Nesting behaviour of the brambling Fringilla montifringilla during feeding nestlings

Differences in parental feeding of the Brambling Fringilla montifringilla in Murmansk Oblast (Russia) were studied in 1987-2011. The most important peculiarities of male and female behavior concerning the nestling age, brood size and environmental conditions are discussed. On the whole, observations were performed during 545 h, and the total number of breeding attempts constituted 41, but the number of broods used in the feeding activity study constituted 24 attempts. The common behavior strategy was based on different relation of sexes to the brood size and the nestling age. In pair-fed broods, the number of feeding per-brood visits increased from 45-60 visits per day in the first days to 210-240 visits per day before the fledging. The positive correlation between nestling age and feeding rate by parents («common»), by female and by male over the entire nesting period was observed. Females constantly increased frequency of visits with food, whereas males fed more selectively. According to the present study, only female feeding frequency (per brood and per nestling) positively correlated with the brood size. In males, this factor was unreliable. The brood size did not correlate with the average nestling weight. On the whole, such indices, as the frequency of feeding was lower in males in comparison with females, but at later breeding dates (in repeated and may be secondary broods), parental attempts were redistributed and the role of the male significantly increased. Nestlings from late broods had larger weight, which is probably associated with differences in food requirement. The results suggest that male and female contribution to such factors as feeding frequency and wet weight of food transported during the nestling stage is nearly equal.