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Human–wildlife interactions are increasing globally due to human population growth and development. Wildlife often develop an increased tolerance of humans through the learning processes of habituation, but habituation of large predators can increase risks to humans. Aversive conditioning is a management strategy that operationalizes learning to reduce wildlife tolerance of humans and thereby improve human safety. However, developed landscapes may select for wildlife phenotypes that are resistant to learning via aversive conditioning. We investigated American alligators', Alligator mississippiensis , response to capture and release (an assumed aversive experience) in coastal resort communities as a model system for understanding wildlife learning in human-dominated landscapes. Our objectives were to investigate whether the degree of human disturbance in the landscape was associated with baseline alligator tolerance of humans or mediated alligators' learning ability. We quantified tolerance using flight initiation trials and estimated learning ability as the response to capture and release using a 'before–after control impact' experimental design. Baseline alligator tolerance did not vary with disturbance, nor did the degree of disturbance impact alligator learning. However, alligators in areas where capture and release occurred were 1.5 times more likely to flee from an approaching human after treatment relative to before. Alligators in control units exhibited similar tolerance to humans over time. Alligator tolerance was also influenced by ambient weather, with alligators least tolerant of humans in cool and cloudy conditions and most tolerant in warm conditions, likely reflecting physiological constraints of ectothermy. While human-dominated landscapes may promote high tolerance of humans through habituation, our findings indicate that high tolerance does not preclude future learning by crocodilians and collectively lend credibility to the use of repeated capture and release as a potential form of aversive conditioning for crocodilians. • We investigated alligators' response to capture–release in human-dominated landscapes. • We examined relations between human disturbance and baseline tolerance and learning. • Baseline tolerance did not vary with disturbance but was influenced by ambient weather. • Alligators were less tolerant of approaching humans after experiencing capture–release. • The degree of landscape level human disturbance did not impact alligator learning. [ABSTRACT FROM AUTHOR]

Simple Summary: The ecological roles and importance of crocodilians (alligators, caiman, crocodiles, gharials) are poorly understood. These large predators are considered to be "ecosystem engineers" because their modification of habitats (e.g., excavation of holes, dens, and tunnels; construction of nests) provides opportunities for vital life activities (e.g., feeding, drinking, breeding, and sheltering) to other wildlife. However, data supporting this contention are scarce for most crocodilian species and, where available, are primarily the result of chance encounters and anecdotal observations; few systematic studies directly focusing on the influence of crocodilian habitat alteration on other wildlife have been conducted. To address this data gap, we monitored American alligator nests with automated game cameras in coastal South Carolina to quantify wildlife visiting nests (faunal associates) and their corresponding behaviors (i.e., how they used nests). From 2016 to 2021, we identified 81 wildlife species at alligator nests, including a wide variety of birds, mammals, reptiles, amphibians, and invertebrates. These animals used alligator nests primarily for feeding/foraging, traveling, and loafing but also basking, burrowing/shelter, breeding, and nesting, and these uses varied by animal group and species. Our results indicate that a diverse assemblage of wildlife uses alligator nest sites in coastal South Carolina for a variety of life activities, and these uses differ among and within animal groups. This study provides a first step for investigations regarding the net impacts of alligator nest-faunal associate interactions and ultimately the greater ecological role of alligators and other crocodilians. Crocodilians are considered to be "ecosystem engineers" because their modification of habitats provides opportunities for feeding, drinking, breeding, and other vital life activities to a wide variety of other animals. One such habitat modification is the construction of nest mounds during the breeding season by most crocodilian species, including American alligators (Alligator mississippiensis). While many reports exist describing wildlife associated with alligator nests, no studies have quantified faunal associates and their corresponding behaviors while visiting nests. To address this data gap, we used automated game cameras to monitor wildlife and their behaviors at alligator nests during the egg incubation period (June–September) in coastal South Carolina, USA (2016–2021). We documented a total of 81 species (79 vertebrates and 2 invertebrates) at 78 alligator nests representing six taxonomic groups, including 48 birds (59.2%), 9 mammals (11.1%), 19 reptiles (23.4%), 3 amphibians (3.7%), 1 malacostracan (1.2%), and 1 insect (1.2%). Collectively, faunal associates primarily used alligator nests for feeding/foraging (51.8%), traveling (29.3%), and loafing (19.9%) and to a much lesser extent basking, burrowing/shelter, breeding, and nesting. However, trends in alligator nest use varied among faunal associate groups (birds, mammals, reptiles, amphibians, etc.), subgroups (e.g., passerines, raptors, wading birds, and waterfowl), and species. Several novel behaviors by some nest associates were also noted during the study, including the first observations of Virginia oppossum (Didelphis virginiana) opening and predating nests, bobcat (Lynx rufus) consuming alligator hatchlings, and Carolina wren (Thryothorus ludovicianus) feeding on the contents of a recently predated alligator egg. The results of this study indicate that a diverse assemblage of vertebrates (and some invertebrates) use alligator nest sites in coastal South Carolina for a variety of life activities during the egg incubation period, and the proportion of the behaviors exhibited varies among animal groups and species. This study provides a first step for investigations regarding the net impacts of alligator nest-faunal associate interactions and ultimately the greater ecological role of alligators and other crocodilians. [ABSTRACT FROM AUTHOR]

