Birds from the Pribilof Islands and Vicinity

Abstract

THIS paper reports unusual species of birds collected or observed on the Pribilof Islands (St. Paul, St. George, Otter, and Walrus islands) and records observations of interest concerning some resident species of the Pribilofs. Observations from the Aleutian and Commander islands are included. Preble and McAtee (1923) summarized available knowledge of Pribilof birds. We here attempt to record only pertinent information obtained in recent years. Our data were collected primarily from 1947 to 1954. In this period Kenyon spent a total of 21 months on the Pribilofs, mostly from May to October. Phillips was on the Pribilofs from 19 June to 24 September 1954. Ornithological observations were made sporadically, incidental to full-time work on studies of Alaska fur seals (Callorhinus ursinus). The data presented represent only a minor fragment of what is needed for an understanding of the ecology and distribution of Pribilof birds. No continuous, long-range studies have been undertaken in this area, although ecological conditions at the Pribilofs are of interest. For example, both the Common Raven (Corvus corax) and Pigeon Guillemot (Cepphus columba) are resident on islands north and south of the Pribilofs, yet neither breeds on the Pribilofs. The raven rarely occurs there and the guillemot is present only in winter months. The Winter Wren (Troglodytes troglodytes) is a common resident of St. George Island. It appears irregularly on St. Paul and Otter islands. Possibly it breeds in some seasons on St. Paul and was established at one time on Otter (Hanna, 1920b). Growth of marine mammal populations has particularly affected populations of the Glaucous Gull (Larus hyperboreus), Glaucous-winged Gull (L. glaucescens), and the Common Murre (Uria aalge). As fur seal and sea lion (Eumetopias jubatus) populations increased in recent years, bird nesting areas were usurped as mammalian breeding grounds. As Hanna (1920a: 248) pointed out, the Pribilofs are ideally situated as a stopping place for birds from many areas. A number of species were added to the North American list on the basis of specimens collected on the Pribilofs. That more could be, and still are being, added is indicated by several observations of unusual birds which could not be collected or identified in the field. Among the 34 forms here listed, 1 (Apus apus pekinensis) is a new record for North America; 9 (Charadrius mongolus, Capella gallinago gallinago, Ereunetes mauri, Larus ridibundus, Aegolius funereus richardsoni, Progne subis, Bombycilla garrula pallidiceps, Dendroica coronata