What can the abundance of Grey Parrots on Príncipe Island tell us about large parrot conservation?

While populations of the Endangered Grey Parrot Psittacus erithacus have collapsed across its range, the species remains remarkably abundant on the island of Príncipe, Gulf of Guinea. We examine how aspects of its ecology interplay with local environmental conditions, to inform conservation strategies for this species and other large parrots. On Príncipe, parrots breed in large trees of common species, with nest densities (42 ± 34 km−2) greatly exceeding those for any comparably sized parrot. Productivity is high (1.9 chicks per cavity), probably reflecting the absence of nest competitors and predators. Food sources are abundant and much of the island is inaccessible to trappers, so many nests are successful each year. Historically harvest has involved taking only chicks from trees in a few traditional patches. These conditions have combined to allow Grey Parrots to thrive on Príncipe, while elsewhere nest trees are timber targets, nest competition and nest predation are likely to be more intense, trapping is indiscriminate, and few areas remain unexploited by trappers. Preservation of large trees as breeding refugia, and vigilance against the indiscriminate trapping of adult birds, are identified as key conditions to stabilize and recover mainland Grey Parrot populations and indeed large parrots generally, given their very similar ecological traits and anthropogenic circumstances.

Bionomic notes on the solitary Evylaeus oenotherae (Stevens) (Hymenoptera: Halictinae), a matinal summer bee visiting cultivated Onagraceae

Overwintered females of Evylaeus oenotherae establish haplometrotic nests in aggregations and rear a single annual generation in from 12 to 20 cells per nest. Competition for suitable nests in early summer appears to keep the breeding population at a certain level and prevents the overexploitation of its exclusive food source, Oenothera pollen. The bee's late active phase is synchronized with the flowering period of the host in June and July. Initially, females are active in the morning and evening, but are quickly trained to a matinal rhythm only, when excursions in the evening fail to yield suitable food.