Avian community response to riparian habitat restoration

Restoration ecology is a young science, and we still need to answer some basic questions such as how to assess success in restoration of avian habitat and what is the appropriate effort needed in monitoring. We analyzed data from a long-term study of a riparian restoration site in the Western United States, near San Jose, California. The site was first planted in 1987, monitoring of vegetation and birds, through standardized mist netting, has been ongoing to the present. Our results confirm that birds have reacted positively to the restored habitat, measured in birds captured per net hour of effort,  but the details are complex. The quality of habitat, as measured by canopy cover, has fluctuated greatly during the study. In turn, bird mist-net capture rates have fluctuated as well. Avian use of the site in the first 5, 10 and 15 years of monitoring has differed significantly. Our results suggest that vegetational changes, both positive and negative in terms of habitat quality, may occur for decades after the initial restoration work and bird populations react to these changes. If the restoration of bird communities is a goal of the habitat restoration, success ctriteria for the project need to be clerly defined and an appropriate time-span of monitoring needs to be decided on before the onset of the program.