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Your search keyword '"Lisa A. Shipley"' showing total 2 results
Start Over Author "Lisa A. Shipley" Publisher public library of science (plos)
2 results on '"Lisa A. Shipley"'

1. Evaluation of micro-GPS receivers for tracking small-bodied mammals

Author

Peter J. Olsoy, Timothy R. Johnson, Lisa A. Shipley, Laura A. McMahon, Janet L. Rachlow, and Jennifer S. Forbey

Subjects
0106 biological sciences, Geographic information system, Physiology, lcsh:Medicine, 01 natural sciences, Software, Medicine and Health Sciences, lcsh:Science, Animal Signaling and Communication, Animal Management, Mammals, Multidisciplinary, Animal Behavior, Ecology, Agriculture, Animal Models, Plants, Habitats, 010601 ecology, Time to first fix, Experimental Organism Systems, Vertebrates, Global Positioning System, Snapshot (computer storage), Rabbits, Research Article, Idaho, Real-time computing, Biology, Research and Analysis Methods, 010603 evolutionary biology, Animals, Satellite geometry, Animal behavior, Burrowing, Behavior, Animal Performance, Biological Locomotion, business.industry, lcsh:R, Ecology and Environmental Sciences, Organisms, Biology and Life Sciences, Lagomorpha, Software deployment, Amniotes, Geographic Information Systems, lcsh:Q, Animal Migration, Shrubs, business, Zoology
Abstract

GPS telemetry markedly enhances the temporal and spatial resolution of animal location data, and recent advances in micro-GPS receivers permit their deployment on small mammals. One such technological advance, snapshot technology, allows for improved battery life by reducing the time to first fix via postponing recovery of satellite ephemeris (satellite location) data and processing of locations. However, no previous work has employed snapshot technology for small, terrestrial mammals. We evaluated performance of two types of micro-GPS (< 20 g) receivers (traditional and snapshot) on a small, semi-fossorial lagomorph, the pygmy rabbit (Brachylagus idahoensis), to understand how GPS errors might influence fine-scale assessments of space use and habitat selection. During stationary tests, microtopography (i.e., burrows) and satellite geometry had the largest influence on GPS fix success rate (FSR) and location error (LE). There was no difference between FSR while animals wore the GPS collars above ground (determined via light sensors) and FSR generated during stationary, above-ground trials, suggesting that animal behavior other than burrowing did not markedly influence micro-GPS errors. In our study, traditional micro-GPS receivers demonstrated similar FSR and LE to snapshot receivers, however, snapshot receivers operated inconsistently due to battery and software failures. In contrast, the initial traditional receivers deployed on animals experienced some breakages, but a modified collar design consistently functioned as expected. If such problems were resolved, snapshot technology could reduce the tradeoff between fix interval and battery life that occurs with traditional micro-GPS receivers. Our results suggest that micro-GPS receivers are capable of addressing questions about space use and resource selection by small mammals, but that additional techniques might be needed to identify use of habitat structures (e.g., burrows, tree cavities, rock crevices) that could affect micro-GPS performance and bias study results.

Published
2017
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2. Linking forest management to moose population trends: The role of the nutritional landscape.

Author

Thomas V Schrempp, Janet L Rachlow, Timothy R Johnson, Lisa A Shipley, Ryan A Long, Jocelyn L Aycrigg, and Mark A Hurley

Subjects
Medicine, Science
Abstract

Forested lands in the western USA have undergone changes in management and condition that are resulting in a shift towards climax vegetation. These changes can influence the quality and quantity of forage for herbivores that rely on early-seral plants. To evaluate how management of forested landscapes might affect nutrition for Shiras moose (A. a. shirasi) at large spatial scales, we focused on shrubs and evaluated summer diet composition, forage availability, and forage quality across 21 population management units encompassing >36,000 km2 in northern Idaho, USA. We identified 17 shrub species in the diets of moose, 11 of which comprised the bulk of the diets. These forage shrubs varied markedly in both energy (mean digestible energy for leaves ranged from 9.62 to 12.89 kJ/g) and protein (mean digestible protein for leaves ranged from 1.73 to 7.90%). By adapting established field sampling methods and integrating recent advances in remote sensing analyses in a modeling framework, we predicted approximations of current and past (i.e., 1984) quantities of forage shrubs across northern Idaho. We also created a qualitative index of population trend for moose across population management units using harvest data. Predicted quantities of forage shrubs varied widely across the study area with generally higher values at more northern latitudes. The quantity of forage shrubs was estimated to have declined over the past 30 years in about half of the population management units, with the greatest declines predicted for high-energy forage species. The population trend index was correlated with the percent change in availability of moderate-energy forage shrubs, indicating that availability of forage shrubs and change in availability over time might be affecting population dynamics for moose in northern Idaho. Our study highlights the importance of assessing how changes in forest management across broad spatiotemporal extents could affect wildlife and their habitats.

Published
2019
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