Avian response to restored wetlands at the Cowaselon Creek Watershed Area near Canastota, New York (New York)

Monitoring wetland restoration is necessary to understand avian response and to ensure project success. I examined avian response to restoration at pre-restored and restored wetlands at the Cowaselon Creek Watershed Area (CCWA) in Central New York in 2001–2002. I measured avian response at 10 pre-restored and 10 restored sites in 2001 and 3 pre-restored, 2 semi-restored, and 15 restored sites in 2002. Overall, 138 species were found using the CCWA for migration, staging, and/or breeding during the 2-year study. Avian response was immediate after restoration, particularly for ducks and geese, and in subsequent years was followed by breeding grebes, coots, moorhens, rails, and marsh wrens. Furthermore, the CCWA served as a significant migratory staging and stopover for ducks, geese, and shorebirds. More than 15,500 waterfowl use days and 1,280 shorebird use days per year were recorded at the CCWA sites during the two-year study. Species richness of wetland-dependent breeding species was correlated with age (r2 = 0.31, P < 0.001) and size (r2 = 0.52, P < 0.001) of wetlands. Additionally, as the wetland complex aged and restored wetland acreage increased, breeding waterfowl numbers increased from 41 pairs in 2001 to 75 in 2002. Percent similarity indices were calculated and revealed differences in avian breeding communities after restoration, which were attributed to colonization by obligate wetland birds. This increase in species richness of breeding obligate wetland birds was significant (P = 0.007). Finally, there were noticeably higher breeding obligate wetland bird species at mineral sites compared to muck sites (6.5 versus 2.7). Muck soil sites tended to be highly disturbed habitats with a non-native dominated flora, whereas mineral sites were less visibly disturbed and native grasses and shrubs dominated. Due to the need for intensive management on muck sites, restoration might favor mineral sites.