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Management programs that successfully recovered wild saltwater crocodile (Crocodylus porosus) populations in the Northern Territory of Australia did so with an expanding commitment to maintaining public safety. One aspect of the program is the ongoing removal of resident and immigrant crocodiles within Darwin Harbor (since 1979), the main urban center. We determined the likely sources of crocodiles caught as problem animals between 2015–2017 by comparing recently developed methods for population assignment. Depending on the assignment model used, we estimated that between 30% and 50% of crocodiles in Darwin Harbor originated from the Adelaide and Mary rivers, and the Kakadu region east of Darwin, and between 20% and 30% of crocodiles originated from the Finniss, Reynolds, and Daly rivers southwest of Darwin. Saltwater crocodiles occur at particularly high densities in these catchments. The remainder came from a mixture of different sources across the Northern Territory. The most common animals captured were immature (150–180 cm) males that have traveled 100–200 km. We did not identify any relationships between the distance from the inferred origin to Darwin Harbor and the size and sex of the crocodiles, or the year of capture. The targeted removal of crocodiles from specific sites such as Darwin Harbor, near where most people live, improves public safety in the highest risk areas, without compromising abundant source populations in most areas. [ABSTRACT FROM AUTHOR]

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Negative interactions between waterbirds and people are increasing. Waterbirds feeding on agricultural crops cause significant losses to farmers worldwide, but so far most research to address these conflicts has been conducted on migratory species in the temperate northern hemisphere. We investigated the space use and habitat selection of the magpie goose (Anseranas semipalmata), a taxonomically distinct waterbird endemic to Australia and southern Papua New Guinea. In tropical northern Australia, magpie geese are protected but are increasingly persecuted by farmers to protect crops during the late dry–early wet season (~Sep–Jan), a bottleneck of natural resources for waterbirds in the monsoonal tropics. Using satellite telemetry of 38 geese spread across 3 seasons (2016–2017, 2017–2018, 2018–2019), we evaluated daily and seasonal space use, individual site fidelity, and habitat selection to determine the extent of use of agricultural fields by geese, and the spatiotemporal scales at which management should be undertaken. Geese used relatively small daily areas (x̄ = 8.2 km2) consistently throughout the late dry–early wet season, and repeatedly used agricultural fields, forested bushlands, and local wetlands. Geese used comparatively large seasonal areas (x̄ = 219.5 km2) encompassing several agricultural areas, and had a low mean overlap between successive weekly core activity areas, indicating that site fidelity rapidly weakened over time. These results suggest that farm‐scale (<30 ha) management of geese is unlikely to be effective because hazed individuals are likely to be replaced soon afterwards. Instead, our findings suggest that goose management should be coordinated strategically at the local (~1,000 ha), or regional (~100,000 ha) scale. Farm‐level management would likely be more effective if implemented in conjunction with the creation of regional sanctuaries where geese could rest and potentially feed undisturbed away from farms. Our findings can be used by wildlife managers for optimizing the location of such sanctuaries and highlight the necessity for management to be adaptive given the opportunistic nature of the species. [ABSTRACT FROM AUTHOR]

Landscape genetics commonly focuses on the effects of environmental resistance on animal dispersal patterns, but there is an emerging focus on testing environmental effects on emigration and settlement choices. In this study, we used landscape genetics approaches to quantify dispersal patterns in the world's largest crocodilian, the saltwater crocodile (Crocodylus porosus), and demonstrated environmental influences on three processes that comprise dispersal: emigration, movement and settlement. We found that both environmental resistance and properties of the source and destination catchments (proportion of breeding habitat) were important factors influencing observed dispersal events. Our habitat quality variables related to hypotheses about resource competition and represented the ratio of breeding habitat (which limits carrying capacity), suggesting that competition for habitat influences emigration and settlement choices, together with the strong effect of environmental resistance to movement (where high‐quality habitat was associated with greatest environmental permeability). Approximately 42% of crocodiles were migrants from populations other than their sampling locations and some outstandingly productive populations had a much higher proportion of emigration rather than immigration. The distance most commonly travelled between source and destination was 150–200 km although a few travelled much longer distances, up to 600–700 km. Given the extensive dispersal range, individual catchments or hydrographic regions that combine two or three adjacent catchments are an appropriate scale for population management. [ABSTRACT FROM AUTHOR]

