Holmes, R. 1960 Erolia alpina 18. 2 july Ikravik, Alaska as nasal (more of a pree, pree...). The trill is often given (by bairdi) in short sequences where the notes are all at the same pitch. This is shown below for bairdi: pree, pree, pree..., ____, pree, pree... When alpina makes its downward glide and gives its long drawn-out trill, it may or may not set its wings in a V-pattern, and it usually glides a considerable distance. vocal - kraa, kraa, kraa..., aerial Positn ( maybe in 1 spot ) In contrast The bairdi has The following situation! vocal pree, pree, pree..., ____, pree..., pa aerial pos! It can be seen that The bairdi dips when the trill is given, but usually returns to its normal altitude. When it glides to the ground it usually begins its way at a 45°L. In Susswell, the pattern