Practicum Project | 2009

Habitat Edges in the Baldwin Hills: Effects on Bird Distribution and California Coastal Sage Scrub

Students: Anna Bugayong, Joshua Lazarus, Shahir Masri, Christine Nguyen, Lucas Salazar, and Adam Taheri.

Advisor: Dr. Travis Longcore

California Coastal sage scrub is a rare type of habitat which supports diverse plants and animals and, consequently, is of critical importance with regard to conservation. Our study looks at degraded coastal sage scrub habitat along native/non-native vegetation interfaces, or edges, in the Baldwin Hills; an area which has future plans for both habitat restoration as well as recreational development. By surveying birds abundance over a 2 week span, we were able to develop an understanding as to how the prevalence of native bird species varies between different types of habitat, including both degraded and non-degraded forms of coastal scrub, in the Baldwin Hills. In addition, our study seeks to determine how plant structure and composition changes with proximity to habitat edges. Using 49 marked points in a one-hectare grid, we calculated the height index of vegetation in order to understand the complexity of the habitat. Also, we analyzed 2 transects of vegetation; one at a degraded (or gradual) edge and one at an abrupt (or non-degraded) edge. The results of our overall study suggest that native birds prefer coastal sage scrub vegetation over non-native habitat in spite of the native habitat being somewhat degraded. In addition, the data shows that an exceptionally low number of birds can be utilize invasive tree species. Finally, our research reveals that the density of coastal sage scrub is independent of the type of edge bordering the native habitat; a finding which has significant implications as it relates to buffers zones as a method for preserving native habitat.