The Mulchatna Caribou Herd in Southwest Alaska
This summer, Andrea interned as a wildlife technician for the Alaska Department of Fish and Game in Palmer, AK. Her primary duties included assisting in Mulchatna caribou field work including spring parturition surveys, calf survival surveys, cause of mortality investigations, and data management tasks towards evaluating archived caribou datasets. In the future, she will continue working with a research biologist in Palmer to analyze the variation in reproductive success, age-specific survival rates, and genetic composition in the herd. This data analysis will be part of Andrea’s dissertation and she is excited to see what the results of these analyses will be. In the following paragraphs, Andrea briefly introduces the Mulchatna caribou herd and its ongoing research.
Alaska has over 30 caribou herds across the state. The Mulchatna caribou herd can be found in Southwest Alaska in an area that spans about 60,000 square miles. In the late 1990s, the Mulchatna herd had its largest annual range and a population peak of about 200,000 animals. However, the annual range has declined in the past 20 years as the herd declined in numbers. Modeling suggests the herd population declined due to many factors such as an older age structure with reduced productivity and increased calf mortality. However, after 20 years of sustained low population abundance and lack of recovery, necessitated research is currently being conducted for better conservation and management of the herd.
In October 2020, research on adult female caribou began under principal investigator and research biologist, Renae Sattler. The goal of this research is to evaluate current indices of herd health and population metrics through a multifaceted study. The objectives of this study include quantifying adult female caribou body condition, disease prevalence, variation in reproductive success, estimating the age-specific survival rates, and identifying the proximate causes of death. This work suggests that the current challenges facing the Mulchatna herd include poorer body conditions assumed to be from limited nutrition, high prevalence of brucellosis (a reproductive disease that can reduce reproductive success), mortality caused by wounding loss, and illegal/out-of-season harvesting.
More information on brucellosis and Mulchatna caribou (closed) hunting season can be found at the following links:
Barten, N. L., and L. N. Watine. 2020. Caribou management report and plan, Game Management Units 9A, 9B, 9C, 17, 18, 19A, 19B: Report period 1 July 2012–30 June 2017, and plan period 1 July 17–30 June 2022. Alaska Department of Fish and Game, Species Management Report and Plan ADF&G/DWC/SMR&P-2020-2, Juneau.
Valkenburg, Patrick, Richard A. Sellers, Ronald C. Squibb, James D. Woolington, Andrew R. Aderman, and Bruce W. Dale. 2003. “Population Dynamics of Caribou Herds in Southwestern Alaska.” Rangelands, April, 131–42.
Andrea grew up in Laredo, Texas. In the Fall of 2020, she received her BS in Wildlife and Fisheries Sciences as a Terry Foundation Scholar at Texas A&M University in College Station, Texas. Currently, she is a second-year graduate student pursuing an M.S. in Wildlife Sciences under Dr. Janna Willoughby in the Conservation Genomics Lab at Auburn University. Her research focuses on compiling and evaluating previously used methodologies for estimating and monitoring mammalian populations and testing the efficacy of the methods using an agent-based model. She will finish her master’s program this summer (2022) and stay in the Willoughby Lab to start her Ph.D. in Wildlife Sciences in the Fall. Her research will focus on understanding the demographic and genetic responses of Alaskan caribou populations to ongoing management operations. This research will be conducted in collaboration with the Alaska Department of Fish and Game to support the long-term stability of caribou populations and the continued availability of these natural resources. Andrea is very excited to see the outcomes of her research.