Research on water exchange in frogs has historically assumed that blood osmotic potential drives water exchange between a frog and its environment, but here we show that the "seat patch" (the primary site of water exchange in many anurans), or other sites of cutaneous water uptake, act as an anatomic "compartment" with a water potential controlled separately from water potential of the blood, and the water potential of that compartment can be the driver of water exchange between the animal and its environment. We studied six frog species (Xenopus laevis, Rana pipiens, R. catesbeiana, Bufo boreas, Pseudacris cadaverina, and P. regilla) differing in ecological relationships to environmental water. We inferred the water potentials of seat patches from water exchanges by frogs in sucrose solutions ranging in water potential from 0 to 1000‐kPa. Terrestrial and arboreal species had seat patch water potentials that were more negative than the water potentials of more aquatic species, and their seat patch water potentials were similar to the water potential of their blood, but the water potentials of venters of the more aquatic species were different from (and less negative than) the water potentials of their blood. These findings indicate that there are physiological mechanisms among frog species that can be used to control water potential at the sites of cutaneous water uptake, and that some frogs may be able to adjust the hydric conductance of their skin when they are absorbing water from very dilute solutions. Largely unexplored mechanisms involving aquaporins are likely responsible for adjustments in hydric conductance, which in turn, allow control of water potential at sites of cutaneous water uptake among species differing in ecological habit and the observed disequilibrium between sites of cutaneous water uptake and blood water potential in more aquatic species. [ABSTRACT FROM AUTHOR]

The water‐permeable skin of amphibians renders them highly sensitive to climatic conditions, and interspecific correlations between environmental moisture levels and rates of water exchange across the skin suggest that natural selection adapts hydroregulatory mechanisms to local challenges. How quickly can such mechanisms shift when a species encounters novel moisture regimes? Cutaneous resistance to water loss and gain in wild‐caught cane toads (Rhinella marina) from Brazil, USA (Hawai'i) and Australia exhibited strong geographic variation. Cutaneous resistance was low in native‐range (Brazilian) toads and in Hawai'ian populations (where toads were introduced in 1932) but significantly higher in toads from eastern Australia (where toads were introduced in 1935). Toads from recently invaded areas in western Australia exhibited cutaneous resistance to water loss similar to the native‐range populations, possibly because toads are restricted to moist sites within this highly arid landscape. Rates of rehydration exhibited significant but less extreme geographic variation, being higher in the native range than in invaded regions. Thus, in less than a century, cane toads invading areas that impose different climatic challenges have diverged in the capacity for hydroregulation. [ABSTRACT FROM AUTHOR]

River red gum woodlands associated with ephemeral river channels in arid Australia are recognised as important habitat for a suite of bird species, due to their distinctive structure, large canopies and abundant tree hollows. We tested the proposition that river red gum woodlands harbour a distinctive bird assemblage that is relatively stable through time. We examined patterns of bird composition between habitats (riparian woodland versus neighbouring habitat) over multiple years (from 2016 to 2018) and locations (three catchments), and we assessed these patterns in the context of variable food resource availability. Assemblages in river red gum woodlands differed from those of adjacent vegetation, despite strong temporal variability caused by arrival of nomadic species in both habitat types following above‐average rainfall. Species richness was reduced in the drier periods, yet bird assemblages in river red gum woodlands retained their distinctiveness from adjacent habitat. Flowering and fruiting of shrubs and trees were largely stimulated by rainfall; in contrast, invertebrate abundance was driven more by temperature and was higher in river red gum woodlands. Our data did not imply that river red gum woodland acted as a refuge in drier times for species from neighbouring habitat. Our study supports the hypothesis that arid bird community composition is influenced more by habitat than by temporal resource variability. [ABSTRACT FROM AUTHOR]

