Abbotts Booby (Papasula abbotti)

[order] SULIFORMES | [family] Sulidae | [latin] Papasula abbotti | [UK] Abbotts Booby | [FR] Fou d’Abbott | [DE] Abbott-Tolpel | [ES] Piquero de Abbott | [NL] Abbotts Gent

Subspecies

Physical charateristics

79 cm. Black-and-white booby. Dark eye and dark-tipped bill, pale grey in male, pink in female. White head, neck and most of underparts. Black upperwing with white flecking on coverts and narrow white leading edge. Black thigh patch and tail. Black patch on mantle and back continuous with wings, remainder white. Blue-grey legs and feet. Juvenile similar to adult male.

Range

Indian Ocean : Northeast. Papasula abbotti breeds only on Christmas Island (to Australia), though it once had a much wider distribution in the Indian and Pacific Oceans. One female was recently observed on Rota Island (Northern Mariana Islands to USA), though it is not known whether it is vagrant or a solitary resident

Habitat

Foraging occurs in the waters of the Indian Ocean, whilst breeding is in rainforest on the plateau and higher terraces of Christmas Island. Nests are constructed in tall, emergent rainforest trees, especially those with access from the northwest into the prevailing wind. Trees preferentially have an open canopy and interwoven terminal growth, which helps to support juveniles.

Reproduction

It nests in tall rainforest trees, mostly above 150 m elevation in the western, central and northern areas of Christmas Island, and lays one egg. Most successful parents can only breed biennally. It may first breed at eight years of age, and its average lifespan may be c.40 years. The species’s breeding cycle takes 15-18 months, meaning that successful pairs nest once every two years whilst unsuccessful pairs may breed in successive years or take ‘rest years’, thus only a proportion of the breeding population breeds in a given year, and this is dependent on nesting success in the previous year.

Feeding habits

It feeds at sea on squid and fish. The at sea distribution of this species is poorly known. It was previously thought that cold water upwellings south of Java could be important feeding areas for breeding boobies, however tracking studies seem to indicate that they simply forage within 40-100 km of Christmas Island and show no association with any clear oceanographic features

Conservation

This species breeds in the limited suitable habitat of just one area of a very small island, and it has a small population which has declined rapidly owing to the effects of past habitat clearance. Recent die-back of some of the breeding habitat indicates that habitat quality continues to decline, although it is unclear whether this die-back has been caused by introduced yellow crazy ants. Because of the significance of even minimal declines in habitat quality within the limited breeding habitat of this booby, it is listed as Endangered.

Migration

Resident throughout range.

Distribution map