Atlantic albatross boon

The first systematic study of the avifauna of a palaeontological dig at Ahl al Oughlam, just outside Casablanca, Morocco, has now been published, 25 years after the fossils were collected.

The material dates from about 2.5 million years ago, just at the end of the Pliocene period when the coastline was 6.5 km further inland from the Atlantic. Three albatross species are present (in addition to more expected forms like Shelduck Tadorna, mergansers Mergus, bustards Otidae, Cory's Shearwater Calonectris diomedea, gannets Morus, bald ibises Geronticus, barn owls Tyto and skuas Stercorarius), and these include individual fossils indistinguishable from Black-footed Phoebastria nigripes and Short-tailed P albatrus Albatrosses, now only found in the North Pacific, as well as an extinct form, P anglica, previously known from deposits in North Carolina, United States, and Suffolk, England.

The giant extinct relative of the pelicans and storks, Pelagornis mauretanicus, is also present, known for its development of false teeth along the cutting edge of its long beak. An extinct and rather large-proportioned ostrich, Struthio asiaticus, completes the assemblage, which has closer affinities to the Western Palearctic than the mammal assemblage, which belong very much to the Afro-tropical biogeographical realm. Other interesting avifaunal titbits include the presence of a hawk owl Surnia robusta, and a large Razorbill Alca species; Surnia is nowadays a strictly Holarctic boreal forest form, but the extinct taxon may have been adapted to the oak forests that are still present in some parts of Morocco.

Albatrosses are also known from Atlantic fossil assemblages around the North Atlantic, but is not known what caused their complete extinction in the region. However, it is entirely possible that glaciation may have pushed them out of their breeding colonies, and the closing of the Panama isthmus may have prevented recolonisation when the ice receded at the beginning of the current interglacial period.

North Africa also experienced rapid aridification at the time of the excavated strata, in common with much of the Mediterranean region, and the land birds found are those expected of such areas in modern times, like bustards and ostriches. A previously unknown species of lovebird Agapornis atlanticus is also present in the deposits, and perhaps nested in rock crevices like the modern Rosy-faced Lovebird A roseicollis of south-western Africa.

Reference: Mourer-Chauviré, C, and Geraads, D. 2010. The Upper Pliocene Avifauna of Ahl al Oughlam, Morocco. Systematics and Biogeography. Records of the Australian Museum 62: 157-184.