Physiological Stress Responses, Aggression, and Social Dominance in Wild Wolves

EPA Grant Number: U915542
Title: Physiological Stress Responses, Aggression, and Social Dominance in Wild Wolves
Investigators: Sands, Jennifer L.
Institution: Montana State University
EPA Project Officer: Hahn, Intaek
Project Period: September 1, 1999 through July 1, 2001
Project Amount: $58,864
RFA: STAR Graduate Fellowships (1999) RFA Text |  Recipients Lists
Research Category: Fellowship - Zoology , Academic Fellowships , Biology/Life Sciences


The objective of this research project is to determine relationships among social dominance, aggression, reproduction, and stress hormone (glucocorticoid) levels in wild wolves (Canis lupus), using noninvasive methods.


Approximately one-half of the Yellowstone wolf population is radio collared, making it possible to locate the wolves on a daily basis. Demographic data, collected by the National Park Service since the reintroduction in 1995, are available so that age, survival, and reproduction are known for all individuals. Detailed behavioral observations and fecal sampling are focused on three observable packs in the northern range of the park. To conduct fecal sampling, pack members are observed with a spotting scope. When individuals defecate, the location is recorded, and the sample is collected after the animal moves away from the area. The samples are frozen until they are extracted and assayed in our laboratory at Montana State University. Behavioral observations are made during full-day follows, using all-occurrences sampling. Because continuous observation is not always possible, the beginning and end of observation periods are recorded, and at 10-minute intervals, scan samples are used to correct for biases in observability among individuals. I record initiator, recipient, and class of behavior (winner/loser, where appropriate) for all aggressive, agonistic, and sexual behaviors. Behaviors other than mating behavior, treated as instantaneous, will be used to calculate daily rates for each individual. The duration of mating behavior also is recorded.

Supplemental Keywords:

fellowship, wolf, Canis lupus, stress hormones, glucocorticoids, endocrinology., RFA, Scientific Discipline, Ecosystem Protection/Environmental Exposure & Risk, Monitoring/Modeling, Environmental Monitoring, Ecology and Ecosystems, social dominance, biomarkers, conservaton, chronic stess model, animal model, stress hormones, environmental stress, glucocorticoids, bioindicator species

Progress and Final Reports:

  • 2000
  • Final