Effect of Coyotes and Release Site Selection on Survival and Movement of Translocated Swift Foxes in the Badlands Ecosystem of South Dakota

<p>Success of different release strategies for swift fox (Vulpes velox) translocation was evaluated in the Badlands Ecosystem in southwestern South Dakota. Release site selection (outside coyote [Canis latrans] core-use areas compared to random release sites) and release method (i.e., hard, semi-hard, and soft) were examined to determine effects on swift fox survival and movements at 50 days post-release. I hypothesized that swift foxes released outside of coyote core-use areas would survive at a higher rate than foxes released at random sites. From 2003-2006, 16 adult coyotes were fitted with Global Positioning System (GPS) radio collars and monitored during the pup rearing season (May-August). Coyote core-use areas were calculated and used in selecting sites where swift foxes would be released in September. Swift foxes were captured in Colorado or Wyoming and transported to Badlands National Park (BNP) for release. A total of 114 swift foxes (51 males, 63 females) were released from 2003-2006. All foxes were fitted with VHF radio collars before release. Mean home range size during the pup rearing season did not differ between male (14.2 ± 1.0 km2) and female (14.9 ± 2.0 km2) (P > 0.75) coyotes. Mean home range size for coyotes located within (15.2 ± 2.9 km2) and outside (14.3 ± 1.0 km2) of BNP was similar (P > 0.78). Size of core-use areas for male (1.4 ± 0.2 km2) and female (1.3 ± 0.2 km2) coyotes did not differ (P > 0.65) from one another. Core-use areas for coyotes located within BNP (1.0 ± 0.6 km2) or adjacent to BNP (1.5 ± 0.6 km2) did not differ (P > 0.11) from one another. Mean nighttime movement rates (km/hr) differed among female coyotes occupying areas within BNP (0.65 ± 0.02 km/hr), female coyotes outside of BNP (0.88 ± 0.02 km/hr), and male coyotes outside of BNP (0.78 ± 0.02 km/hr; P < 0.001). Backward elimination in the Survival Cox Regression demonstrated that release site (P = 0.89), release method (P = 0.38), age (P = 0.91) and gender (P = 0.23) were not significant predictors of swift fox survival. Mean distance moved from release site (P = 0.001) was the only variable that contributed to the final model. Straight-line distance moved from release site at 50 days differed (P = 0.01) for swift foxes that survived (22.6 ± 4.2 km) versus swift foxes that died (10.5 ± 1.2 km). For swift foxes that survived, distance from release site at 50 days did not differ by gender (P = 0.12), age (P = 0.29), release year (P = 0.11), release site (P = 0.39), or release method (P = 0.08). Movement was affected by release method (P < 0.01) and age (P = 0.07). Swift fox translocations should continue with wild animals. Juveniles are the preferred age class of swift fox translocation candidates, but survivorship of all released foxes can be improved with short-term soft release techniques.</p>

Name thesis:degree_name

Master of Science (MS)

Level thesis:degree_level

Thesis - Open Access

Discipline thesis:degree_discipline

Wildlife and Fisheries Science

Year

2007

Author dc:creator

• Schroeder, Greg M.

Contributors dc:contributor

• Jonathan A. Jenks

• coyotes
• swift fox
• badlands
• ecosystem
• south dakota
• survival
• Natural Resources and Conservation

Licence

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language

en

Repository record dc:identifier

https://openprairie.sdstate.edu/etd/396

OAI identifier oai:identifier

oai:openprairie.sdstate.edu:etd-1396