increases mechanical stress in the upper bill and the ventral elements of the skull, regions that are either more robust or more flexible in palaeognaths. Surgically removing the lateral bar from neognath hatchlings led to similar changes. These results indicate that the lateral bar is load-bearing and suggest that this function was transferred to other bony elements when it was lost in palaeognaths. It is possible that the loss of the load-bearing lateral bar might have constrained diversification of skull morphology in palaeognaths and thus limited taxonomic diversity within the group. [ABSTRACT FROM AUTHOR]

Palaeognaths, the sister group of all other living birds (neognaths), were once considered to be vicariant relics from the breakup of the Gondwanan supercontinent. However, recent molecular studies instead argue for dispersal of volant ancestors across marine barriers. Resolving this debate hinges upon accurately reconstructing their evolutionary relationships and dating their divergences, which often relies on phylogenetic information from extinct relatives and nuclear genomes. Mitogenomes from the extinct elephant birds of Madagascar have helped inform the palaeognath phylogeny; however, nuclear information has remained unavailable. Here, we use ancient DNA (aDNA) extracted from fossil eggshell, together with target enrichment and next-generation sequencing techniques, to reconstruct an additional new mitogenome from Aepyornis sp. with 33.5X coverage. We also recover the first elephant bird nuclear aDNA, represented by 12,500 bp of exonic information. While we confirm that elephant birds are sister taxa to the kiwi, our data suggests that, like neognaths, palaeognaths underwent an explosive radiation between 69 and 52 Ma—well after the break-up of Gondwana, and more rapidly than previously estimated from mitochondrial data alone. These results further support the idea that ratites primarily diversified immediately following the Cretaceous-Palaeogene mass extinction and convergently evolved flightlessness. Our study reinforces the importance of including information from the nuclear genome of extinct taxa for recovering deep evolutionary relationships. Furthermore, with approximately 3% endogenous aDNA retrieved, avian eggshell can be a valuable substrate for recovering high quality aDNA. We suggest that elephant bird whole genome recovery is ultimately achievable, and will provide future insights into the evolution these birds. [ABSTRACT FROM AUTHOR]

Copyright of Brazilian Journal of Biology is the property of Instituto Internacional de Ecologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Ostrich farming is an important livestock industry in different world regions with a diverse offer of products and services. In Colombia, as in other countries, this market led the importation of animals from countries like Canada, United States of America and South Africa for breeding objectives. With the animals, specific pathogens for these ratites could be introduced. Libyostrongylus spp. is a strongylid nematode with worldwide distribution, which can induce a severe disease and mortality in infected animals. Limited studies in Colombia have identified parasites in ostrich farming systems. The aim of this study was to identify parasites of the genus Libyostrongylus to a species level in faecal samples from ostrich farms in three departments of Colombia. Five ostrich farms from Boyacá, Meta and Tolima were sampled in 2011 and in 2013 to obtain fresh faecal samples which were further processed by flotation tests for egg visualization and faecal culture for infective larvae identification by morphological and morphometric parameters. One from the five farms, located in Meta department, was positive for strongylid eggs in both sampling periods. After faecal culture, infective larvae were identified as Libyostrongylus douglassii. These results corroborate previous records of Libyostrongylus in ostrich farms from Meta and confirms, for the first time, infection by L . douglassii in ratites from this region. Further studies must identify associated determinants for infection and its effects on the flock health and production. [ABSTRACT FROM AUTHOR]

Summary The Palaeognathae comprise the flightless ratites and the volant tinamous, and together with the Neognathae constitute the extant members of class Aves. It is commonly believed that Palaeognathae originated in Gondwana since most of the living species are found in the Southern Hemisphere [ 1–3 ]. However, this hypothesis has been questioned because the fossil paleognaths are mostly from the Northern Hemisphere in their earliest time (Paleocene) and possessed many putative ancestral characters [ 4 ]. Uncertainties regarding the origin and evolution of Palaeognathae stem from the difficulty in estimating their divergence times [ 1, 2 ] and their remarkable morphological convergence. Here, we recovered nuclear genome fragments from extinct elephant birds, which enabled us to reconstruct a reliable phylogenomic time tree for the Palaeognathae. Based on the tree, we identified homoplasies in morphological traits of paleognaths and reconstructed their morphology-based phylogeny including fossil species without molecular data. In contrast to the prevailing theories, the fossil paleognaths from the Northern Hemisphere were placed as the basal lineages. Combined with our stable divergence time estimates that enabled a valid argument regarding the correlation with geological events, we propose a new evolutionary scenario that contradicts the traditional view. The ancestral Palaeognathae were volant, as estimated from their molecular evolutionary rates, and originated during the Late Cretaceous in the Northern Hemisphere. They migrated to the Southern Hemisphere and speciated explosively around the Cretaceous-Paleogene boundary. They then extended their distribution to the Gondwana-derived landmasses, such as New Zealand and Madagascar, by overseas dispersal. Gigantism subsequently occurred independently on each landmass. [ABSTRACT FROM AUTHOR]

