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Demographic factors are fundamental in shaping infectious disease dynamics. Aspects of populations that create structure, like age and sex, can affect patterns of transmission, infection intensity and population outcomes. However, studies rarely link these processes from individual to population-scale effects. Moreover, the mechanisms underlying demographic differences in disease are frequently unclear. Here, we explore sex-biased infections for a multi-host fungal disease of bats, white-nose syndrome, and link disease-associated mortality between sexes, the distortion of sex ratios and the potential mechanisms underlying sex differences in infection. We collected data on host traits, infection intensity and survival of five bat species at 42 sites across seven years. We found females were more infected than males for all five species. Females also had lower apparent survival over winter and accounted for a smaller proportion of populations over time. Notably, female-biased infections were evident by early hibernation and likely driven by sex-based differences in autumn mating behaviour. Male bats were more active during autumn which likely reduced replication of the cool-growing fungus. Higher disease impacts in female bats may have cascading effects on bat populations beyond the hibernation season by limiting recruitment and increasing the risk of Allee effects.

The Black-footed Ferret Recovery Implementation Team Executive Committee is conducting a project to develop, and (hopefully) eventually implement, a plague vaccination program for prairie dogs. The project is a component of the Western Association of Fish and Wildlife Agencies Grasslands Conservation Initiative. An effective, field-worthy vaccine against plague could be the biggest breakthrough in recovery efforts for the black-footed ferret since the 1981 rediscovery of wild ferrets near Meeteetse, Wyoming. If proven efficacious, the vaccine could help agencies and stakeholder cooperators maintain specific populations of prairie dogs at robust levels, thus enhancing range-wide conservation of those species, as well recovery of the ferret, while enabling control of other prairie dog populations to resolve site-specific agricultural and human health concerns. The results of laboratory and field-testing in the early stages of developing this vaccine are preliminary but mostly encouraging. A plan for broad-scale application is being developed for possible use when testing has been completed and (if warranted) the vaccine is registered for governmental use. An overview of all aspects of the project is discussed.

Clostridium botulinum type C is an anaerobic, spore-forming bacterium found naturally in the sediments of lakes and marshes. A nested PCR was devised for the detection of C. botulinum type C1 toxin gene in sediments obtained from wetlands where avian botulism outbreaks had or had not occurred. The C1 toxin gene was detected in 16 of 18 sites, indicating both the widespread distribution of C. botulinum type C in wetland sediments and the sensitivity of the detection assay.

Utah prairie dogs (Cynomys parvidens) are federally threatened due to eradication campaigns, habitat destruction, and outbreaks of plague. Today, Utah prairie dogs exist in small, isolated populations, making them less demographically stable and more susceptible to erosion of genetic variation by genetic drift. We characterized patterns of genetic structure at neutral and putatively adaptive loci in order to evaluate the relative effects of genetic drift and local adaptation on population divergence. We sampled individuals across the Utah prairie dog species range and generated 2955 single nucleotide polymorphisms using double digest restriction site‐associated DNA sequencing. Genetic diversity was lower in low‐elevation sites compared to high‐elevation sites. Population divergence was high among sites and followed an isolation‐by‐distance model. Our results indicate that genetic drift plays a substantial role in the population divergence of the Utah prairie dog, and colonies would likely benefit from translocation of individuals between recovery units, which are characterized by distinct elevations, despite the detection of environmental associations with outlier loci. By understanding the processes that shape genetic structure, better informed decisions can be made with respect to the management of threatened species to ensure that adaptation is not stymied. [ABSTRACT FROM AUTHOR]