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Showing papers on "Flying squirrel published in 2014"


Journal ArticleDOI
TL;DR: The hypothesis of cavity limitation of a cavity specialist species, the northern flying squirrel, is tested using nest box supplementation on half of 56 trapping sites and it is suggested that this species should not be considered an indicator of old forest attributes in the study area, especially in view of apparent wide population fluctuations across years.
Abstract: Dynamic N-mixture models have been recently developed to estimate demographic parameters of unmarked individuals while accounting for imperfect detection. We propose an application of the Dail and Madsen (2011: Biometrics, 67, 577-587) dynamic N-mixture model in a manipulative experiment using a before-after control-impact design (BACI). Specifically, we tested the hypothesis of cavity limitation of a cavity specialist species, the northern flying squirrel, using nest box supplementation on half of 56 trapping sites. Our main purpose was to evaluate the impact of an increase in cavity availability on flying squirrel population dynamics in deciduous stands in northwestern Quebec with the dynamic N-mixture model. We compared abundance estimates from this recent approach with those from classic capture-mark-recapture models and generalized linear models. We compared apparent survival estimates with those from Cormack-Jolly-Seber (CJS) models. Average recruitment rate was 6 individuals per site after 4 years. Nevertheless, we found no effect of cavity supplementation on apparent survival and recruitment rates of flying squirrels. Contrary to our expectations, initial abundance was not affected by conifer basal area (food availability) and was negatively affected by snag basal area (cavity availability). Northern flying squirrel population dynamics are not influenced by cavity availability at our deciduous sites. Consequently, we suggest that this species should not be considered an indicator of old forest attributes in our study area, especially in view of apparent wide population fluctuations across years. Abundance estimates from N-mixture models were similar to those from capture-mark-recapture models, although the latter had greater precision. Generalized linear mixed models produced lower abundance estimates, but revealed the same relationship between abundance and snag basal area. Apparent survival estimates from N-mixture models were higher and less precise than those from CJS models. However, N-mixture models can be particularly useful to evaluate management effects on animal populations, especially for species that are difficult to detect in situations where individuals cannot be uniquely identified. They also allow investigating the effects of covariates at the site level, when low recapture rates would require restricting classic CMR analyses to a subset of sites with the most captures.

24 citations


Journal ArticleDOI
TL;DR: This study contributes to the understanding of the role of relatedness in rodent group formation, demonstrating a case where close relatedness is not related to group formation and indicates that in a solitarily breeding, rodent huddling may be more driven by other factors than temperature.
Abstract: Research on group living in animals is concentrated on highly social species, but studying less social species may hint at the factors possibly leading to the evolution of increased sociality. Thermoregulation is often thought to explain communal nesting in solitarily breeding mammals but also other factors may be involved. For example, it is observed that even solitary species may have cryptic kin cooperation. We studied factors affecting communal nesting in the Siberian flying squirrel. Flying squirrels breed solitarily but, similar to most other rodents, adults may sometimes huddle in groups. Communal nesting in flying squirrels was most frequent during winter and autumn, but also occurred during other seasons. This pattern was explained by the breeding season, which took place in the spring–summer, when communal nesting was less common. Neither monthly temperature, after accounting for breeding season, nor daily temperatures in winter explained communal nesting. Group size was small, two to three individuals. In most cases the group was a pair consisting of unrelated male and female, possibly indicating that group formation was related to mating behavior. This study contributes to the understanding of mammalian group formation in two major ways. First, our study contributes to the understanding of the role of relatedness in rodent group formation, demonstrating a case where close relatedness is not related to group formation. Second, our study indicates that in a solitarily breeding, rodent huddling may be more driven by other factors than temperature.

23 citations


Journal ArticleDOI
TL;DR: The number of flying squirrels was associated with the amount of available habitat, but the decline in population size was more rapid than the loss of habitat area, and the population might become extinct by the year 2020.
Abstract: To devise effective conservation actions, it is important to know which factors are associated with the population parameters of a declining population. Using mark–recapture methods, we estimated the annual population size, growth rate and survival probability of an ear-tagged flying squirrel population over a 15-year period in a 4,500 ha study area in western Finland. The species is considered vulnerable, but detailed knowledge concerning population sizes or trends is lacking. The population parameters and changes therein were regressed against habitat availability, an indicator of predation pressure, and mean winter temperature (an indicator of climate change), to reveal potential reasons for trends in the population. The best-fit models suggested the annual growth rate to be below one, and on average it was 0.93 (±0.06; SE) across the 15-year period. The survival probability was about 0.22 (±0.03) for juveniles and 0.50 (±0.03) for adults. The population size of adult flying squirrels decreased from 65 (±11) individuals in 1995 to 29 (±6) individuals in 2009. The number of flying squirrels was associated with the amount of available habitat, but the decline in population size was more rapid than the loss of habitat area. If the current decreasing trend in habitat availability continues, the population might become extinct by the year 2020. To halt the population decline, it is necessary to refrain from clear-cutting mature spruce stands until new suitable habitats develop from the maturation of younger forests.

