Supplemental food, in the form of millet seed, was provided to female Alpine Accentors (Prunella collaris) during the 1986-1989 breeding season to test whether 1-year old and older(_??_2-year old) females take advantage of the rich food supply by laying earlier, producing larger clutches, producing more or heavier nestlings, or having second broods. The provision of extra food resulted in earlier breeding of 1-year old females but did not affect clutch size. Food-supplemented older females did not lay larger clutches than control ones, but older females produced larger clutches than 1-year old females. Supplemental food did not (1) improve hatching success, (2) increase the number of fledglings, (3) increase nesting attempts, (4) reduce the starvation rate of nestlings or (5) increase nestling body mass in each age class. Irrespective of the provision of extra food, clutch sizes and nestling mass did not decrease as the breeding season progressed. Older females, because of their early breeding, initiated more breeding attempts per year and achieved higher reproductive success than 1-year old females. However, earlier breeding was not always beneficial for 1-year old females because 43.8% of the females that bred earlier in response to food supplementation encountered bad weather and the nestlings starved.
The avifauna of the U. P. Laguna Land Grant in Southern Luzon consists of 101 species belonging to 41 families. Collectively, a total of 78 bird species were recorded along four transects selected for their different habitats: mature secondary forest (44 species), heavily disturbed forest (35), grassland with scattered remnant forest trees (38) and second growth forest with mixed cultivated areas (35). Species richness and abundance were determined for each transect and the feeding guild, residency and conservation status for each bird species were discussed. Significant reduction in diversity and endemicity are attributed mainly to habitat degradation caused by extensive logging activites, both local and commercial. Non-endemic birds colonized the overlogged areas while only a few strictly forest birds tolerate non-native vegetation. The inclusion of the lowland forests of Luzon such as the Paete-Pakil-Kalayaan zone as one of the most critical Endemic Bird Areas (EBA) in the world should prompt concerned parties to increase its protection efforts in the area and ensure the long-term preservation of its biodiversity.
Chick growth and parental feeding behavior of the Spectaled Guillemot (Cepphus carbo) were studied on Teuri Island, Hokkaido in 1989. Increase in chick body weight was closely fitted to the von Bertalanffy equation. Chick growth rate peaked at a maximum of 22.1g/day at 15.3 days after hatching; being highest among the Alcidae. Its weight was 620g at fledging, 91.2% of the average adult weight. Lengths of wing, culmen and tail for two chicks grew to 60-79% of adult lengths at fledging, with only the tarsus attaining the full length. Chick diets in the nestling period consisted of three species of benthic fishes, Sebastes minor, Ammodytes personatus, and Blennioidei sp. Feeding frequency was 9.8 times/day for one chick brood, and 9.3 times/day for two chick broods. These figures are remarkably high compared to other Alcidae. High feeding ability of the parents may account for high growth rates and large body sizes at fledging for the chicks.