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This paper introduces a multi‐degree of freedom bionic crocodile robot designed to tackle the challenge of cleaning pollutants and debris from the surfaces of narrow, shallow rivers. The robot mimics the "death roll" motion of crocodiles which is a technique used for object disintegration. First, the design incorporated a swinging tail mechanism using a multi‐section oscillating guide‐bar mechanism. By analyzing three‐, four‐, and five‐section tail structures, the four‐section tail was identified as the most effective structure, offering optimal strength and swing amplitude. Each section of the tail can reach maximum swing angles of 8.05°, 20.95°, 35.09°, and 43.84°, respectively, under a single motor's drive. Next, the robotic legs were designed with a double parallelogram mechanism, facilitating both crawling and retracting movements. In addition, the mouth employed a double‐rocker mechanism for efficient closure and locking, achieving an average torque of 5.69 N m with a motor torque of 3.92 N m. Moreover, the robotic body was designed with upper and lower segment structures and waterproofing function was also considered. Besides, the kinematic mechanism and mechanical properties of the bionic crocodile structure were analyzed from the perspectives of modeling and field tests. The results demonstrated an exceptional kinematic performance of the bionic crocodile robot, effectively replicating the authentic movement characteristics of a crocodile. [ABSTRACT FROM AUTHOR]

Early life environments shape phenotypic development in important ways that can lead to long‐lasting effects on phenotype and fitness. In reptiles, one aspect of the early environment that impacts development is temperature (termed 'thermal developmental plasticity'). Indeed, the thermal environment during incubation is known to influence morphological, physiological, and behavioral traits, some of which have important consequences for many ecological and evolutionary processes. Despite this, few studies have attempted to synthesize and collate data from this expansive and important body of research. Here, we systematically review research into thermal developmental plasticity across reptiles, structured around the key papers and findings that have shaped the field over the past 50 years. From these papers, we introduce a large database (the 'Reptile Development Database') consisting of 9,773 trait means across 300 studies examining thermal developmental plasticity. This dataset encompasses data on a range of phenotypes, including morphological, physiological, behavioral, and performance traits along with growth rate, incubation duration, sex ratio, and survival (e.g., hatching success) across all major reptile clades. Finally, from our literature synthesis and data exploration, we identify key research themes associated with thermal developmental plasticity, important gaps in empirical research, and demonstrate how future progress can be made through targeted empirical, meta‐analytic, and comparative work. The thermal environment shapes early reptile development in a range of important ways. Here, we systematically review the literature on thermal developmental plasticity in reptiles, providing suggestions for how future progress can be made through targeted empirical, meta‐analytic, and comparative work.. [ABSTRACT FROM AUTHOR]

In this paper I take up the call to expand the boundaries of social and physical landscapes in order to recognise the creative agencies of human and non‐human actors. In doing so, I wish to draw attention to the ways in which relations between both individuals and collectives combine to shape multi‐dimensional sociality in particular places. The place in question is a crocodile farm in tropical Australia. It is a curious place in that it was fostered by modes of objectification which serve to commoditise and conserve crocodiles at a species level with little attention to individuality. However, the particularity of crocodiles at the farming level compels their human handlers to make concessions to their demands. Crocodiles, by their refusals, attachments and individualities, elicit attention to their needs, which translates into practices and structures that are often at odds with profitability. In this way it is as much social processes as it is practicalities of producing skins which affect the farmed landscape and the beings it produces, creating a nexus of multispecies place‐making where individuals matter. [ABSTRACT FROM AUTHOR]

Copyright of Methods in Ecology & Evolution is the property of Wiley-Blackwell 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.)

1. Top predators such as crocodiles often reflect ecosystem degradation. The recent spate of close to 200 Nile crocodile deaths may reflect the ecosystem state of the Olifants-Letaba River system in the Kruger National Park. This paper investigates whether the crocodile deaths were indeed the consequence of a rare and perhaps acute event given the variability in annual population growth rates of crocodilians. 2. Spotlight- and helicopter-based surveys designed to correct for availability and detectability bias were used to estimate population sizes of crocodiles from 2008 to 2010 in and around the Olifants River Gorge, the focal area of crocodile deaths. 3. Correction factors derived from individually observed crocodiles for both spotlight- and helicopter-based counts were lower than those typically used for Nile crocodiles as well as other crocodile species. Even so, corrected spotlight- and helicopter-based estimates were comparable and the number of crocodiles in the focal study area declined significantly from 780 (95% CI: 637-1222) to between 460 (spotlight estimate, 95% CI 375-665) and 505 (aerial estimate, 95% CI: 559-1746) during the period of crocodile deaths. The average annual decline of 35% was at the lower end of the distribution of annual population growth rates across the rivers of Kruger National Park. 4. The crocodile deaths reflect a possible rare event that suggests a degraded crocodile population, possibly the consequences of broad-scale cascades of environmental deterioration of the Olifants-Letaba River system. 5. Even so, the potential risk of local demise of the population in the focal study area in the short term may be diminished through evolutionary, demographic and spatial resilience inherent within crocodiles that can accommodate the as yet unknown disease dynamics of pansteatitis. [ABSTRACT FROM AUTHOR]

In genetic improvement programs, candidates for breeders are ranked by the profitability of their offspring, expressed as a weighted sum of the genetic gain from selection. In this paper, we estimate the economic values of a genetic improvement program for Australian farmed saltwater crocodiles. A bioeconomic profit function for a representative breeding pair is used to determine the optimal slaughter age following genetic improvement in each selection objective. The results indicate that estimated farm profitability increases by nearly $A111 for a 1-week reduction in juvenile slaughter age, $A78 for a 1 per cent increase in the proportion of first-grade skins produced, and $A33 for an increase in the number of viable hatchlings per clutch. The implications of the analysis for the Australian crocodile industry and the limitations of the research are explored. [ABSTRACT FROM AUTHOR]

