OUP CORRECTED PROOF – FINAL, 6/12/2011, SPi 7 Radio-telemetry equipment and applications for carnivores Mark R. Fuller and Todd K. Fuller Radio-telemetry was not included in the first comprehensive manual of wildlife research techniques (Mosby 1960) because the first published papers were about physiological wildlife telemetry (LeMunyan et al. 1959) and because research using telemetry in field ecology was just being initiated (Marshall et al. 1962; Cochran and Lord 1963). Among the first uses of telemetry to study wildlife, however, was a study of carnivores (Craighead et al. 1963), and telemetry has become a common method for studying numerous topics of carnivore biology. Our goals for this chapter are to provide basic information about radio-telemetry equipment and procedures. Although we provide many references to studies using telemetry equipment and methods, we recommend Kenward’s(2001)comprehensivebook,Amanualofwildliferadiotagging for persons who are unfamiliar with radio-telemetry, Fuller et al. (2005), and Tom- kiewicz et al. (2010). Compendia of uses of radio-telemetry in animal research appear regularly as chapters in manuals (Cochran 1980; Samuel and Fuller 1994), in books about equipment, field procedures, study design, and applications (Amlaner and Macdonald 1980; Anderka 1987; Amlaner 1989; White and Garrott 1990; Priede and Swift 1992; Kenward 2001; MillspaughandMarzluff2001;MechandBarber 2002), and in reviews highlighting new developments (Cooke et al. 2004; Rutz and Hays 2009; Cagnacci et al. 2010). Some animal telemetry products and techniques have remained almost unchanged for years, but new technologies and approaches emerge and replace previously available equipment at an increasing pace. Here, we emphasize recent studies for which telemetry was used with carnivores. 7.1 General background We use “radio-telemetry” to refer to the process of obtaining information from a remote animal by use of radio waves. Most commonly, biologists use radio waves OUP CORRECTED PROOF – FINAL, 6/12/2011, SPi Radio-telemetry equipment and applications for carnivores | 153 that are categorized in the spectral bands of Very High Frequency (VHF = 30–300 MHz) or Ultra High Frequency (UHF = 300–3000 MHz [3 GHz]). In their respective countries, governments authorize the specific frequencies that can be used for wildlife studies. The term band or bandwidth is used to describe a specific range of frequencies (e.g. a 2-MHz band of 164–166 MHz). The signal transmit- ted to, or from, the animal can be used to estimate its location or to carry data about the animal’s motion, condition (e.g. heart rate, body temperature), or its environment (e.g. temperature, atmospheric pressure). Radio-telemetry can be used to gather information that is neither practical nor possible to obtain with other methods from rapid-moving, wide-ranging, and secretive carnivores. Biolo- gists have used radio-tracking to find animals for subsequent observation and to document local movements and estimate space use (e.g. home range, Chapter 9), to map dispersal and migration, and to study resource use and selection by carnivores (Chapters 10 and 11). Estimates of population abundance, survival, and fecundity, and information about causes of mortality, can be obtained using data from radio-marked animals (Chapter 5). Radio-telemetry can be applied to research of intraspecific (e.g. social behavior) and interspecific (predator prey) relationships (Chapter 11). If radio-telemetry seems like a potential technique for addressing objectives, careful study planning is necessary and one must consider several factors relative to alternative techniques (e.g. Long et al. 2008a). The first consideration for using radio-telemetry is its potential effects on marked animals (Murray and Fuller 2000; Withey et al. 2001; Table 7.1). Researchers must use an appropriate transmitter design and attach- ment. A study can fail or produce biased results if radio-marking causes aberrant behavior or physiological stress, increases mortality, or reduces reproduction. Animals require capture and restraint, and perhaps sedation or anesthesia (Cattet et al. 2008a), while being radio-marked (Mulcahy and Garner 1999; Agren et al. 2000; Arnemo et al. 2006), potentially compounding the effects of the telemetry package (Tuyttens et al. 2002). Biologists must investigate options for packaging and attaching the package when they discuss equipment with manufacturers. The expense of using radio-telemetry includes costs of equipment (transmitters, antennas, and receivers), salaries, transportation for field personnel to capture and radio-tag animals, and other labor and transportation (e.g. vehicles, aircraft) costs to locate animals in the field. If data are to be obtained via cell phone or satellite, costs include charges for reception, management, and distribution of data. In addition, effort and new procedures might be required to manage the magnitude of the data accumulated from telemetry (Cagnacci and Urbano 2008; Urbano et al. 2010). Pilot studies might be necessary for testing the performance and usefulness of equipment