Montana Fish, Wildlife and Parks and the University of Montana have completed the second year of a three-year project, in partnership with SCI Foundation, investigating the influence of predation, habitat and nutrition on elk population dynamics in the southern Bitterroot Valley.
As they approach the end of the second year of intensive elk survival monitoring, they continue to see that mountain lion predation is the dominant cause of elk mortality, and they are finding mortality causes from year two were similar to those observed in year one. Heading into the summer, researchers will work to capture and radio tag the third and final cohort of neonatal elk, and monitor cause-specific mortality throughout the following year. This summer they also plan to complete the mountain lion population estimate, and the second and final year of vegetation monitoring.
- In late May and early June 2012, the second cohort of 76 elk calves were captured and marked with radio ear tags. Calves have been monitored several times a week using aerial and ground telemetry. When a mortality signal was detected, the tag was located and a thorough investigation of the site as well as a comprehensive onsite necropsy was conducted. During the summer and early fall of 2012, 18 calves survived, 30 calves died and 28 ear tags failed. The primary cause of mortality was mountain lion predation.
- Mountain lion predation continues to be the dominant cause of elk mortality, and find mortality causes from year two were similar to those observed in year one. The research team investigated the density of the big cats during the winter of 2012-2013using DNA-based mark-recapture methodology. To date, 54 unique animals have been identified in the study area.
- In summer 2012 assessment of forage availability for elk across the study area on private, state, and federal lands began. The researchers want to know what the elks diet’s are during summer and winter, what forage availability is across different landcover types during the peak of the growing season, and what the forage plant phenology is during the growing season from April to October. Answering these questions will give the researchers more information on the diet and nutrition of the elk. This will lead to the development of a seasonally dynamic spatial landscape model of elk forage biomass and quality to link to our estimates of elk nutritional condition and our overall project objective of understanding how elk forage affects population dynamics in the Bitterroot.
For the full progress report go here. For more information about the Bitterroot Elk Project check out the Safari Club International Foundation’s website or Montana Fish, Wildlife and Parks project website.