The rash of unexpected Roseate Spoonbill sightings this summer has been a treat for birders up and down the east coast. While northward movement of juveniles during post-breeding dispersal is known for the species, the numbers of birds involved and the extent of the northward movement this season is impressive.
According to the Birds of North America species account, spoonbills, “especially immatures, occasionally disperse great distances, but seasonal patterns of movement are poorly understood” (Dumas 2000). In past years, the occasional individual has appeared as far north as Pennsylvania, Ohio, Wisconsin, and Nebraska. Spoonbills regularly disperse in small numbers along the gulf coast in the states of Alabama and Mississippi, and north along the Atlantic coast to Georgia. In 1972, a large movement of immatures occurred as far inland as Tennessee. This summer, spoonbills have appeared in many eastern states, including Virginia, Delaware, and New Jersey. In fact, I saw the bird that appeared at Thousand Acre Marsh in Delaware last month.
I’ve been fortunate to be in the Low Country of South Carolina for a couple of weeks, which is where I took the photo below. These birds were part of a larger flock that contained at least 47 individuals. The peak number of Spoonbills observed at this site this summer was 63 a few weeks ago.
I’m sitting in a john boat, taking this photo with a point-and-shoot camera, which gives an idea of how close I am to these birds. They don’t seem too bothered, do they? I keep wondering what drives these irruptions, and whether climate change is a contributing factor. Spoonbill foraging is dependent on fluctuating water depths, so water level changes at foraging habitat in Florida might trigger large-scale movements. Hopefully this year’s irruption (and its documentation by birders) will help us better understand the movements of this fascinating species.
Dumas, Jeannette V. 2000. Roseate Spoonbill (Platalea ajaja), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online: http://bna.birds.cornell.edu/bna/species/490