Explore the vast range of titles available.

Long-lived, group living animals have the potential to form multiyear relationships. In some temperate bat species, maternity groups break apart and rejoin both daily, as females depart to forage and select day roosts to use, and annually, as bats leave for and return from hibernation. Here, we investigated whether bats have persistent social preferences by testing whether relationships between dyads in a focal year could be predicted by previous years. We also hypothesized that experience influences social preferences and predicted that an individual’s age would influence its network position, while familiarity with bats of the same cohort would drive persistent social preferences. We quantified roost co-occurrence in little brown myotis ( Myotis lucifugus ) in Salmonier Nature Park, Newfoundland, Canada both within and among years. We found that roost co-occurrence patterns of previous years still had predictive value even when accounting for potential roost fidelity. However, we found no evidence that cohort familiarity or age explained any of the variation. Overall, we found long-term patterns of association in this temperate bat species that suggest levels of social complexity akin to other large mammal species.

Parasites are an abundant and diverse group of organisms that are often excluded from biodiversity surveys, limiting our understanding of host–parasite relationships and parasite diversity. Parasites are dependent on their hosts for survival and parasite populations are at risk if their host populations decline. The aim of our study was to quantify and compare the ectoparasite communities of two sympatric Atlantic Canadian bat species, Myotis lucifugus and M. septentrionalis. Ectoparasites were collected from bats captured for research throughout Atlantic Canada between 1999 and 2017 during the active season (May–October). The prevalence and mean intensity of infection were calculated for each identified ectoparasite species and generalized linear mixed models were used to assess host differences in infection by the two most abundant ectoparasites. Both bat species hosted ectoparasite communities dominated by the mite Spinturnix americanus and the flea Myodopsylla insignis with other ectoparasites being rarely encountered. Despite being the most common ectoparasites of both bat species, our results suggest that infections of these ectoparasites vary between them with M. insignis prevalence being greater on M. lucifugus and S. americanus prevalence being greater on M. septentrionalis. We suggest these differences in infection burden are related to the social and roosting behaviors of these hosts and the life history of the ectoparasites. Monitoring parasites concurrently with focal species is important for capturing this aspect of biodiversity and for understanding how host–parasite dynamics may be disrupted if hosts undergo drastic demographic changes. Ectoparasite community diversity is similar between two endangered bat species in Atlantic Canada. Ectoparasite burden of the two most common ectoparasites varies between bat species in conjunction with their behavior and roosting differences.

Host–parasite relationships can affect the dispersal and transmission of parasites. Myodopsylla insignis (Rothchild, 1903), a bat flea, and Spinturnix americanus (Banks, 1902), a bat wing mite, are two common ectoparasites of the little brown myotis (Myotis lucifugus, Le Conte 1831) that differ in life cycles and time spent on the host. Our goal was to compare how life history traits and host–parasite relationships influence the genetic structure and biogeography of co‐infecting ectoparasites using S. americanus mites and M. insignis fleas that feed on Myotis lucifugus bats. Ectoparasites were collected from bats captured at maternity roosts between 2010 and 2017 in Atlantic Canada and sequenced for the cytochrome oxidase c subunit 1 gene. We barcoded 223 S. americanus and 87 M. insignis specimens and examined their genetic diversity, genetic structure, and biogeography. We found evidence of a weak association between geographic distance and sequence divergence between Labrador and Nova Scotia for M. insignis and evidence of regional differentiation between the island of Newfoundland and the mainland for S. americanus, similar to previous findings for M. lucifugus. In terms of biogeography, M. insignis likely underwent historical population expansion, particularly in Labrador, whereas S. americanus may have undergone historical population expansion or selection. Our study highlights how host–parasite relationships are influenced at multiple scales by both host and parasite biology and how an understanding of both host and parasite informs predictions on how these dynamics will be affected by disturbances. Spinturnix americanus and Myodopsylla insignis are two common ectoparasites of little brown myotis (Myotis lucifugus) with different life history strategies. These ectoparasites exhibit corresponding differences in genetic diversity and dispersal with their hosts across Atlantic Canada.

