High survival rate and site fidelity in the Siberian Tit Parus cinctus, a focal species of the taiga

Abstract

The Siberian Tit Parus cinctus population of Finland, and probably of the whole of Fennoscandia, has declined dramatically during this century. Understanding its population dynamics is essential for its conservation. We studied annual survival rate and dispersal distance of both breeding and fledgling Siberian Tits during 1989-97 in a moderately managed forest habitat near the southern border of its range in Kuusamo, northeastern Finland. Breeding density was low, averaging 0.51 pairs/km in a nestbox area of about 42 km2. This was probably an underestimate, because we did not search for nests in natural holes. However, following its population decline, overall densities at the southern border of the range are low. The study area was, however, suitable breeding habitat as reflected by their high nesting success. Brood size at fledging averaged 7.45 young, and reproductive output was 6.16 young per breeding pair, including failed nests. Clutch size adjustment was successful among pairs producing fledglings because, on average, 92.6% of the eggs laid produced young in successful broods. Median distance between consecutive breeding attempts was 100 m for both males and females (range 0–2500 m and 0–6000 m, respectively). Natal dispersal distance was significantly longer in females than in males. We applied Cormack-Jolly-Seber modelling to estimate survival and recapture probabilities separately. Survival of breeding birds was not sex-related, averaging 0.69 annually. Some of the ringed fledglings (3.0%) were later captured as breeders in the area. This is an underestimate of local survival rate due to incomplete recapturing of breeding birds. The implications of these results with respect to the conservation status of the species are discussed.