Population Viability of Nonnative Mediterranean House Geckos (Hemidactylus turcicus) at an Urban Site Near the Northern Invasion Front

Golf course living leads to a diet shift for American alligators

Human-driven land use change can fundamentally alter ecological communities, especially the diversity and abundance of large-bodied predators. Yet, despite the important roles large-bodied predators play in structuring communities through feeding, there have been only a few investigations of how the feeding patterns of large-bodied predators change in human-dominated landscapes. One group of large-bodied predators that has been largely overlooked in the context of land use change is the crocodilians. To help fill these gaps, we studied the feeding patterns of juvenile American alligators (Alligator mississippiensis) on neighboring barrier islands on the southeast coast of Georgia, USA. Jekyll Island has multiple golf courses and substantial amounts of human activity, while Sapelo Island does not have any golf courses and a much smaller amount of human activity. We found that juvenile alligator populations on both islands ate the same types of prey but in vastly different quantities. Sapelo Island alligators primarily consumed crustaceans while alligators that lived on Jekyll Island's golf courses ate mostly insects/arachnids. Furthermore, the Jekyll Island alligators exhibited a much more generalist feeding pattern (individuals mostly ate the same types of prey in the same quantities) than the more specialized Sapelo Island alligators (diets were more varied across individuals). The most likely explanation for our results is that alligators living on golf courses have different habitat use patterns and have access to different prey communities relative to alligators in more natural habitats. Thus, land use change can strongly alter the feeding patterns of large-bodied predators and, as a result, may affect their body condition, exposure to human-made chemicals, and role within ecological communities.

The Application of Public Art Design Based on Digital Technology in Urban Landscape Environmental Monitoring

Public art (PA) is a powerful tool for enhancing the environment in public spaces since it not only relieves the oppression caused by urban architecture but also enhances and beautifies urban public spaces. As DT (digital technology) develops so quickly nowadays, it offers PA significant technological assistance to achieve new functions, and changes in modern people's aesthetic preferences and psychological makeup also present new demands for PA. This essay explores the use of PA design in the creation of urban landscapes from the viewpoint of DT. In order to do this, this paper suggests a method for measuring the environmental impact of urban landscapes that combines landscape measurement and semantic assessment. Full-connection algorithm and greedy algorithm are introduced to identify urban functional types with high-dimensional characteristics for the boundary tree classification model of high-dimensional feature classification. The findings indicate that the public service area's producer and user accuracy are, respectively, 0.8783 and 0.7833. It offers a fresh concept for the identification of urban functional zones while solving the issues of low identification efficiency and poor accuracy.

Parameter affecting the I3S algorithm reliability: how does correcting for body curvature affect individual recognition?

Abstract ContextIn recent years, multiple computer algorithms, which allow us to perform photographic capture–recapture analysis, have been developed. Their massive application, also in wildlife demographic and ecological studies, is largely due to the fact that these tools are non-invasive and non-expensive. To maximise the performance of these programs, it is essential to have a good photo-standardisation so as to avoid bias in the results. A lot of ‘non-standardised’ photos are not usable for capture–mark–recapture (CMR) analysis, entailing the loss of potentially exploitable data. AimsNo study has accurately investigated the effect of the corporal bending of an animal on the performance of the interactive individual identification system (I3S) algorithm. For this reason, we assessed the effect of this photographic standardisation parameter (PSP) on the reliability of this algorithm. MethodsWe assessed the effect of the body position of Triturus cristatus between capture and recapture photos on the error rates of a group of standardised pictures, performing a generalised linear model analysis. We have also evaluated the effect of image correction (i.e. straightening of newts’ bodies) on the error rates (expressed by false rejection rates, FRRs) of the first (standardised) photo-group (G1) and of a non-standardised photo-group (G2). To perform this, we used I3S-Pattern+ for the photo-matching analysis and I3S-Straighten for the correction of the pictures. Key resultsThe difference of body angles between capture and recapture pictures had a significantly increased error rates in G1. Digital correction of body bending reduced the error rates. For the pictures where corporal bending was not digitally corrected, the top 20 FRRs were 0.38 and 0.33 for G1 and G2 respectively. For corrected (straightened) pictures, the top 20 FRRs were 0.026 and 0.15. ConclusionsOur findings showed a high impact of newt corporal bending and photographic treatment on the I3S algorithm reliability. ImplicationsWe provide some recommendations to avoid or minimise the effects of this PSP and improve photo-standardisation during and after CMR studies of species of Urodela. In this way, pictures that would be unusable in photo-matching software under current practice could become usable, increasing the available data to conduct a survey.

Eurythermic Sprint and Immune Thermal Performance and Ecology of an Exotic Lizard at Its Northern Invasion Front

AbstractThermal performance of immunity has been relatively understudied in ectotherms, especially in the context of invasive species or in relation to other fitness-related traits and thermoregulatory patterns in the field. For reptiles, thermal biology is a primary factor determining physiological performance and population viability, and suboptimal thermal conditions may limit the expansion of exotic species along the edges of their invasion fronts. This study examined thermoregulatory ecology and thermal performance of immunity and sprinting in a population of Mediterranean geckos (Hemidactylus turcicus) at the northern edge of their invasion front in a temperate zone of the United States. In the field, we quantified temperatures of geckos of varied age classes in relation to air, wall, and refugia temperatures. We also quantified temperature-dependent sprint performance and immune function in field-collected geckos to detail thermal performance patterns that may contribute to the capacity for this species to invade cool climates. Although body temperature (T_b) of wild-caught geckos correlated with wall temperature, average T_b exhibited wide distributions, suggesting eurythermy. Furthermore, the thermal performance of immune swelling responses to phytohemagglutinin injections and sprinting was optimized over a similarly wide temperature range that overlapped with the field T_b's that suggest eurythermy in this species. The wide thermal performance breadths in these traits could buffer against variation in factors such as pathogen exposure and environmental temperatures that could otherwise suppress functional performance. Thus, eurythermy of sprint and immune performance may facilitate the invasive potential of H. turcicus.

Critical thermal tolerance of invasion: Comparative niche breadth of two invasive lizards

Understanding the evolution of thermal tolerance in ectotherms is particularly important given the current period of rapid change in the environment and thermal climate. Specifically, introduced species have the potential to evolve different thermal tolerances than native populations due to rapid evolution and novel selection pressures. Our study examined critical thermal tolerance in two introduced lizard species, the European wall lizard (Podarcis muralis) in Ohio and Kentucky, and the Mediterranean gecko (Hemidactylus turcicus) from Texas through Alabama. We tested the hypotheses that critical thermal maximum, minimum, and breadth varies among introduced populations of P. muralis and H. turcicus, and that critical thermal tolerance broadens when moving away from the introduction site, because dispersal across novel environments may remove dispersers with narrow thermal tolerances. We found that among P. muralis populations, CT_min and thermal breadth were significantly different. Specifically, when moving away from the introduction site, lizards exhibited increased cold tolerance and broader thermal breadth. Variability in thermal parameters were also lowest at the site closest to the introduction point in P. muralis. In contrast, H. turcicus had no significant differences in critical thermal minimum, maximum, or breadth among sites, or with respect to distance from introduction point. However, we did find little variability in thermal maximum, compared to greater variability in overall tolerance and critical thermal minimums. Thus, this study shows that selection on thermal tolerance and dispersal characteristics occur in novel climatic environments. Understanding how thermal tolerance changes over time can aid in predicting establishment and movement of introduced species, with applications for native species during a time of global climatic change.