Baru is a genus that includes several large mekosuchine crocodylians from the Oligo‐Miocene of Australia. Here we describe Baru iylwenpeny sp. nov. from a large sample of cranial bones from the Upper Miocene Alcoota Local Fauna of the Northern Territory. Baru iylwenpeny can be diagnosed by several autapomorphies that include, but are not limited to: extreme reduction of the pneumatic foramina associated with the diverticula that invade the bones of the suspensorium; and enlargement of the postcaniniform maxillary teeth resulting in crowding of the postcaniniform alveoli and a reduction in the number of maxillary alveoli to 12. The new species is the geologically youngest known member of the genus. While species of Baru are a ubiquitous component of Oligo‐Miocene crocodylian assemblages from northern Australia, they are absent from all known Plio‐Pleistocene sites, suggesting the extinction of the genus by the latest Miocene. We suggest that the marked taxonomic turnover of crocodylian assemblages between the Upper Miocene Alcoota Local Fauna and the Lower Pliocene is the result of a short period of severe aridity during the latest Miocene, causing widespread crocodylian extinctions across Australia, followed by the establishment of taxonomically novel crocodylian faunas in the Pliocene. This event mirrors similar contemporary losses of crocodylian diversity in Africa and South America, although these cases are partly driven by local tectonic events. It is likely that late Cenozoic global cooling also played a role in these extinctions. [ABSTRACT FROM AUTHOR]

The range of the threatened American crocodile (Crocodylus acutus) in the United States is limited to the southernmost parts of Florida. As this species has recovered concurrently with an increasing human population, human–crocodile conflicts have also increased. Resolving conflicts can involve translocating crocodiles; however, they often return to the site from which they were removed. We examined the effects of translocation on crocodile movements, habitat use, body condition, and survival in Florida, USA, in 2018–2019 to refine recommendations for managers considering translocation to resolve human–crocodile conflict. We captured and attached global positioning system (GPS) units to 17 crocodiles, 10 of which served as a reference group (free‐ranging crocodiles released at their capture site) and 7 served as a treatment group (crocodiles that were translocated 14–158 km from their capture site). We collected location data from individual crocodiles for 34–661 days (x¯ $\mathop{x}\limits^{̅}$ ~ 250 days for each group). Body condition was similar for both groups. Corticosterone levels measured periodically during handling indicated that crocodiles experienced increasing stress levels during handling. Three crocodiles translocated ≤45 km from their original capture site returned to that location within 13 days. Three crocodiles translocated ≥110 km did not return. One female translocated 152 km was recaptured 0.42 km from its original capture site 965 days after its release. We identified 2 states of characteristic movement patterns: state 1 indicated individuals moving slowly and somewhat randomly, and state 2 indicated individuals exhibiting fast, active directional movement. Translocated individuals were more likely than reference individuals to switch to, and stay in, state 2. Because of concerns regarding return rates and heightened stress as a result of capture and translocation, we suggest crocodile translocations have limited conservation value and may only be worth considering once all other reasonable options are exhausted. [ABSTRACT FROM AUTHOR]

More than two million species have been described so far, but our knowledge on most taxa remains scarce or inexistent, and the available biodiversity data is often taxonomically, phylogenetically and spatially biased. Unevenness in research effort across species or regions can interact with data biases and compromise our ability to properly study and conserve biodiversity. Herein, we assess the influence of biological, conservation, geographic and socioeconomic correlates of reptile research effort globally and across six biogeographic realms. We combine bibliometric data from the Scopus database with trait‐based approaches and provide research effort information for 10 531 reptile species, modelling it as a function of 10 putative correlates of species‐level variation in research effort through negative binomial generalised mixed effect models. We show that reptile research effort is highly skewed toward certain taxa and regions, such as turtles, crocodiles, tuatara, viperids, pythons and some anguimorph lizards, as well as for temperate compared to tropical regions. Our findings indicate that greater research attention is directed towards large‐sized and early described reptile species, particularly those whose geographic range overlap with biodiversity institutions. Although we demonstrate that biological and socioeconomic factors more strongly affect reptile research effort variation, geography and conservation‐related factors also matter. Global patterns are mostly consistent, but variation across realms were observed and likely reflects differences in socioeconomic attributes as well as in the amount of species to be studied in each realm. Directing researchers and citizen scientists' attention toward understudied taxa will contribute to alleviate this biased biodiversity knowledge, although the sheer amount of species in tropical regions inevitably makes it a long‐term solution. Performing comparative studies across species with similar levels of research attention could represent a more immediate and feasible alternative. [ABSTRACT FROM AUTHOR]

In vertebrates, active movement is driven by muscle forces acting on bones, either directly or through tendinous insertions. There has been much debate over how muscle size and force are reflected by the muscular attachment areas (AAs). Here we investigate the relationship between the physiological cross‐sectional area (PCSA), a proxy for the force production of the muscle, and the AA of hindlimb muscles in Nile crocodiles and five bird species. The limbs were held in a fixed position whilst blunt dissection was carried out to isolate the individual muscles. AAs were digitised using a point digitiser, before the muscle was removed from the bone. Muscles were then further dissected and fibre architecture was measured, and PCSA calculated. The raw measures, as well as the ratio of PCSA to AA, were studied and compared for intra‐observer error as well as intra‐ and interspecies differences. We found large variations in the ratio between AAs and PCSA both within and across species, but muscle fascicle lengths are conserved within individual species, whether this was Nile crocodiles or tinamou. Whilst a discriminant analysis was able to separate crocodylian and avian muscle data, the ratios for AA to cross‐sectional area for all species and most muscles can be represented by a single equation. The remaining muscles have specific equations to represent their scaling, but equations often have a relatively high success at predicting the ratio of muscle AA to PCSA. We then digitised the muscle AAs of Coelophysis bauri, a dinosaur, to estimate the PCSAs and therefore maximal isometric muscle forces. The results are somewhat consistent with other methods for estimating force production, and suggest that, at least for some archosaurian muscles, that it is possible to use muscle AA to estimate muscle sizes. This method is complementary to other methods such as digital volumetric modelling. [ABSTRACT FROM AUTHOR]

Copyright of African Journal of Ecology is the property of Wiley-Blackwell 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.)

