An Evaluation of Historical Mule Deer Fawn Recruitment in North Dakota

The evaluation of mule deer (Odocoileus hemionus) fawn-recruitment data is crucial to making sound management decisions regarding this important big game species. Young:female ratios have been declining and those recorded in western North Dakota during the past decade were well below the long-term average. Indeed, fawn production in 2008-2012 was the lowest documented since the first demographic surveys of mule deer began in 1962.

Concern about the decline in fawn recruitment motivates a thorough analysis of these long-term data to identify factors affecting mule deer fawn recruitment. Many factors have been implicated in fluctuations in fawn recruitment including weather, harvest management, predation by coyotes (Canis latrans), and rapid landscape change associated with oil and gas development. How to efficiently manage and harvest wild ungulates in the presence of stochastic events, predation, and human disturbance has been a continuing challenge for ungulate managers. Primary objectives of our investigation were to:

1. Document associations between weather conditions and weather packages on variation in mule deer fall fawn recruitment (Chapter 1);
2. Explore the possible role of coyote predation, using coyote population indices, on fall fawn recruitment (Chapter 2); and
3. Evaluate the importance of increasing energy development on annual fall fawn recruitment rates and the probable consequences to the long-term sustainability of mule deer populations in the badlands (Chapter 2).