| Abstract: | Global Positioning System (GPS) telemetry is used extensively to study animal distribution and resource selection patterns but is susceptible to biases resulting from data omission and spatial inaccuracies. These data errors may cause misinterpretation of wildlife habitat selection or spatial use patterns. We used both stationary test collars and collared free-ranging American black bears (Ursus americanus) to quantify systemic data loss and location error of GPS telemetry in mountainous, old-growth temperate forests of Olympic National Park, Washington, USA. We developed predictive models of environmental factors that influence the probability of obtaining GPS locations and evaluated the ability of weighting factors derived from these models to mitigate data omission biases from collared bears. We also examined the effects of microhabitat on collar fix success rate and examined collar accuracy as related to elevation changes between successive fixes. The probability of collars successfully obtaining location fixes was positively associated with elevation and unobstructed satellite view and was negatively affected by the interaction of overstory canopy and satellite view. Test collars were 33% more successful at acquiring fixes than those on bears. Fix success rates of collared bears varied seasonally and diurnally. Application of weighting factors to individual collared bear fixes recouped only 6% of lost data and failed to reduce seasonal or diurnal variation in fix success, suggesting that variables not included in our model contributed to data loss. Test collars placed to mimic bear bedding sites received 16% fewer fixes than randomly placed collars, indicating that microhabitat selection may contribute to data loss for wildlife equipped with GPS collars. Horizontal collar errors of >800 m occurred when elevation changes between successive fixes were >400 m. We conclude that significant limitations remain in accounting for data loss and error inherent in using GPS telemetry in coniferous forest ecosystems and that, at present, resource selection patterns of large mammals derived from GPS telemetry should be interpreted cautiously. |
| Genre: | Article |
| ProdID: | 1016418 |
| Citation Author: | Sager-Fradkin, Kimberly A.; Jenkins, Kurt J.; Hoffman, Robert L.; Happe, P.; Beecham, J.; Wright, R. G. |
| Citation Contributing Office: | Forest and Rangeland Ecosystem Science Center |
| Citation Datum: | |
| Citation Day: | |
| Citation Edition: | |
| Citation Editor: | |
| Citation End Page: | 1308 |
| Citation Issue: | 4 |
| Citation Keywords: | |
| Citation Language: | English |
| Citation Larger Work Title: | Journal of Wildlife Management |
| Citation LatN: | |
| Citation LatS: | |
| Citation LonE: | |
| Citation LonW: | |
| Citation Month: | JUN |
| Citation No Pagination: | |
| Citation Number Of Pages: | 11 |
| Citation Online Only Flag: | |
| Citation Phsyical Description: | p. 1298-1308 |
| Citation Projection: | |
| Citation Public Comments: | |
| Citation Publisher: | |
| Citation Series: | |
| Citation Series Code: | |
| Citation Series Number: | |
| Citation Search Results Text: | Fix success and accuracy of GPS radio collars in old-growth temperate coniferous forests; 2007; Article; Journal; Journal of Wildlife Management; Sager-Fradkin, Kimberly A.; Jenkins, Kurt J.; Hoffman, Robert L.; Happe, P.; Beecham, J.; Wright, R. G. |
| Citation Start Page: | 1298 |
| Citation Volume: | 71 |
| Citation Year: | 2007 |
| Type: | citation/reference |
| Text: | Fix success and accuracy of GPS radio collars in old-growth temperate coniferous forests; 2007; Article; Journal; Journal of Wildlife Management; Sager-Fradkin, Kimberly A.; Jenkins, Kurt J.; Hoffman, Robert L.; Happe, P.; Beecham, J.; Wright, R. G. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| Date Other: | Mon, 1 Jan 2007 00:00 -0600 |
| Publisher: | |
