FISH AND WILDLIFE TECHNICAL REPORT 30 



higher for polar (Ursus maritimus) and brown (U. arctos) bears than for caribou (Rangifer tarandus). 

 Efficiency of gathering both locational and sensor data was related to both latitude and topography. 



Mean error of locations was estimated to be 954 m (median = 543 m) for transmitters on captive 

 animals; 90% of locations were <1,732 m from the true location. Argos's new location class zero 

 processing provided many more locations than normal processing, but mean location error was much 

 higher than locations estimated normally. Locations were biased when animals were at elevations 

 other than those used in Argos's calculations. 



Long-term and short-term indices of animal activity were developed and evaluated. For several 

 species, the long-term index was correlated with movement patterns and the short-term index was 

 calibrated to specific activity categories (e.g., lying, feeding, walking). 



Data processing and sampling considerations were evaluated. Algorithms for choosing the most 

 reliable among a series of reported locations were investigated. Applications of satellite telemetry data 

 and problems with lack of independence among locations are discussed. 



Biotelemetry techniques are used to locate and obtain 

 physiological and behavioral data from free-ranging ani- 

 mals and to advance our understanding and management 

 of wildlife. Biologists commonly use radio-tracking 

 equipment that operates in the very high frequency (VHP) 

 range of the electromagnetic spectrum. However, limited 

 reception range is a drawback of conventional VHP equip- 

 ment, particularly for species that move long distances or 

 inhabit remote or mountainous areas. Adequate sampling 

 is often constrained by the high cost of locating the animal, 

 by problems with weather conditions, darkness, safety 

 considerations, and extensive animal movements. The use 

 of satellites for locating animals and obtaining other data 

 from them has become available with the recent technolo- 

 gy to construct accurate and reliable transmitters small 

 enough to be attached to animals. 



This report summarizes two years of research and de- 

 velopment of satellite telemetry for large mammals by the 

 Alaska Fish and Wildlife Research Center (AFWRC) of 

 the U.S. Fish and Wildlife Service, working in conjunction 

 with the Alaska Department of Fish and Game (ADFG), 

 Arctic National Wildlife Refuge (ANWR), Idaho Depart- 

 ment of Fish and Game, Yellowstone National Park, Cana- 

 dian Wildlife Service, Yukon Department of Renewable 

 Resources, the University of Idaho, and the University of 

 Alaska (Institute of Arctic Biology and Alaska Coopera- 

 tive Wildlife Research Unit [ACWRU]). Service Argos 

 (referred to hereafter as Argos) and Telonics, Inc. (Mesa, 

 Arizona), have participated in the development of this 

 technology. We present results of our studies on the re- 

 liability, accuracy, and precision of the system and on 

 developments in sensor technology and local user termi- 

 nals (LUT's). We summarize our experiences using the 

 Argos system to obtain locational and behavioral data on 

 polar bears (Ursus maritimus), caribou (Rangifer taran- 

 dus), muskoxen (Ovibos moschatus), brown bears (Ursus 

 arctos), gray wolves (Canis lupus), moose (Alces alces), 

 Pacific walrus (Odobenus rosmarus divergens), and Dall 



sheep (Ovis dalli) in Alaska and elk (Cervus elaphus) and 

 mule deer (Odocoileus hemionus) in the Rocky Mountain 

 region. 



To provide the reader a more complete understanding of 

 the Argos system and its applications to tracking animals, 

 we have included an updated and shortened overview of 

 the Argos system as presented by Fancy et al. (1988). 



Our experience has primarily been with large mam- 

 malian herbivores and carnivores, and our conclusions are 

 restricted to those species. Mate (1987) provided a com- 

 pilation of experiences using satellite telemetry on various 

 cetaceans. Other researchers have used lightweight, solar- 

 powered satellite transmitters to track large birds (Fuller 

 et al. 1984; Strikwerda et al. 1985, 1986). The use of 

 satellites to obtain data on free-ranging animals is expand- 

 ing rapidly. New technology and improved equipment are 

 continually being developed. However, we have reported 

 the most recent advances with which we are familiar for 

 use by prospective users of the technology. 



Overview of Argos 



The Argos Data Collection and Location System 

 (DCLS) is a cooperative international project of the Centre 

 National d'Etudes Spatiales (CNES) of France, the Na- 

 tional Oceanic and Atmospheric Administration 

 (NOAA), and the National Aeronautics and Space Ad- 

 ministration (NASA). The primary purpose of Argos is to 

 collect environmental data (e.g., meteorology, hydrology, 

 oceanography, ecology). The system consists of transmit- 

 ters on ocean buoys, glaciers, animals, and other places; 

 equipment on polar-orbiting Tiros-N satellites (currently 

 NOAA- 10 and NOAA- 1 1 ) that receive signals from trans- 

 mitters during <28 overpasses each day; and a network of 

 satellite tracking stations and ground and satellite commu- 

 nication links that transfer satellite data to processing cen- 

 ters that distribute results to users (Argos 1984). 



