L. Stempniewicz et al., THE LITTLE AUK ALLE-ALLE-POLARIS OF FRANZ JOSEF LAND - A COMPARISON WITH SVALBARD ALLE-A-ALLE POPULATIONS, Polar research, 15(1), 1996, pp. 1-10
Breeding biology, nestling growth and development, and biometry of the
little auk Alle alle polaris were studied in Franz Josef Land. A tota
l of 103 adult birds were measured, 60 in the field and 43 in the St.
Petersburg Museum. The development of 16 chicks was compared with that
of Alle a. alle chicks from Spitsbergen. At particular stages of deve
lopment, both adults and nestlings of A. a. polaris are larger than th
ose of A. a. alle. In Franz Josef Land the breeding season is more ext
ended and less synchronised than that of Svalbard. The majority of the
little auks in the studied colonies in Franz Josef Land nested on ste
ep rocky cliffs, possibly as an adaptation to the severe climatic cond
itions and heavy mammalian predation in subcolonies located on accessi
ble mountain slopes. Glaucous gulls Larus hyperboreus exerted negligib
le predatory pressure. This study confirms the existence of morphologi
cally distinguishable populations of the little auk on Franz Josef Lan
d and Svalbard, supported by recent studies of climatic and oceanograp
hic conditions in the two areas that parallel the morphological differ
entiation.