Record Details
Spatial modeling of carnivore distribution and viability
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | Spatial modeling of carnivore distribution and viability |
| Names |
Carroll, Carlos
(creator) Noss, Reed F. (advisor) Bradshaw, Gay A. (advisor) |
| Date Issued | 2000-12-05 (iso8601) |
| Note | Graduation date: 2001 |
| Abstract | Viability analysis of well-selected focal species can complement other types of conservation planning by revealing thresholds in habitat area and landscape connectivity that may not be evident from ecosystem-level evaluations. I used focal species analysis of five carnivores to suggest conservation planning guidelines for the Rocky Mountains and adjacent areas in the Pacific states. I compared static and dynamic viability models for carnivores to assess whether the increased complexity of dynamic simulation models was appropriate given the level of demographic field data typical for carnivore species. I developed models of fisher, lynx, and wolverine distribution from a data set of trapping and sighting records and predicted grizzly bear habitat by adapting previously published regional-scale habitat models. Highquality habitats for wolverine and grizzly bear are strongly associated with low levels of human population and roads. High-quality habitats for fisher and lynx are naturally fragmented by topography and vegetation gradients and are poorly represented in existing protected areas. A comprehensive conservation strategy for carnivores in the region must therefore consider the needs of several species rather than a singie presumed umbrella species. Because many large carnivores are habitat generalists limited by human persecution, and easily-measured attributes such as road density provide robust surrogates for human impact, extrapolation of static habitat models to potential reintroduction areas provides useful guidance for prioritizing carnivore restoration efforts. I also incorporated the static modeling results into a dynamic model. For the wolf; incorporating pack structure into the simulation model increased resilience to human-associated landscape change. For the lynx, relatively low levels of population cycling were found to greatly increase extinction risk when the region was isolated from boreal lynx populations. For the fisher, mortality levels were found to interact strongly with habitat area and isolation to create tlaeshold effects on distribution. Further range contraction is predicted for all species unless coordinated regional planning for habitat restoration occurs. The results suggest that a hybrid approach that builds complex dynamic models on a foundation of data from empirical static models can provide complementary results with a range of perspectives on species' persistence. |
| Genre | Thesis/Dissertation |
| Topic | Carnivora -- Rocky Mountains -- Geographical distribution |
| Identifier | http://hdl.handle.net/1957/13331 |
