SNAKE ASSEMBLAGE STRUCTURES AND SEASONAL ACTIVITY PATTERNS ON A MILITARY BASE IN SOUTH-CENTRAL PENNSYLVANIA:: LAND MANAGEMENT IMPLICATIONS FOR SNAKE CONSERVATION

We ascertained the assemblage structures of snakes occurring in a mixed habitat matrix of natural and disturbed habitats during 2008–2011 at Letterkenny Army Depot (LEAD), a 7200 ha U.S. Army base in south-central Pennsylvania, to understand the patterns of species abundance as they related to habitat type of managed lands. We detected eight species in 12 sites comprising natural and disturbed habitats of wetlands, forest, and thicket and open fields. The Common Gartersnake (Thamnophis sirtalis) occurred in the most sites, the Red-bellied Snake (Storeria occipitomaculata) was the rarest species in the study. Two to six species occupied each site and were distributed unevenly. Dynamics of assemblages could be explained in part by habitat and also by the presence of the North American Racer (Coluber constrictor). All species for which data were available exhibited a unimodal pattern to their seasonal activity (mostly May and June); however, seasonal activity peaks differed between sexes. Sex ratios varied among species but were consistently female–biased in the Common Gartersnake and Ring-necked Snake (Diadophis punctatus) in Pennsylvania and surrounding areas. As elsewhere in Pennsylvania and the Northeast, body sizes of adults were larger for species syntopic with the North American Racer than for species not syntopic with this potential predator. We found a degree of predictability with respect to snake assemblage dynamics among habitats at LEAD, which in turn can prove useful in resource management of this large and protected human-impacted system

GEOGRAPHIC VARIATION IN SELECTED LIFE HISTORY TRAITS OF THE EASTERN NARROWMOUTH TOAD, GASTROPHRYNE CAROLINENSIS (HOLBROOK, 1836), ALONG THE NORTHEASTERN EDGE OF ITS GEOGRAPHIC RANGE

We examined the Eastern Narrowmouth Toad,Gastrophryne carolinensis, along the northeastern edge of its geographic range in Virginia to determine the extent to which selected life history traits in this region adhered to patterns associated with a latitudinal gradient in this species. As in studies elsewhere, a significant difference in mean adult body size between males (28.3 mm SVL) and females (30.1 mm SVL) was typical of this species as was the absence of a relationship between clutch size and female body size. Mean body sizes of both sexes appeared larger in northern populations than southern counterparts. Geographically predictable, the breeding season in Virginia was severely curtailed in response to climatic constraints despite extended fertility, and its breeding activity peaked in mid-summer as it has been reported to do throughout its geographic range. Thus, along the northern edge of its geographic range, the Eastern Narrowmouth Toad retains its ability breed for a longer season despite present climatic constraints, an advantage in the face of climate change that could alter timing and duration of acceptable breeding atmospheric conditions

Artificial intelligence reporting guidelines: what the pediatric radiologist needs to know

There has been an exponential rise in artificial intelligence (AI) research in imaging in recent years. While the dissemination of study data that has the potential to improve clinical practice is welcomed, the level of detail included in early AI research reporting has been highly variable and inconsistent, particularly when compared to more traditional clinical research. However, inclusion checklists are now commonly available and accessible to those writing or reviewing clinical research papers. AI-specific reporting guidelines also exist and include distinct requirements, but these can be daunting for radiologists new to the field. Given that pediatric radiology is a specialty faced with workforce shortages and an ever-increasing workload, AI could help by offering solutions to time-consuming tasks, thereby improving workflow efficiency and democratizing access to specialist opinion. As a result, pediatric radiologists are expected to be increasingly leading and contributing to AI imaging research, and researchers and clinicians alike should feel confident that the findings reported are presented in a transparent way, with sufficient detail to understand how they apply to wider clinical practice. In this review, we describe two of the most clinically relevant and available reporting guidelines to help increase awareness and engage the pediatric radiologist in conducting AI imaging research. This guide should also be useful for those reading and reviewing AI imaging research and as a checklist with examples of what to expect

Biology and Impacts of Pacific Island Invasive Species: 8. Eleutherodactylus planirostris, the Greenhouse Frog (Anura: Eleutherodactylidae)

