Abstract
Using GIS to Quantify Common Raven threats Track: Forestry, Wildlife, and Fisheries Management Author(s): Thomas Leuteritz, Blowyn McIntrye Ravens (Corvus corax) are a known threat to the desert tortoise (Gopherus agassizii) as they predate juvenile tortoises. Raven populations in the Mojave Desert have expanded rapidly for the past 20 to 30 years while desert tortoise populations have been drastically reduced. Research efforts have included analyzing historical population trends and raven "hot spots," determining "raven attractants" in the west Mojave Desert using GIS and statistical analyses to identify raven nesting sites in the Mojave and more specifically nesting sites with evidence of juvenile tortoise predation. We quantified the threats ravens pose to translocated desert tortoises in the translocation area outside Ft. Irwin. Using GIS, we (1) Estimated raven population numbers, which allows for a comparison to raven densities at this site in the future and (2) Quantified raven nest locations and predation behaviors, which allows for a comparison to raven nesting at this site in the future. Thomas Leuteritz University of Redlands Redlands Institute 1200 East Colton Avenue Redlands , CA 92373 US Phone: 9093355268 E-mail: Leti_franco@redlands.edu Blowyn McIntrye University of Redlands Redlands Institute 1200 E. Colton Avenue Redlands , CA 92373 US Phone: 9093355268 E-mail: leti_franco@redlands.edu |
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