Moose population change in British Columbia: An inquiry

As a reaction to the observation of a declining Moose population in certain areas of British Columbia, the Ministry of Forests, Lands and Natural Resource Operations (FLNRO) and its partners set up a five-year research program in order to determine and better comprehend the possible causes of the observed decline. The research is labelled the ‘landscape change hypothesis’ and the program took off in December 2013 and will finish March 2018.

What

The two main possible causes under investigation are the mountain pine beetle outbreaks and the increase in salvage logging. The focus is on five study areas: Bonaparte, Big Creek, Entiako, Prince George South and John Prince Research Forest. These areas range from 3000 to over 10,000 km2.

Salvage logging and mountain pine beetle can cause a change in the forest age structure and may lead to an increase in road density. As a consequence, Moose could become more vulnerable to hunters and predators when moving in cutblocks. Moreover, reduced density of mature trees, which provides less snow interception, might increase the energetic requirements for winter feeding and the possibility of reduced thermal cover which will reduce the Moose’s body condition when entering winter. These effects could present themselves immediately post-logging, but could also have an impact over a longer period of time. On the contrary, salvage logging could have long lasting positive effects on the Moose population: regenerating forest stands could increase the food availability in the region 5 to 40 years after the logging.

Next to the two main possible causes under investigation, area-specific objectives per region have been set. These objectives have been developed based on regional and funding partner interest. For example, in Entiako, the largest region under investigation (i.e. 10,543 km2), besides determining how factors relating to changes in the forest landscape affect Moose behaviour and mortality risk, they define population units by documenting seasonal movements, compare the Moose distribution with that of the Caribou Tweedsmuir herds and investigate how Moose respond to a large wildfire.

As a final step, the study will try to assist in determining what processes can be influenced by management actions and how to do so.

How

The research will be conducted by identifying three response variables, cow and calf survival and population growth rate, and by applying several field methods: capture and handling of cows, mortality site investigations, biological samples from non radio-collared Moose, surveys to measure population change and composition, predator assessment and GPS radio collars. By using GPS radio-collars, the researchers will try to determine how cows survive. This method was chosen because population growth is assumed to be affected by the magnitude and variation in non-licensed hunting and given the fact that changing moving patterns are in relation to vulnerability to predator, food and snow conditions.

In order the analyze all the data gathered, a project database will be developed including all of the areas under investigation.

Finally, it is important to note that due to financial and logistical constraints, although important, the following three subject areas are not being investigated: calf survival and their behaviour from 6-12 months of age, the influence of nutritional constraints on Moose survival and the relative importance of Moose in diet of predators.

Next

By investigating the landscape change hypothesis over a five-year research program which will finish beginning 2018, researchers from the Ministry of Forests, Lands and Natural Resource Operations and their partners will try to find an answer as to why the Moose population in certain areas of British Columbia are declining. Is the observed decline in Moose population caused by salvage logging and the mountain pine beetle outbreaks? At this time we are not sure yet. However, the stage is set, the research program took off and we hope to be able to answer these questions when the research will come to an end.

Canadian Moose in:

  • Source Kuzyk, G., and D. Heard. 2014. Research design to determine factors affecting moose population change in British Columbia: testing the landscape change hypothesis. B.C. Minist. For., Lands and Nat. Resour. Operations. Victoria, BC. Wildl. Bull. No. B-126. 16pp. Available at : https://www2.gov.bc.ca/assets/gov/environment/plants-animals-and-ecosystems/wildlife-wildlife-habitat/wildlife-health/wildlife-health-documents/2014_bc_moose_research_design.pdf [Accessed 03/2021].