Accurate identification of animal species is necessary to understand biodiversity richness, monitor endangered species, and study the impact of climate change on species distribution within a specific region. Camera traps represent a passive monitoring technique that generates millions of ecological images. The vast numbers of images drive automated ecological analysis as essential, given that manual assessment of large datasets is laborious, time-consuming, and expensive. Deep learning networks have been advanced in the last few years to solve object and species identification tasks in the computer vision domain, providing state-of-the-art results. In our work, we trained and tested machine learning models to classify three animal groups (snakes, lizards, and toads) from camera trap images. We experimented with two pretrained models, VGG16 and ResNet50, and a self-trained convolutional neural network (CNN-1) with varying CNN layers and augmentation parameters. For multiclassification, CNN-1 achieved 72% accuracy, whereas VGG16 reached 87%, and ResNet50 attained 86% accuracy. These results demonstrate that the transfer learning approach outperforms the self-trained model performance. The models showed promising results in identifying species, especially those with challenging body sizes and vegetation.

Context: Research has shown many negative effects of roads and traffic on wildlife and other biodiversity. The direct and indirect mechanisms through which roads and traffic harm animal populations vary across taxa, making mitigation of road effects a great challenge for conservation. As such, a large toolkit of species-specific management techniques may be needed to mitigate the negative effects of roads for wildlife and other biodiversity. The dunes sagebrush lizard, Sceloporus arenicolus, is a psammophilic (sand-loving) habitat specialist endemic to the Mescalero–Monahans Sandhills ecosystem of New Mexico and Texas. Within this ecosystem, roads fragment shinnery oak sand-dune landforms occupied by the species. Aims: In the present study, we conducted behaviour trials in experimental enclosures to test whether the smallest roads restrict movements of the dunes sagebrush lizard. In addition, we also conducted trials to evaluate whether a sand-filled wildlife-crossing feature could facilitate road crossing. Methods: We conducted behavioural trials on 24 dunes sagebrush lizards in our control enclosure and 22 lizards in our road and sand-filled wildlife-crossing enclosure. Movements were recorded for 15 min. The final locations at the end of each trial were analysed using circular statistics to determine whether movements in the road or the sand-filled wildlife-crossing enclosures were different from the control. Key results: Our results supported the hypotheses that dunes sagebrush lizards avoid roads and do so according to a surface-avoidance mechanism. We also found that the wildlife crossing-feature design tested here had no effect on the movements or road-crossing frequency of dunes sagebrush lizard. Conclusions: Surface-avoidance behaviour indicated that roads will persistently affect the movements of dunes sagebrush lizard, even when traffic is not present. Also, more research into an effective wildlife crossing is needed to increase connectivity of fragmented populations. Implications: These findings help evaluate the impact of roads in creating isolated populations that experience increased demographic stochasticity and, in some instances, localised extirpation in this species. Our study can guide conservation plans for the dunes sagebrush lizard, and contribute to our understanding of road effects on biodiversity in general.

The conservation of rarely encountered species is notoriously difficult mainly because of the lack of information about their natural history. This is definitely the case for the spot-tailed earless lizards (Holbrookia lacerata and H. subcaudalis). Sparse distributional records and infrequent observations at known sites were used as evidence to petition these species for protection under the Endangered Species Act. For this study, we did surveys in historic and new areas to determine the current distribution of both species. We also radio-tracked individuals from two populations to estimate movement potential and home range sizes, as well as understand habitat use. Distribution surveys indicate that H. lacerata has undergone range contraction (39%); however, H. subcaudalis was historically found in 21 counties but we only observed them in five. We found home ranges to be relatively large compared to similarly sized insectivores and at least four times larger than the similar H. maculata. Both species are inhabitants of historic grasslands, but within this habitat type they used sites that were more open compared to what was available, including areas such as row-crop agriculture and frequently mowed fields. Frequent habitat disturbance seems to be important for both species. Urbanisation, invasive woody vegetation and invasive grasses are all considered threats that may have already caused declines to both species.

Patterns of habitat use in animals can vary over time and space in predictable ways. For ectotherms, behavioral cycles are tightly linked to varying temperatures in the environment such that microhabitat availability can constrain individual performance, fitness, and life history. A long history of research on diurnal microhabitat use in lizards exists; however, comparatively little is known about nocturnal microhabitat use that might also constrain individual lizard performance, fitness, and life history. In this study, we compared diurnal and nocturnal microhabitat sites of the reticulate collared lizard (Crotaphytus reticulatus), a threatened species in Texas, to available microhabitat sites. We found significant differences between diurnal and nocturnal microhabitat characteristics, and both of these were significantly different from random microhabitat sites available. We observed that C. reticulatus used diurnal and nocturnal microhabitats with a gravel substrate and scattered boulders that were covered by a short overstory of woody and succulent plants rather than more heavily vegetated sites with dense grasses and forbs. We also observed that diurnal microhabitats were moderately open, shallow gravel slopes compared with nocturnal microhabitats that contained dense thickets of woody and succulent plants. The open, gravelly characteristics of diurnal microhabitats with occasional vegetative structure were more consistent with microhabitat descriptions of other Crotaphytids, which as a group are visual predators. However, the daily shift to dense, thorny plant cover at night appears unique to C. reticulatus among Crotaphytids in general. This study suggests that private land stewardship across the C. reticulatus distribution in Texas has benefitted the species by maintaining habitat used by the lizard, and it suggests that future conservation actions for the species will be most successful with continued engagement with private landowners.