Wolf predation in a multiple-ungulate system in northern British Columbia

The problem with wolf predation as well as bear in BC has been regarded as a limiting factor in the growth of moose and caribou population. The report will focus on testing the limiting effect and dependence of wolf predation in the survival of young ungulates in BC. It is stated that four of the ungulate species moose, caribou, sheep and elk are lightly hunted. The major question for this study is understanding whether the death of young ungulates ( 0-12 months) by predators is density-dependent or density-independent. For this reason the effects and density-dependence of wolf predation for all four species has been tested by regressing recruitment. If the results of the test were curvilinear and included survival decrease at an alarming rate as the numbers of recruits were reduced this would confirm the density-dependent argument.

The two areas that were used in BC as a study area were Kechika which comprises of sheep, moose and a small herd of caribou, and Muskwa that has a vast variety of ungulates such as elk, moose, caribou, sheep, mountain goats, mule deer and buffalo.


In order to study the wolves helicopter surveys were done during winter and flying along routes that were most likely used by wolves. The aerial surveys would take place between 24-48 hours after a fresh snowfall with two observers in the helicopter. This was made to make tracking easier and if fresh tracks were found they were followed until the wolves were located or the tracks were separated to enable a complete count.

As for the ungulate’s recruitment they were identified and classified by sex and age by helicopter survey in fall where the young ones were about 5 months old or in March with an approximate age of 9 months old. For the study young ones were counted as the number of calves 5-9 month of age per 100 females. The lambs were calculated per 100 ewes plus male yearlings and it was assumed that the number of male yearlings was equal to that of the female yearlings. Additionally, the moose and elk calculation was done by doubling the male yearlings summed up and corrected to the total number of adult females by subtracting the actual number of male yearlings counted. Moreover, females yearling sheep had to be doubled in total to account for male yearlings that were confounded with adult females and then correct to the totals of females by subtracting the actual number of female yearlings counted. It was bothersome in using calves instead of yearlings for sheep and elk because calves are still vulnerable to predation compared to an average adult.


Before the study and the removal of wolf numbers, the ungulate population was either stable or decreasing. After wolves were reduced in the studied areas the ungulate populations started to increase. Therefore, with the result of the study in mind it confirms that wolves were a major limiting factor in the growth population of ungulates.

There are a few hypotheses which are: wolves self-regulate across territorial behaviour or wolves accustom their number on the basis of prey biomass. But by analysing the results of the study the explanation is leaning more towards the second hypothesis.

Each year wolves were removed yet they would repopulate even as the density of the population was approaching the pre-removal numbers. This dispersal is a primary mechanism for the regeneration of wolves when prey are present and increasing in survival.

Public opinion is concerned with wolf management and conservation by means of removal programs. Therefore, this confirms that the best management of wolf conservation program should be regulated as a predator/ prey management plan. There will be a greater biomass of ungulates and wolves can be better predicted when there is management.


The study was focused on wolf management and impact that was induced on the ungulate population. This allowed researchers to understand how areas the ungulate populations were able to increase and to understand that wolf predation is a major limitation on the increase of prey population.

  • Source A.T. Bergerud and J.P. Elliott. 1998. Can. J. Zool. Vol. 76. Wolf predation in a multiple-ungulate system in northern British Columbia. Available at : https://cdnsciencepub.com/doi/pdf/10.1139/z98-083 [Accessed 03/2021].