It Was Built...Did They Come? Habitat Characteristics of Yellow-billed Cuckoo in Restored Riparian Forests Along the Sacramento River, California

ABSTRACT IT WAS BUILT… DID THEY COME? HABITAT CHARACTERISTICS OF YELLOW-BILLED CUCKOO IN RESTORED RIPARIAN FORESTS ALONG THE SACRAMENTO RIVER, CALIFORNIA by Jessica E. Hammond Master of Science in Biological Sciences California State University, Chico Spring 2011 The global degradation of wildlife habitat by humans has created the need for and interest in the field of restoration ecology. The overarching goal of restoring degraded lands aims to create a more natural state either through planting native vegetation or restoring physical ecosystem processes. Restoring lands also strives to create habitat for wildlife with the hopes of sustaining and increasing populations that have been negatively impacted by habitat loss. The ongoing restoration effort along the Sacramento River, California, has identified a suite of target wildlife species that indicate habitat health and help to measure restoration success by their use of newly created habitats. The yellow-billed Cuckoo (Coccyzus americanus) is one such species, although they are not readily detected in bird surveys due to their cryptic nature. I investigated cuckoo presence and absence along the Sacramento River, California in the 2007 and 2008 breeding season for this species. I investigated variables at various spatial scales to see what habitat features cuckoos were associated with. I found that where cuckoos were present, there was significantly higher shrub area, particularly willow shrub area, than at randomly selected control points. Where cuckoos were present I found that willow shrubs and cottonwood forests were an important component of the vegetative species composition at various spatial scales. As many species of birds select habitat on more than one scale, the results of this research indicate that cuckoos may be using habitat features at various spatial scales when selecting habitat on the breeding ground. The results of this investigation will help land managers and restoration biologists design restoration that might be suitable for cuckoo occupancy, though this study does not examine habitat use by cuckoos.