Monday, March 4, 2013

Adaptive Management Techniques: How coyote sterilization can work towards red wolf recovery efforts

A frequently asked question here at the Red Wolf Recovery Program is “Do red wolves breed with coyotes?” The short answer is yes, they can. Red wolves, gray wolves, domestic dogs, and coyotes are capable of interbreeding and producing fertile offspring.  While social structures and territoriality usually prevent such interbreeding, the combination of a small red wolf population, a large coyote population, and limited space in the recovery area can result in a breakdown of the natural barriers.

  Coyote. Photo by B. Bartel/USFWS.

During the initial site selection process for the red wolf restoration program, the northeastern North Carolina (NENC) Red Wolf Recovery Area was uninhabited by coyotes.  However, coyotes have expanded their range eastward; individuals were observed in NENC beginning in the early-1990s.  As a result, an adaptive management plan was needed to eliminate the threat of hybridization.  Research has demonstrated that sterilized coyotes remain territorial and continue to defend space. It is this concept of holding space that is being applied to manage hybridization by providing managers time, information, and a higher degree of control over the recovery landscape, while simultaneously providing reproductive advantage to the red wolf.   Ultimately, sterilization is a method that allows territorial space to be held until that animal can be replaced naturally or by management actions. Sterile “placeholder” coyotes are then naturally replaced when the larger red wolves displace or kill the coyote.  Occasionally, we may remove a coyote from an area when we have the opportunity to insert a wild or translocated red wolf into that territory or if we have a red wolf dispersing into that area.  

The bottom line is that space is limited in the recovery area. Ideally, within the restored red wolf population in NENC, that space is initially best occupied by breeding pairs of red wolves, non-breeding mixed (red wolf/coyote) pairs, and non-breeding coyote pairs.  By sterilizing coyotes, introgression of non-wolf genes will be controlled and territories will be unavailable for colonization by breeding coyote pairs or red wolf-coyote pairs.  As the red wolf population grows, having space available for dispersing red wolves becomes increasingly important, and this space is provided through natural interspecific competition and/or management actions.

Currently, in addition to the ~65+ radio-collared red wolves, we are actively tracking and monitoring 50 sterilized, placeholder coyotes.  They are captured, processed, and released similar to red wolves (with the additional step of sterilization at a local veterinary hospital).  

 A coyote being processed and fitted for a radio-telemetry collar. 
Photo by B. Bartel/USFWS.

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