As anthropogenic impacts on ecosystems increase, novel solutions are needed to mitigate increasing human–wildlife conflict. Aversive conditioning is one strategy that can reduce the risks of humans living alongside wildlife by modifying the behavior of animals through their experiences with humans. Although considered rare, American alligator (Alligator mississippiensis) attacks on humans most often occur in human‐dominated landscapes and can be fatal. Our goal was to determine if capture and release protocols might serve as a form of aversive conditioning to reduce alligator tolerance of humans. Specifically, we compared the behavioral response of alligators in South Carolina, USA, in 2009–2018 to an approaching human for animals with 3 different levels of capture experience: alligators from a reference site where no captures occurred, alligators from a site where captures occurred that directly experienced capture and release, and alligators from the site where captures occurred that indirectly experienced capture and release (never captured but likely observed capture of others). We used a hurdle model and information‐theoretic approach to evaluate support for 8 hypotheses regarding factors that influence alligator probability of flight in response to an approaching human and the flight initiation distance (FID) of alligators that did flee. Our hypotheses considered the effects of capture experience, exposure to non‐capture (visual) surveys, alligator size, ambient temperature, and season. The best‐supported models provided strong evidence that capture experience increased the probability of flight and, to a lesser extent, increased FID of alligators that did flee, but that the strength of the effect varied with alligator size or some correlate. Furthermore, the effect of capture may extend beyond animals with direct experience. Capture and release protocols can result in an aversive conditioning response in alligators, effectively reducing habituation to humans. Given the geographic limitations of our study, more work is necessary to determine whether the utility of aversive conditioning may be site‐dependent, or similarly effective across a wider selection of developed landscapes. [ABSTRACT FROM AUTHOR]

The article discusses research on the specie, "Alligator Mississippiensis (American Alligator)" and explores about its geographical distribution and collection of specimen, along with explores diet and prey of the species.

The nuclear-follower relationship is a specialized interspecific foraging association in which the nuclear species excavates the substrate while foraging, and follower species access food items flushed or uncovered by the nuclear species. We observed a nuclear-follower association between Apalone spinifera (Spiny Softshell Turtle) and fish (Micropterus salmoides [Largemouth Bass] and Lepomis spp.) in an urban drainage canal (Wards Creek) in Baton Rouge, LA, during June and July of 2020. Groups of Largemouth Bass and Lepomis spp. numbering 0-2 and 1-20, respectively, followed foraging Spiny Softshell Turtles. When foraging, Spiny Softshell Turtles were observed moving along the creek bottom, thrusting their probosces into and vigorously excavating the substrate. The accompanying fish then entered the cloud of suspended sediment to pursue and capture prey. Excavation of the substrate by Spiny Softshell Turtles appears to be the critical component of this nuclear-follower relationship, flushing or exposing prey that would otherwise be unavailable to fish. This nuclear-follower relationship is apparently one of commensalism, i.e., while fish probably benefit from increased foraging success, few if any benefits accr ue to foraging turtles. [ABSTRACT FROM AUTHOR]

Morelet's crocodile (Crocodylus moreletii) and hybrid crocodiles (C. moreletii × acutus) are mound-nesting crocodilians found in the lowlands of northern and southern Belize, respectively. Nests of both crocodilians consist of large mounds of soil, vegetation, leaf litter, and in some cases sand. We here report on the fauna associated with nest mounds of C. moreletii and C. moreletii × acutus, and describe the associations between crocodiles and commensal fauna. Our data were collected during various ecological studies conducted from 1992 through 2000, and we examined 138 active (containing eggs) nests of C. moreletii and 11 active nests of C. moreletii × acutus. We noted the occurrence of at least 14 species of fauna associated with 45 (32.6%) C. moreletii and three (27.2%) C. moreletii × acutus nests. Nest-associated fauna included ants, bees, termites, turtles, squamates, birds, and mammals. Associations included five species dwelling within crocodile nest mounds, four species that deposited eggs in crocodile nest mounds, and five species nesting in close proximity to crocodile nests. Nest-associated fauna presumably benefit from the protection afforded by nest attendance and aggressive defence behaviour of female crocodiles, although these benefits have yet to be empirically established. [ABSTRACT FROM AUTHOR]

Leucism (white skin, dark eyes) is a rare color disorder occurring in a range of invertebrates and vertebrates, and as a result, relatively few reports exist of leucistic individuals in the wild. In March 2014, we found 6 leucistic Alligator mississippiensis (American Alligator) hatchlings in coastal South Carolina. All individuals were basking under cool, cloudy conditions within ∼15 m of the den, appeared moderately emaciated, and were somewhat lethargic upon capture. The animals were removed from the field and treated for malnutrition under veterinary supervision. Three Alligators died within 6 days of collection, and the remaining 3 individuals were transferred to different institutions for long-term care and display. These animals also eventually died after surviving in captivity for ∼4.5–45 months. Leucistic Alligators are known to suffer from a variety of health problems, and the mortalities and associated causes of death in the animals we describe here were consistent with previous reports of other leucistic Alligators. The incidence of leucism among wild crocodilians is very low, and disease, increased susceptibility to predation, and collection by humans further exacerbate its rarity. [ABSTRACT FROM AUTHOR]

The article reports the discovery of a previously unreported bird species in the diet of American Alligators, specifically Alligator mississippiensis, highlighting the consumption of a tern found in the stomach of an alligator harvested in South Carolina.

The article focuses on the micro-sympatric associations between the Rough-footed Mud Turtle (K. hirtipes) and the Yellow Mud Turtle (K. flavescens) in west Texas. Topics include the lack of knowledge about K. hirtipes, their coexistence in wetlands, and the potential habitat partitioning between the two species based on their physiological differences.

