Reproductive Biology and Natural History of the White-lipped Pit Viper (\u3cem\u3eTrimeresurus albolabris\u3c/em\u3e Gray, 1842) in Hong Kong

The White-lipped Pit Viper (Trimeresurus albolabris) is broadly distributed through South and Southeast Asia, and very little is known about the natural history of the species. In this study, we report on the ecology, demography, reproductive states, and growth rates of T. albolabris in Hong Kong, China. The sex ratio is even in Trimeresurus albolabris populations. This species displays sexual dimorphism from birth. Females attain larger sizes, and all males, including neonates, displaying a white supralabial stripe on the head and have longer relative tail lengths. Males attain sexual maturity at about 410 mm snout-vent length (SVL). Females reach sexual maturity at about 460 mm SVL, but only begin reproducing at about 520 mm SVL. Mating occurs between August to October, coinciding with the onset of spermatogenesis. Trimeresurus albolabris displays post-nuptial vitellogenesis, and long-term sperm storage in females likely occurs over the winter. Females gestate over the summer and parturition occurs in late July to August. Females reproduce once every two or more years, except for very large females that may reproduce annually. Brumation by females occurs within the first three weeks of December, but snakes will emerge to bask on sunny days. Understanding its demography and reproductive ecology can provide insights into the conservation and management of T. albolabris populations in the region and increase our understanding of sexual dimorphism, reproduction, and evolution of the cryptic Trimeresurus species complex

Activity Patterns and Habitat Use of \u3cem\u3eAnsonia hanitschi\u3c/em\u3e on Gunung Kinabalu, Sabah, Malaysia

Ansonia hanitschi is a small, stream-breeding toad endemic to Borneo. Little is known about its ecology or behavior. We documented diurnal activity patterns and habitat use, nocturnal habitat use, and body sizes of A. hanitschi near streams and in forests on Gunung Kinabalu, Sabah, Malaysia, on the island of Borneo. We identified 12 unique diurnal behaviors in this species. Ansonia hanitschi are sit-and-wait predators that spend \u3e 75% of their time during the day, on average, sitting inactive in shady areas within 1.2 m of the stream. Observed toads spent 6% of their time jumping, 4% of their time crawling, and 4% of their time engaging in an arm waving behavior. During the day, individuals were more commonly found on smaller sand and cobble substrates. At night, individuals rested on the leaves of slender-stemmed plants within 2 m of the ground surface and at a mean distance of 2.3 m from the stream edge. Female snout-vent length averaged 32 mm, and gravid females ranged from 28 to 35 mm in length. We found that 88% of females near the stream during the day were gravid, compared with 80% of females away from streams at night. Our observations indicate that this species is diurnal and retreats to the leaves of small plants at night, possibly to avoid predation

The heterogeneous herd : drivers of close‐contact variation in African buffalo and implications for pathogen invasion

Many infectious pathogens are shared through social interactions, and examining host connectivity has offered valuable insights for understanding patterns of pathogen transmission across wildlife species. African buffalo are social ungulates and important reservoirs of directly‐transmitted pathogens that impact numerous wildlife and livestock species. Here, we analyzed African buffalo social networks to quantify variation in close contacts, examined drivers of contact heterogeneity, and investigated how the observed contact patterns affect pathogen invasion likelihoods for a wild social ungulate. We collected continuous association data using proximity collars and sampled host traits approximately every 2 months during a 15‐month study period in Kruger National Park, South Africa. Although the observed herd was well connected, with most individuals contacting each other during each bimonthly interval, our analyses revealed striking heterogeneity in close‐contact associations among herd members. Network analysis showed that individual connectivity was stable over time and that individual age, sex, reproductive status, and pairwise genetic relatedness were important predictors of buffalo connectivity. Calves were the most connected members of the herd, and adult males were the least connected. These findings highlight the role susceptible calves may play in the transmission of pathogens within the herd. We also demonstrate that, at time scales relevant to infectious pathogens found in nature, the observed level of connectivity affects pathogen invasion likelihoods for a wide range of infectious periods and transmissibilities. Ultimately, our study identifies key predictors of social connectivity in a social ungulate and illustrates how contact heterogeneity, even within a highly connected herd, can shape pathogen invasion likelihoods