Up to 37 species of the birds and microbats inhabiting inland Australia are dependent on tree cavities for breeding or roosting. The river red gum (Eucalyptus camaldulensis), a well‐known hollow‐bearing tree species, occurs in linear semi‐arid woodland along thousands of kilometres of ephemeral river channels and is the only tree species that provides widespread, aggregated hollow resources across a landscape otherwise dominated by shrublands. Here we assess the type and quantity of hollows available along ephemeral rivers of the MacDonnell Ranges bioregion in central Australia and determine which characteristics of river red gums best predict the abundance and characteristics of different tree hollows, as first steps towards assessing the current availability of hollows in the region. Approximately a third of all river red gums sampled were hollow‐bearing, but individual trees with abundant hollows were rare. Further, 36% of hollows had an entrance ≤ 5 cm, and 37% had entrances which were 6–10 cm in diameter, whereas only 13% of hollows had an entrance diameter > 20 cm suitable for larger hollow‐using species. Large and high hollows only occurred on trees that did not display post‐disturbance resprouting. Trees with multiple and diverse hollows were rare and tended to be in advanced stages of senescence and had larger stems (82.3 ± 3.33 cm) and were taller (14.4 ± 0.53 m) compared to non‐hollow‐bearing trees (23.44 ± 1.68 cm, 8.0 ± 0.34 m). Further research is required to establish whether the current abundance of hollows and diversity of hollow types are limiting to cavity‐dependent wildlife, and to identify any threats to availability of hollows. [ABSTRACT FROM AUTHOR]

Dehydration is considered a physiological challenge, and many organisms live in environments that undergo periods of reduced water availability that can lead to dehydration. Recent studies have found a positive relationship between dehydration and innate immune function in animals adapted to xeric or semixeric environments. To explore the generality of this relationship, we examined the impact of dehydration on innate immune performance in water pythons (Liasis fuscus), a semiaquatic snake from the wet‐dry tropics of Australia. We collected blood samples from male and female water pythons held in the laboratory without food and water for 4 weeks. We also collected blood from free‐ranging snakes throughout the Austral dry‐season. We evaluated plasma osmolality and innate immune function (agglutination, lysis, and bacterial‐killing ability) and found that increased osmolality, whether manipulated in the laboratory or as a result of natural water limitation, resulted in enhanced aspects of innate immune performance. Counter‐intuitively, snakes in the wild became more hydrated as the dry season progressed, suggesting the dehydrated snakes move to water sources periodically to rehydrate. Comparing our data with those from previous studies, we suspect species divergence in the level of dehydration (i.e., hyperosmolality) that triggers enhanced immune capabilities. [ABSTRACT FROM AUTHOR]

The microbiota of frog skin can play an important role in protecting against diseases and parasites. The frog skin microbial community represents a complex mix of microbes that are promoted by the chemical environment of the frog skin and influenced by the animal's immediate past environment. The microbial communities of six species of frogs sampled from the campus of Charles Darwin University (CDU) were more similar within species than between species. The microbiota of the introduced cane toad (Rhinella marina) was most dissimilar among the species. Pairwise comparisons showed that the microbial communities of each species were different, except for the terrestrial Litoria nasuta and the arboreal L. rothii. The microbial communities of the six species were not related to ecological habit (arboreal or terrestrial), and neither was the alpha diversity of the microbes. The core microbes (defined as being on ≥90% of individuals of a species or group) were significantly different among all species, although 89 microbial operational taxonomic units (OTUs) were core microbes for all six species at CDU. Two species, Rhinella marina and Litoria rothii, were sampled at additional sites approximately 10 and 30 km from CDU. The microbial communities and the core OTU composition were different among the sites, but there were nevertheless 194 (R. marina) and 181 (L. rothii) core OTUs present at all three sites. Thus, the core microbiota varied with respect to geographic range and sample size. The skin microbiota of six frog species was studied at one site, and there were substantial species‐specific differences despite there being very close geographic associations among the species. Two species were sampled at additional sites 10 and 30 km from the first site, and this information was used to evaluate the utility of the concept of a core microbiota. [ABSTRACT FROM AUTHOR]