Red-shouldered Hawks (Buteo lineatus) feed primarily on mammals, amphibians, and reptiles, but invertebrates also comprise a significant portion of the diet. The majority of invertebrates consumed are insects and crustaceans, with the latter represented to date only by crayfish. In 2016, we observed a Red-shouldered Hawk attack and dismember another crustacean, the ghost crab (Ocypode quadrata), on a coastal beach in South Carolina, USA. Actual consumption of the crab by the hawk was not observed but is probable. Consumption of ghost crabs by Red-shouldered Hawks is not unexpected, as these crustaceans are abundant within their range, active when hawks are foraging, and occur in open habitats (beaches and dunes) where they are more vulnerable to avian predators. To our knowledge, this is the first report of a Red-shouldered Hawk attacking and presumably consuming any species of crab and the first report of probable ghost crab predation by a raptor in North America. [ABSTRACT FROM AUTHOR]

The article presents a report regarding the discovery and geographical distribution of Nile Crocodile, Crocodylus Niloticus, along with mentions about stream habitat use of the Crocodylus Niloticus.

An unusually large Alligator mississippiensis (American Alligator) was harvested in Alabama in 2014. We report on the animal’s length and mass, and document the techniques used to obtain those measurements. We compare our measurements to other extreme lengths and weights reported for the species. We show that the size of the American Alligator is consistent with known allometric relationships of head length, total length, snout–vent length, tail girth, and weight. The specimen’s straight-line total length of 450.0 cm (14 ft 9.25 in) makes it the longest officially measured American Alligator for Alabama and arguably the longest credible record for the species. We recommend using standardized techniques, particularly the straight-line total-length measurement, for documenting record-length or near-record-length American Alligators. [ABSTRACT FROM AUTHOR]

The article focuses on examining the demography, sex ratio, and sexual size dimorphism of Kinosternon hirtipes, particularly in the Big Bend Region of Texas, USA, shedding light on its conservation status and population dynamics.

The article describes observations of behavior during flooding of an adult female and male Terrapene carolina or Eastern Box Turtle that were encountered in a wooded area inundated by backwater flooding near Siegen Lane at Interstate Highway 12 in Baton Rouge, Louisiana on May 4, 1991. The researchers note the risk for turtles of exposure to adverse environmental conditions and predation and suggest their avoidance behavior by seeking elevated refugia like woody debris and vegetation.

Simple Summary: Immunoglobulin Y (IgY) was purified from American alligator, Alligator mississippiensis, serum and used to develop a monoclonal antibody (mAb AMY-9) specific for the heavy chains of IgY. This antibody tool was then used to develop an ELISA for quantifying serum antibody responses against whole bacterial pathogens in alligators sampled in Florida, USA and South Carolina, USA. Antibody responses against some of the bacteria were very robust and varied by location and year, and in general these antibody responses correlated well with body condition factors, such as body-mass-indices (BMI). A novel mAb is now available to the scientific community interested in disease ecology of alligators. Little is known about the disease ecology of American alligators (Alligator mississippiensis), and especially how they respond immunologically to emerging infectious diseases and zoonotic pathogens. In this study, we examined serum samples collected from wild alligators in Florida (2010–2011) and South Carolina (2011–2012, 2014–2017) for antibody responses to multiple bacteria. Immunoglobulin Y (IgY) was purified from serum to generate a mouse monoclonal antibody (mAb AMY-9) specific to the IgY heavy chain. An indirect ELISA was then developed for quantifying antibody responses against whole cell Escherichia coli,Vibrio parahaemolyticus, Vibrio vulnificus, Mycobacterium fortuitum, Erysipelothrix rhusiopthiae, and Streptococcus agalactiae. In Florida samples the primary differences in antibody levels were between January–March and late spring through summer and early fall (May-October), most likely reflecting seasonal influences in immune responses. Of note, differences over the months in antibody responses were confined to M. fortuitum, E. rhusiopthiae, V. vulnificus, and E. coli. Robust antibody responses in SC samples were observed in 2011, 2014, and 2015 against each bacterium except E. coli. All antibody responses were low in 2016 and 2017. Some of the highest antibody responses were against V. parahaemolyticus, M. fortuitum, and E. rhusiopthiae. One SC alligator estimated to be 70+ years old exhibited the highest measured antibody response against V. parahaemolyticus and M. fortuitum. By combining data from both sites, we show a clear correlation between body-mass-indices (BMI) and antibody titers in all six of the bacteria examined. Our study provides a critical antibody reagent and a proof-of-concept approach for studying the disease ecology of alligators in both the wild and in captivity. [ABSTRACT FROM AUTHOR]

The article reports that Kleptoparasitism is the stealing of already procured food by individuals of the same or different species. Topics include considered that observations of kleptoparasitism in Nerodia are noteworthy for two reasons and to our knowledge, these observations constitute the first report of kleptoparasitic behaviors among any Nerodia.

The article presents a report regarding the discovery and geographical distribution of Eastern Box Turtle, Terrapene Carolina, along with mentions about omnivore behavior of the Terrapene Carolina.

