Migratory Stopover

          Especially because the greatest number of birds were seen in the YEW during the migration times of spring and fall, it’s possible that the YEW is currently more useful for birds as a refueling station on their long migrations than it is as a place to nest. The YEW sits between East Rock and West Rock, both important rest stops for migrating birds. Because the YEW is so close to East Rock and West Rock, it can serve as supplementary stopover site. For example, a bird stopping in the YEW might also forage in East Rock Park.

            Managed patches of urban forest, like the YEW, can be useful for migrating birds (Mehlman et al., 2005). Some studies have found that birds can use urban areas for migratory stopover as long as there is enough food and space available (Buler et al., 2007). A study evaluating a New York City park as a stopover site found that bird mass gains within the park were similar to those in more wild and pristine areas. These results suggest that migrants can replenish energy stores at urban stopover sites (Seewagen and Slayton 2008).

            A 2010 study examined the use that Swainson’s Thrush, observed in the YEW, made of forest patches within an urban landscape (Matthews and Rodewald, 2010). 100% of the thrushes remained at the five largest (11.0-38.4 ha) forest patches until migratory departure. 28% of birds left the smallest sites (0.7-4.5 ha) sites during stopover. This study suggests that urban forest patches can be adequate migratory stopover sites, but that there are minimum area requirements. These space requirements probably vary from bird to bird, and depend on a range of other factors, such as available vegetation. The size of the YEW (2.2 ha) suggests that it may be suitable as a stopover site for some birds. However, further studies are needed on the species stopping in the YEW to determine whether it provides adequate area and food for those species. Near the coastline and many migrating routes, the YEW has the potential to provide an important migratory stopover point, or refueling and resting place, for birds.