The greenhouse frog, Eleutherodactylus planirostris, is a direct-developing (i.e., no aquatic stage) frog native to Cuba and the Bahamas. It was introduced to Hawaii via nursery plants in the early 1990s and then subsequently from Hawaii to Guam in 2003. The greenhouse frog is now widespread on five Hawaiian Islands and Guam. Infestations are often overlooked due to the frog’s quiet calls, small size, and cryptic behavior, and this likely contributes to its spread. Because the greenhouse frog is an insectivore, introductions may reduce invertebrates. In Hawaii, the greenhouse frog primarily consumes ants, mites, and springtails, and obtains densities of up to 12,500 frogs ha-1. At this density, it is estimated that they can consume up to 129,000 invertebrates ha-1 night-1. They are a food source for the non-native brown tree snake in Guam and may be a food source for other non-native species. They may also compete with other insectivores for available prey. The greatest direct economic impacts of the invasions are to the nursery trade that must treat infested shipments. Although various control methods have been developed to control frogs in Hawaii, and citric acid, in particular, is effective in reducing greenhouse frogs, the frog’s inconspicuous nature often prevents populations from being identified and managed

GREEN IGUANAS (\u3ci\u3eIGUANA IGUANA\u3c/i\u3e): THE UNINTENDED CONSEQUENCE OF SOUND WILDLIFE MANAGEMENT PRACTICES IN A SOUTH FLORIDA PARK

We examined the demographic response of the Green Iguana (Iguana iguana) to the removal of Raccoons in an urban maritime state park in southern Florida. The rapid growth of iguanas to sexual maturity in an underexploited, if not vacant, niche contributed to the rapid recruitment of a large and growing population during the four and one half years since removal of its limiting predator. We proffer here that at sites where Green Iguanas and high density Raccoons are syntopic, future Raccoon removal programs should be concurrent with an equally concerted effort to remove resident Green Iguanas. In this fashion, by replacing one limiting predator with another, a population explosion can be prevented and an advantage can be maintained in the local control of this exotic species

Fine-Scale Genetic Structure Arises during Range Expansion of an Invasive Gecko

Processes of range expansion are increasingly important in light of current concerns about invasive species and range shifts due to climate change. Theoretical studies suggest that genetic structuring may occur during range expansion. Ephemeral genetic structure can have important evolutionary implications, such as propagating genetic changes along the wave front of expansion, yet few studies have shown evidence of such structure. We tested the hypothesis that genetic structure arises during range expansion in Hemidactylus mabouia, a nocturnal African gecko recently introduced to Florida, USA. Twelve highly variable microsatellite loci were used to screen 418 individuals collected from 43 locations from four sampling sites across Florida, representing a gradient from earlier (∼1990s) to very recent colonization. We found earlier colonized locations had little detectable genetic structure and higher allelic richness than more recently colonized locations. Genetic structuring was pronounced among locations at spatial scales of tens to hundreds of meters near the leading edge of range expansion. Despite the rapid pace of range expansion in this introduced gecko, dispersal is limited among many suitable habitat patches. Fine-scale genetic structure is likely the result of founder effects during colonization of suitable habitat patches. It may be obscured over time and by scale-dependent modes of dispersal. Further studies are needed to determine if such genetic structure affects adaptation and trait evolution in range expansions and range shifts

A far-ultraviolet-driven photoevaporation flow observed in a protoplanetary disk.

Most low-mass stars form in stellar clusters that also contain massive stars, which are sources of far-ultraviolet (FUV) radiation. Theoretical models predict that this FUV radiation produces photodissociation regions (PDRs) on the surfaces of protoplanetary disks around low-mass stars, which affects planet formation within the disks. We report James Webb Space Telescope and Atacama Large Millimeter Array observations of a FUV-irradiated protoplanetary disk in the Orion Nebula. Emission lines are detected from the PDR; modeling their kinematics and excitation allowed us to constrain the physical conditions within the gas. We quantified the mass-loss rate induced by the FUV irradiation and found that it is sufficient to remove gas from the disk in less than a million years. This is rapid enough to affect giant planet formation in the disk