Abstract: Biological invasions can stimulate rapid shifts in organismal performance, via both plasticity and adaptation. We can distinguish between these two proximate mechanisms by rearing offspring from populations under identical conditions and measuring their locomotor abilities in standardized trials. We collected adult cane toads (Rhinella marina) from invasive populations that inhabit regions of Australia with different climatic conditions. We bred those toads and raised their offspring under common‐garden conditions before testing their locomotor performance. At high (but not low) temperatures, offspring of individuals from a hotter location (northwestern Australia) outperformed offspring of conspecifics from a cooler location (northeastern Australia). This disparity indicates that, within less than 100 years, thermal performance in cane toads has adapted to the novel abiotic challenges that cane toads have encountered during their invasion of tropical Australia. [ABSTRACT FROM AUTHOR]

Photosynthetic microbial communities under translucent rocks (hypolithic) are found in many arid regions. At the global scale, there has been little intercontinental gene flow, and at a local scale, microbial composition is related to fine-scale features of the rocks and their environment. Few studies have investigated patterns of hypolithic community composition at intermediate distances. We examined hypolithic cyanobacterial diversity in semi-arid Australia along a 10-km transect by sampling six rocks from four adjacent 1 m2 quadrats ('distance zero') and from additional quadrats at 10, 100, 1,000, and 10,000 m to test the hypothesis that diversity would increase with the number of rocks sampled and distance. A total of 3,108 cyanobacterial operational taxonomic units ( OTUs) were detected. Most were neither widespread nor abundant. The few that were widespread tended to be abundant. There was no difference in the community composition between the four sites at distance zero, but the samples 10 m away were significantly different, as were those at all other distances compared to distance zero. Many additional OTUs were recorded with increasing distance up to 100 m. These patterns of distribution are consistent with a colonization model involving dispersal from rock to rock. Our results indicate that distance was a significant factor that can be confounded by interrock differences. Most diversity was represented in the first 100 m of the transect, with an additional 1.5% of the total diversity added by the sample at 1 km, but only 0.2% added with the addition of the 10-km site. [ABSTRACT FROM AUTHOR]

The author discusses the calculation of evaporative water loss to improve estimates of species distribution models. It compares the method to the traditional measurement of skin resistance through a mathematical model. It implies that estimates in both approaches differ and require further investigation to determine water loss from living animals.

Amphibians are typically intolerant of high temperatures and dehydrating conditions, and small species are particularly susceptible to desiccation. The rockhole frog, Litoria meiriana (Hylidae), is diurnal and is often observed on rocks in the sun near streams in tropical Australia. These hot, desiccating conditions are avoided by most frog species. We measured the microclimate in the areas used by frogs and the activity, body temperatures and hydric state of free-ranging individuals of this small frog. We also used plaster models to further explore the dynamic nature of hydric state by combining estimates of water loss and water uptake with behavioural observations of activity and microhabitat selection. Both direct measures and estimates of dynamic hydric state indicated that free-ranging frogs generally maintained a hydric state above 95% of full hydration, but occasionally, particularly during the afternoon, frogs allowed their hydric state to fall as low as 85%. Body temperatures of frogs remained below the critical thermal maximum (CTmax) even when the frogs were in the sun, because this species has no cutaneous resistance to evaporative water loss and so they cool by evaporation. However, during the hotter part of the day, on dry sunny substrates, the hydric state of the frogs could fall to near lethal hydration states (approximately 70% of full hydration) within a short period (approximately 20 min). Thus, the threat of desiccation appears to be more limiting than the threat of overheating. These diurnal frogs rely on frequent bouts of rehydration to support their ability to venture onto hot, dry rocks during the day. [ABSTRACT FROM AUTHOR]