Monotypic stands of cane (Arundinaria Michx.) known as canebrakes were a dominant landscape feature in the southeastern United States at the time of European settlement. Canebrakes disappeared rapidly as a consequence of altered fire regimes, agricultural clearance, and overgrazing by livestock, and are now regarded as critically endangered ecosystems. Canebrake fauna remains incompletely known and recent biodiversity studies of this ecosystem are few. In an earlier paper we used historic and contemporary sources to reconstruct the faunal diversity of canebrakes. However, because information is fragmentary and often found in obscure historical sources, inadvertent omissions were unavoidable in our earlier report. We here revisit this topic, provide additional records of canebrake fauna, and discuss the importance of canebrakes to wildlife. We documented the occurrence of an additional 28 species of vertebrates in canebrake habitats, including one reptile, 20 birds, and seven mammals. Canebrake herpetofauna (amphibians and reptiles) remains poorly documented. Birds use canebrakes as nesting, foraging, and winter roosting habitat, probably consume cane seeds when available, and incorporate cane foliage in nests. Much of what is known about the mammalian fauna of canebrakes is heavily biased towards megafauna, although a small number of studies suggest rodent and insectivore diversity is comparable to other early and mid-successional habitats in the southeast. Canebrakes provide mammals with escape cover, maternal den sites, foraging habitat, and food in the form of foliage and seeds. We reiterate our earlier recommendation for region-wide faunal inventories of existing canebrakes to address deficiencies in our knowledge as highlighted in this paper. Baseline data generated by these studies, combined with information gleaned from the literature, will provide a means to rigorously evaluate future conservation and restoration efforts. [ABSTRACT FROM AUTHOR]

The Central American river turtle (Dermatemys mawii) is a large Critically Endangered freshwater turtle historically found in the coastal lowlands of southern Mexico, northern Guatemala, and Belize. Due to years of intense harvesting for its meat, D. mawii has been virtually eliminated from much of its former range in southern Mexico, while its status in Guatemala remains unclear. During April and May 2010, we conducted a countrywide survey in Belize to assess the current conservation status of D. mawii in what is believed to be its last stronghold. We surveyed approximately 30 localities from deep southern to extreme northern Belize, including 17 areas previously surveyed during the early 1980s and 1990s. Results indicate D. mawii is heavily depleted in most of Belize, but healthy populations remain in a few remote areas (including multiple, previously unsurveyed localities in southern Belize), especially those receiving some level of protection. While this mirrors the trend observed in previous surveys, the current findings are of particular concern because the number of localities where turtles were observed and the number of turtles observed at these localities were both much reduced compared to earlier surveys. Large turtles (reproductive adults) continue to be targeted during harvests, significantly reducing the most demographically important segment of the population. Further, interviews with fishermen and hunters indicate that laws and regulations enacted for the protection of D. mawii are largely ignored by locals, as broad-scale enforcement is difficult or impossible to achieve. In this paper, we discuss survey results in the context of previous investigations, describe levels and sources of exploitation, and provide conservation recommendations. [ABSTRACT FROM AUTHOR]

The article presents a study which determines the sexual size dimorphism, size population, morphometrics, sex ratio, and biomass of Crocodylus (C.) acutus in the coastal zone of Belize. It mentions that the measurements obtained from the crocodiles captured during 1996-1998, 2002, and 2008-2009 include total length, snout-vent length (SVL), and dorsal cranial length (DCL). It notes that the sexual size dimorphism index (SDI) for C. acutus was 2.10. It adds that the C. acutus in coastal Belize seem to have a smaller body size than those reported populations.

We studied the biomagnification of total mercury and methylmercury in a subtropical freshwater lake, Caddo Lake, Texas and Louisiana, USA. The present study is unique in that it not only included invertebrates (seven species) and fish (six species) but also an amphibian (one species), reptiles (three species), and mammals (three species). Nonfish vertebrates such as those included in the present study are often not included in assessments of trophic transfer of Hg. Mean trophic position (determined using stable isotopes of nitrogen) ranged from 2.0 (indicative of a primary consumer) to 3.8 (indicative of a tertiary consumer). Mean total Hg concentrations ranged from 36 to 3,292 ng/g dry weight in muscle and whole body and from 150 to 30,171 ng/g dry weight in liver. Most of the Hg in muscle and whole-body tissue was found as methylmercury, and at least 50% of the Hg found in liver was in the inorganic form (with the exception of largemouth bass, Micropterus salmoides). Mercury concentrations were positively correlated with trophic position, indicating that biomagnification occurs in the food web of Caddo Lake. The food web magnification factors (FWMFs; slope of the relationship between mean Hg concentration and trophic position) for both total Hg and methylmercury were similar to those observed in other studies. Because most of the total Hg in consumers was methylmercury, the FWMF for methylmercury was not significantly different from the FWMF for total Hg. Some vertebrates examined in the present study had low Hg concentrations in their tissues similar to those observed in invertebrates, whereas others had concentrations of Hg in their tissues that in previous studies have been associated with negative health consequences in fish. Environ. Toxicol. Chem. 2011; 30:1153-1162. © 2011 SETAC [ABSTRACT FROM AUTHOR]

We report observations of turtle (Dermatemys mawii and Trachemys venusta) predation by Lontra longicaudis at Cox Lagoon, Belize. On 10 June 1994, we observed an otter swimming with a juvenile D. mawii in its jaws. During a subsequent search (25 June and 5 July 1994) we found 35 D. mawii shells or partially eaten carcasses, and a single, partially eaten adult T. venusta that had apparently been killed by otters. Based on the size of these turtles, juvenile and subadult D. mawii seem most vulnerable to otter predation. Because otter predation of D. mawii appears rare in Belize, and most reproductively mature D. mawii are probably too large to be caught and killed by foraging otters, we do not consider predation by L. longicaudis to be a serious threat to populations of this critically endangered turtle. [ABSTRACT FROM AUTHOR]

