Variance in Female Reproductive Success Differentially Impacts Effective Population Size in the Short-Nosed Fruit Bat, Cynopterus sphinx

High Frequency of Multiple Paternity in Eastern Red Bats, Lasiurus borealis, Based on Microsatellite Analysis

Most species of bats give birth to only 1 pup each year, although Eastern red bats (Lasiurus borealis) can produce up to 5 pups per litter. Offspring in a single litter have been documented to be at different stages of development, suggesting that multiple paternity occurs. We tested the null hypothesis of genetic monogamy in red bats using 6 autosomal microsatellites and 1 X-linked microsatellite from 31 parent/offspring groups for a total of 128 bats. We sampled both pregnant females and mothers with pups that were obtained from bats submitted to departments of health in Oklahoma and Texas for rabies testing. Multiple paternity was assessed using a maximum-likelihood approach, hypothesis testing, and X-linked locus exclusion. The mean polymorphic information content of our markers was high (0.8819) and combined non-exclusion probability was low (0.00027). Results from the maximum-likelihood approach showed that 22 out of 31 (71%) parent/offspring groups consisted of half siblings, hypothesis testing rejected full sibship in 61% of parent/offspring groups, and X-linked locus exclusion suggested multiple paternity in at least 12 parent/offspring groups, rejecting our hypothesis of genetic monogamy. This frequency of multiple paternity is the highest reported thus far for any bat species. High levels of multiple paternity have the potential to impact interpretations of genetic estimates of effective population size in this species. Further, multiple paternity might be an adaptive strategy to allow for increased genetic variation and large litter size, which would be beneficial to a species threatened by population declines from wind turbines.

Fluctuating fortunes: genomes and habitat reconstructions reveal global climate-mediated changes in bats' genetic diversity

Over the last approximately 2.6 Myr, Earth's climate has been dominated by cyclical ice ages that have profoundly affected species' population sizes, but the impact of impending anthropogenic climate change on species' extinction potential remains a worrying problem. We investigated 11 bat species from different taxonomic, ecological and geographical backgrounds using combined information from palaeoclimatic habitat reconstructions and genomes to analyse biotic impacts of historic climate change. We discover tightly correlated fluctuations between species' historic distribution and effective population size, identify frugivores as particularly susceptible to global warming, pinpoint large insectivores as having overall low effective population size and flag the onset of the Holocene (approx. 10-12 000 years ago) as the period with the generally lowest effective population sizes across the last approximately 1 Myr. Our study shows that combining genomic and palaeoclimatological approaches reveals effects of climatic shifts on genetic diversity and may help predict impacts of future climate change.