RABIES VIRUS SEROSURVEY OF THE SMALL INDIAN MONGOOSE (URVA AUROPUNCTATA) ACROSS MULTIPLE HABITATS IN PUERTO RICO, 2014-21.

The small Indian mongoose (Urva auropuncata) is a rabies reservoir in Puerto Rico and accounts for over 70% of reported animal rabies cases annually. The presence of rabies virus-neutralizing antibodies (RVNA) is often used as a tool to measure exposure to rabies virus in wildlife populations. We conducted a serosurvey of mongooses at 11 sites representing six habitat types across Puerto Rico. We collected a serum sample from 464 individual mongooses during 2014-21. Overall, 80/464 (17.0%; 95% confidence interval, 14.1-20.9%; 55 male, 23 female, and two sexes not recorded) of individual mongooses sampled across all habitats were RVNA positive. The geometric mean (SD) RVNA titer for 80 unique seropositive animals was 0.58 (2.92) IU/mL. Our models indicated that the probability of mongooses being RVNA seropositive mostly varied by habitat, with some influence of sex in the individual-level analyses. Population-level RVNA seroprevalence is dynamic in mongoose populations, but these data may shed light on rabies virus transmission across regions to help inform rabies management activities in Puerto Rico.

Unraveling the Gut Microbiome of the Invasive Small Indian Mongoose (Urva auropunctata) in the Caribbean.

Small Indian mongooses (Urva auropunctata) are among the most pervasive predators to disrupt the native ecology on Caribbean islands and are strongly entrenched in their areas of introduction. Few studies, however, have considered the microbial ecology of such biological invasions. In this study, we investigated the gut microbiota of invasive small Indian mongooses in terms of taxonomic diversity and functional potential. To this end, we collected fecal samples from 60 free-roaming mongooses trapped in different vegetation zones on the island Saint Kitts. The core gut microbiome, assessed by 16S rRNA amplicon gene sequencing on the Ion S5TM XL platform, reflects a carnivore-like signature with a dominant abundance of Firmicutes (54.96%), followed by Proteobacteria (13.98%) and Fusobacteria (12.39%), and a relatively minor contribution of Actinobacteria (10.4%) and Bacteroidetes (6.40%). Mongooses trapped at coastal sites exhibited a higher relative abundance of Fusobacterium spp. whereas those trapped in scrubland areas were enriched in Bacteroidetes, but there was no site-specific difference in predicted metabolic properties. Between males and females, beta-diversity was not significantly different and no sex-specific strategies for energy production were observed. However, the relative abundance of Gammaproteobacteria, and more specifically, Enterobacteriaceae, was significantly higher in males. This first description of the microbial profile of small Indian mongooses provides new insights into their bioecology and can serve as a springboard to further elucidating this invasive predator's impact throughout the Caribbean.

Rapid evolution by sexual selection in a wild, invasive mammal.

Sexual selection theory provides a framework for investigating the evolution of traits involved in attracting and competing for mates. Given the sexual function of such traits, studies generally focus on individual interactions (i.e., displays and contests) in explaining trait origin and persistence. We show that ecological factors can strongly influence the adaptive value of these traits, and changes to these factors can lead to rapid evolutionary change. We compared sexually selected traits in the small Indian mongoose (Urva auropunctata) between their sparsely populated native range and four tropical islands to which they were introduced within the last 150 years and where, due to a lack of interspecific competition and predation, they have become invasive and densely populated. Because of a likely increase in encounter rate, we predicted that selection on long-distance chemical advertisement by males would relax in the introduced range. Accordingly, male, but not female, anal pads (used in scent marking) decreased in size in relation to both time since introduction and population density, and their relationship to body size and condition weakened. Concurrently, as predicted by intensified sperm competition, testis size increased following introduction. The small Indian mongoose thus experienced an inversion in the relative contributions to fitness of two sexual traits, followed by their rapid evolution in line with ecological changes.