The Usefulness of GPS Telemetry to Study Wolf Circadian and Social Activity

Abstract:  This study describes circadian and social movement patterns of 9 wolves and illustrates capabilities and limitations of Global Positioning System (GPS) telemetry for analysis of animal activity patterns. Wolves were studied at the Camp Ripley National Guard Training Site in Little Falls, Minnesota, and were captured via helicopter net gunning. All study wolves showed nocturnal movement patterns regardless of time of year. One wolf's movement pattern switched to diurnal when he conducted an extraterritorial foray from his natal territory. All data sets with GPS intervals ≤1 hour (n = 4) showed crepuscular movement peaks. We identified patterns of den visitation and attendance, estimated minimum distances traveled and minimum rates of movement, and observed that GPS location intervals may affect perceived rates of wolf travel. Global Positioning System telemetry was useful in determining when pack members were traveling together or apart and how long a breeding female wolf spent near her pups (e.g., 10 month old pups were left unattended by their mother for as long as 17 days).

Key words:  activity, Canis lupus, circadian, Global Positioning System, GPS, movements, telemetry, wolf

Table of Contents

• Introduction
• Study Area
• Methods
• Results
• Discussion
• Literature Cited

Tables and Figures

• Table 1 -- Details about 10 wolves studied by Global Positioning System telemetry.
• Table 2 -- Location attempt intervals and mean and maximum travel rates for wolves studied by GPS telemetry.
• Table 3 -- Onset and cessation of excursions from 2 rendezvous sites by 10 month old wolf pups 820 and 860.

• Figure 1 -- Activity (mean distance between locations) plots for all wolves studied, except male 399.
• Figure 2 -- Locations of yearling male wolf 399 before and during an extraterritorial foray; (2 March 1998-27 July 1998).
• Figure 3 -- a) Mean distance between successive location attempt intervals versus time of day for GPS collared male wolf 399 prior to an extraterritorial foray; (3 February 27-July 98). b) Mean distance between successive GPS location intervals versus time of day for breeding female wolf 850 before, during, and after bearing pups; (20 February-9 March 1997, 10 April-24 May 1997, and 25 May-9 July 1997).
• Figure 4 -- Locations of GPS collared yearling male wolf 399 before an extraterritorial foray; (2 March 1998-31 May 1998).
• Figure 5 -- Movement data collected by GPS collar on breeding female wolf 850; (20 February-9 March 1997).
• Figure 6 -- Movement data collected by GPS collar on breeding female wolf 850; (10 April-9 July 1997).
• Figure 7 -- Number of GPS locations >1.5 km from the den for breeding female wolf 850; (10 April-25 May 1997).
• Figure 8 -- Movement data collected by GPS collars on wolf pups 860 and 820, breeding female wolf 850, and yearling male wolf 840; (24 February-12 March 1997).

Acknowledgments

This research was supported by the Minnesota National Guard, the Minnesota Department of Natural Resources, the Biological Resources Division of the United States Geological Survey, and the University of Minnesota. Advanced Telemetry Systems, Inc. donated several of the GPS radiotelemetry collars used in the study. We thank G. Blum, J. Brezinka, W. Brown, C. Erickson, M. Skoglund, G. Swenson, and E. Perry for assistance with implementation. G. DelGiudice, P. Jordan, and D. Siniff provided assistance with reviewing drafts.

Samuel B. Merrill, Environmental Office, Camp Riley Headquarters, 15000 Highway 115, Little Falls, MN 56345-4173, USA; present address: New England Environmental Finance Center, Edmund S. Muskie School of Public Service, University of Southern Maine, 49 Exeter Street, #205, Portland, ME 04104, USA; e-mail: smerrill@usm.maine.edu.

L. David Mech, Biological Resources Division, U.S. Geological Survey, Northern Prairie Wildlife Research Center, 8711 37^th St. SE, Jamestown, ND 58401-7317, USA; mailing address: The Raptor Center, 1920 Fitch Avenue, University of Minnesota, St. Paul, MN 55108, USA.

Samuel B. (Sam) Merrill (photo) is Projects Director at the New England Environmental Center, through the Muskie School of Public Service at the University of Southern Maine. For 6 years he worked for the Minnesota Department of Natural Resources as Animal Survey Coordinator at the Camp Ripley National Guard Training Site. He now works on smart growth policy and research in the six New England states. He received a B.A. in zoology from the University of Maine at Orono and an M.S. in conservation biology and a Ph.D. in wildlife conservation from the University of Minnesota. L. David (Dave) Mech is a senior research biologist with the Biological Resources Division of the United States Geological Survey and an adjunct professor at the University of Minnesota. He holds a Ph.D. from Purdue University. He has studied wolves and their prey for 45 years and published several books and numerous articles.