Like most of Madagascar's endemic primates, ring-tailed lemurs (Lemur catta) face a number of threats to their survival. Although habitat loss is of greatest concern, other anthropogenic factors including environmental contamination may also affect lemur health and survival. In this study, we examined ring-tailed lemurs from the Beza Mahafaly Special Reserve (BMSR), southern Madagascar for exposure to organochlorine (OC) pesticides and metals and examined differences in contaminant concentrations between sexes and among age groups, troops, and habitats. A total of 14 pesticides and 13 metals was detected in lemur blood (24 individuals) and hair (65 individuals) samples, respectively. p,p′-DDT, heptachlor, aldrin, heptachlor epoxide, endrin aldehyde, and endrin were among the most prevalent pesticides detected. Surprisingly, the persistent metabolite of p,p′-DDT, p,p′-DDE, was not detected. The most commonly detected metals were aluminum, zinc, boron, phosphorus, silicon, and copper, whereas metals considered more hazardous to wildlife (e.g. arsenic, cadmium, lead, selenium, vanadium) were not found above detection limits. Overall, concentrations of OC pesticides and metals were low and similar to those considered to be background concentrations in other studies examining the ecotoxicology of wild mammals. Few inter-sex, -age, -troop, and -habitat differences in contaminant concentrations were observed, suggesting a uniform distribution of contaminants within the reserve. Several statistically significant relationships between lemur body size and contaminant concentrations were observed, but owing to the lack of supportive data regarding contaminant exposure in wild primates, the biological significance of these findings remains uncertain. Results of this study document exposure of ring-tailed lemurs at BMSR to multiple OC pesticides and metals and provide essential baseline data for future health and toxicological evaluations of lemurs and other wild primates, especially those in regions with expanding agricultural and mining operations. Am. J. Primatol. 71:998–1010, 2009. © 2009 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]

Diet of the barn owl (Tyto alba) has been well studied in temperate regions of the world, but there is a notable paucity of dietary data from the Neotropics. In this study, we examined diet of barn owls at Gold Button Lagoon in northern Belize. Pellets and prey remains were collected at roosting sites during 1997-1998. Diet was composed primarily of small mammals. Sigmodon hispidus was the most common prey in terms of frequency of occurrence and biomass, with lesser numbers of other rodents being consumed. Similar to other reports for the Neotropics, barn owls in our study consumed relatively larger prey than conspecifics inhabiting temperate regions. Birds and amphibians were a minor component of diet. [ABSTRACT FROM AUTHOR]

The article presents information on a study which conducted spotlight surveys and nest counts to evaluate the current status of American crocodile or Crocodylus (C.) acutus populations in Turneffe Atoll, Belize. Observations were made on 23 C. acutus along the survey route in May 2008 and eight crocodiles during late June-early July. It revealed that overall crocodile encounters were significantly lower compared to surveys conducted in 2002. The same goes with the number of nests which is indicative of a reduction in breeding females in the Turneffe Atoll crocodile population.

Despite high animal diversity in the Neotropics and the largely unregulated use and disposal of pesticides and industrial chemicals in Central America, few data exist regarding accumulation of environmental contaminants in Central American wildlife. In this study we examined accumulation of metals and organochlorine (OC) pesticides in caudal scutes of crocodiles from Belize and Costa Rica. Scutes from Morelet''s crocodiles (Crocodylus moreletii) from two sites in northern Belize were analyzed for metals, and scutes from American crocodiles (C. acutus) from one site in Costa Rica were analyzed for metals and OC pesticides. All scutes (n =25; one scute from each of 25 individuals) contained multiple contaminants. Mercury was the predominant metal detected, occurring in all scutes examined from both species. Other metals detected include cadmium, copper, lead, and zinc. American crocodile scutes from Costa Rica contained multiple OC pesticides, including endrin, methoxychlor, p,p′-DDE, and p,p′-DDT, all of which occurred in 100% of scutes analyzed (n =6). Mean metal and OC concentrations varied in relation to those previously reported in crocodilian scutes from other localities in North, Central, and South America. OC concentrations in American crocodile scutes were generally higher than those previously reported for other Costa Rican wildlife. Currently, caudal scutes may serve as general, non-lethal indicators of contaminant accumulation in crocodilians and their areas of occurrence. However, a better understanding of the relationships between pollutant concentrations in scutes, internal tissues, and environmental matrices at sample collection sites are needed to improve the utility of scutes in future ecotoxicological investigations. [Copyright &y& Elsevier]

Storm surge associated with Hurricane Katrina and the breach of levees protecting New Orleans, Louisiana allowed floodwaters from Lake Pontchartrain to inundate 80% of the city. Environmental samples were collected during September 16-18, 2005 to determine immediate human and wildlife health hazards from pathogens and toxicants in the floodwaters. Baseline information on potential long-term environmental damage resulting from contaminants in water and sediments pumped into Lake Pontchartrain was also collected. Concentrations of aldrin, arsenic, lead, and seven semivolatile organic compounds in sediments! soils exceeded one or more United States Environmental Protection Agency (USEPA) thresholds for human health soil screening levels and high priority bright line screening levels. High numbers of Aeromonas spp., pathogenic Vibrio spp., and other coliform bacteria were found in floodwater samples. Alligator and snake tissues did not contain excessive toxicant concentrations. Initial findings suggest numerous environmental contaminants are present in New Orleans and support the need for further evaluation of the extent of those threats. [ABSTRACT FROM AUTHOR]

