A very habitat-specific species fond of scrub oak
Florida Scrub Jay
The Florida scrub jay ( Aphelocoma coerulescens) historically roamed the Florida peninsula, but its distribution has always been fragmented within its range. The scrub jay is exclusively associated with scrub oak habitat and requires that habitat to be in the early stages of vegetation succession where the trees are 10 feet or less and the habitat is interspersed with open sand. It cannot occupy scrub oak habitat that has greater than 50 percent canopy cover of nonscrub trees such as sand pine and turkey oak. Scrub oak vegetation is associated with well-drained, white, fine, siliceous sands deposited during the Pleistocene high sea-level era.
Examples of scrub oak vegetation include myrtle oak, Chapman oak, scrub oak and sand live oak. Other vegetation that can be scattered throughout scrub habitat is saw palmetto, scrub palmetto, garberia, silk bay, Florida rosemary and rusty lyonia. Sand pine and turkey oak can be scattered throughout Florida scrub jay habitat if they are less than 20 to 50 percent canopy cover. Scrub oak habitat requires a natural or prescribed burn every 10 to 20 years.
The Florida Fish and Wildlife Conservation Commission and the United States Fish and Wildlife Service have listed the Florida scrub jay as a threatened species. Its population was estimated to be 7,000-11,000 birds in 2001, predominantly on the Merritt Island/ Cape Canaveral Complex, Ocala National Forest and southern Lake Wales Ridge. These three subregions are the “core populations” of Florida scrub jays because this is where more than 50 percent of the scrub jay population is found.
The Gulf Coast has smaller subpopulations that are isolated to varying degrees. Extensive habitat fragmentation and loss of scrub oak habitat has occurred in this region, which extends from Levy County south to Lee County. Consequently, this population has been divided into two subregions: the Northern Gulf Coast and the Southern Gulf Coast.
The Florida scrub jay is approximately the same size as a blue jay, but the two do not resemble each other. The scrub jay is 10 to 12 inches in length and weighs approximately 2.5 ounces (female) to 2.7 ounces (male). Its crown, nape, wings, rump and tail are dull blue, and it is pale gray on its belly and back. A necklace of blue feathers separates the gray underparts from the white throat. The male and female are indistinguishable in appearance and can be told apart only by the female’s “hiccup” calls. Scrub jays less than five months old have a duller overall body color, and the head and neck are dusky brown rather than dull blue found in adults. The blue jay has a crest, shorter tail and legs, bold black markings and conspicuous white-tipped tail and wing feathers. The scrub jay is nonmigratory. It is a monogamous and cooperative breeder. The nonbreeding young (about two years old) assist the breeding pairs in all rearing and territorial activities. A breeding unit size is usually three but can include up to six helpers. This cooperative breeding social structure is most likely a result of evolutionary adaptation for surviving Florida’s fragmented scrub habitat. The Florida scrub jay is sexually mature at one year but usually does not breed until the age of four. It is still able to breed at the age of 14. The breeding season lasts about 90 days from March to the end of June. Scrub oaks including sand live oak and myrtle oak are preferred for nesting. Nests are constructed 3 to 6 feet above ground. Nests, which are 7 to 8 inches in diameter, are constructed with oak twigs formed into a thick cup lined with sabal palmetto fibers. Both the female and the male gather nest material, construct the nest, and feed and attend the young. The female does all the incubating and brooding, during which the male brings her food. Clutch size averages two to five eggs. Incubation lasts for 18 days, and fledging occurs 18 days after that. A scrub jay pair can have one to four broods per season. Territory size averages 24 acres with a density of two to six scrub jays per 100 acres. They feed mostly on insects in the spring/summer and acorns in the fall/winter. Predators include many species of hawks, owls and snakes, as well as bobcats. Threats are fire suppression, agriculture conversion and suburban development. The best sites to observe these people-friendly birds are Archbold Biological Station near Lake Placid, Lake Wales Ridge State Forest, Merritt Island National Wildlife Refuge, Ocala National Forest and Oscar Scherer State Park in Sarasota County. William R. Cox has been a professional nature photographer and ecologist for more than 35 years. Visit him online at williamrcoxphotography.com.