Biomass‐derived porous carbon materials have received extensive attention in electromagnetic wave absorbing (EMA) materials due to their stability, lightweight, and friendliness. Adjusting the morphology of porous carbon materials is an effective way to improve their absorbing properties. In this work, the crocodile skin‐like biomass hierarchical porous carbon (BHPC) material was synthesized from waste rice husk via a carbonization and alkali activation process. The effect of the consistency of the activator on the porous morphology is investigated. Under ultra‐low filler content of 10 wt%, the minimum reflection loss (RLmin) of the BHPC‐10 composite material reaches −47.46 dB, and the effective absorption bandwidth (EAB) is up to 3.40 GHz in the X‐band at a thickness of 2.8 mm. This work provides a reference for preparing porous carbon materials derived from pure biomass and a feasible scheme for designing high‐performance microwave absorbing materials. [ABSTRACT FROM AUTHOR]

The Add‐my‐Pet collection of data on energetics and Dynamic Energy Budget parameters currently contains 92 species of turtles and 23 species of crocodiles. We discuss patterns of eco‐physiological traits of turtles and crocodiles, as functions of parameter values, and compare them with other taxa. Turtles and crocodiles accurately match the general rule that the life‐time cumulated neonate mass production equals ultimate weight. The weight at birth for reptiles scales with ultimate weight to the power 0.6. The scaling exponent is between that of amphibians and birds, while that for mammals is close to 1. We explain why this points to limitations imposed by embryonic respiration, the role of water stress and the accumulation of nitrogen waste during the embryo stage. Weight at puberty is proportional to ultimate weight, and is the largest for crocodiles, followed by that of turtles. These facts explain why the precociality coefficient, sHbp—approximated by the ratio of weight at birth and weight at puberty at abundant food—decreases with ultimate weight. It is the smallest for crocodiles because of their large size and is smaller for turtles than for lizards and snakes. The sea turtles have a smaller sHbp than the rest of the turtles, linked to their large size and small offspring size. We link their small weight and age at birth to reducing risks on the beach. The maximum reserve capacity in both turtles and crocodiles clearly decreases with the precociality coefficient. This relationship has not been found that clearly in other taxa, not even in other reptiles, with the exception of the chondrichthyans. Among reptiles, crocodiles and sea turtles have a relatively large assimilation rate and a large reserve capacity. [ABSTRACT FROM AUTHOR]

Clade ages within the crocodylomorph clade Neosuchia have long been debated. Molecular and morphological studies have yielded remarkably divergent results. Despite recent advances, there has been no comprehensive relative comparison of the major time calibration methods available to estimate clade ages based on morphological data. We used four methods (cal3, extended Hedman, smoothed ghost lineage analysis (sGLA) and the fossilized birth–death model (FBD)) to date clade ages derived from a published crocodylomorph supertree and a new neosuchian phylogeny. All time‐scaling methods applied here agree on the origination of Neosuchia during the Late Triassic or Early Jurassic, and the presence of the major extant eusuchian groups (Crocodyloidea, Gavialoidea, Alligatoroidea and Caimaininae) by the end of the Late Cretaceous. The number of distinct lineages present before the K/Pg boundary is less certain, with support for two competing scenarios in which Crocodylinae, Tomistominae and Diplocynodontinae either: (1) diverged from other eusuchian lineages before the K/Pg boundary; or (2) evolved during a 'burst' of diversification after the K/Pg event. Cal3 and FBD proved to be the most suitable methods for time‐scaling phylogenetic trees dominated by fossil taxa. Extended Hedman estimates are substantially older than the others, with larger standard deviations and a strong sensitivity to taxon sampling and topological changes; sGLA has similar problems. We conclude that a detailed understanding of phylogenetic relationships, tree reconstruction methods, and good taxonomic coverage (in particular the inclusion of the oldest taxon in each clade) is essential when evaluating the results of such dating analyses. [ABSTRACT FROM AUTHOR]

Clarithromycin (CLA) is a new β‐lactamase‐resistant macrolide antibiotic with potent activity against gram‐positive and some gram‐negative bacteria. To the authors' best knowledge, limited pharmacokinetic information to establish suitable therapeutic plans is available for freshwater crocodiles. To assess the prudent use of antibiotic in reptiles, this study was conducted to explore the pharmacokinetic characteristics of CLA in the freshwater crocodile, Crocodylus siamensis, following either single intravenous (i.v.) or intramuscular (i.m.) administration at a dosage of 2.5 mg/kg body weight (b.w.). Blood samples were collected at assigned times up to 168 h. CLA plasma samples were cleaned up using liquid–liquid extraction, and analysed by a validated liquid chromatography tandem–mass spectrometry (LC‐MS/MS). CLA was quantifiable from 5 min to 72 h after i.v. administration, whereas it was detectable for 168 after i.m. administration at an identical dose rate. A non‐compartmental model was used to fit the plasma concentration of CLA versus time curve for each crocodile. The t1/2λz value, similar for both routes (20 h), indicated that the overall rate of elimination of CLA in crocodiles is relatively slow. The average i.m. F% was complete. The protein plasma bound was found to be about 30%. CLA is a time‐dependent antibiotic, and the T > MIC is the best PK/PD predictor for its efficacy. The CLA dosage of 2.5 mg/kg appeared to produce an appropriate value of the PK‐PD surrogate that predicts antibacterial success for disease caused by susceptible bacteria. [ABSTRACT FROM AUTHOR]

