Midwinter Breeding by Some Birds in the High Andes of Southern Peru

Abstract

As far as can be gathered from the very scanty information available, most of the land birds of the high Andes of southern Peru breed during or immediately after the summer rains, between November and April. At this season food, both animal and vegetable, is more readily obtained than in the rest of the year which, away from the humid eastern slopes, is characterized by severe drought. I was therefore surprised recently to obtain proof of midwinter breeding by the three species of birds detailed below. Since little has been published concerning the nesting of these species, I include the details of nest placement. Rhodopis vesper. Oasis Hummingbird. On 5 July 1979 I found a nest containing two recently hatched young birds near Chiguata (Dept. Arequipa) at an elevation of 2,750 m, close to the uppermost limit of the vertical range of the species in this part of Peni. The nest was placed approximately one meter off the ground in the branches of a bush (Tessaria integrifolia) growing near a small stream. Johnson (The birds of Chile and adjacent regions of Argentina, Bolivia and Perui. Vol. 2. Platt, Buenos Aires. 1967) mentioned September to December as breeding dates for the species in northernmost Chile (Arica and Tarapaca), which coincides with my experience at Mollendo, on the Pacific Coast (Dept. Arequipa). I know of no previous record of midwinter breeding by this species in any part of its restricted range along the coast and west Andean slopes of Peni and northern Chile. Metallura phoebe. Black Metaltail. On the same date I also found a nest near the top of a steep, moss-covered bank near Chiguata at 2,720 m altitude. The nest was suspended from overhanging vegetation at the top of the bank, kept permanently damp by water filtering down from the agricultural terraces above. Although its contents could not be checked, the female was sitting on th nest when found, and her subsequent behavior, ext eme agitation and reludtance to leave the area, indicated that it might have contained eggs or