21 citations


Journal ArticleDOI
TL;DR: It is suggested that squirrels forage and cache alone in their summer home range and make solitary returns to this summer range to collect their cache during the winter months, despite exhibiting social winter nesting.
Abstract: It can be challenging to understand the evolution of sociality, particularly the occurrence of co-operation by non-kin. Southern flying squirrels (Glaucomys volans) are an interesting example of non-kin co-operation because of the mutual benefits obtained by social thermoregulation during winter. Because group survival confers benefits to the entire group, flying squirrels may also follow an aggregation economy, whereby co-operative foraging during winter is advantageous. However, the extent of such social foraging in flying squirrels is unknown. We tested for social foraging of southern flying squirrels, and also for relatedness among foraging groups. To determine the structure of foraging groups, we set up and remotely monitored feeding stations and nest cavities. All squirrels at the study site were tagged with passive integrated transponder (PIT) tags and nests and feeding stations were monitored with automated PIT-tag recorders for a 24-month period. Squirrels were found most often foraging alone. Squirrels that were recorded foraging together comprised unrelated individuals that were also found to share nest cavities. Squirrels were also recorded travelling farther distances between nest cavity and feeding station in the winter season than in the summer season, suggesting that, during winter, squirrels trade-off proximity to food caches for membership in a nest group. Our data suggest that squirrels forage and cache alone in their summer home range and make solitary returns to this summer range to collect their cache during the winter months, despite exhibiting social winter nesting. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 113, 1126–1135.

8 citations


Journal ArticleDOI
TL;DR: This survey provides additional multi-season occupancy data for an elusive mammal species under managed habitat regimes and recommends that management plans include a wildlife habitat component that maintains snag trees and live cavity-trees in forest stands.
Abstract: Artificial habitat enhancements are important forest structural components that can increase the survival of squirrels (Sciuridae) and thus warrant study. Investigations of squirrel nest box usage can provide useful demographic and community information such as occupancy rates, litter size, habitat preference, species richness and abundance estimates. This artificial nest box study investigated the nesting patterns of squirrels from late winter through early fall 2011 in managed forest stands in Clinton County, New York. Squirrels are sensitive to forest disturbance, hence we compared sites of varying silvicultural activity (e.g., managed for production of timber or maple syrup versus an undisturbed reference stand). A total of 48 nest boxes were constructed and monitored across three separate sites (e.g., reference, logged, and sugaring). Prior research suggested that occupancy may be a function of nest box height (~3.5m and ~5m) and site-specific tree cavity/snags/drey abundance, thus height preference and alternative nesting options were monitored in the survey and analyzed to report detection probability and occupancy estimates in Program Presence. Visual confirmation of northern flying squirrels (Glaucomys sabrinus Shaw) was made in 81%, 44%, and 13% of the nest boxes in the reference, logged, and sugar site, respectively. Approximately 79% of the nest boxes showed evidence of wildlife visitation (e.g., scat, crushed seeds, or nesting material). Additionally, 87% of the high boxes (5m) versus 71% of the low boxes (3.5m) were utilized, and 17% of all occupancies contained multiple individuals. This survey provides additional multi-season occupancy data for an elusive mammal species under managed habitat regimes. We recommend that management plans include a wildlife habitat component that maintains snag trees and live cavity-trees in forest stands. When appropriate, stand management plans could also include installing habitat enhancement structures such as artificial nest boxes for squirrels.

3 citations


Journal ArticleDOI
TL;DR: This paper presents the results of a two-year study conducted at the National University of Thailand in Bangkok on the basis of a probabilistic method to identify the alleles of EMTs.
Abstract: 1 Genetics and Environmental Toxicology Research Group, Department of Biology, Faculty of Science, Khon Kaen University, Muang, Khon Kaen 40002, Thailand 2 Biology Program, Faculty of Science and Technology, Prince of Songkla University, Muang, Pattani 94000, Thailand 3 Program in Computer Science, Faculty of Science, Buriram Rajabhat University, Muang, Buriram 31000, Thailand 4 Program in Applied Biology, Faculty of Science, Buriram Rajabhat University, Muang, Buriram 31000, Thailand 5 Biology Program, Faculty of Science, Ubonratchathani Rajabhat University, Ubon Ratchathani, Muang 34000, Thailand

2 citations