Variation in prey resources influences the diet and behaviour of predators. When prey become limiting, predators may travel farther to find preferred food or adjust to existing local resources. When predators are habitat limited, local resource abundance impacts foraging success. We analysed the diet of Myotis lucifugus (little brown bats) from Nova Scotia (eastern Canada) to the Northwest Territories (north-western Canada). This distribution includes extremes of season length and temperature and encompasses colonies on rural monoculture farms, and in urban and unmodified areas. We recognized nearly 600 distinct species of prey, of which ≈30% could be identified using reference sequence libraries. We found a higher than expected use of lepidopterans, which comprised a range of dietary richness from ≈35% early in the summer to ≈55% by late summer. Diptera were the second largest prey group consumed, representing ≈45% of dietary diversity early in the summer. We observed extreme local dietary variability and variation among seasons and years. Based on the species of insects that were consumed, we observed that two locations support prey species with extremely low pollution and acidification tolerances, suggesting that these are areas without environmental contamination. We conclude that there is significant local population variability in little brown bat diet that is likely driven by seasonal and geographical changes in insect diversity, and that this prey may be a good indicator of environment quality.

Article impact statement: Data sharing and coordinated monitoring are needed to assess species' response to threats to inform conservation planning at relevant scales.

Moose, Alces alces, occur naturally throughout most of Canada but successful introductions of known numbers of animals have been made to the islands of Newfoundland and Cape Breton. Five microsatellite loci were used to investigate the population genetic structure and any change in genetic variability due to founder events of moose in Canada. Comparisons of allele frequencies for moose from 11 regions of the country suggested that there are at least seven genetically distinct populations (P < 0.05) in North America, namely Alberta, eastern Ontario, New Brunswick, Cape Breton, Labrador, western Newfoundland, and the Avalon Peninsula of Newfoundland. The average population heterozygosity was approximately 33% (range from 22 to 41%). upgma analysis of Nei’s genetic distances produced phenograms similar to what would be expected when geographical location and population history are considered. The loss of heterozygosity due to a single founder event (n = 3; two introductions and a natural colonization) ranged from 14 to 30%, and the cumulative loss of heterozygosity due to two successive founder events (an introduction followed by a natural colonization) was 46%. In these examples loss of genetic variability has not been associated with any known phenotypic deviances, suggesting that populations may be established from a small number of founders. However, the viability of these founded populations over evolutionary timescales cannot be determined and is highly dependent upon chance.

Abstract:Mood disorders are more frequent in women than men, however, the majority of research has focused on male rodents as animal models. We used a variety of common behavioral tests to look for differences in anxiety-like and social behaviors between and within C57BL/6J and BALB/cJ mice. Our results show that female C57BL/6J mice exhibited lower levels of anxiety-like behavior and higher levels of activity than female BALB/cJ during the open field and elevated plus maze tests. Principal component analysis generated more factors in the behavioral variables of males than females. In the open field, a sex difference was also found and factor 1 emerged as anxiety in males, and motor activity in females. While C57BL/6J mice were found to have higher levels of social exploration and social contacts, differences were found between the sexes (females were more social) in both strains for this measure and also for anxiety-like behaviors. When interacting with animals of the same sex, levels of sniffing body and huddling in both male and female C57BL/6J mice were higher than those in male and female BALB/cJ mice. However, in the between-sex interactions, male C57BL/6J mice sniffed the stimulus mouse less, and female C57BL/6J mice sniffed the stimulus more compared to BALB/cJ mice. This study provides important behavioral phenotypes and confirms the multidimensional behavioral structure of two widely used mice strains.

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Although only 2 bat species are common in the Greater Fundy National Park Ecosystem of New Brunswick, Canada, 4 distinct groups occur in terms of roost-site selection due to sexual segregation. We found that female northern long-eared bats (Myotis septentrionalis) roosted alone or as part of maternity colonies in mature, shade-tolerant deciduous stands. A roost site was 24 times more likely to be in a shade-tolerant deciduous tree than a coniferous tree, and trees in the mid-decay classes were 5.2 times more likely to be used than live or recently dead trees. Male northern long-eared bats roosted alone in coniferous stands or conifer-dominated mixedwood stands, and they selected roost trees that were in the mid-decay stages. Trees in mid-decay stages were selected more than twice as often as trees at the early or late stages of decay. For every 10% increase in the proportion of coniferous trees in the plot, the chances of a male northern long-eared bat roosting in the plot increased 1.5 times. Female little brown bats (M. lucifugus) in our study area were transients. Male little brown bats primarily roosted alone in coniferous stands, or conifer-dominated mixedwood stands. Their selection of roost sites was highly dependent on the number of snags in the vicinity. For every increase of 5 snags in a 0.1-ha plot, the odds of use for male little brown bats on that site increased by 2.5 times. The long-term availability of roost sites for males of both species in our study area may be linked to spruce budworm (Choristoneura fumiferana) epizootics, which is the major mortality factor for coniferous species in the region. Female northern long-eared bat roosts probably are more consistantly available because suitable sites are created by continuously occurring, individual-tree stressors in mature shade-tolerant forests. JOURNAL OF WILDLIFE MANAGEMENT 68(3):602-610

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