Foraging areas of adult prothonotary warblers (Protonotaria citrea) were determined using standard radiotelemetry techniques to determine if soil concentrations of p,p′dichlorodiphenyltrichloroethane (p,p′DDT) and mercury in foraging areas could be used to predict contaminant levels in diets and tissues of nestling warblers. Adult warblers were fitted with transmitters and monitored for approximately 2 d while foraging and feeding 6- to 8-d-old nestlings. Foraging ecology data were integrated with contaminant levels of soil, diets, and tissues into a comprehensive analysis of geographic variation in contaminant exposure and uptake using linear regression. Concentrations of 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (DDE) and mercury in nestling tissues varied considerably across the study site. Mean concentration of DDE was greater in eggs than all other tissues, with individual samples ranging from 0.24 to 8.12 µg/kg. In general, concentrations of DDT in soil were effective in describing the variation of contaminants in adipose samples. Concentrations of mercury in soils accounted for 78% of the variation in kidney samples. This was the best relationship of any of the paired variables. All other relationships showed relatively poor predictive ability. [ABSTRACT FROM AUTHOR]

The article focuses on the evaluation of historic records of large pythons that have not previously appeared in the herpetological literature. Topics discussed include exploration by author Charles Challisé Long around by Lake Victoria in modern-day Uganda in 1876; personal encounter with large snake of Charles Challisé Long and memoirs of Boris Hamby (2011),British rubber planter, regarding encounter of a large snake rubber trees.

Information on kinosternon hirtipes from U.S. including information related to topics like scattered emergent vegetation Typha and Scirpus, and methodologies for sampling turtles like wire-mesh funnel traps is presented.

We present two noteworthy observations of foraging Turkey Vultures (Cathartes aura), including consumption of a marine toad (Bufo marinus) and a live juvenile cotton rat (Sigmodon hispidus). To our knowledge, these observations are the first reports of any North American vulture consuming B. marinus or a Turkey Vulture taking live mammalian prey. Our observations highlight the potential for mechanical mowers to provide carrion for Turkey Vultures. [ABSTRACT FROM AUTHOR]

The article presents an observation of the scavenging behavior in Chelydra serpentina known as common snapping turtle in the Great Swamp in Putnam County, New York. It mentions that a juvenile C. serpentina was captured on September 1, 2017 and examined while feeding on the carcass of Icteria virens, yellow-breasted chat. It notes that the species is omnivorous with a varied diet including carrion and fresh prey.

Maternal provisioning and the developmental environment are fundamental determinants of offspring traits, particularly in oviparous species. However, the extent to which embryonic responses to these factors differ across populations to drive phenotypic variation is not well understood. Here, we examine the contributions of maternal provisioning and incubation temperature to hatchling morphological and metabolic traits across four populations of the American alligator (Alligator mississippiensis), encompassing a large portion of the species' latitudinal range. Our results show that whereas the influence of egg mass is generally consistent across populations, responses to incubation temperature show population‐level variation in several traits, including mass, head length, head width, and residual yolk mass. Additionally, the influence of incubation temperature on developmental rate is greater at northern populations, while the allocation of maternal resources toward fat body mass is greater at southern populations. Overall, our results suggest that responses to incubation temperature, relative to maternal provisioning, are a larger source of interpopulation phenotypic variation and may contribute to the local adaptation of populations. [ABSTRACT FROM AUTHOR]

The environment experienced during embryonic development is a rich source of phenotypic variation, as environmental signals have the potential to both inform adaptive plastic responses and disrupt normal developmental programs. Environment-by-embryo interactions are particularly consequential for species with temperature-dependent sex determination, a mode of sex determination common in non-avian reptiles and fish, in which thermal cues during a discrete period of development drive the formation of either an ovary or a testis. Here we examine the impact of thermal variation during incubation in combination with developmental exposure to a common endocrine-disrupting contaminant on fitness-related hatchling traits in the American alligator (Alligator mississippiensis), a species with temperature-dependent sex determination. Using a factorial design, we exposed field-collected eggs to five thermal profiles (three constant temperatures, two fluctuating temperatures) and two environmentally relevant doses of the pesticide metabolite dichlorodiphenyldichloroethylene; and we quantified incubation duration, sex ratios, hatchling morphometric traits, and growth (9–10 days post-hatch). Whereas dichlorodiphenyldichloroethylene exposure did not generally affect hatchling traits, constant and fluctuating temperatures produced diverse phenotypic effects. Thermal fluctuations led to subtle changes in incubation duration and produced shorter hatchlings with smaller heads when compared to the constant temperature control. Warmer, male-promoting incubation temperatures resulted in larger hatchlings with more residual yolk reserves when compared to cooler, female-promoting temperatures. Together, these findings advance our understanding of how complex environmental factors interact with developing organisms to generate phenotypic variation and raise questions regarding the mechanisms connecting variable thermal conditions to responses in hatchling traits and their evolutionary implications for temperature-dependent sex determination. [ABSTRACT FROM AUTHOR]

