Breeding success and predation on artificial nests of the endemic pigeons Bolle's Laurel Pigeon Columba bollii and White-tailed Laurel Pigeon Columba junoniae in the laurel forest of Tenerife (Canary Islands)

摘要

Breeding sucess and nest predation effects on the two Canarian endemic pigeons, Bolle's Laurel Pigeon Columba bollii and White-tailed Laurel Pigeon C junoniae were studied during 1995 in five zones of laurel forest on Tenerife Island Nest predation was the more important cause of nesting failure of both species (88%), but principally affecting the White-tailed Laurel Pigeon. Experiments using artificial nests showed a greater predation on the ground than in trees and a lower predation in the Frebuary-March period than in June-July and September October. The abundance of predators, estimated by bait consumption, showed a similar seasonal pattern, while fruit availability decreased over time from the first to third period. Predators identified by automatic cameras showed that Black Rat Rattus rattus was the major nest predator of both pigeons. These general patterns of nest predation alfect the White-tailed Laurel Pigeon which breeds on the ground mainly during April-July, much more than Bolle's laurel Pigeon, which breeds in trees especially in February-June. All seems to indicate that rats are the key factor causing the scarcity of the White-tailed Laurel Pigeon on Tenerife.