Emergent Properties of Animal Social Networks: Five Stories in Five Systems

Animals aggregate and interact in nonuniform and nonrandom patterns, which lead to group level characteristics that have important evolutionary and ecological consequences. Network analysis provides a useful conceptual framework for linking animal interactions at all scales from dyads to communities, to populations and ecosystems. Despite exciting theoretical and applied advances in the study of animal social networks in the past decade, however, this field is still in its relative infancy. A host of unanswered questions remain about the processes that generate and maintain animal social networks, as well as their consequences and applications in real-world problems. In this dissertation, I examine four aspects of animal social networks and their emergent properties in four different systems. In Chapter 2, I utilize an eastern spadefoot spatial proximity network to ask how landscape configuration is related to spatial patterns of these frogs in the upland (i.e., non-wetland) environment. I found that despite their solitary lifestyle outside of explosive breeding bouts, eastern spadefoots assort by both sex and size, as well as by size within demographic category. I determined that the spatial configuration of extremely ephemeral wetlands, which last ~2 weeks a year, may drive life history stage assortativity, as well as size assortativity for males up to 150 m away from wetlands. Despite their small size and extreme ephemerality, these breeding wetlands may have significant impact on the conspecific associations of eastern spadefoots and their spatial arrangement on the landscape. In Chapter 3, I use a longitudinal dataset of African buffalo contact networks obtained from proximity collar data, to quantify the nuanced relationships between contact heterogeneity (exposure) and infection risk (incidence) across a suite of pathogens. Co-infection was the most consistent predictor of infection risk, although the strength of some pathogen interactions was modulated by contact heterogeneity. Frequency-defined networks were a better predictor of infection risk than duration-defined networks. Relationships between contact heterogeneity and infection risk are understood only in the light of coinfection within multi-pathogen hosts, and indirect connections between individuals. In Chapter 4, I draw from information theoretic and statistical learning tools to examine a multi-decade public dataset of global wildlife trade to identify fundamental drivers of wildlife trade topology. Using network portrait divergence as a metric for comparing networks, I determined that taxonomic characteristics of a species (especially genus) overwhelmingly drove network structure similarity between species, followed by economic metrics of income inequality among trading countries. The effects of geographic distribution on trade structure were modest, while the effects of conservation listings were almost negligible. Taxa identified as ‘beacon species’ (species with trade structure most representative of the overall trade) spanned many taxonomic classifications, conservation statuses, and geographic ranges, although reptiles were under-represented. In Chapter 5, I pose a ten-year challenge to the field of herpetology (the study of amphibians and reptiles) to match academic DEI (diversity, equity, inclusion) efforts with measurable change using an inclusive definition of authorship networks and influence. I detail an analysis I will conduct on authorship support networks in ten years from the publication of this chapter, using data from an online public repository of self-reported herpetologists around the globe who identify as women. In Chapter 6, I draw from complex adaptive systems theories to understanding equity, social justice, and inclusion as emergent properties, not components, of institutions. Using concepts such as poverty traps and resilience thinking, I describe how institutions will continue to be trapped in ‘inequity wells’ without changing fundamentals of how diversity, equity and inclusion work is approached and conducted, and pathways for escaping these traps. In chapter 7, the general conclusion, I review the results and conclusions of Chapters 2-6 within the context of key knowledge gaps in various fields

Snakebite Management and One Health in Asia Using an Integrated Historical, Social, And Ecological Framework