Cattle Egrets (Bubulcus ibis) are active foragers that typically pursue and capture insects flushed by grazing mammals. Arboreal foraging by Cattle Egrets has occasionally been reported, although this behavior appears to be rare, poorly documented, and not well understood. We observed Cattle Egrets arboreally foraging at 2 locations in Myanmar: Yangon University (24 Dec 2018–7 Jan 2019) and Khamti (1 Apr 2019). We observed Cattle Egrets at Yangon University feeding in the canopy of a mango tree (Mangifera indica) on swarms of pollinating insects attracted to flowers. Foraging egrets were scattered throughout the canopy; most remained stationary beside a single flower cluster to catch insects, although on occasion more active behaviors were employed. In Khamti, we observed Cattle Egrets perched on trees above an emergence of winged termite alates (Isoptera). Egrets remained stationary and attempted to capture flying termites in close proximity. Our observations together with other published reports suggest arboreal foraging by Cattle Egrets may occur under the following conditions: (1) when insects are concentrated in trees (e.g., pollinators swarming at flowers) and/or (2) when an elevated perch provides access to flying insects. Our observations at Khamti appear to be the second record of Cattle Egrets among bird assemblages opportunistically preying on alate termites. [ABSTRACT FROM AUTHOR]

Many ectotherms rely on temperature cues experienced during development to determine offspring sex. The first descriptions of temperature‐dependent sex determination (TSD) were made over 50 years ago, yet an understanding of its adaptive significance remains elusive, especially in long‐lived taxa.One novel hypothesis predicts that TSD should be evolutionarily favoured when two criteria are met—(a) incubation temperature influences annual juvenile survival and (b) sexes mature at different ages. Under these conditions, a sex‐dependent effect of incubation temperature on offspring fitness arises through differences in age at sexual maturity, with the sex that matures later benefiting disproportionately from temperatures that promote juvenile survival.The American alligator (Alligator mississippiensis) serves as an insightful model in which to test this hypothesis, as males begin reproducing nearly a decade after females. Here, through a combination of artificial incubation experiments and mark‐recapture approaches, we test the specific predictions of the survival‐to‐maturity hypothesis for the adaptive value of TSD by disentangling the effects of incubation temperature and sex on annual survival of alligator hatchlings across two geographically distinct sites.Hatchlings incubated at male‐promoting temperatures (MPTs) consistently exhibited higher survival compared to those incubated at female‐promoting temperatures. This pattern appears independent of hatchling sex, as females produced from hormone manipulation at MPT exhibit similar survival to their male counterparts.Additional experiments show that incubation temperature may affect early‐life survival primarily by affecting the efficiency with which maternally transferred energy resources are used during development.Results from this study provide the first explicit empirical support for the adaptive value of TSD in a crocodilian and point to developmental energetics as a potential unifying mechanism underlying persistent survival consequences of incubation temperature. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Species displaying temperature-dependent sex determination (TSD) are especially vulnerable to the effects of a rapidly changing global climate due to their profound sensitivity to thermal cues during development. Predicting the consequences of climate change for these species, including skewed offspring sex ratios, depends on understanding how climatic factors interface with features of maternal nesting behaviour to shape the developmental environment. Here, we measure thermal profiles in 86 nests at two geographically distinct sites in the northern and southern regions of the American alligator’s (Alligator mississippiensis) geographical range, and examine the influence of both climatic factors and maternally driven nest characteristics on nest temperature variation. Changes in daily maximum air temperatures drive annual trends in nest temperatures, while variation in individual nest temperatures is also related to local habitat factors and microclimate characteristics. Without any compensatory nesting behaviours, nest temperatures are projected to increase by 1.6–3.7°C by the year 2100, and these changes are predicted to have dramatic consequences for offspring sex ratios. Exact sex ratio outcomes vary widely depending on site and emission scenario as a function of the unique temperature-by-sex reaction norm exhibited by all crocodilians. By revealing the ecological drivers of nest temperature variation in the American alligator, this study provides important insights into the potential consequences of climate change for crocodilian species, many of which are already threatened by extinction. [ABSTRACT FROM AUTHOR]

Dioxins and related contaminants are highly pervasive in aquatic systems and elicit deleterious effects in exposed organisms. Because dioxins exhibit a proclivity to bioaccumulate, long-lived predatory species are particularly vulnerable to their persistence in the environment. We have previously reported elevated expression of CYP1A2 , a biomarker of dioxin exposure, in American alligator embryos collected from the Tom Yawkey Wildlife Center (YWC). This coastal population inhabits a system with historical dioxin contamination associated with industrial activities. Herein, we utilize ecological attributes of the alligator to address the persistence of dioxins and furans in yolk and their potential to drive changes in hepatic function. Specifically, we assess variation in expression of AHR signaling components in embryos and its connection to contaminant levels in matched yolk samples. Compared to a reference population, TEQ levels and total penta-, hexa-, octa-substituted CDDs were elevated at YWC. Contrary to predictions, TEQ levels were not significantly related to hepatic AHR1B or CYP1A2 expression. However, a significant association was detected between expression of both factors and embryo:yolk mass ratios, wherein decreasing embryo mass was negatively associated with CYP1A2 but positively associated with AHR1B. These findings suggest that variation in embryonic metabolism and developmental progression likely influence AHR signaling and dioxin toxicity in alligators and potentially other oviparous species. While dioxin concentrations observed in alligators in this study are lower than historical values reported for other wildlife species inhabiting this system, they indicate the continued presence and possible long-term influence of these contaminants in a high trophic status species. • Elevated dioxins, TEQ in egg yolks from a historically-contaminated site. • Variation in AHR, CYP1A expression associated with clutch. • Yolk utilization associated with changes in AHR, CYP1A expression. [ABSTRACT FROM AUTHOR]

The article focuses on the diet of American alligators, highlighting their opportunistic nature and extensive predation on various species of birds, including wading birds, with a new observation of predation on a species not previously reported in their diet.

