Florida Grasshopper Sparrow: Ammodramus savannarum
Florida grasshopper sparrows are small, short-tailed birds, about 5 inches long and weighing less than one ounce. This not-so-drab sparrow is mostly black and gray with some brown streaks on the back. Underneath, it is light gray or buff color with no streaking.
Feathers at the bend of the wing are bright yellow and there is an orange patch in front of the eyes. A white stripe marks the top of the head. The male's primary song is weak and grasshopper-like, giving rise to the bird's common name.
Florida grasshopper sparrows are found in the prairies of south-central Florida in Osceola, Polk, Highlands, and Okeechobee counties. This non-migratory subspecies uses grasslands dominated by bunch grasses such as wiregrass and bluestem, with a patchy cover of low shrubs and saw palmetto. A breeding population of fifty pairs requires about 2,000 acres of treeless prairie. A contraction in the range of the Florida grasshopper sparrow since the early 1900s corresponds to habitat loss due to prairie conversion to improved cattle pastures, sod production, and other agricultural uses.
Adult Florida grasshopper sparrows are very sedentary, most occupying the same 4 - acre territory for their entire life span of 2-3 years. The sparrow appears feeble in flight, seeming more at home running along the ground. Frequent burning and cattle grazing provide open areas this ground-dwelling bird needs for foraging.
Florida grasshopper sparrows forage opportunistically as they skulk along the ground and low in the grass. Adults eat grasshoppers, crickets, moths, caterpillars, flies, and seeds of grasses and sedges. Nestlings are fed katydids, grasshoppers, and spiders. Adults remove the legs and wings from insects before feeding them to their young. Food usually is not considered a limiting factor for grassland birds.
Nesting is from late-March to August with two or three broods attempted per year. Males sing from the tops of shrubs early in the morning during the nesting season. The domed nests are made of grass and located in a slight depression in the ground so that the opening edge is at ground level. Nests are well concealed by dwarf live oak, clumps of grass, or saw palmetto fronds. The female incubates 3-5 eggs for 11-12 days. Eggs are white with flecks of reddish-brown at the large end. Young fledge about 9 days after hatching. Given the hazards of nesting on the ground, breeding success is usually less than 25 percent.
Predators of Florida grasshopper sparrow eggs and nestlings include snakes, skunks and feral hogs. Some nests are destroyed by flooding from rainfall or by wildfires. Hawks and loggerhead shrikes take juveniles and adults. Mortality from a vehicle collision was reported.
The Florida grasshopper sparrow is known from only seven breeding locations, with a total estimated population of fewer than 1,000 birds. Fortunately, six populations are located on protected lands. The Florida grasshopper sparrow was classified as endangered by the U.S. Fish and Wildlife Service and the Florida Fish and Wildlife Conservation Commission because of its low numbers, restricted distribution, and loss of habitat. No critical habitat was designated. However, prairie habitat has been acquired and is managed by prescribed fire every 2-3 years to prevent the invasion of trees and to provide suitable foraging and nesting areas for Florida grasshopper sparrows.
View the Florida grasshopper sparrow at Kissimmee Prairie Preserve State Park.
Image Credit: Dameron Black IV