OBSERVATIONS ON THE BIRDS OF PICO, AZORES.

Abstract

SUMMARY .1. A visit was made to the island of Pico, in the Azores, in the spring of 1949. 2. The relative frequency of the bird species in the three main vegetation zones is estimated from the data obtained fron a series of transects and the results are discussed. 3. Ecological‐niche expansion is seen to occur in Motacilla cinerea, Regulus regulus, Sylvia atrieapUla and Leucopolius alexandrinus. 4. Song and call‐notes differ from the corresponding British birds in Fringitta coelebs, Regulus regulus, Sylvia atricapiUa and Turdus merula , and the two former are also thought to exhibit voice‐range extension, due to the absence of some closely related species. 5. An annotated list of all the species seen is given, with notes on the feeding habits, etc.