Florida Scrub-Jay: Aphelocoma coerulescens
The Florida scrub-jay is a 12-inch-long, blue and gray crestless jay that lacks the white wing spots and tail feather tips of the more common and widespread blue jay. A necklace of blue feathers separates the whiter throat from the gray whitish forehead. The tail is long and loose in appearance, and the back is gray.
Scrub-jays that are less than about 5 months old can be identified by their dusky brown head and neck, but there are no such physical traits that distinguish males from females.
Scrub-jays range over much of the western United States and Mexico, but the physically and behaviorally unique Florida scrub-jay is restricted to scattered, often small and isolated patches of sand pine scrub, xeric oak scrub, and scrubby flatwoods in peninsular Florida. They have very specific habitat requirements. Scrub-jays prefer these various forms of scrub habitat which burn frequently enough to maintain a shrub height that averages 3.5 to 8 feet tall. They actively avoid other forest types, wetlands, and large, open areas such as agricultural lands. While scrub-jays can be found in areas where scrub has been recently converted to other uses such as residential developments or farmland, their survival and reproductive success are generally very poor in these areas
Florida scrub-jays eat a variety of animal and plant items. Insects comprise a major food source during spring and summer. These birds also prey on other terrestrial invertebrates, and on small vertebrates including frogs, toads, lizards, snakes, birds' eggs, and even mice. Acorns are consumed year-round and are the birds' staple diet, especially during the winter when drupes, greenbrier berries, and tread-softly fruits are not available.
Florida scrub-jays mate for life. Breeding rarely occurs before 2 years of age, and often not until the birds are 3 or 4 years old. Their breeding season is short compared with other Florida perching birds; nests with eggs or young occur from early March through June. Scrub-jays build a new nest each year. The nest, a shallow basket of twigs lined with palmetto fibers, is typically built about 3-10 feet above ground in one of the shrubby oaks. Scrub-jays usually raise only one brood per year, but in case of nest failures, they may lay two, three, or even four clutches a season, each in a new nest. Clutch size is usually three or four eggs, but may vary from two to five eggs. Incubation requires 17 days, and the nestlings fledge about 17 days after hatching.
Florida scrub-jays live in family groups composed of a breeding pair, their offspring from years past and present, and sometimes even birds "adopted" from other families. In contrast to other Florida songbirds, nonbreeding scrub-jays (especially males) may remain in their parents' territory as helpers for several years before dispersing to establish their own territory or join another family. A well-defined hierarchy exists within these extended family groups.
Cooperation among family members is a complex and fascinating aspect of scrub-jay family life. Each family maintains a permanent territory ranging from about 5 to 50 acres (averaging about 25 acres), which it defends from adjacent families. Scrub-jays exhibit a well-established sentinel system in which each bird, in turn, will watch for predators while other family members go about their daily activities. The helpers assist in defending the breeding territory, nest, and young from neighboring scrub-jays and predators. They also help feed the nestlings and fledglings. They do not, however, assist in nest-building, incubating, or brooding activities. Long-term studies have established that helpers contribute to the reproductive effort: Breeding pairs with helpers successfully raise more young than do lone pairs.
The original range of the jay, estimated at 7,000 square miles, has been reduced considerably by suburban development and conversion of scrub habitats to agricultural uses. Many isolated populations have been eliminated, and the historically almost continuous population along the Atlantic coast has been radically fragmented by urban development. Due to extensive habitat loss and elimination of scrub-jays from much of their former range, they are now legally protected as a Threatened Species by the United States Fish and Wildlife Service and the Florida Fish and Wildlife Conservation Commission. Preservation of existing populations is of paramount importance, as is habitat management within designated sanctuaries.
Habitat management for scrub-jays essentially consists of periodically burning scrub tracts to maintain the desired shrub height, canopy closure, and percentage of bare ground. Optimal fire frequency for scrub-jay management is about once every 5 to 20 years. Mechanical site renovation may also prove satisfactory for scrub-jay habit management where prescribed burning is inadvisable.
Because of the territoriality of this species and the requirement for maintaining specific habitat conditions, it is unlikely that a "viable" population can be supported on any but the very largest scrub preserves. It is likely, however, that even small populations scattered throughout a region actually function as a metapopulation, or "population of populations." It is important, therefore, that scrub jays be preserved wherever they occur, with each isolated population being recognized as an integral part of a larger, regional scrub-jay population. As little as 5-10 acres of suitable habitat may support a mated pair, but a minimum of 25 acres per family is recommended as a general guideline for establishing scrub-jay preserves.
Biologists in several regions of the state are currently studying scrub-jays, both in undisturbed, natural habitats, and in areas undergoing rapid development. Because it is often difficult to determine a jay's sex or age in the field, marking each bird being studied with a unique set of colored plastic and aluminum leg bands is required. These banding techniques have been used on scrub-jays for over 20 years, and do not harm or distress the birds in any way.
By identifying families and individual birds, banding studies provide information on territory size and stability, kinship of birds within and between families, nesting success, survival and dispersal of jays, and many other aspects of scrub-jays and their environment. In many cases, interested citizens can assist the biologists by reporting observations of banded birds to the appropriate agency.
Predators are the number one cause of mortality for scrub-jays, but disease also plays a role in scrub-jay population dynamics.
Translocation often is used as a conservation tool to boost small populations or to move species back to places where they used to live.
What You Can Do To Help:
- Support establishment of regional and local scrub-jay preserves. Protection of scrub-jay populations on managed tracts of optimal habitat is the best means of protecting this species.
- Provide habitat for scrub-jays. Plant, protect, and cultivate patches of shrubby scrub live oak, Chapman's oak, myrtle oak, and scrub oak on your property. Maintain all of your landscaping at a maximum of 10 feet in height if you live on or near scrub-jay habitat.
- Protect scrub-jays from your pets. Encourage passage and strict enforcement of leash lows for cats and dogs in your community. Protect areas being used by nesting scrub-jays from domestic animals, especially cats.
- Restrict use of pesticides. Scrub-jays feed on insects usually considered pests around golf courses and homes. Pesticides may limit or contaminate food used by the jays. Reduce use of pesticides if possible; if you must use them, please do so with caution.
- Report malicious destruction or harassment of scrub-jays or their nests. 888-404-FWCC (3922)