A dependable and efficient wildlife species identification system is essential for swift dispensation of the justice linking wildlife crimes. Development of molecular techniques is befitting the need of the time. The forensic laboratories often receive highly ill-treated samples for identification purposes, and thus, validation of any novel methodology is necessary for forensic usage. We validate a novel multiplex polymerase chain reaction assay, developed at this laboratory for the forensic identification of three Indian crocodiles, Crocodylus palustris, Crocodylus porosus, and Gavialis gangeticus, following the guidelines of Scientific Working Group on DNA Analysis Methods. The multiplex PCR was tested for its specificity, reproducibility, sensitivity, and stability. This study also includes the samples treated with various chemical substances and exposed to various environmental regimes. The result of this validation study promises this technique to be an efficient identification tool for Indian crocodiles and therefore is recommended for forensic purposes. [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]

Aim: Although at least five Tylototriton species were recorded in Thailand, only Tylototriton verrucosus is registered as a protected species under the Wildlife Preservation and Protection Act in Thailand. Populations of T. uyenoi are now severely declining, caused by anthropogenic activities. As intense human pressure is having profound effects on the diminishment in T. uyenoi populations, a conservation plan is needed. Information such as the abundance and distribution of a species is necessary. Yet, current established survey methods are either time‐consuming or labour‐intensive. Here, eDNA‐based detection was developed for tracking the presence of the T. uyenoi. Location: Thailand. Methods: We target the surveillance of T. uyenoi using eDNA. Primers and a probe specific to T. uyenoi were designed and tested for their specificity and sensitivity. Water samples were collected once a month from August to January at three sites in Doi Suthep and at three extra sites within the range of the species. Three hundred ml samples of water were collected and filtered. Environmental DNA was extracted and then subjected to qPCR assay in an attempt to detect T. uyenoi. Results: The qPCR assay was found to be species‐specific to T. uyenoi. Both PCR and qPCR did not result in any positive detection of three congeners or other non‐target species. The LOD and the LOQ of the assay were determined by an analysis of the standard curve, and it was found that the LOD and the LOQ were 7.99 and 9.0 copies per reaction, respectively. Environmental DNA was detected in water samples from all sites where T. uyenoi has been known to occur, but detection varied among sites and sampling times. In addition, low amounts of eDNA were detected in three sites with unknown occupancy of newts, but within the species' range. Conclusions: Our findings suggest that eDNA survey is a powerful tool for tracking T. uyenoi throughout the year regardless of the sampling site conditions. Similar to other amphibians, T. uyenoi is severely declining due to anthropogenic factors. In order to have an effective conservation plan, knowledge of a species' distribution is needed. To our knowledge, this was the first study that used eDNA to track the crocodile newt in Thailand. [ABSTRACT FROM AUTHOR]

Understanding the impact of land‐cover mosaics on crocodile distribution and habitat patterns is essential to prioritize areas for their conservation in human‐dominated landscapes. This is especially important for species with specialist requirements; or where there is human–wildlife conflict, as is the case in many areas with crocodiles, such as Myanmar's Ayeyarwady Delta.The saltwater crocodile is used as a surrogate species in this study to identify important conservation areas, and to propose potential protected areas for the Ayeyarwady coastal mangrove ecoregion. In total, 684 locations of saltwater crocodile encounters were collected, 444 for the wet season (May to June), and 240 for the dry season (December to January) between 1999 and 2018. Suitable habitats of saltwater crocodiles in the Ayeyarwady Delta were modelled for wet and dry seasons, using 12 predictor variables at 300‐m resolution.The area of suitable habitat in the wet season is about 1,272.3 km2 but reduces to 563.7 km2 in the dry season. Distance to the cropland, distance to the sea, mangrove cover, and wetland cover are identified as the key landscape variables that contributed to the seasonal habitat distribution of saltwater crocodiles in the Ayeyarwady Delta.Protecting core and buffer areas in Kadonkani Reserved Forest and Pyindayae Reserved Forest would safeguard the seasonal habitats of saltwater crocodiles. Khaing Thaung Island, an unprotected area with suitable habitat areas for saltwater crocodiles, is proposed as a potential marine protected area in the Ayeyarwady Delta of Myanmar. [ABSTRACT FROM AUTHOR]

We developed a three‐dimensional, computational biomechanical model of a juvenile Nile crocodile (Crocodylus niloticus) pelvis and hindlimb, composed of 47 pelvic limb muscles, to investigate muscle function. We tested whether crocodiles, which are known to use a variety of limb postures during movement, use limb orientations (joint angles) that optimise the moment arms (leverages) or moment‐generating capacities of their muscles during different limb postures ranging from a high walk to a sprawling motion. We also describe the three‐dimensional (3D) kinematics of the crocodylian hindlimb during terrestrial locomotion across an instrumented walkway and a treadmill captured via X‐ray Reconstruction of Moving Morphology (biplanar fluoroscopy; 'XROMM'). We reconstructed the 3D positions and orientations of each of the hindlimb bones and used dissection data for muscle lines of action to reconstruct a focal, subject‐specific 3D musculoskeletal model. Motion data for different styles of walking (a high, crouched, bended and two types of sprawling motion) were fed into the 3D model to identify whether any joints adopted near‐optimal poses for leverage across each of the behaviours. We found that (1) the hip adductors and knee extensors had their largest leverages during sprawling postures and (2) more erect postures typically involved greater peak moment arms about the hip (flexion‐extension), knee (flexion) and metatarsophalangeal (flexion) joints. The results did not fully support the hypothesis that optimal poses are present during different locomotory behaviours because the peak capacities were not always reached around mid‐stance phase. Furthermore, we obtained few clear trends for isometric moment‐generating capacities. Therefore, perhaps peak muscular leverage in Nile crocodiles is instead reached either in early/late stance or possibly during swing phase or other locomotory behaviours that were not studied here, such as non‐terrestrial movement. Alternatively, our findings could reflect a trade‐off between having to execute different postures, meaning that hindlimb muscle leverage is not optimised for any singular posture or behaviour. Our model, however, provides a comprehensive set of 3D estimates of muscle actions in extant crocodiles which can form a basis for investigating muscle function in extinct archosaurs. [ABSTRACT FROM AUTHOR]

