Ivory-Billed Woodpecker – The Rarest Species of All

Ivory-billed-woodpecker-bird-the-rarest-species-of-all

Of those birds reliably recorded within the last few years, the ivory-billed woodpecker (Campephilus principalus) appears to be the most endangered entire species (i.e. not just a sub-species or race).  There are/were two sub-species — Campephilus principalus principalus of the south-eastern USA, of which most experts have not accepted records since 1951, and C.p.bairdii of Cuba, which was rediscovered by Cuban biologists on 16 March 1986.

History

Just two birds were clearly identified by the white stripe down the back, and in the autumn another pair were seen. The US ivory-bill race was very, very similar to the Cuban race, the latter having 5 mm (0.2 in) more white on the face but no other distinguishing feature. The former range of the US main-land race was from east Texas to south-east North Carolina, south and up the Mississippi drainage to southern Illinois and Ohio.

Its last stronghold seems to have been in the wilderness areas of South Carolina, Florida and Louisiana, where the preferred habitat was a mature southern-hardwood forest, each pair requiring a very large territory of about four square miles.

Ivory-Billed Woodpecker Bird Habitat

History of Campephilus Principalus

In these extensive forests, where the birds nested high up in tree holes, the ideal habitat was in diseased trees where ivory-bills fed principally on the larvae of wood-boring beetles.

Many of the mature forests were cleared very early in the USA (pre-naturalists) so all the ivory-billed woodpecker records which came in were from the big timber and swamp forests. Hunting contributed to declining but habitat destruction was the main factor as extensive felling removed old and diseased trees and increased disturbance.

‘Clean’ forests were useless for specialist-feeding ivory-bills which needed big hardwood trees or large dying pines to maintain a family of two adults and two young weighing 1 lb (0.45 kg) each.

However, these new forests favoured the pileated woodpecker (Dryocopus pileatus), which overlaps in feeding with the ivory-bill, is less demanding and certainly competed with the ivory-bill once the latter’s prime habitat and population were reduced.

In Cuba, too, habitat destruction was the major factor in the decline, though hunting pressure was more significant than in the USA. In eastern Cuba (Oriente Province) the ivory-bill became restricted to mixed montane/pine/hardwood forest where just 12—13 pairs were known in 1956, falling to six pairs in 1974 and none located in some subsequent years.

Last Confirmed Seen of Ivory-Billed Woodpecker

The 1986 sightings in the mountains 500 miles east of Havana were later confirmed by Dr. Lester Short, chairman of ornithology at the American Museum of Natural History. A male crossed his path but there was insufficient time to take a photograph. The Cuban Ministry of Agriculture ordered an immediate end to forest logging within 6.4 km (4 miles) of where the birds were seen.

Aerial surveys indicate that apparently suitable habitat in the zoologically little-known Jaguani forest reserve, east of the rediscovery area, may hold another small group of ivory-bills. If so they would be from another distinct genetic group and that would bode well, greatly increasing the species’ chances of survival, which must otherwise be viewed as very low.

There is certainly some hope as the birds have held out in Cuba, where there is no competition with pileateds or other species in cutover pinelands, but with considerable help from the Cubans.

A few people insist that one or two birds survive in the USA, but none have been photographed. Hundreds of pictures have been submitted to Dr. Short and his colleagues for scrutiny, but they have all been of pileated woodpeckers or unclear.

The ivory-bill’s allospecies (very close relative), the imperial woodpecker (Campephilus imperialis) of the Mexican high pinelands, has not been certainly seen since 1950 and may well be extinct. The odds against the imperial woodpecker are even greater than those restraining the ivory-bill, for a pair of imperials needs 15.5—18 sq km (6-7 square miles) of territory and they have traditionally been shot and eaten in western Mexico by numerous gunners. At 58 cm (22.8 in), the imperial is the world’s largest woodpecker.

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