Energy Expenditure and Heart Rate for Activities of White-Tailed Deer

Abstract

Energy expenditure and heart rate during several activities in July were measured in whitetailed deer (Odocoileus virginianus) through the use of tracheal cannulas and implanted heart-rate transmitters. The energy expenditure and oxygen consumption for lying, standing/walking, and running activities were 1.01 kcal (0.21 liters of oxygen), 1.72 kcal (0.36 liters of oxygen), and 2.56 kcal (0.51 liters of oxygen) per kgo.75 per minute, respectively. These values were different (P < 0.05) from one another, as were the heart rates for these 3 activity levels: 65, 74, and 106 beats per minute. A linear relationship (P <0.01) was found between heart rate and energy expenditure as expressed by the equation kcal/kg075/ minute = 0.00143(heart rate) 0.0186. The r' value of the heart rate and energy expenditure relationship was 0.36 for all data combined, and ranged from 0.21 for lying activity to 0.53 for running activity. J. WILDL. MANAGE. 44(2):333-342 Knowledge of white-tailed deer biology has progressed to the stage where it is important to understand the energy expenditure of these animals in their natural environment. A knowledge of energy expenditure and subsequent energy requirement is essential to allow successful application of previously gathered food and feeding information. However, there have been few studies designed to determine energy expenditure of big game species. Such studies generally have employed the use of indirect respiration calorimeters or chambers. Chamber trials have been conducted with white-tailed deer (Silver et al. 1959, 1969, 1971; Holter et al. 1976), black-tailed deer (0. hemionus columbianus) (Nordan et al. 1970), pronghorn (Antilocapra americana) (Wesley et al. 1973), caribou (Rangifer tarandus) (McEwan 1970), and mountain goat (Oreamnos americanus) (Krog and Monson 1954). Respiration chambers play an essential role in the development of baseline information, but they impose a condition of strict confinement on the test animal and few natural conditions or activities can be simulated. Res arch emphasis is being placed on the search for an alternative to the respiration chamber. Energy expenditure has been determined for reindeer (R. tarandus) (Hammel et al. 1962, White and Yousef 1978), white-tailed deer (Mattfeld 1974), and mule deer (0. hemionus) (Kautz 1978) using face masks in order to reduce restriction of experimental animals. A procedure is n eded that, ideally, will provide energy expenditure information from a totally free-roaming animal without hampering its movement or behavior. Perhaps the m st attractive methodology proposed is to predict energy expenditure from heart rate because of its ease of measurement. Implantable heart-rate transmitters that allow the test animal totally unrestrained activity are available. The development of long-range transmitters makes it possible to monitor heart rate of animals from distances exceeding 1.6 km (Weeks et al. 1977). The relationship between heart rate and energy expenditure, however, has not been published for big game, except for chamber trials with white-tailed deer 1 Scientific Contribution 926 from the New Hampshire Agricultural Experiment Station. J. Wildl. Manage. 44(2):1980 333 This content downloaded from 157.55.39.35 on Wed, 31 Aug 2016 05:08:44 UTC All use subject to http://about.jstor.org/terms 334 ENERGY EXPENDITURE BY DEER' Mautz and Fair (Holter et al. 1976). That work showed a correlation between heart rate and energy expenditure with r2 ranging from 0.55 to 0.94, depending on season. However, whether this relationship and the subsequent predictive equation derived from chamber trials will apply to free-roaming animals performing a variety of physical and mental activities is subject to question. This paper reports a study aimed at measuring the relationship between heart rate and energy expenditure for whitetailed deer.