The North Island Brown Kiwi ( Apteryx mantelli) is a nocturnal endangered species endemic to New Zealand. The protection of suitable habitat is key to the species' recovery; however, little is known about their habitat requirements. We studied the diurnal roosting behaviours of kiwis by intensely tracking 41 radio-tagged, non-breeding adults from May 2010 to February 2012 on Ponui Island, New Zealand. From these birds, we collected 3,997 roosting locations in three different macro-habitat types (scrub, forest, and swamp) and described 223 roosting burrows in the forest macro-habitat. Overall, we discovered that kiwis were roosting generalists; three quarters of the study population was found in more than one macro-habitat and just 5% used only a single type of micro-habitat. However, using compositional analyses, we found that they did show some clear preferences. On a macro-habitat level, kiwis preferred forest habitat over scrub or swamp. Furthermore, on a micro-habitat level, they preferred roosting inside trees, either living or dead, and holes in the ground over roosting in decomposing vegetation or holes associated with creeks. The least preferred micro-habitat type consisted of overhangs produced by ground slips. Kiwis were most likely to use long burrows with small entrances that were oriented downhill. Our findings suggest that priority should be given to protecting mixed landscapes with large, mature, dynamic native forests. [ABSTRACT FROM AUTHOR]

Head shaping in mammalian sperm is regulated by a number of factors including acrosome formation, nuclear condensation and the action of the microtubular manchette. A role has also been suggested for the attendant Sertoli cells and the perinuclear theca (PT). In comparison, relatively little information is available on this topic in birds and the presence of a PT per se has not been described in this vertebrate order. This study revealed that a similar combination of factors contributed to head shaping in the ostrich, emu and rhea, although the Sertoli cells seem to play a limited role in ratites. A fibro-granular structure analogous to the mammalian PT was identified, consisting of sub- and post-acrosomal components. The latter was characterized by stage-specific finger-like projections that appeared to emanate from the cytoplasmic face of the nuclear envelope. They were particularly obvious beneath the base of the acrosome, and closely aligned, but not connected to, the manchette microtubules. During the final stages of chromatin condensation and elongation of the sperm head the projections abruptly disappeared. They appear to play a role in stabilizing the shape of the sperm head during the caudal translocation of the spermatid cytoplasm. [ABSTRACT FROM AUTHOR]

The cloacal bursa is an organ in fowls, which triggers lymphocyte maturation and transference to other tissues. Since there is scanty information on its morphology in wild species in spite of its importance in the fowls´ immunological system, current analysis describes the arterial vascularization of the cloacal bursa in the greater rhea. Twenty juvenile rheas (male and female), which died of natural causes, were obtained from the Center for the Multiplication of Wild Animals (CEMAS/UFERSA). The animals were dissected and their thoracic aorta cannulated and red-stained Latex Neoprene 650 was introduced. The cloacal bursa was irrigated from the terminal branches of the abdominal aorta similar to the caudal mesenteric artery and to the right and left internal iliac arteries. The right and left internal pudenda arteries originated from the right and left internal iliac arteries which, in their turn, gave rise to cloacal-bursa arteries and to the right and left cloacal arteries in all studied animals. The caudal mesenteric artery contributed to the arterial blood of the cloacal bursa in almost all studied animals through the anastomosis of right or left internal pudenda artery, with direct branches to the cloacal bursa. The cloacal bursa of the greater rhea is irrigated by cloacal-bursa arteries and cloacal right and left and also by the mesenteric caudal artery, with small variations with regard to the number and layout of the anastomoses and branches from the arteries. The latter are specific characteristics and differentiate them from standards perceived in other fowls.