and methods, and to learn about variability in telemetry data OUP CORRECTED PROOF – FINAL, 6/12/2011, SPi 154 | Carnivore Ecology and Conservation Table 7.1 Uses of radio-telemetry to study carnivores—considerations. Topic Species References Attachment capture collar wolves Mech and Gese 1992 collars weasels Gehring and Swihart 2000 ferrets Biggins et al. 2006 brown bears Schwartz and Arthur 1999 collar release mechanisms wolves Merrill et al. 1998 black bears Garshelis and McLaughlin 1998 expandable implants black bear Vashon et al. 2003 cubs otters Soto-Azat et al. 2008 badgers A˚gren et al. 2000 fishers Weir and Corbould 2007 foxes Fuglei et al. 2002 wolves Crawshaw et al. 2007 multiple methods otters Neill et al. 2008 subcutaneous polar bears Mulcahy and Garner 1999 Effects of collars badgers Tuyttens et al. 2002 of handling cougars Fiorello et al. 2007 bears Cattet et al. 2008a Aerial tracking cougars Stoner et al. 2008 lynx Vashon et al. 2008 wolves Hebblewhite and Merrill 2008 Triangulation bobcats, bison Riley 2006 pumas Laundre and Hernandez 2008 red foxes Van Etten et al. 2007 Auto-tracking ocelots Mares et al. 2008 system Video and MacNulty et al. 2008 Telemetry System Satellite system brown bears Graves and Waller 2006 performance Heard et al.2008 Walton et al. 2001a GPS performance Frair et al. 2004 Jozwiak et al. 2006 Johnson et al. 2002 Lewis et al. 2007 lynx DeCesare et al. 2005 Mattisson et al. 2010 brown bears Sundell et al. 2006 Gau et al. 2004 cougars Lindzey et al. 2001 Ruth et al. 2010 maned wolves Coelho et al. 2007 OUP CORRECTED PROOF – FINAL, 6/12/2011, SPi Radio-telemetry equipment and applications for carnivores | 155 quantity and quality, which affect sample size, study design, and interpretation of results (Girard et al. 2002; Lindberg and Walker 2007; Mills et al. 2008). Finally, the number of animals that must be radio-marked, the spatial scale over which they must be sampled, the duration of the study, and training of personnel, affect the expense of using radio-telemetry. After identifying the study objective(s) and reviewing relevant literature, corre- spondence with telemetry vendors (via http://www.biotelem.org; accessed March 17 2011) and biologists who have done similar research with the equipment and species is a critical step in deciding how technology can best be applied to the research question. Biologists must be able to describe the environment in which a study is to take place and how they expect the equipment to function. Biologists should test the performance of their radio-telemetry “system” (transmitters, recei- vers, antennas, coaxial cables, data loggers; Mills and Knowlton 1989; Merrill et al. 1998; D’Eon and Delparte 2005), including field-testing in the topographic (D’Eon et al. 2002; Zweifel-Schielly and Suter 2007) and vegetative conditions of the study area (Dussault et al 1999; Di Orio et al. 2003; DeCesare et al. 2005). When equipment is used in naturally varying environments, and when animal behavior causes variability, it often does not perform to the specifications obtained by manufacturers from controlled laboratory testing (Gau et al. 2004; Coelho et al. 2007; Hwang and Garshelis 2007; Mattisson et al. 2010). When a minimum sample of radio-marked animals is critical, researchers must estimate average opera- tional life and failure rates from a sample of transmitters acquired for the study. Some transmitters will surely fail before their predicted operation life is achieved. The scheduled reception of data can be interrupted (Graves and Waller 2006) by factors such as atmospheric interference, vegetation, terrain, and buildings, thus reducing sample size (Hebblewhite et al. 2007). Observation bias results when the probabil- ities of obtaining scheduled location estimates are not equal along animals’ move- ment paths or within a period of interest, and when measurement error occurs when the true location of the animal is different from the estimated location. Equipment performance can affect any use of radio-telemetry data (Hupp and Ratti 1983; White and Garrott 1990; Land et al. 2008) and the application of relatively accurate, regular, Global Positioning System (GPS) and other satellite technology has re- newed focus on these issues (Rempel et al. 1995; Hurlbert and French 2001; D’Eon 2003; Cain et al. 2005; Hansen and Riggs 2008). Researchers must understand the performance of the telemetry equipment to correctly use and interpret telemetry data (Belant and Follmann 2002; Theuerkauf and Jedrzejewski 2002; Frair et al. 2004; Mills et al. 2006; Hebblewhite et al. 2007; Horne et al. 2007; Andersen et al. 2008; Frair et al. 2010). If the telemetry unit on an animal fails to function, and each animal is a sample unit, then sample OUP CORRECTED PROOF – FINAL, 6/12/2011, SPi 156 | Carnivore Ecology and Conservation size is reduced. If data are received less often than expected, or if the telemetry does not perform consistently among all study conditions (e.g. weather, terrain, vegeta- tion), then the quantity or regularity of data might be insufficient for an analysis that had been planned.