Genetic variation within a species of parasitic nematode, Skrjabingylus chitwoodorum, in skunks.

Carnivores in the families Mustelidae and Mephitidae are essential hosts for the cranial roundworm genus Skrjabingylus. A high prevalence of Skrjabingylus chitwoodorum has been observed in the striped skunk, Mephitis mephitis. Genetic barcoding studies of other nematodes have successfully used the cytochrome oxidase I (COI) mitochondrial gene to analyze genetic variation and divergence. We tested the hypothesis that low population structuring occurs within S. chitwoodorum because M. mephitis is widespread across much of North America and has high levels of gene flow. We extracted DNA from 38 samples of Skrjabingylus removed from the sinuses of M. mephitis and one from the plains spotted skunk, Spilogale putorius interrupta, for amplification and sequencing of COI. Analysis of 492 base pairs confirmed all samples were S. chitwoodorum and showed low genetic divergence (1.0%) within Texas, but high haplotype diversity. Supporting our hypothesis, no obvious divergent lineages based on geographic location were recovered within the samples based on Maximum Likelihood analysis and median joining haplotype network analysis. In fact, samples of Skrjabingylus from New York and South Dakota showed little difference compared with samples from Texas.

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.

Field Identification Key and Guide for Bats of the United States of America.

Bats are the second most speciose lineage of mammals with more than 1,300 recognized species. Overall, bats are extremely ecologically and morphologically diverse, making them of interest to a wide variety of biologists. Bats are also known reservoirs for an assortment of zoonotic diseases, including rabies, for which they are commonly tested if identified as sick, behaving abnormally, or in instances where there has been a significant human exposure. In these cases, proper identification of bat species is important to public health experts as it will inform future testing procedures and management practices, as well as broaden our understanding of rabies virus bat variant distributions and disease ecology. Despite the multiple disciplines interested in bats, no key has been developed which includes all species found within the United States. For this reason, a dichotomous key and bat identification guide, designed to differentiate bats to species level, has been developed. This document can be used by people with a variety of backgrounds to morphologically identify bats quickly and accurately using only a scale, a ruler, and attention to detail.

Molecular diet analysis finds an insectivorous desert bat community dominated by resource sharing despite diverse echolocation and foraging strategies.

Interspecific differences in traits can alter the relative niche use of species within the same environment. Bats provide an excellent model to study niche use because they use a wide variety of behavioral, acoustic, and morphological traits that may lead to multi-species, functional groups. Predatory bats have been classified by their foraging location (edge, clutter, open space), ability to use aerial hawking or substrate gleaning and echolocation call design and flexibility, all of which may dictate their prey use. For example, high frequency, broadband calls do not travel far but offer high object resolution while high intensity, low frequency calls travel further but provide lower resolution. Because these behaviors can be flexible, four behavioral categories have been proposed: (a) gleaning, (b) behaviorally flexible (gleaning and hawking), (c) clutter-tolerant hawking, and (d) open space hawking. Many recent studies of diet in bats use molecular tools to identify prey but mainly focus on one or two species in isolation; few studies provide evidence for substantial differences in prey use despite the many behavioral, acoustic, and morphological differences. Here, we analyze the diet of 17 sympatric species in the Chihuahuan desert and test the hypothesis that peak echolocation frequency and behavioral categories are linked to differences in diet. We find no significant correlation between dietary richness and echolocation peak frequency though it spanned close to 100 kHz across species. Our data, however, suggest that bats which use both gleaning and hawking strategies have the broadest diets and are most differentiated from clutter-tolerant aerial hawking species.

Phylogeography of a widespread small carnivore, the western spotted skunk (Spilogale gracilis) reveals temporally variable signatures of isolation across western North America.

We analyzed phylogeographic patterns in the western spotted skunk, Spilogale gracilis Merriam, 1890 (Carnivora: Mephitidae) in relation to historical events associated with Pre-Pleistocene Divergence (PPD) and Quaternary climate change (QCC) using mitochondrial DNA from 97 individuals distributed across Western North America. Divergence times were generated using BEAST to estimate when isolation in putative refugia occurred. Patterns and timing of demographic expansion was performed using Bayesian skyline plot. Putative climatic refugia resulting from Quaternary climate change were identified using paleoecological niche modeling and divergence dates compared to major vicariant events associated with Pre-Pleistocene conditions. We recovered three major mitochondrial clades corresponding to western North America (California, Baja, and across the Great Basin), east-central North America (Texas, central Mexico, New Mexico), and southwestern Arizona/northwestern Mexico. Time to most recent common ancestor for S. gracilis occurred ~1.36 Ma. Divergence times for each major clade occurred between 0.25 and 0.12 Ma, with signature of population expansion occurring 0.15 and 0.10 Ma. Ecological niche models identified three potential climatic refugia during the Last Interglacial, (1) west coast of California and Oregon, (2) northwestern Mexico, and (3) southern Texas/northeastern Mexico as well as two refugia during the Last Glacial Maximum, (1) western USA and (2) southern Texas/northeastern Mexico. This study supports PPD in shaping species-level diversity compared to QCC-driven changes at the intraspecific level for Spilogale, similar to the patterns reported for other small mammals (e.g., rodents and bats). Phylogeographic patterns also appear to have been shaped by both habitat and river vicariance, especially across the desert southwest. Further, continuing climate change during the Holocene coupled with anthropogenic modifications during the Anthropocene appears to be removing both of these barriers to current dispersal of western spotted skunks.