Bird Response to Climate-smart Restoration in the San Joaquin Valley
(Above) Point Blue staff conduct bird surveys in restored fields at Dos Rios Ranch in 2015
Habitat loss in California has severely impacted birds and other wildlife species, and climate change is predicted to worsen the situation. As a result, many large-scale habitat restoration projects are designed to target bird populations in addition to flood safety, carbon sequestration, public recreation, and other benefits. As habitat is restored and its quality improves, birds quickly respond as evidenced by improvements in both the number of species and the size of their populations.
As a benchmark for successful riparian habitat restoration, the Central Valley Joint Venture has developed quantitative objectives, including total number of acres restored and densities of 12 riparian focal bird species. Focal species are those associated with important habitat elements or ecosystem attributes, as well as those species with special conservation needs. By achieving these objectives, we advance toward the long-term goal of riparian ecosystems that can support healthy populations of birds and other wildlife, and which will be more resilient to climate change and other environmental stressors. By monitoring bird populations from the beginning of a restoration project, progress toward these objectives can be measured as the project matures, and the project can be evaluated in terms of creating habitat for focal species.
At our 2,100 ac. Dos Rios Ranch project in Stanislaus County, River Partners has contracted Point Blue Conservation Science to conduct bird surveys to assess restoration success. Tom Gardali, Director of Point Blue’s Pacific Coast and Central Valley Group notes “Our work with River Partners over the past several decades has illustrated the utility of bird monitoring to demonstrate project success and has evolved into designing restoration projects that are prepared for the consequences of climate change.”
The first phase of restoration at Dos Rios Ranch includes 198 acres planted in 2013 and 402 acres planted in 2014. In May and June of 2015, Point Blue ecologists conducted bird surveys in the area planted in 2013, during which all birds seen and heard were recorded. After only two growing seasons, a total of 29 species were detected, including seven Central Valley Joint Venture riparian focal species: Ash-throated Flycatcher, Black-headed Grosbeak, Common Yellowthroat, Nuttall’s Woodpecker, Song Sparrow, Spotted Towhee, and Yellow Warbler.
Based on average species densities in the Central Valley, Point Blue researchers would typically expect that approximately 3,300 individuals of the riparian focal species could use the 600 acres planted in the first phase. However, researchers consider the restored riparian habitat at Dos Rios Ranch to be of well-above average quality. Therefore, if the Central Valley Joint Venture’s density objectives are achieved, Dos Rios Ranch could potentially support >4,500 individuals of focal riparian species in the first phase alone, and >15,000 individuals in the entire 2,100 ac. project. Preliminary estimates derived from this year’s surveys suggest that 1,700 individuals are already present, which is more than 50% of the long-term goal based on average species densities. In the coming years, we all look forward to tracking the arrival of new species, changes in population sizes, and progress toward meeting the full potential of this multi-benefit restoration project.