Fed­er­ally threat­ened species in Florida

RSWLiving - - Departments - BY WIL­LIAM R. C OX

Audubon’s crested caracara ( Caracara plan­cus audubonii) is the most wide­spread of the nine caracara species, all of which are neotrop­i­cal in dis­tri­bu­tion. Other ver­nac­u­lar names in­clude the black-capped ea­gle, caracara ea­gle and Mex­i­can buz­zard. It is both a scav­enger and a rap­tor and is closely re­lated to the fal­con. This trop­i­cal fal­con (in­clud­ing two sub­species) is the only caracara found in the United States, pri­mar­ily in south­ern Ari­zona, Texas and Florida. The best chance to ob­serve crested caracara in Florida is along state roads in the state’s south-cen­tral ranch coun­try. The sub­species C. p. audubonii is found only in south-cen­tral Florida, and its pop­u­la­tion is es­ti­mated at 500. This es­ti­mate is con­ser­va­tive as it is based only on road sur­veys. The U.S. Fish and Wildlife Ser­vice lists it as a fed­er­ally threat­ened species in Florida. This species is found south of Or­lando, with its breed­ing core con­cen­trated in the south-cen­tral prairie re­gion near Lake Okee­chobee and the Kis­sim­mee River flood­plain. This in­cludes Osce­ola, Okee­chobee, High­lands, Hendry, Glades and De­Soto coun­ties. It can also be found in Lee and Col­lier coun­ties. The adult caracara has a black body, black crest and crown, white head, black-and-white barred neck, pink or yel­low fa­cial skin and long yel­low legs. The fe­male is slightly larger than the male. Ju­ve­niles have a brown body and brown-and-white streaked neck. The fa­cial skin, feet and legs are gray rather than yel­low. Ju­ve­niles ac­quire adult plumage at four years of age. In flight all ages show a white tail with a wide, black sub­ter­mi­nal band and white wing tips. His­tor­i­cally, caracara nested within the St. Johns River, De­Soto and Kis­sim­mee prairies. With the con­ver­sion of na­tive habi­tat to sug­ar­cane farms, cit­rus groves and res­i­den­tial de­vel­op­ment, the crested caracara has adapted to nest­ing within open pas­ture with short veg­e­ta­tion in­clud­ing scat­tered cab­bage palm and live oak ham­mocks. This habi­tat also in­cludes scat­tered sloughs and ephemeral wet­lands. The crested caracara’s home range is ap­prox­i­mately 3,000 acres, or a ra­dius of 1.2-1.9 miles from the nest (though home ranges have been re­ported to range from 1,500-6,300 acres, or a ra­dius of 2.3 to 9.8 miles from the nest). Its nest­ing ter­ri­tory is 25 per­cent of the home-range core. Sig­nif­i­cant changes in ac­tiv­ity lev­els or habi­tat near the nest could re­sult in the

breed­ing pair leav­ing the nest site even if this oc­curs dur­ing the non­breed­ing sea­son. If habi­tat changes oc­cur over a wide area within the over­all home range, the breed­ing pair might aban­don the home range al­to­gether.

Caracara nests are gen­er­ally placed in sin­gle cab­bage palms or in groups of three to 10 palms in open pas­ture or prairie, with an av­er­age tree height of 16 feet. Nests are also placed in live oak trees and, rarely, in cy­press trees. The caracara is the only fal­conid that con­structs its nest from gath­ered nest­ing ma­te­rial, which in­cludes very small sticks, vines, grass and weed stalks. The nest is ap­prox­i­mately 2.2 feet wide and 1.1 feet deep. Al­ter­na­tive nest­ing trees used by a caracara pair are usu­ally within 0.3 mile of each other.

The breed­ing cy­cle is ap­prox­i­mately 25 weeks long, en­com­pass­ing nest build­ing, egg lay­ing, in­cu­ba­tion, nestling and post-fledg­ing de­pen­dency pe­ri­ods. Clutch size is one to three eggs with an av­er­age of two eggs. In­cu­ba­tion takes 28 to 32 days. The nestling pe­riod lasts seven to eight weeks. Fledg­ing usu­ally hap­pens in March or April. The post-fledg­ing de­pen­dency pe­riod is gen­er­ally eight to 12 weeks. Fam­i­lies will re­main to­gether for three to six months af­ter fledg­ing. Ju­ve­niles ex­plore out­side their natal range af­ter three months but re­turn to their home range. Per­ma­nent de­par­ture from the natal home range can oc­cur from 11 to 45 weeks af­ter fledg­ing. The caracara hunts and kills an­i­mals, as well as feed­ing on car­rion. Prey in­cludes: rats, mice, skunks, rab­bits, squir­rels, piglets, fish, tur­tles, frogs, sirens, snakes, lizards, birds, bird eggs, cray­fish, bee­tles and grasshop­pers. The caracara may be found with vul­tures and bald ea­gles feed­ing on car­rion. It pa­trols roads at twi­light for in­jured an­i­mals and road­kill, pri­mar­ily opos­sums, ar­madil­los, rac­coons, rab­bits, tur­tles and snakes. It also pur­sues and ha­rasses vul­tures, crows and other caracaras pi­rat­ing food (klep­topar­a­sitism). The caracara spends a lot of time on the ground search­ing for food and wad­ing in shal­low water in search of fish, tur­tles and other aquatic an­i­mals.

Be­cause of its ap­pear­ance, the crested caracara is some­times called a black-capped ea­gle.

From top: Crested caracara bring­ing a stick to its nest; a ju­ve­nile feed­ing on a snake.

Newspapers in English

Newspapers from USA

© PressReader. All rights reserved.