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Geology topics

Christine A. Kelly

Publications and source records attributed to Christine A. Kelly.

7 recordsLinked to original sources
USGS2026

Resource selection for an endangered flying squirrel, Glaucomys sabrinus coloratus, in a montane sky-island system

Geographically isolated endemic species and their habitats in montane systems face stressors of rapid climate change as well as legacy and contemporary land use change. In the case of endangered species in fragmented terrestrial montane habitats, effectively sky-islands, insight into habitat use and resource selection is vital for effective conservation measures. We created a resource selection function using a long-term dataset of multiple monitoring techniques (live-trapping, radio-telemetry, camera traps, acoustic detectors, and nest boxes) across a wide geographical range for an endangered subspecies, the Carolina northern flying squirrel Glaucomys sabrinus coloratus , in a vulnerable high-elevation sky-island boreal forest ecosystem in the southeastern USA. Using fine-scale habitat and topographic coverage on 8 sky-islands, we employed various models to capture nuanced habitat relationships that can better inform the conservation of remaining subpopulations as well as other endemic species that share their habitat. Our analyses confirmed that red spruce Picea rubens -Fraser fir Abies fraseri was the most significant habitat component for determining Carolina northern flying squirrel presence, but that relationships varied somewhat among sky-islands owing to differences in extent, elevation range, and forest community configurations. Further, we found that solely using nest boxes, as previously reported, to create a resource selection function biased the results, but that nest boxes remain an effective tool for overcoming habitat fragmentation and decreasing exposure to antagonistic species.

North Carolina, Tennessee, Virginia↗
USGS2023

Winter distribution of golden eagles in the Eastern USA

Golden Eagles ( Aquila chrysaetos ) have a Holarctic distribution, but some details of that overall distribution are poorly understood, including parts of the range in eastern North America. Recent studies in the region suggest that Golden Eagles may be more widely distributed than previously recognized. For species specific conservation efforts to be effective, an understanding of the distribution of the species is essential. Thus, the goal of this study was to map the winter distribution of Golden Eagles in the eastern half of the USA. To accomplish this, we reviewed and compiled 11,981 Golden Eagle records from eight data sources, including literature and ornithology records, community science data, survey data, and telemetry data. We found that Golden Eagles were observed in winter in each of the 31 states that lie completely east of the 100th meridian and in 1244 of the 2045 counties (61%) in those states. The proportion of counties with records varied by physiographic province, with higher proportions in physiographic provinces with more rugged terrain and greater forest cover. Our study shows that Golden Eagles are more widely distributed during winter in eastern USA states than was previously recognized. This work provides an important foundation for future management and research at a time when threats to this species are expanding rapidly on the landscape.

Journal of Raptor Research↗
USGS2021

Resource selection functions based on hierarchical generalized additive models provide new insights into individual animal variation and species distribution

Habitat selection studies are designed to generate predictions of species distributions or inference regarding general habitat associations and individual variation in habitat use. Such studies frequently involve either individually indexed locations gathered across limited spatial extents and analyzed using resource selection functions (RSFs) or spatially extensive locational data without individual resolution typically analyzed using species distribution models. Both analytical methodologies have certain desirable features, but analyses that combine individual- and population-level inference with flexible non-linear functions may provide improved predictions while accounting for individual variation. Here, we describe how RSFs can be fit using hierarchical generalized additive models (HGAMs) using widely available software, providing a means to explore individual variation in habitat associations and to generate species distribution maps. We used GPS tracking data from golden eagles Aquila chrysaetos from across eastern North America with four environmental predictors to generate monthly distribution models. We considered three model structures that assumed different amounts of individual variation in the functional relationship between predictors and habitat use and used k -fold cross-validation to compare model performance. Models accounting for individual variability in shape and smoothness of functional responses performed best. Eagles exhibited the least amount of individual variation in response to land cover variables during winter months, with most individuals more closely adhering to the population-level trend. During the summer months, eagles exhibited more substantial individual variation in shape and smoothness of the functional relationships, suggesting some need to account for individual variation in eagle habitat use for both inferential and predictive purposes, during this time of year. Because they allow users to blend flexible functions with random effects structures and are well-supported by a variety of software platforms, we believe that HGAMs provide a useful addition to the suite of analyses used for modeling habitat associations or predicting species distributions.

