White-crowned pigeon

In the first half of the 18th century the white-crowned pigeon was described and illustrated by several naturalists including John Ray in 1713, Hans Sloane in 1725 and Mark Catesby in 1731. When in 1758 the Swedish naturalist Carl Linnaeus updated his Systema Naturae for the tenth edition, he placed the white-crowned pigeon with all the other pigeons in the genus Columba. Linnaeus included a brief description, coined the binomial name Columba leucocephala and cited the earlier authors. The specific epithet combines the Ancient Greek leukos meaning "white" and -kephalos meaning "-headed". Although Linnaeus gave the location as North America, the type locality is taken to be the Bahamas following Catesby. The species is now placed in the genus Patagioenas that was introduced by the German naturalist Ludwig Reichenbach in 1853 with the white-crowned pigeon as the type species. The species is monotypic: no subspecies are recognised. ==Description==

. The white-crowned pigeon can measure in length, span across the wings, and weigh . It is around the same size as the common rock pigeon, but weighs a bit less since it is generally less chunky and has a relatively longer and more square tail. Adult birds' plumage varies from a slate gray to an almost-black color. Its iridescent collar-patch is notably only seen under good lighting, shining a barred white pattern with green. Their distinct crown-patch can vary in shade of color from a more bright white in males to a more gray-white in most females. Juveniles can have a grayish-brown color for They have a white iris and a pale-tipped red bill. Juveniles are a less dark shade of grey, lack the nape pattern and white iris, and show only a few pale feathers on the crown. Their call is a loud, deep coo-cura-coo or coo-croo. This species is a member of a diverse clade of Patagioenas which vary much in appearance, but are united by their triple coos (except in the scaled pigeon). ==Distribution and habitat==

It is a resident breeder mainly in the Bahamas, Cuba, Jamaica and Antigua. It breeds in smaller numbers in Hispaniola (the Dominican Republic and Haiti), Puerto Rico, the Virgin Islands, the Cayman Islands, Anguilla and other Caribbean islands. It also breeds along the Caribbean coast of Central America. In the United States, it is found only in the Florida Keys, Everglades, and the southern tip of mainland Florida. They will often spend the winter in the Caribbean islands. It has been spotted as far south as Fuerte Island, off of the northern coast of Colombia. The white-crowned pigeon primarily lives and breeds in nest colonies or individually in low lying, coastal, mangrove forests, and will travel inland to feed on the fruits and seeds of a wide variety of plants. In Florida, the white-crowned pigeon has historically been documented nesting exclusively on remote, tidally inundated mangrove islands in wildlife refuges. Recent observations have confirmed nesting on the southern tip of mainland Florida. ==Threats and conservation==

A main threat to this species is loss of habitat due to deforestation and habitat degradation. The white-crowned pigeon needs two distinct habitats: one for nesting and one for feeding. They typically breed in coastal red mangroves (Rhizophora mangle), which continue to be clear-cut for crops such as sugarcane. Agriculture and deforestation have become a problem for the species' feeding grounds, typically inland hardwood forests. The bird is very skittish, and is known to simply abandon its nest when it is encroached upon. In Florida, white-crowned pigeons often feed on the fruit of poisonwood (Metopium toxiferum). Unfortunately, this native plant causes severe human dermatitis and is often removed. The white-crowned pigeon is also hunted, often illegally, throughout much of its range. Although, changes have been made to hunting regulations in the Bahamas, illegal hunting is still a problem for these pigeons. Other threats to this species include (in Florida) a major cause of mortality is collision with man-made objects; and pesticide use. ==References==