The recovery of 25 southern short-tailed shrew (Blarina carolinensis) skulls from a single discarded bottle in Louisiana appears to be the largest number of Blarina ever found in one bottle and reported in the literature. Conservation concerns about the impact of discarded bottles on small mammal faunas seem justified and warrant investigation. [ABSTRACT FROM AUTHOR]

Toxic trace element exposure occurs through release of the ubiquitous and naturally occurring elements arsenic (As), cadmium (Cd), lead (Pb), and mercury (Hg). The unique environmental conditions of the wetland ecosystems along the southeastern Atlantic coast of the United States lead to the accumulation of Hg which is greater than in most other ecosystems in the country. There are also point sources of As, Cd, and Pb in this region. To effectively monitor trace element concentrations, and consequently the potential human exposure, accessible local sentinel species are needed. In this study, concentrations of As, Cd, Pb, Hg and six other trace elements (Al, Ni, Cu, Zn, Se, Mo) were examined in American alligators (Alligator mississippiensis) from seven wetland sites in South Carolina and Florida and assessed for their utility as a sentinel species for human trace element exposure. Alligators were chosen as a potential sentinel as they share a common exposure with the local human population through their aquatic diet, and they are directly consumed commercially and through recreation hunting in this region. Sex was significantly related to the concentration of Zn, Mo, and Al, but not As, Pb, Hg, Cd, Se, or Cu. Site specific differences in element concentrations were observed for As, Pb, Hg, Cd, Se, Zn, and Mo. Size/age was significantly related to the element Hg and Pb concentrations observed. The observed concentration ranges for the four toxic elements, As (6–156 ng/g), Cd (0.3–1.3 ng/g), Pb (3–4872 ng/g), and Hg (39–2765 ng/g), were comparable to those previously reported in diverse human populations. In this region alligators are hunted recreationally and consumed by the local community, making them a vehicle of direct human toxic element exposure. We propose that the similarity in As, Cd, Pb, and Hg concentrations between alligators observed in this study and humans underscores how alligators can serve as a useful sentinel species for toxic element exposure. • Alligators in the southeast have Hg concentrations comparable to many diverse human populations. • The toxic elements As, Cd, Hg and Pb are reported in concentrations comparable to humans. • Mo, and Ni are reported in low concentrations in alligators in this region. [ABSTRACT FROM AUTHOR]

Little is known concerning predation of rough-footed mud turtles (Kinosternon hirtipes), a species of conservation concern in Texas, USA. During field studies conducted from 2007 to 2016, we documented 8 instances (1 juvenile, 2 males, and 5 females) of predation among individuals of one of the few (<10) remaining populations of K. hirtipes in Texas. Predation was attributed to raccoons (Procyon lotor; n = 5) and feral pigs (Sus scrofa; n = 2); the predator responsible for the death of one of the turtles could not be determined. Turtles are vulnerable to predation when exposed by low water levels in ponds, when making overland movements between ponds, and during nesting forays ashore. To reduce the likelihood of predation, we recommend maintaining adequate water levels in wetlands, linking wetlands with ditches, encouraging the growth of aquatic vegetation, and providing experimental raccoon-proof nest mounds. [ABSTRACT FROM AUTHOR]

Abstract This study focused on an estuarine wildlife species exhibiting high site fidelity and ubiquitous distribution in coastal environments along the Atlantic and Gulf coasts of the United States to monitor per- and polyfluoroalkyl substances (PFAS). A total of 75 diamondback terrapin (Malaclemys terrapin) plasma samples were collected from five creeks associated with Kiawah (Oyster Creek, Fiddler Creek, Sandy Creek, Gnat Creek) and Edisto (Townsend Creek) islands in Charleston County, South Carolina and investigated for 15 legacy PFAS. Of those, PFHxS was the only PFAS found in all terrapin plasma samples. Four additional PFAS were routinely detected (greater than 90% of the samples) and were included in statistical analyses: PFOS, PFNA, PFDA, and PFUnA. Sex-differences were observed for two creeks with male plasma containing higher PFAS than female plasma (PFHxS at Townsend Creek, PFOS at Oyster Creek). Sex-specific site differences in PFAS concentrations were observed primarily for males, suggesting male terrapins may be more sensitive indicators of localized contaminant profiles than females. Three PFAS were observed to have negative correlations with body mass: PFOS in males (p = 0.045, tau = −0.220), PFNA in males (p = 0.016, tau = −0.269), and PFHxS in both males (p = 0.007, tau = −0.302) and females (p = 0.001, tau = −0.379). No relationships for body mass and PFDA and PFUnA were observed. Highlights • PFOS, PFNA have negative correlations with body mass in male terrapin. • PFHxS have a negative correlation with body mass in males & females. • Site differences observed in males indicate male terrapins are a more sensitive indicators than females. [ABSTRACT FROM AUTHOR]

We critically evaluated a published historic account purported to be a new size record for A. mississippiensis (American Alligator). According to a newspaper article published in 1885, this large alligator was killed in Natchitoches, LA, and reportedly measured 823 cm (27 ft) in length and weighed 355.3 kg (783.5 lbs). We compared the reported values for total length (TL) and body mass (BM) with those predicted by a growth model describing the allometric relationship between these 2 variables. According to this model, an American Alligator with a TL of 823 cm would have a BM of 2534 kg; alternatively, an American Alligator weighing 355.3 kg would measure only 432 cm in length. Given these morphometric discrepancies, we are unable to accept this record. The largest credible size record for an American Alligator remains an individual measuring 450 cm in length and weighing 458 kg, harvested in Wilcox County, AL, in 2014. [ABSTRACT FROM AUTHOR]