Ecography↗
USGS2020

Using ultrasonic acoustics to detect cryptic flying squirrels: Effects of season and habitat suitability

New technologies allow for more efficient and effective monitoring of rare or elusive species. However, standardizing protocol to ensure high detection rates is important prior to widespread use of a new technique. The use of ultrasonic acoustic detectors to survey for flying squirrels ( Glaucomys spp.) is a novel method that is more efficient than traditional methods. However, certain methodologies for this technique still need to be refined. During 2015, we conducted a seasonal and habitat quality study on the endangered Carolina northern flying squirrel ( G. sabrinus coloratus ) in western North Carolina, USA. Our seasonal study examined differences in probability of detection (POD) and latency to detection (LTD) at 30 high-quality sites across 10 survey nights in spring, summer, and autumn. The habitat quality study focused on POD and LTD among 15 sites with varying habitat quality (5 High, 5 Medium, 5 Low) across 20 survey nights. We found POD similar between seasons, with POD 15–20% greater during spring. The LTD was comparable among seasons. We found that POD and LTD varied at sites with different habitat quality. The POD was similar between High and Medium sites (0.26 ± 0.04 SE and 0.29 ± 0.05, respectively), but greater than Low sites (0.02 ± 0.02). The LTD was not different among sites with differing habitat quality, although LTD at High sites was 2.7 and 4.5 times lower than Medium and Low sites, respectively. Trill calls, the most distinctive species-specific call type produced by species of flying squirrels, was recorded at greater rates in spring versus other times of the year. Our results indicate flying squirrels can be surveyed during any season, although habitat quality needs to be considered when determining survey length. For Carolina northern flying squirrel, the optimal time to perform acoustic surveys is during the spring season for 6–10 survey nights at sites with high or medium habitat quality.

North Carolina↗
USGS2017

Home range, den selection and habitat use of Carolina northern flying squirrels (Glaucomys sabrinus coloratus)

Context: Understanding habitat selection is important for determining conservation and management strategies for endangered species. The Carolina northern flying squirrel (CNFS; Glaucomys sabrinus coloratus ) is an endangered subspecies found in the high-elevation montane forests of the southern Appalachians, USA. The primary use of nest boxes to monitor CNFS has provided biased information on habitat use for this subspecies, as nest boxes are typically placed in suitable denning habitat. Aims: We conducted a radio-telemetry study on CNFS to determine home range, den site selection and habitat use at multiple spatial scales. Methods: We radio-collared 21 CNFS in 2012 and 2014–15. We tracked squirrels to diurnal den sites and during night-time activity. Key results: The MCP (minimum convex polygon) home range at 95% for males was 5.2 ± 1.2 ha and for females was 4.0 ± 0.7. The BRB (biased random bridge) home range at 95% for males was 10.8 ± 3.8 ha and for females was 8.3 ± 2.1. Den site ( n = 81) selection occurred more frequently in montane conifer dominate forests (81.4%) vs northern hardwood forests or conifer–northern hardwood forests (9.9% and 8.7%, respectively). We assessed habitat selection using Euclidean distance-based analysis at the 2nd order and 3rd order scale. We found that squirrels were non-randomly selecting for habitat at both 2nd and 3rd order scales. Conclusions: At both spatial scales, CNFS preferentially selected for montane conifer forests more than expected based on availability on the landscape. Squirrels selected neither for nor against northern hardwood forests, regardless of availability on the landscape. Additionally, CNFS denned in montane conifer forests more than other habitat types. Implications: Our results highlight the importance of montane conifer to CNFS in the southern Appalachians. Management and restoration activities that increase the quality, connectivity and extent of this naturally rare forest type may be important for long-term conservation of this subspecies, especially with the impending threat of anthropogenic climate change.

Appalachian Mountains↗
USGS2015

Atypical den use of Carolina Northern Flying Squirrels ( Glaucomys sabrinus coloratus ) in the southern Appalachian Mountains

Glaucomys sabrinus coloratus (Carolina Northern Flying Squirrel) is a federally endangered subspecies that occurs in high elevation forests of the southern Appalachian Mountains. Denning sites may be a limiting factor for this subspecies in areas where cavity trees are not abundant or where interspecific competition from other tree squirrels occurs. This shortage can result in use of unusual denning sites, such as subterranean dens. Herein, we report atypical denning habits of radio-collared Carolina Northern Flying Squirrels in southwestern Virginia and western North Carolina from 2008 to 2011 and 2014. Increased knowledge of denning habitats may be beneficial for conservation and habitat management of this subspecies, particularly in sub-optimal or degraded habitats.

North Carolina↗