Since 1999, PRBO has been studying riparian
songbirds to guide and evaluate the restoration effort on the Clear
Creek Floodway Rehabillitation Project.
Clear Creek is a
foothill stream that was severely mined. It is currently recovering
both passively as well as with the help of a major salmonid restoration
project funded by CALFED.
By
monitoring birds, we are learning the key habitat components necessary
to ensure diverse and productive wildlife populations at Clear Creek. Read more below.
In California’s Central Valley, many partners came together in 1998 to form the Lower Clear Creek Floodway Rehabilitation Project with the goal of restoring the riparian system that was degraded through over 100 years of mining. PRBO joined the restoration team in 2000 to help guide and evaluate restoration efforts towards high quality riparian bird habitat.
Project Goals
Guide habitat restoration efforts on Clear Creek with a bird’s eye view.
Measure effects of restoration by monitoring bird response over time, and share information with partners throughout California to enhance our understanding of the status and needs of riparian birds.
Provide outreach to educate the local community about birds and the benefits of restoration and conservation of riparian zones.
By monitoring the breeding birds, we are learning the key habitat components necessary to ensure diverse and productive populations at Clear Creek. We have identified plant species such as Mugwort, California Blackberry, and Elderberry as having positive effects on avian abundance and nest success.
Song Sparrow (Melospiza melodia)
Black-headed Grosbeaks and Song Sparrows are responding positively to restoration efforts. At 5 to 8 year-old restored sites, these species are now nesting and raising young in greater densities compared to sites that have not been restored.
However, some focal species have not yet colonized restoration sites. Our ability to link key habitat attributes to nest success and breeding densities helps identify habitat attributes to manage for to ensure the full compliment of species. Information gained in this project will be represented in future restoration sites.
Birds continue to teach us what is needed to create better habitat that will ensure their long-term survival as well as the ecosystem as a whole.
PRBO established a riparian songbird monitoring program at Clear Creek, Shasta Co., California in 1999.
Clear Creek is a foothill stream that was severely mined. It is currently recovering both passively as well as with the help of a major salmonid restoration project funded by CALFED.
True to its name, the waters of Clear Creek run cool and clear. The vegetation at Clear Creek is riparian and consists of various willow species, white alder, valley oak, and Fremont Cottonwood. The upland habitat consists of gray pine, interior live oak, and manzanita.
In order to aid in the restoration process at Clear Creek, PRBO is collecting data on songbird abundance, diversity, and breeding productivity. Because management activities at Clear Creek are primarily focused on salmonid restoration, measuring the response of songbirds to such activities fills an information gap.
We used three standardized monitoring techniques: (1) Point counting (2) Mist-netting, and (3) Nest searching.
Project hypotheses:
Breeding productivity for riparian associated songbirds (e.g., Song Sparrow, Yellow Warbler, and Yellow-breasted Chat) are at levels high enough to maintain viable populations at Clear Creek and serve as "source" populations for other riparian areas in the Sacramento River watershed.
Salmonid restoration activities (which include improved channel-to-floodplain connectivity, increased native riparian vegetation, and reduced exotic vegetation) will positively influence the riparian bird community. This assumes that restoration design incorporates the habitat requirements of riparian birds.
Restoration activities that do not attempt to mimic or restore natural processes may have negative long-term effects on the bird community; i.e., the loss of early successional riparian vegetation may have negative effects on breeding Yellow Warblers.
