Title

Pika (O. princeps) home range use and habitat preference outside talus rock patches in relation to potential dispersal corridors

Presenter Information

Jill Hooghkirk

Document Type

Oral Presentation

Location

SURC 137B

Start Date

16-5-2013

End Date

16-5-2013

Abstract

For species that live in discrete habitat patches, the ability of individuals to move between subsections of a population is important for maintaining genetic variability and long-term viability. Understanding where animals move and how they use different habitat features is critical for managing habitats to support population connectivity, especially in habitats further fragmented by human activities. The objective of our study was to quantify American pika (Ochotona princeps) movements and habitat use adjacent to their primary rocky habitat patches (talus slopes) in the I-90 corridor near Snoqualmie Pass. Eight adult pikas and five juveniles were radio-collared to track movements away from core rocky patches and to detect potential dispersal. Habitat preference was determined by comparing habitat variables at used and unused locations. Logistic regression showed that pika use was positively associated with complex habitat characterized by broadleaf trees and layered substrate (logs and rocks), and negatively associated with both vertical distance from the ground to overhead plant cover and amount of bare ground. Pikas living in areas with a greater availability of layered substrate left the main patch more frequently and traveled further into the surrounding area. No successful dispersal events were recorded; all individuals that moved from primary habitat patches into non-protective habitats were presumably killed by predators. Providing preferred habitats adjacent to rocky patches and enhancing them with specific habitat features in corridors between existing rocky patches and new wildlife crossing structures on I-90 is predicted to increase dispersal distances and improve population connectivity across the highway.

Faculty Mentor(s)

Kristina Ernest

Additional Mentoring Department

Biological Sciences

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Pika (O. princeps) home range use and habitat preference outside talus rock patches in relation to potential dispersal corridors

SURC 137B

For species that live in discrete habitat patches, the ability of individuals to move between subsections of a population is important for maintaining genetic variability and long-term viability. Understanding where animals move and how they use different habitat features is critical for managing habitats to support population connectivity, especially in habitats further fragmented by human activities. The objective of our study was to quantify American pika (Ochotona princeps) movements and habitat use adjacent to their primary rocky habitat patches (talus slopes) in the I-90 corridor near Snoqualmie Pass. Eight adult pikas and five juveniles were radio-collared to track movements away from core rocky patches and to detect potential dispersal. Habitat preference was determined by comparing habitat variables at used and unused locations. Logistic regression showed that pika use was positively associated with complex habitat characterized by broadleaf trees and layered substrate (logs and rocks), and negatively associated with both vertical distance from the ground to overhead plant cover and amount of bare ground. Pikas living in areas with a greater availability of layered substrate left the main patch more frequently and traveled further into the surrounding area. No successful dispersal events were recorded; all individuals that moved from primary habitat patches into non-protective habitats were presumably killed by predators. Providing preferred habitats adjacent to rocky patches and enhancing them with specific habitat features in corridors between existing rocky patches and new wildlife crossing structures on I-90 is predicted to increase dispersal distances and improve population connectivity across the highway.