Short-tailed Hawk

Short-tailed hawks breed in the tropical and subtropical Americas from southeastern Brazil and northern Argentina north through Central America to the mountains of the Mexico-Arizona border area, as well as in southern Florida, United States; it is also found on the Caribbean island of Trinidad. This species is generally found below 4,500 ft (1,400 m) ASL and most common below 2,500 ft (760 m). It is replaced by the white-throated hawk (B. albigula) in the Andes of southern Colombia and south to central Argentina and Chile; the short-tailed hawk is found in the Cordillera Central and Cordillera Occidental of Colombia, while B. albigula occurs south of these locales. As far as is known, B. brachyurus is a year-round resident except that most of the Florida population migrates in winter to the southern tip of the state, including the Keys. It is somewhat habitat adaptable but only passes areas with dense human populations when foraging. The species may be found in wooded savannah, patchy woodlands near water, cypress swamps, mangrove swamps or high pine-oak woodlands. In the tropics, it is most common in lowland foothills. Most of what is known about its natural history has been studied in the Floridian population, and might not apply to birds at the south of the species' range. In general, this species is associated with woodland, often near water.

In Florida, it eats mainly smaller birds (such as ground doves). The short-tailed hawk hunts from a soaring flight, often at the borders between wooded and open areas. A frequent maneuver is "kiting" – coming to a stop, the bird heads into the wind, with its wings held stationary. It typically attacks prey with a nearly vertical swoop, sometimes pausing and then continuing downward in a "stair-step" manner. Typical prey ranges from a New World warbler (Parulidae) to a bobwhite (Colinus sp.) in size. In Florida, icterids—namely the red-winged blackbird (Agelaius phoeniceus), the common grackle (Quiscalus quiscula), the boat-tailed grackle (Quiscalus major) and the eastern meadowlark (Sturnella magna)—make up the bulk of the prey. In one case, 95% of a single hawk's prey selection was found to consist of red-winged blackbirds. Hunting success is apparently relatively low. In one study, 30 hours of observation showed that only 12 of 107 hunting attempts (or around 11%) were successful. There are isolated records of short-tails preying on sharp-shinned hawks (Accipiter striatus) and American kestrels (Falco sparverius). Among tropical populations, they are several records of this species regularly taking frogs (especially tree frogs), lizards, snakes, large insects such as wasps and locusts. …