African mahogany Khaya senegalensis is a high-value timber tree. Pilot plantings showed that the fruit-spotting bug Amblypelta lutescens causes severe damage of the tree in the wet-dry tropics of northern Australia. The weaver ant Oecophylla smaragdina is an efficient biocontrol agent in some horticulture crops. To investigate whether the ants control this pest, field experiments were conducted from April 2006 to January 2009 at two study sites in the Darwin area, Australia. A laboratory experiment was carried out in March 2007 at Berrimah Farm., During the experimental period, in the weaver ant treatments, the overall percentage of trees damaged by the pest was 0-8% at both sites, and the damaged trees were attacked once only. In the treatments without weaver ants, however, the damage level was > 80% at Berrimah Farm and 31-100% at Howard Springs, and the damaged trees were attacked more than once., The mean percentage of trees damaged per monitoring occasion was 0-2.6% in the weaver ant treatments at both sites, whereas, in the treatments without the ants, the damage percentages were 14.2-27.0% at Howard Springs and 28.2-48.6% at Berrimah Farm., Extrafloral nectar of African mahoganies is attractive to weaver ants. Fruit-spotting bugs only damage the tender parts of flushing shoots and growing tips. Weaver ants live on sugar solution and meat, and they frequently harvest extrafloral nectar on growing shoots, on which they catch nymphs of the pest for their meat supply. The aggressive behaviour of the ants also repels the pest away from flushing shoots., The data suggest that weaver ants were effective biocontrol agents of fruit-spotting bugs, and the ants can be used to manage the pest on African mahoganies., The present study demonstrates that the introduced African mahogany comprises another major host of the fruit-spotting bug. [ABSTRACT FROM AUTHOR]

We used simulations from a biophysical model that integrates interlinked exchanges of energy and water between frogs and their environments to address questions about the limits to thermoregulation and about adaptations for arboreality. Body size and cutaneous resistance (Rc) both significantly affected body temperature (Tb) and the time to desiccate to 70% of standard mass (an ecologically relevant metric of desiccation). Cutaneous resistances < 25 s/cm allow basking frogs to elevate their Tb several degrees above ambient, but Rc above 25 had little additional effect on Tb. Small frogs (<10 g) are able to elevate their Tb above ambient while basking, even with small Rc. Large frogs must have greater skin resistances to be able to elevate body temperatures above ambient, yet large frogs take longer to desiccate to 70% of their standard mass. Frogs can avoid rapid desiccation with high Rc, a large body size, or some combination of these traits. Our literature survey indicates that frogs with a combination of Rc and body size that would result in long times to desiccate to 70% of standard mass tend to be arboreal, suggesting that those species may be selectively favored in a niche that often requires frogs to be away from water sources for extended periods of time. [ABSTRACT FROM AUTHOR]

Hypolithic microbes, primarily cyanobacteria, inhabit the highly specialized microhabitats under translucent rocks in extreme environments. Here we report findings from hypolithic cyanobacteria found under three types of translucent rocks (quartz, prehnite, agate) in a semiarid region of tropical Australia. We investigated the photosynthetic responses of the cyanobacterial communities to light, temperature and moisture in the laboratory, and we measured the microclimatic variables of temperature and soil moisture under rocks in the field over an annual cycle. We also used molecular techniques to explore the diversity of hypolithic cyanobacteria in this community and their phylogenetic relationships within the context of hypolithic cyanobacteria from other continents. Based on the laboratory experiments, photosynthetic activity required a minimum soil moisture of 15% (by mass). Peak photosynthetic activity occurred between approximately 8°C and 42°C, though some photosynthesis occurred between −1°C and 51°C. Maximum photosynthesis rates also occurred at light levels of approximately 150–550 μmol m−2 s−1. We used the field microclimatic data in conjunction with these measurements of photosynthetic efficiency to estimate the amount of time the hypolithic cyanobacteria could be photosynthetically active in the field. Based on these data, we estimated that conditions were appropriate for photosynthetic activity for approximately 942 h (∼75 days) during the year. The hypolithic cyanobacteria community under quartz, prehnite and agate rocks was quite diverse both within and between rock types. We identified 115 operational taxonomic units (OTUs), with each rock hosting 8–24 OTUs. A third of the cyanobacteria OTUs from northern Australia grouped with Chroococcidiopsis, a genus that has been identified from hypolithic and endolithic communities from the Gobi, Mojave, Atacama and Antarctic deserts. Several OTUs identified from northern Australia have not been reported to be associated with hypolithic communities previously. [ABSTRACT FROM AUTHOR]