To the best of the authors' knowledge, pharmacokinetic information to establish suitable therapeutic plans for freshwater crocodiles is limited. Therefore, the purpose of this study was to clarify the pharmacokinetic characteristics of enrofloxacin (ENR) in freshwater crocodiles, Crocodylus siamensis, following single intravenous and intramuscular administration at a dosage of 5 mg/kg body weight (b.w.). Blood samples were collected at assigned times up to 168 hr. The plasma concentrations of ENR and its metabolite ciprofloxacin (CIP) were measured by liquid chromatography tandem–mass spectrometry. The concentrations of ENR and CIP in the plasma were quantified up to 144 hr after both the administrations. The half‐life was long (43–44 hr) and similar after both administrations. The absolute i.m. bioavailability was 82.65% and the binding percentage of ENR to plasma protein ranged from 9% to 18% with an average of 10.6%. Percentage of CIP (plasma concentrations) was 15.9% and 19.9% after i.v. and i.m. administration, respectively. Based on the pharmacokinetic data, susceptibility break point and PK‐PD indexes, i.m. single administration of ENR at a dosage of 5 mg/kg b.w. might be appropriate for treatment of susceptible bacteria (MIC > 1 μg/mL) in freshwater crocodiles, C. siamensis. [ABSTRACT FROM AUTHOR]

While puberty is an animal commonality, little is known of its timing or process in crocodylians. Males copulate with an intromittent phallus that has a distinct glans morphology which directly interacts with the female cloaca, putatively effecting effective semen transfer and ultimately increased fecundity. Here we present, during the Morelet's crocodile lifecycle, a well‐defined body length (65 cm snout‐vent length) inflection point that marks a subsequent increase of phallic glans growth rates. Putatively, this postpubescent growth produces a copulatory‐effective phallus. While not as robust of a trend as snout‐vent length, this growth inflection concomitantly begins with a body condition index (CI = BM/SVL3) between 2.0 and 2.5 and is most distinct above a CI of 2.5. Also, in males, this 65 cm size threshold also aligns with the initiation of more robust growth in caniniform alveoli associated with prominent maxillary and mandibular teeth. This inflection was not observed in females, thus marking a sexual dimorphism that begins to present with the onset of puberty. This bodily manifestation of puberty other than those changes observed in the reproductive tracts is a novel observation for crocodylians and lays a foundation for further study among species of how changing endocrine signaling within sexually maturing males may also influence a broader range of secondary sex characteristics. Research Highlight: Male Morelet's crocodile phalli increase growth rates of glans height and glans tip length after achieving 65 cm snout‐vent length. The glans size of increase corresponds with the initiation of sexually dimorphic maxilla and mandible features. [ABSTRACT FROM AUTHOR]

The Siamese Crocodile (Crocodylus siamensis) is a critically endangered medium‐size crocodilian endemic to Southeast Asia. Extirpated from much of its natural range, conservation efforts in the Cardamom Mountains of Cambodia include the release of captive‐reared juveniles and sub‐adults into river reaches known to support adult C. siamensis populations. Despite conservation concerns, the biology of wild C. siamensis is not well studied and the ecology of ecosystems at release locations is poorly understood.Fish are thought to comprise a major component of the diet of C. siamensis. Here, the aim was to characterize fish communities within three potential C. siamensis release locations, focusing on community composition, density, size class structure and food web dynamics. The survey sites varied in both C. siamensis density and human fishing pressure, and the results are interpreted in light of these drivers.Genomic interrogation of fishes of the Cardamom Mountains distinguished 13 distinct fish species, contributing to genetic databases and adding to the documented taxon list for the region. The presence of two previously unconfirmed fish genera in the region is confirmed. The first estimates of fish density, biomass and size class distribution for three rivers in the Cardamom Mountains are provided.The three potential C. siamensis release reaches that were sampled showed clear differences in fish community composition, structural and trophic dynamics. Fish density and biomass were highest in the high‐density C. siamensis survey reach and lowest in the high human fishing pressure reach. Survey reaches with food webs that were more reliant on autochonously driven food webs supported higher densities and biomass of fish. These results have important implications for future C. siamensis conservation efforts in Cambodia and contribute valuable ecological information on a relatively unexplored region. [ABSTRACT FROM AUTHOR]

Abstract: Allometric relationships linking species characteristics to body size or mass (scaling) are important in biology. However, studies on the scaling of life history traits in the reptiles (the nonavian Reptilia) are rather scarce, especially for the clades Crocodilia, Testudines, and Rhynchocephalia (single extant species, the tuatara). Previous studies on the scaling of reptilian life history traits indicated that they differ from those seen in the other amniotes (mammals and birds), but so far most comparative studies used small species samples and also not phylogenetically informed analyses. Here, we analyzed the scaling of nine life history traits with adult body mass for crocodiles (n = 22), squamates (n = 294), turtles (n = 52), and reptiles (n = 369). We used for the first time a phylogenetically informed approach for crocodiles, turtles, and the whole group of reptiles. We explored differences in scaling relationships between the reptilian clades Crocodilia, Squamata, and Testudines as well as differences between reptiles, mammals, and birds. Finally, we applied our scaling relationships, in order to gain new insights into the degree of the exceptionality of the tuatara's life history within reptiles. We observed for none of the life history traits studied any difference in their scaling with body mass between squamates, crocodiles, and turtles, except for clutch size and egg weight showing small differences between these groups. Compared to birds and mammals, scaling relationships of reptiles were similar for time‐related traits, but they differed for reproductive traits. The tuatara's life history is more similar to that of a similar‐sized turtle or crocodile than to a squamate. [ABSTRACT FROM AUTHOR]

