Effects of age on breeding performance of Tengmalm's owl Aegolius funereus in western Finland

Call Number:

Keywords:

Abstract:

Age composition of breeding Tengmalm's Owls in relation to population fluctuations of voles and age-related breeding performance were studied in 1981-86 in western Finland. Three age classes were identified: first-year, second-year, and older owls. The most common age class of females was 1-year-old and that of males was 2-year-old. A larger proportion of females than males bred as yearlings, possibly because the breeding success of a pair is largely dependent on the male's ability to provide food. First-year breeders were most frequent in peak years, when many immigrant young owls entered the breeding population. Yearling-yearling pairs performed less well in their breeding attempts than did pairs of 2-year-old mates, which in turn did less well than did older pairs. The nests of first-year males had smaller prey stores than those of second-year males, which in turn had smaller stores than nests of older males. A lack of experience and shortage of food, rather than "saving themselves for later life", seemed to cause poor performance of yearlings.

Notes:

Reference Code: A88KOR06IDUS

Full Citation: Korpimäki, E. 1988. Effects of age on breeding performance of Tengmalm's owl Aegolius funereus in western Finland. Ornis Scandinavica 19(1): 21-26.

Location: ANIMAL EF: AEGOLIUS FUNEREUS