Accurate predictions of the potential distribution of range-shifting species are required for effective management of invasive species, and for assessments of the impact of climate change on native species. Range-shifting species pose a challenge for traditional correlative approaches to range prediction, often requiring the extrapolation of complex statistical associations into novel environmental space. Here we take an alternative approach that does not use species occurrence data, but instead captures the fundamental niche of a species by mechanistically linking key organismal traits with spatial data using biophysical models. We demonstrate this approach with a major invasive species, the cane toad Bufo marinus in Australia, assessing the direct climatic constraints on its ability to move, survive, and reproduce. We show that the current range can be explained by thermal constraints on the locomotor potential of the adult stage together with limitations on the availability of water for the larval stage. Our analysis provides a framework for biologically grounded predictions of the potential for cane toads to expand their range under current and future climate scenarios. More generally, by quantifying spatial variation in physiological constraints on an organism, trait-based approaches can be used to investigate the range-limits of any species. Assessments of spatial variation in the physiological constraints on an organism may also provide a mechanistic basis for forecasting the rate of range expansion and for understanding a species’ potential to evolve at range-edges. Mechanistic approaches thus have broad application to process-based ecological and evolutionary models of range-shift. [ABSTRACT FROM AUTHOR]

The introduced and highly toxic cane toad (Bufo marinus) is rapidly spreading across northern Australia where it may affect populations of large terrestrial vertebrate predators. The ecological impact of cane toads will depend upon the diets, foraging modes and habitat use of native predators, and their feeding responses to cane toads. However, intraspecific niche partitioning may influence the degree of vulnerability of predators to toxic prey, as well as the time course of the impact of alien invaders on native species. We studied the diet of the northern death adderAcanthophis praelongusand their feeding responses to cane toads. In the laboratory, death adders from all size classes and sexes readily consumed frogs and cane toads. Diets of free rangingA. praelongusfrom the Adelaide River floodplain were more heterogeneous. Juvenile snakes ate mainly frogs (39% of prey items) and small scincid lizards (43%). Both sexes displayed an ontogenetic dietary shift from lizards to mammals, but adult males fed on frogs (49%) and mammals (39%) whereas adult females (which grew larger than males) fed mainly on mammals (91%) and occasionally, frogs (9%). Feeding rates and body condition of adult snakes varied temporally and tracked fluctuations in prey availability. These results suggest that cane toads may negatively affect populations of northern death adders in the Darwin region. However, we predict that different size and sex classes ofA. praelonguswill experience differential mortality rates over different timescales. The initial invasion of large toads may affect adult males, but juveniles may be unaffected until juvenile toads appear the following year, and major affects on adult female death adders may be delayed until annual rainfall fluctuations reduce the availability of alternative (rodent) prey. [ABSTRACT FROM AUTHOR]