1. Successful species conservation is dependent on adequate estimates of population dynamics, but age-specific demographics are generally lacking for many long-lived iteroparous species such as large reptiles. Accurate demographic information allows estimation of population growth rate, as well as projection of future population sizes and quantitative analyses of fitness trade-offs involved in the evolution of life-history strategies. 2. Here, a long-term capture--recapture study was conducted from 1978 to 2014 on the American crocodile (Crocodylus acutus) in southern Florida. Over the study period, 7,427 hatchlings were marked and 380 individuals were recaptured for as many as 25 years. We estimated survival to be strongly age dependent with hatchlings having the lowest survival rates (16%) but increasing to nearly 90% at adulthood based on mark--recapture models. More than 5% of the female population were predicted to be reproductive by age 8 years; the age-specific proportion of reproductive females steadily increased until age 18 when more than 95% of females were predicted to be reproductive. Population growth rate, estimated from a Leslie--Lefkovitch stage-class model, showed a positive annual growth rate of 4% over the study period. 3. Using a prospective sensitivity analysis, we revealed that the adult stage, as expected, was the most critical stage for population growth rate; however, the survival of younger crocodiles before they became reproductive also had a surprisingly high elasticity. We found that variation in age-specific fecundity has very limited impact on population growth rate in American crocodiles. 4. We used a comparative approach to show that the original life-history strategy of American crocodiles is actually shared by other large, long-lived reptiles: while adult survival rates always have a large impact on population growth, this decreases with declining increasing growth rates, in favour of a higher elasticity of the juvenile stage. 5. Crocodiles, as a long-lived and highly fecund species, deviate from the usual association of life histories of "slow" species. Current management practices are focused on nests and hatchling survival; however, protection efforts that extend to juvenile crocodiles would be most effective for conservation of the species, especially in an ever-developing landscape. [ABSTRACT FROM AUTHOR]

Aim To map and assess the richness patterns of reptiles (and included groups: amphisbaenians, crocodiles, lizards, snakes and turtles) in Africa, quantify the overlap in species richness of reptiles (and included groups) with the other terrestrial vertebrate classes, investigate the environmental correlates underlying these patterns, and evaluate the role of range size on richness patterns. Location Africa. Methods We assembled a data set of distributions of all African reptile species. We tested the spatial congruence of reptile richness with that of amphibians, birds and mammals. We further tested the relative importance of temperature, precipitation, elevation range and net primary productivity for species richness over two spatial scales (ecoregions and 1° grids). We arranged reptile and vertebrate groups into range-size quartiles in order to evaluate the role of range size in producing richness patterns. Results Reptile, amphibian, bird and mammal richness are largely congruent ( r = 0.79-0.86) and respond similarly to environmental variables (mainly productivity and precipitation). Ecoregion size accounts for more variation in the richness of reptiles than in that of other groups. Lizard distributions are distinct with several areas of high species richness where other vertebrate groups (including snakes) are species-poor, especially in arid ecoregions. Habitat heterogeneity is the best predictor of narrow-ranging species, but remains relatively important in explaining lizard richness even for species with large range sizes. Main conclusions Reptile richness varies with similar environmental variables as the other vertebrates in Africa, reflecting the disproportionate influence of snakes on reptile richness, a result of their large ranges. Richness gradients of narrow-ranged vertebrates differ from those of widespread taxa, which may demonstrate different centres of endemism for reptile subclades in Africa. Lizard richness varies mostly with habitat heterogeneity independent of range size, which suggests that the difference in response of lizards is due to their ecological characteristics. These results, over two spatial scales and multiple range-size quartiles, allow us to reliably interpret the influence of environmental variables on patterns of reptile richness and congruency. [ABSTRACT FROM AUTHOR]

The fauna of the Pleistocene Homo-bearing sites of Java has been well known for more than a century. A recent revision of the crocodylian remains confirmed both the validity of Gavialis bengawanicus and the synonymization of Crocodylus ossifragus with C. siamensis. Here we report on a still unpublished crocodylian specimen collected by Eugene Dubois in the latest Early Pleistocene of Kali Gedeh that can be tentatively referred to the genus Crocodylus. The size of the specimen, the approximately 1 m long lower jaw in particular, indicated that this crocodile attained a total length of approximately 6 or 7 m. Along with specimens from the Plio-Pleistocene of Africa, this material provides evidence for gigantism in Crocodylus. It is not clear whether or not the 'temperature-size rule' applies to fossil crocodylians, but due to the growing interest in predicting future temperature-related size changes of the extant organisms, it would be interesting to study in detail the past reaction to temperature changes of crocodylians and other terrestrial ectothermic animals. [ABSTRACT FROM AUTHOR]

Dispersal via pelagic larval stages plays a key role in population connectivity of many marine species. The degree of connectivity is often correlated with the time that larvae spend in the water column. The Antarctic notothenioid fishes develop through an unusually long pelagic larval phase often exceeding 1 year. Notothenioids thus represent a prime model system for studying the influence of prolonged larval phases on population structure in otherwise demersal species. Here, we compare the population genetic structure and demographic history of two sub- Antarctic crocodile icefish species ( Chaenocephalus aceratus and Champsocephalus gunnari) from the Scotia Arc and Bouvet Island in the Atlantic sector of the Southern Ocean to delineate the relative importance of species-specific, oceanographic and paleoclimatic factors to gene flow. Based on 7 ( C. aceratus) and 8 ( C. gunnari) microsatellites, as well as two mitochondrial DNA markers (cytochrome b, D-loop), we detect pronounced population genetic structure in both species ( amova FSTs range from 0.04 to 0.53). High genetic similarities were found concordantly in the populations sampled at the Southern Scotia Arc between Elephant Island and South Orkney Islands, whereas the populations from Bouvet Island, which is located far to the east of the Scotia Arc, are substantially differentiated from those of the Scotia Arc region. Nonetheless, haplotype genealogies and Bayesian cluster analyses suggest occasional gene flow over thousands of kilometres. Higher divergences between populations of C. gunnari as compared to C. aceratus are probably caused by lower dispersal capabilities and demographic effects. Bayesian skyline plots reveal population size reductions during past glacial events in both species with an estimated onset of population expansions about 25 000 years ago. [ABSTRACT FROM AUTHOR]

