April 11, 2019
While Rookery Bay staff are very proud of the shorebirds that call reserve beaches their “winter getaway” or “permanent home,” we are equally proud of the wading birds that rely on the estuary for roosting or nesting. In fact, Rookery Bay Reserve has a deep history with wading birds and has been monitoring nesting wading birds near Marco Island since 1979. This colony, called the ABC Islands, and the dynamic nature of wading bird behavior, is what makes me love my job as an avian biologist. My favorite work in Rookery Bay Reserve is monitoring breeding wading birds and I always appreciate the opportunity to share my passion and knowledge of these birds.
Peak breeding season is beginning for wading birds, with the busiest time in April/May. But birds don’t follow the field guides, and Rookery Bay Reserve has had nests and chicks almost consistently since January. Within the past few months, I have already witnessed a handful of great blue heron chicks screaming out for their parents, and brown pelicans incubating in their nests. Rookery Bay staff gather this data biweekly to determine an estimate nest initiation date and an estimate of peak nests or chicks in a season. These numbers are crucial not only for the species, but for the entire ecosystem.
Wading bird nesting success is strongly correlated with hydrology of the surrounding area. While the legs of wading birds are long, these birds prefer foraging in water no deeper than 20 cm. I call this water level the “buffet” of the bird world. Shallow water has a higher concentration of fish, making it easier for birds to find food. Deeper water gives fish more space to spread out, making it more difficult for birds to find food, and more time to lose energy in the process of hunting.
For wading bird colonies to develop and chicks to fledge, water levels must be an optimal depth, or around 20 cm. The very presence of large wading birds in a habitat reminds us of this simple science. So, next time you see a wading bird, take a minute and appreciate all that it is teaching us. The simple behavior of one bird tells a story far greater than we can imagine.
Anne Mauro, Avian Biologist