The fruit spotting bug,Amblypelta lutescens lutescens,is one of the principal insect pests of cashews in Australia. Its population dynamics were studied using field observations and long-term monitoring to find suitable management methods. Observations of bugs reared in netting bags showed a sequence of change in bug-damage symptoms after 12 h and up to 3 d. Field observations revealed that adults preferred to feed and rest on the shady side of the tree. The number of bugs observed accounted for only 17–35% of the total variability in the number of damaged shoots, suggesting that the number of flushing shoots (leaf, flower or young nuts) with fresh damage symptoms was a more reliable parameter for determining the presence and level of activity of bugs than was a direct estimate of the number of bugs. The green tree ant,Oecophylla smaragdina(F), was the most important factor regulating bug populations. When predation was excluded as a factor, the number of flushing shoots and maximum temperature accounted for 80% of the total variability in the bug damage. Green tree ants should be considered as an important biological control agent for fruit spotting bug, and monitoring should be commenced when cashew trees start to flush (using damaged shoots as indicator). [ABSTRACT FROM AUTHOR]

The nests of the mangrove ant Polyrhachis sokolova are found in soil in intertidal mangrove communities, and are thus inundated at high tides for several hours. Some of the nest galleries are flooded, but others retain air pockets, to which the ants retreat. During and following inundation, we measured carbon dioxide concentrations in air samples collected from different levels in the nests and from artificial ‘control’ holes in the mud. To account for the relative contribution of different sources of carbon dioxide, we also measured the carbon dioxide production by individual ants (including larvae and pupae) and small samples of mud collected near the ant nests. Nest carbon dioxide concentrations were high (2.5−11%) during and immediately following inundation, but the concentrations in the upper regions of the nest fell as soil water levels receded. However, at depths>10 cm below the level soil surface, the carbon dioxide concentrations remained relatively high and stable (at approximately 2%) over the 11 days between one high tide and the next. The contribution of the mud (and associated microorganisms) to the carbon dioxide concentration in the nests was substantial, and the contribution of the respiration of the ants was approximately 10−15% of the total. The carbon dioxide concentrations in the nests of this species during high tides are among the highest recorded for insect nests, suggesting that these ants may have unusual physiological attributes to match the behavioural and ecological challenges associated with living in the intertidal zone. [ABSTRACT FROM AUTHOR]

Presents a comparison of thermal ecology for species of various lizards which occupy a range of habitats and climatic regions. Assessment of the efficacy of evaluation methods to which ectothermic animals exploit their thermal environments; Thermoregulatory characteristics of tropical monitor lizards; How body temperatures of free ranging animals were measured; Estimation of operative temperatures by biophysical models for each set of animal characteristics.

Studies the seasonal changes in body temperature regulation by the frillneck lizard, Chlamydosaurus kingii in northern Australia. Studies on reptile thermoregulation; Study area and animals; Measurement of lizard body temperature by radio telemetry; Thermoregulatory pattern similarities in other lizards; Explanation for seasonal shifts in body temperature.

Considerable research has focused on microbes on amphibian skin, as they act as the first line of defense against invading pathogens. This effort has generated substantial data on patterns across species, space, time, and ontogeny, alongside a growing list of beneficial antifungal symbionts. Though there is evidence of stability in amphibian skin microbial communities, there is also an indication that regular skin shedding reduces cultivable bacteria, with regrowth and recolonization in the period between sheds. This suggests that skin communities are in constant flux, and we lack an understanding of how the membership and structure of those communities are affected by shedding events. In this study, we conducted experiments on cane toads (Rhinella marina) to investigate the influence of shedding on skin microbiomes. We first used quantitative PCR to verify a positive correlation between bacterial loads and time in the days after shedding. We then resampled individuals over time to describe changes in community composition in the 38 h after shedding using amplicon sequencing. Similar to trends of bacterial loads, we found increases in alpha diversity over time after shedding, suggesting that shedding reduces bacterial diversity as it knocks down bacterial loads. During the 38‐h period, community structure became similar to pre‐shed communities in some individuals, but there was no consistent pattern in structural changes among individuals. In light of the amphibian chytridiomycosis pandemic, understanding how physiological events such as skin shedding affect beneficial bacteria and communities on amphibians would provide important insight into amphibian ecology. [ABSTRACT FROM AUTHOR]