Most animals select nest sites non-randomly, reflecting benefits of specific locations or incubation conditions for offspring viability as well as risks or costs to the reproducing adult. If few or no available nest sites offer suitable conditions, we expect animals to make the best of a bad lot, by selecting nest sites that provide the best conditions available. In tropical north-western Australia, freshwater crocodiles ( Crocodylus johnstoni: Crocodylidae) in a large artificial lake (Lake Argyle) experience this challenge: the types of nest sites used by this species in other parts of its range (moist, shaded sandy soils, far from the water's edge) are scarce. Measurements of 89 crocodile nests and 89 test holes (abandoned attempts at nesting) at Lake Argyle, and 28 nests on the nearby Ord River, show that most areas along the lakeshore are too steep and rocky for nesting. Crocodiles at the lake therefore are forced to nest at sites that are sun-exposed, in dry gravelly substrates, and close to the water's edge. Comparisons of test holes and actual nests within such areas show that nesting crocodiles actively select sites that are less rocky, are suitable hydrically, and that provide stable thermal regimes. Those hydric and thermal attributes allow successful development of the offspring. The ability of freshwater crocodiles in Lake Argyle to flexibly modify their nest-site selection criteria, under severe constraints enforced by this open rocky landscape, are critical to the species' success in exploiting the opportunity created by the dam's construction. [ABSTRACT FROM AUTHOR]

There is little quantitative data on the cost effectiveness of environmental communication and education efforts. This study evaluates a public awareness campaign for the conservation of the Philippine crocodile in the northern Sierra Madre in terms of outputs, outreach, cognitive and affective outcomes, and impact through a counterfactual comparison. The campaign succeeded in raising awareness on and transforming attitudes toward in situ Philippine crocodile conservation: most people living in close proximity to crocodiles now know that the species is legally protected and support in situ conservation. As a result, crocodiles are no longer purposively killed. Substantial gains can be made in environmental conservation by investing more in communication, education, and public awareness campaigns, particularly in developing countries. Awareness on legislation and pride in the conservation of a rare and iconic species are strong incentives for poor, rural communities to support in situ wildlife conservation. [ABSTRACT FROM AUTHOR]

A new neosuchian crocodylomorph, Susisuchus jaguaribensis sp. nov., is described based on fragmentary but diagnostic material. It was found in fluvial-braided sediments of the Lima Campos Basin, north-eastern Brazil, 115 km from where Susisuchus anatoceps was found, in rocks of the Crato Formation, Araripe Basin. S. jaguaribensis and S. anatoceps share a squamosal–parietal contact in the posterior wall of the supratemporal fenestra. A phylogenetic analysis places the genus Susisuchus as the sister group to Eusuchia, confirming earlier studies. Because of its position, we recovered the family name Susisuchidae, but with a new definition, being node-based group including the last common ancestor of Susisuchus anatoceps and Susisuchus jaguaribensis and all of its descendents. This new species corroborates the idea that the origin of eusuchians was a complex evolutionary event and that the fossil record is still very incomplete. [ABSTRACT FROM AUTHOR]

The article explores the population status, basking site selection and water depth preferences of various size-classes of gharial based on a research conducted in the National Chambal Sanctuary in India. A 40 percent decline in the gharial population was observed between 1992 and 2007. Gharial are believed to prefer sandy parts of the river banks and sand bars for basking. They demonstrate less preference for rocky river banks and rocky outcrops. Factors that may affect gharial and other aquatic species are cited.

The cane toad Bufo marinus has been migrating westward across northern Australia since its introduction as a biological control agent in 1935. It has been implicated in the widespread decline of many native frog-eating predators. To investigate the impacts of this invasive species on native predatory reptiles, annual surveys were conducted from 2001 to 2007 to document variation in the relative abundances of three varanid lizards ( Varanus mertensi, Varanus mitchelli and Varanus panoptes) and one crocodile Crocodylus johnstoni species known to consume toads. In addition, the indirect effects of this variation on one agamid lizard Amphibolurus gilberti, a known prey item of V. panoptes, were also examined. Surveys were performed at two sites in northern Australia before and after the arrival of B. marinus. Significant declines in the relative abundances of all three species of varanid lizard were observed following toad arrival. Declines in the abundance of V. panoptes, V. mitchelli and V. mertensi at the two sites ranged 83–96, 71–97 and 87–93%, respectively. In contrast, A. gilberti increased by 23–26%; whereas there were no significant population-level declines in C. johnstoni despite observations of individual effects (i.e. several dead crocodiles with B. marinus in their stomachs). These findings suggest population-level changes in Australian lizards caused by an invasive species. [ABSTRACT FROM AUTHOR]

A detailed description of the postcranial skeleton of the Hyposaurinae is presented, based on the hitherto known and new postcranial material. The postcranial skeleton of the hyposaurine Dyrosauridae differs from that of all other crocodilians by the high neural spines, which can reach up to four times the length of the vertebral body, thoracic ribs, which are five times longer than the adjacent vertebral body, dorsal osteoderms lacking an external keel, deep haemal arches, which reach up to 3·4 times the length of the vertebral body, an ilium with a prominent craniodorsal tubercle, and a scapula with an expanded and lateromedially flattened scapular wing, which makes the scapula 1·5 times as large as the coracoid. The similarity of the postcranium of Dyrosaurus, Hyposaurus, Congosaurus and Rhabdognathus allows a uniform skeletal reconstruction for the Hyposaurinae. Only fragmentary material is known from the Phosphatosaurinae. The comparative osteological description of all hyposaurine specimens known to date establishes a basis for future constructional morphological analyses and the reconstruction of their evolutionary history. [ABSTRACT FROM AUTHOR]

