Biology subjects

Kailing, M. J.

Publications and source records attributed to Kailing, M. J..

7 recordsLinked to original sources

bioRxiv2026

Decoupled seasonal effects of an environmentally transmitted wildlife disease

O_LISeasonal forcing is a dominant factor shaping host-pathogen interactions and disease dynamics across many wildlife systems, including species impacted by environmentally transmitted parasites. How seasonality in parasite dynamics translates to the host when the infection and disease impacts operate at different timescales, however, remains poorly understood. C_LIO_LIWe investigate how seasonality shapes sarcoptic mange in bare-nosed wombats, Vombatus ursinus, a disease caused by the environmentally transmitted parasitic mite Sarcoptes scabiei, causing a protracted clinical time-course in the host. Using an empirically informed state-based deterministic model we explore how wombat population trajectories are influenced by (i) seasonal constraints to mite survival and (ii) in context of host-pathogen encounter rates, as measured by the ratio of burrows to wombats. C_LIO_LIWe demonstrate three long-term outcomes of wombat-mange: host and parasite extinction, endemic disease, and disease-free. We find seasonal environments narrow the range of host-pathogen encounter rates that support S. scabiei persistence relative to stable environments, and prevalence and population sizes vary more in seasonal compared to stable environments except under moderate host-pathogen encounter rates when seasonal effects are less apparent. We also find that a protracted infectious period is essential for host-parasite coexistence in the wombat-mange system. C_LIO_LIOur seasonal model results are consistent with field observations, such that mange prevalence in natural populations increases during seasons of longer off-host mite survival. Application of these findings suggest management efforts could reduce host population impacts through disease management in seasons with longer off-host parasite survival or reduce the environmental reservoir through disease management in seasons with shorter off-host survival. C_LIO_LIWe provide novel, mechanistic explanations for distinctive population trajectories that arise from a seasonally forced wildlife disease, including climate factors that operate independently on parasites, host demography, and disparate timescales over which seasonality affects parasites and hosts. Broadly, linking seasonality to long-term population dynamics can improve the predictability and management of wildlife diseases, but requires an understanding of how local intrinsic factors interact with seasonal pressures over time. C_LI

ecology↗

bioRxiv2026

Amplified transmission in host communities following disease-induced declines

Pathogen transmission is a fundamental component of infectious disease systems, governing the speed and extent of pathogen outbreaks. Predicting transmission within and among species is therefore critical for outbreak preparedness and the effective implementation of control strategies. Epidemics themselves can alter host populations in ways that fundamentally reshape transmission, but the long-term consequences remain poorly understood. Here, we quantify changes in transmission using a surrogate pathogen in bat communities before and after the emergence of white-nose syndrome, a fungal disease that has caused widespread population declines across North America. We find that transmission increased following disease-induced declines across all species in the community. We also observed an increase in environmental contacts and expanded habitat use by individuals, suggesting that surviving bats, on average, increased their activity and opportunities for interaction despite the substantial reductions in density and costs of infection. Together, these findings demonstrate that pathogen emergence can fundamentally alter host contact patterns and transmission dynamics, emphasizing the importance of considering behavioral and ecological changes imposed by epidemics when predicting pathogen spread in naive host populations.

ecology↗

bioRxiv2026

Environmental conditions drive selection and recovery following disease-induced declines

Emerging infectious diseases threaten public health and biodiversity across the globe1,2. Disease outcomes are frequently dependent on local environmental conditions3-5, but how these factors shape host adaptation and long-term recovery are often unknown6. Here we combine two decades of population, disease, and environmental data with a common garden experiment to investigate the drivers of variable declines and recovery for remnant bat populations following the emergence of the fungal disease, white-nose syndrome. We find that initial declines were greater and faster in warmer sites (88.3% vs. 74.2% in cold sites), but these populations recovered more quickly and hosts developed higher resistance (1.5x reduction of fungal loads) than populations from colder sites that were buffered from initial impacts. Our experimental data suggest that warm sites served as hotspots of host adaptation where selective pressures were stronger because thermal conditions approached optimal growth for the pathogen, which eventually favored the development of high pathogen resistance. Populations in colder sites experienced weaker selective pressure and thus remain more susceptible, although bats from larger colonies were more likely to survive, suggesting that adaptive traits exist in these populations, but at much lower frequency. These findings show that the environmental conditions that initially buffer populations from collapse can simultaneously constrain their evolutionary response to emerging threats, and ultimately determine differential recovery following disease-induced declines.

