Trent University Ph.D. Study Shows Human Influence Disturbs Animal Social Systems


Study by Environmental & Life Sciences Ph.D. Graduate
Linda Rutledge Confirms Human-Caused Mortality
Influences Social Fabric of Wolf Packs

Monday, March 22, 2010, Peterborough

New research conducted by Dr. Linda Rutledge during her time at Trent University as a Ph.D. student in the Environmental & Life Sciences Graduate Program, confirms what wolf biologists have long suspected: human-caused mortality influences the social fabric of wolf packs.

The research, recently published in Biological Conservation, was part of Dr. Rutledge’s Ph.D. research at Trent, which she completed in January 2010 under the academic supervision of Dr. Bradley White, chair and professor of Biology, and Dr. Brent Patterson, a research scientist at the Ontario Ministry of Natural Resources (MNR). The research resulted from collaboration between professors in Trent University’s Biology Department, graduate students in the Environmental & Life Sciences Graduate Program, and the MNR.

“My research focused on the evolutionary origins, pack structure, and hybridization of the eastern wolf. I also developed an improved method for individual identification of wolves from scat samples, and I analyzed some 500 year old canid samples from a pre-historic Iroquois village,” says Dr. Rutledge who is currently working as a post-doctoral researcher with the Natural Resources DNA Profiling and Forensic Centre (NRDPFC) at Trent University. “Trent was essential to the success of my Ph.D. work because it holds an extensive wolf genetic database from samples across North America. The equipment and lab space in the DNA Building is exceptional and allowed for great efficiency in seeing my project to completion.”

Based on genetic profiles and field observations, Dr. Rutledge constructed pedigrees of eastern wolf packs in Ontario’s Algonquin Provincial Park and compared her results to previously published research. The results demonstrate that packs have been restored to a natural family-based state after the implementation of a ban on hunting and trapping in townships surrounding the park. Prior to the ban, humans were the primary cause of death for wolves, with most mortalities occurring when Algonquin wolves traveled outside the park boundary in search of deer. Although wolf densities have remained stable, natural causes of mortality have largely replaced the formerly predominant human-caused mortality. But what is particularly important is that there has been a dramatic change in the social structure of the wolf packs in response to the ban.

Before the ban, 12 of 15 packs under study had unrelated animals that had been adopted into the pack, but that number dropped to only 1 pack of 17 studied after the ban, demonstrating that family based social bonds that are typically found in naturally regulated wolf populations had been restored. This research suggests that human influences can dramatically shape the social structure of wolf packs, independent of any changes in overall wolf numbers. Maintaining these familial bonds is important for social animals likes wolves because it facilitates effective predatory behaviours and pup survival. Based on research from other species that live in family-based social groups, wolf packs with high kinship may benefit from lower stress levels and improved reproductive output.

“This research is exciting because we are just starting to understand the importance that social structure has for many species,” Dr. Rutledge says, adding, “These social systems have evolved under natural selection for millions of years, and what scientists are finding more and more is that when human influences disrupt these social systems, there are serious implications for fitness, survival, reproduction and ultimately persistence of animal populations.”

According to Dr. Rutledge, the study also plays an important role in conservation policy making. “Conservation policy tends to focus on population size with little consideration of more cryptic aspects of population and social ecology,” she explains. “This research suggests that conservation plans and management strategies need to look beyond numbers and consider the impact that human influences have on social structure as well. In doing so, species that have evolved strong familial bonds within their social systems will reap these additional benefits.”


For more information, please contact:
Dr. Linda Rutledge, Post-Doctoral Researcher, Natural Resources DNA Profiling and Forensic Centre, Trent University, (705) 755-2258 or