Social network analysis is increasingly applied to understand animal groups. However, it is rarely feasible to observe every interaction among all individuals in natural populations. Studies have assessed how missing information affects estimates of individual network positions, but less attention has been paid to metrics that characterize overall network structure such as modularity, clustering coefficient, and density. In cases such as groups displaying fission-fusion dynamics, where subgroups break apart and rejoin in changing conformations, missing information may affect estimates of global network structure differently than in groups with distinctly separated communities due to the influence single individuals can have on the connectivity of the network. Using a bat maternity group showing fission-fusion dynamics, we quantify the effect of missing data on global network measures including community detection. In our system, estimating the number of communities was less reliable than detecting community structure. Further, reliably assorting individual bats into communities required fewer individuals and fewer observations per individual than to estimate the number of communities. Specifically, our metrics of global network structure (i.e., graph density, clustering coefficient, R com ) approached the ‘real’ values with increasing numbers of observations per individual and, as the number of individuals included increased, the variance in these estimates decreased. Similar to previous studies, we recommend that more observations per individual should be prioritized over including more individuals when resources are limited. We recommend caution when making conclusions about animal social networks when a substantial number of individuals or observations are missing, and when possible, suggest subsampling large datasets to observe how estimates are influenced by sampling intensity. Our study serves as an example of the reliability, or lack thereof, of global network measures with missing information, but further work is needed to determine how estimates will vary with different data collection methods, network structures, and sampling periods.

White‐nose syndrome is a skin disease of bats caused by the fungus Pseudogymnoascus destructans (Pd). Pd has devastated populations of some bat species in North America, where environmental reservoirs of the fungus are considered a threat to the persistence of bat populations. However, long‐term patterns of Pd environmental persistence in North American hibernacula are unknown. We swabbed hibernacula walls 11 years after the invasion of Pd into Maritime Canada in 2011. This is the first study to examine the persistence of Pd in North American hibernacula >7 years after the first documentation of Pd at a site. The proportion of hibernacula wall swabs with viable Pd decreased over time, with 40.6% of wall swabs positive (n = 32) in 2012, 35.0% (n = 40) in 2015, and 1.7% (n = 120) in 2022. In early winter 2022, 41.18% (n = 17) of bats (Myotis lucifugus, M. septentrionalis, and Perimyotis subflavus) were Pd‐positive compared to 6.67% (n = 15) in late winter, a low prevalence and the opposite pattern compared to the first 4 years after Pd invasion to sites. Our results suggest that Pd loads in the environment naturally decrease to low or undetectable levels over time in our study region. Since attempts to reduce environmental reservoirs have a high likelihood of negative nontarget effects on hibernacula ecosystems, and a low likelihood of completely eradicating Pd, actions to reduce environmental reservoirs in hibernacula should consider deprioritizing sites where Pd has been present >10 years. We urge the collection of further data across hibernacula sites with varied geochemistry, microclimates, organic matter availability, timing of Pd arrival, and surviving bat colony sizes. This will allow a more comprehensive assessment of this strategy.

Migratory patterns of bats are not well understood and traditional methods to study this, like capture-mark-recapture, may not provide enough detail unless there are many records. Stable isotope profiles of many animal species have been used to make inferences about migration. Each year Myotis lucifugus and M. septentrionalis migrate from summering roosts to swarming caves and mines in the fall, but the pattern of movement between them is not well understood. In this study, fur δ13C and δ15N values of 305 M. lucifugus and 200 M. septentrionalis were analyzed to make inferences about migration patterns between summering areas and swarming sites in Nova Scotia, Canada. We expected that there would be greater variability in δ13C and δ15N among individuals at swarming sites because it was believed that these sites are used by individuals originating from many summering areas. There was extensive overlap in the standard ellipse area, corrected for small sample sizes (SEAc), of bats at swarming sites and much less overlap in SEAc among groups sampled at summering areas. Meaningful inference could not be made on M. septentrionalis because their low variation in SEAc may have been the result of sampling only 3 summering areas. However, for M. lucifugus, swarming sites had larger SEAc than summering areas and predictive discriminant analysis assigned swarming bats to multiple summering areas, supporting the contention that swarming bats are mixed aggregations of bats from several summering areas. Together, these data support the contention that swarming sites have catchment areas for bats from multiple summering areas and it is likely that the catchment areas for swarming sites overlap. These data suggest that δ13C and δ15N profiling of bat fur offer some potential to make inferences about regional migration in bats.