Crocodile morphometric (head, snout-vent and total length) measurements were recorded at three stages during the production chain: hatching, inventory [average age (±SE) is 265.1 ± 0.4 days] and slaughter (average age is 1037.8 ± 0.4 days). Crocodile skins are used for the manufacture of exclusive leather products, with the most common-sized skin sold having 35–45 cm in belly width. One of the breeding objectives for inclusion into a multitrait genetic improvement programme for saltwater crocodiles is the time taken for a juvenile to reach this size or age at slaughter. A multivariate restricted maximum likelihood analysis provided (co)variance components for estimating the first published genetic parameter estimates for these traits. Heritability (±SE) estimates for the traits hatchling snout-vent length, inventory head length and age at slaughter were 0.60 (0.15), 0.59 (0.12) and 0.40 (0.10) respectively. There were strong negative genetic (−0.81 ± 0.08) and phenotypic (−0.82 ± 0.02) correlations between age at slaughter and inventory head length. [ABSTRACT FROM AUTHOR]

Mystriosuchus westphali is based on a large, well-preserved cranium and a snout fragment from the Stubensandstein (Norian) of south-west Germany. The hypodigm is redescribed and new or poorly known cranial structures in phytosaurs are discussed. For the first time, the presence of a premaxillary crest is substantiated in a phytosaur. The type specimen shows a supernumerary occipital element (=‘tabular’) that is probably fused to the parietal in other phytosaurs, and an orbitosphenoid. A computerised parsimony analysis confirms the hypothesis that Mystriosuchus is nested within Pseudopalatinae, the most derived clade of phytosaurs, and thus does not fall within basal phytosaurs. Mystriosuchus is characterised by five unique features (slit-like interpremaxillary fossa, triangular cross-section of the postorbito-squamosal bar, strongly reduced posttemporal fenestra, and two features of the cranial sculpture), plus eight synapomorphies that also occur in some more distantly related taxa. Mystriosuchus westphali is diagnosed by, among other apomorphies, a distinct premaxillary crest, a squamosal-proo¨tic contact, absence of a posterior process of the squamosal, and a slit-like posttemporal fenestra. The type species Mystriosuchus planirostris shows, most significantly, the naris facing forward anteriorly and upward posteriorly, and the longest rostrum and the highest degree of depression of the supratemporal opening in any phytosaur. Mystriosuchus exemplifies a common pattern in phytosaurids in being a genus that includes a gracile, elongated, slender-snouted and a more robust species with a broader, often crested snout. This study demonstrates that a detailed analysis of the cranial anatomy and the rigorous application of cladistic principles to identified character states help to clarify current inconsistencies in the taxonomy and nomenclature of phytosaurs. [ABSTRACT FROM AUTHOR]

The new goniopholidid crocodile Goniopholis baryglyphaeus sp. nov. from the Kimmeridgian of Guimarota/Leiria, Portugal is based on the oldest known relatively complete skeleton of Goniopholis from Europe and consists of a nearly complete skull together with a mandible and various postcranial remains. G. baryglyphaeus shows characters that hitherto have only been described for Goniopholis simus : a caudal expansion of the prefrontal that excludes the frontal from the medial margin of the orbit; and the loss of contact between the paroccipital process and the lateral surface of the squamosal and the quadrate, which exposes the cranioquadrate canal laterally. This new species can be distinguished from other European Goniopholis species by an articular facet placed ventral to the retroarticular process, and directed slightly medioventrally; a caudal margin of the mandible forming almost a right angle at its caudoventral corner; an almost square rostrolateral corner of the cranial table; a straight transverse suture between the parietal and the frontal with a median rostral process; a rostrally tapering wedge-like lacrimal, and a regular heavy skull-sculpturing. The new find of Goniopholis in Portugal shows that this genus was distributed in a larger area, and was present much earlier, than hitherto reported in south-western Europe. [ABSTRACT FROM AUTHOR]

(1) Changes in the absolute abundance of Nile crocodiles (Crocodylus niloticus Laurenti) at Lake Ngezi, Zimbabwe, were followed in 1979-82 by mark-recapture in three size-classes ( < 1.2 m, 1.2-2.5 m, > 2.5 m total length). (2) Throughout the study period, there were twenty-eight crocodiles > 2.5 m long and forty crocodiles of 1.2-2.5 m in the population, but the number of animals < 1.2 m long declined from fifty-four in 1979 to eleven in 1982. (3) Over the same period, forty-six spotlight counts, standardized with respect to observer, route, speed and time of night, were conducted. Twelve environmental variables of probable importance to crocodile activity or visibility were measured during each count. These were included in a multiple regression analysis to quantify the effect of the environment on the proportion of the population seen during counts. (4) The proportion of the population counted by spotlight ranged from 0.10 to 0.63 with a mean of 0.36±0.13 (S.D.) over the study period. (5) Two environmental variables, water-level and the difference between water and air temperatures, accounted for 64% of the variation in the proportion of the total population seen during counts. (6) Correction factors to convert spotlight counts to absolute numbers were calculated for the whole population and separately for each size- class. (7) Analysis shows that uncorrected counts undertaken in October/November at the time of lowest water and highest temperatures would have been useful indices of abundance at Ngezi. The use of simple standardized spotlight counts to monitor crocodile abundance is discussed. [ABSTRACT FROM AUTHOR]

The article focuses on the fossil of a metriorhynchid crocodile discovered in Wiltshire, England. The metriorhynchid crocodiles were found to be specialized marine crocodiles that first appeared in the geological record at the start of the Middle Jurassic and vanished in the period of early Cretaceous. It was anticipated that the full preparation and conservation of the crocodile's skeleton would take a year to be completed.