Swallow-tailed Kites are some of the most graceful and beautiful birds gliding and soaring through the skies over Southwest Florida from February through August during their nesting and pre-migration roosting seasons. They are also very popular: drawings of Swallow-tailed Kites are featured elements in the CREW and Great Florida Birding Trail logos.
Swallow-tailed Kite nest monitoring is currently being conducted in CREW and its adjoining lands in order to better understand the habitat needs for their nesting and foraging success in Southwest Florida.
Swallow-tailed Kites once nested in 21 states. Records from the 1800s show nesting pairs as far north as Minnesota and Wisconsin. Then the population underwent a sudden decline. By 1940, the kite’s range had shrunk to seven states from coastal South Carolina to eastern coastal Texas and all of the Florida panhandle.
Currently, fewer than 2500 nesting pairs are believed to exist in the United States (*ARCI 2016). Hence, the need for monitoring and research so that land managers can understand the optimal conservation approaches to preserving the habitats that sustain the kites.
A number of factors contribute to the vulnerability of Swallow-tailed Kites.
They have high mortality during their summer migration between the southern United States and southern Brazil when they fly across the Gulf of Mexico and again when they fly back to the United States the following spring. They do not usually begin breeding until they are three to four years old, and nesting adults and their young are subject to predation by Great Horned Owls. Plus, there just aren’t very many of them.
Habitat loss is also a factor in their decline. Freshwater forested wetlands and cypress swamps, where the birds nest, have been dwindling for centuries. Since the 1700s, about half the nation’s wetlands have disappeared, threatened by agriculture, development, logging, dams, dredging and invasive species, as well as natural disturbances like hurricanes. The rate of wetlands loss has wavered, but it hasn’t stopped: A 2011 U.S. Fish and Wildlife Service report found that wetland losses were outdistancing gains, especially in those freshwater forested wetlands the kites need.
Habitat is more important for kites than some other species because Swallow-tailed Kites are one of the very few social raptors. They forage in groups, nest in “neighborhoods,” and roost in groups. That makes them especially vulnerable; being social ties large groups of them to a single place. If those places where they forage, nest, and roost are not protected, the population will decline further.
This spring, FWC biologists and CREW volunteers have been monitoring 10 different nests in and around the CREW lands. Those nests have produced 12 known kite fledglings, and four more are suspected to have fledged.
Data about the nest locations, habitats, and activities are housed at the CREW office. They will be added to FWC’s Habitat and Species Conservation migratory bird database once it is complete. In addition, the CREW data is available for use by the FWRI (Fish and Wildlife Research Institute, the branch of FWC that conducts wildlife research) and by the Avian Research and Conservation Institute which monitors kites nationally.
Locally, the data will be used in a couple of ways.
First, FWC is interested in collecting data on which avian species are breeding on the CREW Management Area property and what type of success these species have from year to year.
Second, using the nests discovered this year, a finer model of CREW’s kite nesting habitat can be created by using the data collected at the nest tree and surrounding habitat. Then, desirable habitats can be maintained and created.
However, preserving habitat for kites is not as simple as just figuring out where the birds are nesting right now. It’s also necessary to determine where they could thrive in the future. That information will be crucial for land managers throughout the kite range.
*For more information about Swallow-tailed Kites, visit the Avian Research and Conservation Institute (ARCI) web site at http://www.arcinst.org/
Written by CREW Trust volunteer Dick Brewer