Animals are expected to adjust their behavioral patterns to improve fitness outcomes, such as fecundity or offspring survival. For long‐lived hibernators, decisions made in each annual cycle may reflect considerations not just for concurrent survival and reproduction but also the pressure to maximize overwinter survival and future reproductive success. We examined how these elements manifest themselves in the body mass variation patterns of North American northern latitude temperate bats, whose size and roosting habits present considerable monitoring challenges. We characterized and compared the summer and fall mass variation patterns of little brown myotis (Myotis lucifugus) and northern myotis (M. septentrionalis) from a historic dataset. In summer, the estimated date of parturition was strongly associated with spring foraging conditions (low wind, low precipitation, and warm temperatures), and mass gain associated with female reproduction conferred considerable differentiation between the mass variation patterns of females and males. In fall, differences were most apparent among species, although adults exhibited a greater capacity for rapid mass gain than juveniles. These results demonstrate how reproductive constraints and interannual survival have important influences on the behavior of temperate bats. Future work should seek to quantify the fitness benefits of patterns identified in this study, such as the rate of prehibernation mass gain. Temperate hibernating bats are constrained by energetic tradeoffs associated with hibernation and reproduction. We identified sex‐associated differences in summer mass variation and characterized an age‐associated difference in the capacity for prehibernation mass gain in little brown (Myotis lucifugus) and northern myotis (M. septentrionalis). We also identified a positive relationship between relatively good foraging conditions and early parturition in females.

During late summer and early autumn, temperate bats migrate from their summering sites to swarming sites, where mating likely occurs. However, the extent to which individuals of a single summering site migrate to the same swarming site, and vice versa, is not known. We examined the migratory connectivity between summering and swarming sites in two temperate, North American, bat species, the little brown bat (Myotis lucifugus) and the northern long-eared bat (Myotis septentrionalis). Using mitochondrial and microsatellite DNA markers, we examined population structuring within and among summering and swarming sites. Both species exhibited moderate degrees of mitochondrial DNA differentiation (little brown bat: FST(SUMMER) = 0.093, FST(SWARMING) = 0.052; northern long-eared bat: FST(SUMMER) = 0.117, FST(SWARMING) = 0.043) and little microsatellite DNA differentiation among summering and among swarming sites[corrected]. Haplotype diversity was significantly higher at swarming sites than summering sites, supporting the idea that swarming sites are comprised of individuals from various summering sites. Further, pairwise analyses suggest that swarming sites are not necessarily comprised of only individuals from the most proximal summering colonies.

Animal fitness is closely linked to accessing and capitalizing on local resources such as prey and shelter. Resources vary in quality, thus individuals may demonstrate selectivity for particular resource types. We examined resource selection in roost selection patterns of temperate bats on Prince Edward Island. To complement existing work examining roost structural characteristics, we evaluated whether roost selection by little brown myotis (Myotis lucifugus) could be explained by landscape characteristics. Given a sample of roosts identified through radio telemetry, community reports and a randomly selected sample of comparison structures, we determined that a combination of proximity to forest and open wetland best explained roost selection. Roost selection appears to reflect the optimization of time and energy budgets, and the proportion of maternity roosts within the sample suggests that these constraints may be more acute in reproductive females. Given the importance of roosts for reproductive success in females, future work should seek to quantify the role of physical characteristics on roost structure selection and the preservation of suitable roosting structures.

Neotropical bat communities are among the most diverse mammal communities in the world, and a better understanding of these assemblages may permit inferences about how so many species coexist. While broad trophic guilds (e.g., frugivore, insectivore) of bats are recognized, details of diet and similarities among species remain largely unknown. We used stable isotope ratios of carbon (δ¹³C) and nitrogen (δ¹⁵N) to characterize the community structure of a diverse Neotropical bat fauna from Belize to test predictions of niche theory and the competitive exclusion principle. We predicted that (1) interspecific variation in isotopic overlap would be greater within guilds than between guilds, and (2) no two sympatric populations would have isotopic niches that overlap completely, unless there is variation along some other axis (e.g., temporal, spatial). We additionally tested body size as an explanatory metric of potential overlap and predicted that larger-bodied animals would have greater niche breadths. Results suggest that while guild-level characterizations of communities are at least somewhat informative, there are multiple examples of intra- and inter-guild species pairs with significantly overlapping isotopic niches, suggesting that, counter to predictions, they may compete for resources. Understanding the trophic structure of animal communities is fundamental to conservation and management of endangered species and ecosystems and important for evolutionary studies, and stable isotope analyses can provide key insights as well as informing hypotheses of the diet of species that are not well known.