ABSTRACT. Snakebite envenomation continues to contribute to high fatality and morbidity rates across Asia. Yet snake bite is one of many outcomes due to human-snake conflicts, which themselves are only one type of human-snake relationship among the diversity of such interactions. We propose that human-snake relationships need to be explored from a perspective integrative of history, ecology, and culture in order to adequately and holistically address snake bite. In order to contextualize this concept within a language already understood in conservation research, we characterize and develop four interconnected themes defining human-snake relationships as a social ecological system. By breaking down the multifaceted nature of human-snake relationships under a social ecological systems framework, we explore its applicability in contributing to a unified strategy, drawing from both social and natural sciences for ending the snakebite crisis.</jats:p

Reticulated Python Diet and Sarcocystis infection

Lengths, locations, diet and presence of Sarcocystis infection in reticulated pythons captured between June 2009 and May 201

Data from: Pythons, parasites and pests: anthropogenic impacts on Sarcocystis (Sarcocystidae) transmission in a multi-host system

Parasites are essential components of ecosystems and can be instrumental in maintaining host diversity and populations; however, their role in trophic interactions has often been overlooked. Three apicomplexan parasite species of Sarcocystis (S. singaporensis, S. zamani, and S. villivillosi) use the reticulated python as their definitive hosts and several species within the Rattus genus as intermediate hosts, and they form a system useful for studying interactions between host–parasite and predator–prey relationships, as well as anthropogenic impacts on parasite transmission. Based on predictions from a 1998 survey, which detected an inverse relationship between urban development and Sarcocystis infection in Rattus, we tested the hypothesis that Sarcocystis transmission in Singapore will decrease over time due to anthropogenic activities. Despite a large proportion of the reticulated python diet consisting of Rattus species at all sizes of pythons, Sarcocystis infection rates decreased from 1998 to 2010. Pythons found in industrial areas had lower Sarcocystis infection rates, particularly in the western industrial area of Singapore Island. Average python size also decreased, with implications that we predict may disrupt host–parasite relationships. Anthropogenic activities such as habitat modification, fragmentation, and systematic removal and translocation of pythons have negative impacts on Sarcocystis transmission in Singapore, which in turn may augment pest rat populations. Trends observed may ultimately have negative impacts on human health and biodiversity in the region

Assortative mixing in eastern spadefoot (Scaphiopus holbrookii) spatial networks is driven by landscape features

Abstract Biotic and abiotic factors drive assortative mixing (preference for or sorting with individuals with similar characteristics) in animal populations on a landscape, with implications for dispersal, population structuring, and other ecological and evolutionary processes. However, patterns and generative mechanisms of assortative mixing are overlooked in amphibians outside of specific life history events such as reproduction. The aims of this project were to determine whether there is assortative mixing by size and life history category in eastern spadefoots (Scaphiopus holbrookii), whether these patterns are preserved across time and spatial scale, and quantify the nature and relative role of various habitat and soil features in explaining observed patterns in spatial organization of individuals. We conducted field surveys in southeastern Virginia, USA, in 2016 and 2017 during nonbreeding periods to create spatial networks of S. holbrookii. We quantified spatial assortativity by size and life history stage and evaluated the roles of multiple landscape features in explaining spatial organization of S. holbrookii. We found that S. holbrookii sorted spatially by size and sex outside of breeding periods, with juveniles and adults less likely to sort with each other. Within each life history stage, S. holbrookii sorted by size. These patterns were similar across time and spatial scale. Soil and habitat types had no effect on assortativity. Instead, the distance to nearest breeding pool, wetland, and meadow were related to life history stage assortativity, as well as size assortativity in males and subadults. Adult males and females displayed affinity for breeding pools and meadows and avoidance of other types of wetlands, while subadults and nonbreeding adults showed opposite patterns compared with breeding adults. Our results indicate that (1) previously established guidelines for the minimum size of buffer zones to protect wetland‐breeding amphibians may be inadequate, (2) nonbreeding wetlands may be important core habitat for subadults, and (3) the upland spatial organization of amphibians may be used to predict locations of undetected breeding pools