CR 29:157-165 (2005)  -  doi:10.3354/cr029157

Migration dates at Eyre Bird Observatory: links with climate change?

Lynda E. Chambers*

Bureau of Meteorology Research Centre, GPO Box 1289, Melbourne, Victoria 3001, Australia

ABSTRACT: In contrast to the Northern Hemisphere, relatively little is known about the influence of climate, in particular climate change, on the timing of bird migration in Australia. This paper examines a new dataset, comprising daily abundance records for 8 landbird species at Eyre Bird Observatory (EBO), Western Australia, for the period 1984 to 2003. Five of the 8 species were present at Eyre for only part of the year, while the 3 species present all year round exhibited seasonal changes in abundance. For most species, changes in migration dates were related to observed changes in the regional climate; 3 species showed no trend in migration timing, and these had no regular period of absence from EBO. Of the remaining species, the Purple-crowned Lorikeet Glossopsitta porphyrocephala and Grey Fantail Rhipidura fuliginosa showed strong trends in arrival dates: both winter visitors arrived suddenly at EBO and earlier over time, with lorikeets arriving earlier in years of warmer night-time temperatures. Two species, Fork-tailed Swift Apus pacificus and Rainbow Bee-eater Merops ornatus, had strong trends in departure dates and were summer visitors. These species responded differently to warming night-time temperatures, perhaps reflecting their breeding characteristics. The Budgerigar Melopsittacus undulatus arrived and departed suddenly and showed no trend in migration timing, though wetter years corresponded to earlier arrivals. Consistent with global trends, this region warmed, particularly in minimum temperatures (0.05°C yr–1). There was no trend in rainfall.

KEY WORDS: Migration dates · Climate change · Phenology · Australia · Birds

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