Breeding success, nestling diet and parental care in the White-backed WoodpeckerDendrocopos leucotos
1997
Hogstad, Olav | Stenberg, Ingvar
In western Norway, pairs of White-backed Woodpecker breeding in coastal areas (<2 km from the sea) started egg laying earlier than pairs in inland areas (2–15 km from the sea). Laying was earlier in years when the ambient temperature was higher during the pre-laying period. About half of 69 pairs studied started laying within the period 25–30 April over the 10 study years. Clutch size ([Formula: see text] = 4.0 eggs) and breeding success values (fledglings per egg;[Formula: see text] = 0.63) did not differ between years. The mean number of fledglings per nest was 2.4. The mean body mass of fledglings differed between years and were negatively correlated with the laying date. Fledgling mass differed between sexes (males[Formula: see text] = 87.8g, females[Formula: see text] = 84.2g), and both sexes were heavier in coastal than in inland areas. The mean hourly feeding rate of nestlings increased with nestling age, but feeding rate per nestling did not vary with nestling number. The nestling food was mainly comprised by wood-living beetle larvae ([Formula: see text] = 72% by dry mass). It is suggested that breeding success is related to territorial quality, which, in turn, strongly influences female quality.
显示更多 [+] 显示较少 [-]