University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln USGS Northern Prairie Wildlife Research Center US Geological Survey 2007 A Proposed Ethogram of Large-Carnivore Predatory Behavior, Exemplified by the Wolf Daniel MacNulty University of Minnesota, St. Paul L. David Mech USGS Northern Prairie Wildlife Research Center, [email protected] Douglas Smith Yellowstone Center for Resources Follow this and additional works at: https://digitalcommons.unl.edu/usgsnpwrc Part of the Other International and Area Studies Commons MacNulty, Daniel; Mech, L. David; and Smith, Douglas, "A Proposed Ethogram of Large-Carnivore Predatory Behavior, Exemplified by the Wolf" (2007). USGS Northern Prairie Wildlife Research Center. 105. https://digitalcommons.unl.edu/usgsnpwrc/105 This Article is brought to you for free and open access by the US Geological Survey at DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in USGS Northern Prairie Wildlife Research Center by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln. Journal of Mammalogy, 88(3):595–605, 2007 A PROPOSED ETHOGRAM OF LARGE-CARNIVORE PREDATORY BEHAVIOR, EXEMPLIFIED BY THE WOLF DANIEL R. MACNULTY,* L. DAVID MECH, AND DOUGLAS W. SMITH Department of Ecology, Evolution, and Behavior, University of Minnesota, 100 Ecology Building, 1987 Upper Buford Circle, St. Paul, MN 55108, USA (DRM) Biological Resources Division, United States Geological Survey, Northern Prairie Wildlife Research Center, 8711 37th Street SE, Jamestown, ND 58401, USA (LDM) Yellowstone Center for Resources, P.O. Box 168, Yellowstone National Park, WY 82190, USA (DWS) Although predatory behavior is traditionally described by a basic ethogram composed of 3 phases (search, pursue, and capture), behavioral studies of large terrestrial carnivores generally use the concept of a ‘‘hunt’’ to classify and measure foraging. This approach is problematic because there is no consensus on what behaviors constitute a hunt. We therefore examined how the basic ethogram could be used as a common framework for classifying large- carnivore behavior. We used .2,150 h of observed wolf (Canis lupus) behavior in Yellowstone National Park, including 517 and 134 encounters with elk (Cervus elaphus) and American bison (Bison bison), respectively, to demonstrate the functional importance of several frequently described, but rarely quantified, patterns of large- carnivore behavior not explicitly described by the basic ethogram (approaching, watching, and attacking groups). To account for these additionally important behaviors we propose a modified form of the basic ethogram (search, approach, watch, attack-group, attack-individual, and capture). We tested the applicability of this ethogram by comparing it to 31 previous classifications and descriptions involving 7 other species and 5 other wolf populations. Close correspondence among studies suggests that this ethogram may provide a generally useful scheme for classifying large-carnivore predatory behavior that is behaviorally less ambiguous than the concept of a hunt. Key words: behavioral classification, Bison bison, Canis lupus, carnivore, Cervus elaphus, ethogram, predator behavior, predator–prey interaction, wolf The description and classification of behavior are funda- Predatory behavior is traditionally subdivided into 3 natural mental to quantitative studies of animal behavior. Although units or phases: search, pursue, and capture (Holling 1965; sometimes neglected, this stage of a behavioral study is crucial MacArthur and Pianka 1966). This basic ethogram underlies because it determines the scope of analysis and often dictates decades of predation research and is the standard approach for the course of future research (Bekoff 1979; Hinde 1970; Hutt classifying the behavior of nearly all predators with the and Hutt 1970). However, classifying behavior is difficult exception of the large terrestrial carnivores. Behavioral studies because it occurs as a continuous stream of movement, and of large carnivores generally classify predatory behavior in observer biases affect how units of behavior are separated and terms of a ‘‘hunt.’’ Authors have complained about this term recombined from this stream (Fentress 1990). Nevertheless, reg- since its 1st application to large carnivores because its ularities and discontinuities in patterns of movement do provide definition is too subjective (Caro 1994; Creel and Creel an empirical basis by which to subdivide behavioral streams 1995, 2002; Kruuk 1972; Mills 1990; Schaller 1972; Scheel into natural units (Altmann 1965; Lehner 1996; Martin and and Packer 1991; Stander 1992; Stander and Albon 1993). Bateson 1993). Investigators can therefore minimize bias in the Specifically, it is not obvious which behaviors should be scored classification of behavior by selecting behavior units that reflect as ‘‘hunting.’’ As a result, a hunt can refer to any 1 of several these natural subdivisions. behaviors, individually or collectively (Table 1). Creel and Creel (1995, 2002) note that no single definition of a hunt can apply to all large carnivores because of variation in hunting * Correspondent: [email protected] techniques (stalking versus coursing). Nevertheless, the lack of a standard hunting definition has complicated taxonomic Ó 2007 American Society of Mammalogists comparisons (Caro and FitzGibbon 1992; Gittleman 1989; www.mammalogy.org Packer and Ruttan 1988). 595 596 JOURNAL OF MAMMALOGY Vol. 88, No. 3 a TABLE 1.—Definitions used by studies of large carnivores to classify a hunt. Species Definition Reference Cheetah Stalking, attacking, or both Eaton 1970b Cheetah Approaching prey undetected or running after prey Schaller 1972 Cheetah Stalking or pursuing a prey group, or both FitzGibbon and Fanshawe 1988 Cheetah Crouching at, stalking, or trotting toward prey Caro 1986 Cheetah Crouching at, stalking, trotting toward, rushing, or chasing a group of prey animals Caro 1987 Cheetah Crouching at, stalking, trotting toward, rushing at, or chasing prey Caro 1994 Coyote Walking, running, or lunging Lingle 2000 Dingo Pursuing or attacking prey Thompson 1992 Spotted hyena Pursuing a selected individual from a prey group for Gasaway et al. 1991; Holekamp at least 50 m et al. 1997; Kruuk 1972 Spotted hyena Stalking or pursuing a prey group, or both Fitzgibbon and Fanshawe 1988 Spotted hyena Moving toward prey at an increased speed Mills 1990 Lion Pursuing an individual or herd at a trot or run if the lion approached to within 60 m or closer Schaller 1972 Lion Pursuing a prey animal at a run or trot, or approaching prey by assuming a stalking posture Van Orsdol 1984 Lion Moving toward prey while exhibiting any one of the following behavior patterns: alert face Scheel and Packer 1991 (oriented toward prey) combined with waiting in ambush, alert walk, standing walk, crouching walk, crouch, trot, head-low trot, or rush Lion Movement by at least 1 lion toward potential prey while using a typical stalking stance Scheel 1993 Lion Stalking or running at prey, or both Mills and Shenk 1992 Lion Staring at prey with an alert posture and alert facial expression, and stalking for more Stander 1992; Stander and than 10 m Albon 1993 Lion Stalking or chasing prey, or both Funston et al. 2001 African wild dog Stalking or chasing a prey group, or both FitzGibbon and Fanshawe 1988 African wild dog Pursuing a prey group Fanshawe and FitzGibbon 1993 African wild dog Pursuing prey; identified by the increased change in gait oriented toward prey Fuller and Kat 1993 African wild dog Pursuing prey for at least 50 m at a full run, ending with the wild dog testing prey at Creel and Creel 1995, 2002 bay, or ending in a kill a Studies of wolves did not define hunt. Defining a hunt also is problematic because it involves ex- 1972; Mech 1970; Schaller 1972). Although much qualitative cluding predation phases, combining them into single mea- evidence suggests that these additional behaviors are function- surement units, or both, and many aspects of predator and prey ally important, quantitative evidence is generally lacking. behavior are differentially affected by different phases. For The reintroduction of wolves to Yellowstone National Park example, predator diet preferences can be generated by dif- provides a new opportunity to study the predatory behavior of ferences among prey types in any of the phases, and inter- large carnivores (Smith et al. 2004). However, the lack of pretations of predator diet can be affected by the phase that is a standard scheme to classify such behavior presents a meth- sampled (Creel and Creel 2002; Sih and Christensen 2001). odological dilemma. To address this we developed a new This is especially relevant to optimal diet theory because it approach to classifying large-carnivore predatory behavior makes predictions about only 1 phase of predation, the prob- based upon the basic ethogram. Not surprisingly, the basic ability of attack given an encounter with prey, and differences ethogram is not a complete description of all the phases of among prey types in other phases can produce diet patterns that predation that have been described for large carnivores. Modi- do not fit the theory (Sih and Christensen 2001). Likewise, fying it to account for these phases is difficult because as variation in the effectiveness of antipredator traits among phases are added that tailor the ethogram to 1 or a few species, phases can lead to incorrect conclusions about the value of an its usefulness as a general description