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Subsidized predators are animals whose populations proliferate through association with humans. As subsidized predators, birds in the family Corvidae (Corvus spp., crows and ravens) pose an additive mortality threat to turtle eggs, juveniles, and, in some cases, adults. In this synthesis, I (1) review published and unpublished case studies of corvids as predators of chelonians, (2) examine regional population trends of corvids relative to the status of co-occurring chelonian species, and (3) evaluate our current understanding of subsidized corvids as threats to chelonians. Hyperpredation of chelonians by corvids is geographically widespread, locally severe where and when predation occurs, facilitated by anthropogenic subsidies (e.g., food, water, and perching, nesting, and roosting sites) and linear corridors (e.g., roads, electrical infrastructure), commonly associated with nesting corvids as predators, and co-occurring with corvid population increases. Hyperpredation by corvids appears to affect demographically sensitive stages of chelonian populations (juveniles and reproductive females) and very likely has long-term detrimental consequences given the slow life history of chelonians. The threat posed to chelonian populations by subsidized corvids is more widespread than currently recognized on the basis of substantial regional increases in corvid populations, the underreporting of predation observations, and the broad geographic areas over which hyperpredation of chelonians is occurring. [ABSTRACT FROM AUTHOR]

Temperate ectotherms have responded to recent environmental change, likely due to the direct and indirect effects of temperature on key life cycle events. Yet, a substantial number of ectotherms are fossorial, spending the vast majority of their lives in subterranean microhabitats that are assumed to be buffered against environmental change. Here, we examine whether seasonal climatic conditions influence body condition (a measure of general health and vigor), reproductive output, and breeding phenology in a northern population of fossorial salamander (Spotted Salamander, Ambystoma maculatum). We found that breeding body condition declined over a 12‐year monitoring period (2008–2019) with warmer summer and autumn temperatures at least partly responsible for the observed decline in body condition. Our findings are consistent with the hypothesis that elevated metabolism drives the negative association between temperature and condition. Population‐level reproduction, assessed via egg mass counts, showed high interannual variation and was weakly influenced by autumn temperatures. Salamander breeding phenology was strongly correlated with lake ice melt but showed no long‐term temporal trend (1986–2019). Climatic warming in the region, which has been and is forecasted to be strongest in the summer and autumn, is predicted to lead to a 5%–27% decline in salamander body condition under realistic near‐future climate scenarios. Although the subterranean environment offers a thermal buffer, the observed decline in condition and relatively strong effect of summer temperature on body condition suggest that fossorial salamanders are sensitive to the effects of a warming climate. Given the diversity of fossorial taxa, heightened attention to the vulnerability of subterranean microhabitat refugia and their inhabitants is warranted amid global climatic change. [ABSTRACT FROM AUTHOR]

Sexually coercive reproductive tactics are widespread among animals, where one sex employs specialized structures, called sexual weapons, to harass, intimidate, and/or physically force the other sex to mate. Painted turtles (Chrysemys picta) have been extremely well-studied over the last two centuries, and their mating system has been described as female choice based on male courtship display. The present study arises from observation that males seemingly have more protracted and serrated anterior marginal scutes than females. We hypothesized that the anterior carapace is sexually dimorphic, and that this morphology is a weapon used by males in coercive mating. We quantified anterior carapacial morphology using geometric morphometric analysis of digital photographs, drawing on samples of painted turtles from North American museum collections and our field site in Algonquin Provincial Park. We found that the anterior carapace of males had a significantly more serrated and projected shape compared to females, consistent with the sexual weapon hypothesis. Additionally, anterior carapacial shape was more strongly related to body size in males. Behavioural field observations strongly suggest that males use this morphology as a weapon to harm females during reproduction. The present study complements and strengthens the recent hypothesis that male painted turtles engage in coercion as an alternative reproductive tactic, questioning the long-understood paradigm of exclusive female choice in this well-studied species. Our study invites new avenues of research on the evolution of female harm in a system with extreme selection on female longevity and for which operational sex ratios vary among populations. Further, our work underlines how basic natural history observations can transform our understanding of well-studied systems. [ABSTRACT FROM AUTHOR]

The article discusses a study that reports on the longevity and captive husbandry of a male Uromastyx dispar maliensis, a spiny-tailed agama, for a period of 19 years and 5 months. The lizard was maintained on a sand substrate in an enclosure with stacks and crevices of shale rock, and was fed a diet of mixed vegetables, leafy greens, miscellaneous vegetables, and animal protein. This study provides valuable information on the husbandry and longevity of Uromastyx in captivity.

We examined captures of Painted Turtle (Chrysemys picta) in Algonquin Provincial Park, Ontario, Canada, during the understudied summer-autumn transition period (August-September). The proportion of captured male turtles increased relative to the proportion of females during the late summer and early autumn sampling period, leading to male-biased capture rates in a population with a strongly female-biased sex ratio. We consider explanations for the capture bias in relation to sex-specific activity patterns and briefly discuss the implications of sampling period on the outcome of population structure studies. [ABSTRACT FROM AUTHOR]