ecology↗

bioRxiv2024

Mating strategies explain sex-biased infections in an emerging fungal disease

O_LIMating dynamics can govern species impacts from rapid global change by influencing population rates of growth and adaptation, as well as individual traits that affect mortality risks from novel pressures. C_LIO_LIHere, we examined sex differences in activity of Myotis lucifugus during their mating season, which coincides with exposure to the lethal fungal pathogen (Pseudogymnoascus destructans) that causes white-nose syndrome. We expected differences in activity between sexes to modify seasonal P. destructans dynamics as the pathogen can replicate only at the cool temperatures at which bats hibernate. C_LIO_LIWe used passive antenna systems installed at the entrances of hibernacula and PIT tags to characterize activity patterns of bats. We also measured pathogen loads on bats during the autumn mating and early hibernation periods to assess how infection changed according to host phenology. C_LIO_LIWe found that females spent fewer days active during autumn, arrived after males, and were primarily active on the warmest nights. Males remained highly active throughout the mating season and later in autumn than females. Importantly, differences in phenology corresponded to higher pathogen loads on females during early hibernation as male activity, and thus warm body temperatures, inhibit pathogen growth. C_LIO_LIDifferences in activity between sexes and in the transition from swarm to hibernation likely reflects males maximizing their mating opportunities while females conserve energy to meet the cost of spring migration and reproduction. More broadly, our results show how activity during the mating season and phenology can contribute to sex-biased impacts of a novel disease and highlight the value of understanding species mating systems to anticipate the impacts of environmental change. C_LI

ecology↗

bioRxiv2022

Shifting effects of host physiological condition following pathogen establishment

Understanding host persistence with emerging pathogens is essential for conserving populations. Hosts may initially survive pathogen invasions through pre-adaptive mechanisms. However, whether pre-adaptive traits are directionally selected to increase in frequency depends on the heritability and environmental dependence of the trait and the costs of trait maintenance. Body condition is likely an important pre-adaptive mechanism aiding in host survival, although can be seasonally variable in wildlife hosts. We used data collected over seven years on bat body mass, infection, and survival to determine the role of host body condition during the invasion and establishment of the emerging disease, white-nose syndrome. We found that when the pathogen first invaded, bats with higher body mass were more likely to survive, but this effect dissipated following the initial epizootic. We also found that heavier bats lost more weight overwinter, but fat budgeting depended on infection severity. Lastly, we found little support that bat mass increased in the population after pathogen arrival, and there was high annual plasticity in individual bat masses. Overall, our results suggest that factors that contribute to host survival during pathogen invasion may diminish over time, and are potentially replaced by other host adaptations.

ecology↗

bioRxiv2022

Wildlife exposure to SARS-CoV-2 across a human use gradient

Pervasive SARS-CoV-2 infections in humans have led to multiple transmission events to captive animals. While SARS-CoV-2 has a potential broad wildlife host range, most documented infections to date are found in a single species, the white-tailed deer. The extent of SARS-CoV-2 exposure among wildlife species and the factors that influence wildlife transmission risk remain unknown. We sampled 23 wildlife species for SARS-CoV-2 and examined the effects of urbanization and human use on seropositivity. Here, we document positive detections of SARS-CoV-2 RNA in six species, including the deer mouse, Virginia opossum, raccoon, groundhog, Eastern cottontail, and Eastern red bat. In addition, we found that sites with high human activity had three times higher seroprevalence than low human-use areas. We detected SARS-CoV-2 genomic sequences from nine individuals of six species which were assigned to seven Pango lineages of the Omicron variant. The close match to variants circulating in humans at the time suggests at least seven recent human-to-animal transmission events. Our data support that exposure to SARS-CoV-2 has been widespread in wildlife communities and suggests that areas with high human activity may serve as points of contact for cross-species transmission.

ecology↗

bioRxiv2022

SEX-BIASED INFECTIONS SCALE TO POPULATION IMPACTS FOR AN EMERGING WILDLIFE DISEASE

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 behavior. 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.

ecology↗