The ability to identify the sex of animals accurately is important in population studies. Emydid turtles (Testudines: Emydidae) demonstrate a number of sexually dimorphic characters, including head (cranial) size and structure. Field observations from a long-term study of midland painted turtles ( Chrysemys picta marginata) in Algonquin Provincial Park, Ontario, Canada, suggested distinct differences in external head morphology between the sexes. We evaluated these putative sexual differences in C. picta head morphology by conducting a visual questionnaire involving human observers of varying levels of experience (novice, beginner, intermediate, and advanced). Observers were capable of distinguishing the sexes based solely on head morphology with a high degree of accuracy (between 79% and 86% success) across experience levels. Observers identified head shape as a defining character distinguishing the sexes. We suggest that visual questionnaires are a quantifiable method of assessing dimorphic characters that can be used in addition to traditional morphometrics or geometric morphometrics to demonstrate a visual, rather than simply statistical, difference among characters and sexes. Despite the breadth of research conducted on C. picta, our study is among the first to describe, assess, and discuss the functional significance of head dimorphism in this model species. [ABSTRACT FROM AUTHOR]

We report summer caching of a partial carcass of a White-tailed Deer (Odocoileus virginianus) fawn by an Eastern Wolf (Canis sp. cf. lycaon) in a Sphagnum bog in Algonquin Provincial Park, Ontario, Canada. The microhabitat conditions in bogs (i.e., low temperature, acidity, and organochemical compounds) likely inhibit food spoilage, making bogs potentially important sites for food caching. Wolves in Algonquin Park experience low summer food availability and high pup mortality from starvation. Caches likely serve as necessary reserve food stores for adults and pups. Recent research has shown that wetland habitats are important den and rendezvous sites for Algonquin Eastern Wolves based on prey availability and, we suggest, perhaps for food storage and accessibility. This caching behaviour was recorded on video. We recommend that future research investigate Eastern Wolf selection of food-caching sites, as a complement to other spatial ecology studies. [ABSTRACT FROM AUTHOR]

Kyphosis, a congenital humpback condition of the spinal column, has been reported across a broad range of chelonian taxa. These reports are often of single observations and lack background information about the history of the animal(s) involved. A kyphotic female midland painted turtle ( Chrysemys picta marginata) reported herein is a member of a long-term mark-recapture study in Algonquin Park (Ontario, Canada), providing a unique opportunity to document life-history characters of a kyphotic turtle over 18 yrs and draw comparisons to other members of her cohort and population. Despite her spinal deformity, the somatic growth, body size, age at sexual maturity, and reproduction of the kyphotic female have been similar to those of nonkyphotic females in our long-term study population, suggesting that the condition has not compromised her fitness. [ABSTRACT FROM AUTHOR]

We compare diet and feeding behaviour of Snapping Turtles (Chelydra serpentina) and Midland Painted Turtles (Chrysemys picta marginata) in Algonquin Provincial Park, Ontario, Canada. We observed young Chelydra and Chrysemys turtles feeding on insect and amphibian larvae in ephemeral ponds, adult Chrysemys terrestrially foraging on odonate larvae, and adult Chelydra consuming aquatic vegetation and seeds. These and other observations highlight the importance of seasonally available habitat and food for juvenile turtles. We also discuss the evidence for, and importance of, turtles as seed-dispersal agents for aquatic vegetation. Illustrative video recordings accompany our dietary observations. [ABSTRACT FROM AUTHOR]

Ictalurid catfishes have sharp spines on their dorsal and pectoral fins that can be hazardous to predators. The pectoral spines may lock in an abducted position, effectively increasing body size and preventing ingestion by gape-limited predators. Further, sharp spines may injure predators or increase prey handling time, affording catfish opportunities for escape. As part of a long-term mark-recapture study of turtle ecology in Algonquin Provincial Park, Ontario, Canada, we documented the presence of Brown Bullheads, Ameiurus nebulosus, in the diet of Snapping Turtles, Chelydra serpentina. Here, we report on injuries inflicted by the pectoral spines of bullheads on Snapping Turtles during predator-prey interactions and provide a brief literature review of the functional significance and potential dangers of catfish pectoral spines to predators. [ABSTRACT FROM AUTHOR]

The article presents a study on the wounding, conspecific aggression, and reproductive behavior of Pseudemys (P.) concinna (River cooter) which was observed while snorkeling Poe Spring, Alachua County, Florida on March 4, 2020. Topics include probable explanation for the observed wounds of the P. concinna, observations on reproductive behavior in P. conccina, and indication that reproductive behaviors and social organization of these animals are more complex than currently appreciated.

In the original publication of the article, Fig. 2 and Fig. 3 were published with an error. [ABSTRACT FROM AUTHOR]

There is only one I stigma i (that of plants, the pollen-receiving organ!) associated with having food on your face, at least where pollen and island-dwelling lizards are concerned. This ornate day gecko ( I Phelsuma ornata i ) on Round Island, Mauritius, hopped from plant to plant, enthusiastically feeding on the nectar of endemic plants, and transporting pollen in the process. [Extracted from the article]

To decide whether to remain underground or to emerge from overwintering, fossorial ectotherms simultaneously process environmental, gravitational and circannual migratory cues. Here, we provide an experimental framework to study the behaviour of fossorial ectotherms during soil temperature inversion - a phenomenon that marks the transition between winter and spring - based on three non-mutually exclusive hypotheses (thermoregulation, negative geotaxis and migration restlessness). Using a vertical thermal gradient, we evaluated how temperature selection (Tsel), activity and vertical position selection differed under simulated soil temperature inversion (contrasting the active versus overwintering thermal gradients) in the spotted salamander (Ambystoma maculatum). Salamanders had different Tsel and activity levels between gradients, but selected similar heights regardless of thermal gradient orientation. Negative geotaxis may explain responses to changes in vertical thermal gradient orientation, with migratory restlessness contributing to differences in activity levels. Ultimately, our work should benefit those who aim to better understand the biology of fossorial ectotherms., Competing Interests: Competing interests The authors declare no competing or financial interests., (© 2024. Published by The Company of Biologists Ltd.)