From November 1997 to February 1998, the diet of geese and swans was investigated at 12 lakes in Japan. Middendorff's Bean Goose Anser fabalis middendorffii, Whooper Swan Cygnus cygnus and Bewick's Swan C. columbianus were all frequently observed to forage on aquatic vegetation at the surface of inland waters. The rhizomes of Zizania latifolia occupied more than 50% of diets of all three species. Phragmites australis, Typha angustifolia and submerged plants were rarely foraged on by geese or swans, suggesting that these are not important foods for them. This study also showed that Middendorff's Bean Goose and Whooper Swan frequently used inland water surfaces as foraging sites whereas Greater White-fronted Goose A. albifrons did not. Utilization of inland water surfaces as a foraging site by Bewick's Swan was observed only in a limited region. Whooper Swan mainly foraged on the rhizomes of Z. latifolia under water whereas Bewick's Swans mainly exploited Z. latifolia on shore.

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We used radio telemetry to examine habitat selection within home ranges of 14 adult male Northern Goshawks Accipiter gentilis during the breeding season from the nestling stage in June to the post-fledging stage in August, and during the non-breeding season from October to December in Tochigi Prefecture, central Japan. We assessed habitat selection using logistic regression analyses with telemetry locations and 1,000 random points within each home range (estimated with the 95% fixed kernel method) as response variables. We included the distance from a nest as an explanatory variable in the logistic regression analyses. Male habitat use declined with distance from the nest in the non-breeding season, but did not decline in the breeding season. In both seasons, males strongly preferred forests and strongly avoided urban land. However, males did not avoid areas close to urban land. In regard to open land, males preferred upland fields and grassland to rice fields in the breeding season, whereas most males preferred rice fields to upland fields and grassland in the non-breeding season. When using forests, males preferred the forest margin within 50 m of the forest edge to forest interior in the breeding season, but the preference for forest margin declined and males used the forest interior more in the non-breeding season. These results suggest that maintenance and management of forest fragments with adjacent upland fields and grassland, and prevention of urban land enlargement are important in order to conserve Goshawk foraging areas in agricultural landscapes that are mosaics of arable fields and forest fragments. It is also important to conserve areas around nests in the breeding season although males did not frequently use areas close to nests.

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Greater White-fronted Geese Anser albifrons have historically wintered in large numbers around Lake Izunuma-Uchinuma, northern Honshu, Japan. Since 1971, when goose hunting was prohibited, the number of geese has increased 7.6 fold from 14,647 in 1987/88 to 110,816 in 2006/07. Currently more than 80% of the Japanese A. albifrons population winters here. Agriculture in the surroundings of the lake system has also changed. The total average area of soybean fields increased 2.8 fold from 1,780 ha in 1996 to 4,940 ha in 2005. We investigated temporal and spatial changes in goose foraging strategies by comparing data on habitat selection between 1997/98–1998/99 and 2007/08. In 1997/98–1998/99, geese only foraged on rice fields, and shifted from rice fields near the lake to fields further away as these fields became depleted as winter progressed. In 2007/08, just after harvesting in late September, although waste rice grains on fields amounted to 65 kg/ha (N=6, range: 52–78), post harvest waste soybeans amounted to 355 kg/ha (N=9, range: 120–940) and the amount increased from mid November to mid January. Geese depleted waste rice grains by early December in areas within 10–12 km of the lake, and foraged on soybeans within 10 days of harvesting. In relation to these changes in relative food abundance, the geese now forage exclusively on rice fields in November, but switch to feeding primarily on soybeans in December and in January. With both the number of geese and the area of soybean fields increasing over the decade (1997/98 to 2007/08), geese now experience a shift in food resources from waste rice grains in early winter to soybeans in late winter.

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The relationship between individual variation in foraging trip duration in Japanese Cormorants Phalacrocorax filamentosus and their ability to feed their chicks was examined. The dietary mass of different prey types (epipelagic or epi- and benthic fish) was estimated and compared, and the nest attendance patterns and breeding performance of adult birds were observed. There was no difference in dietary mass of each prey type. The duration of foraging trips varied significantly among individuals, and individuals that conducted repeated short trips had higher provisioning rates than individuals that conducted longer trips. Chicks that received high provisioning rates had a higher proportion fledged. These results suggest that variation in foraging trip duration affects breeding success.

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The coastal area off eastern Hokkaido, Japan, in the North Pacific, is an important foraging area for many seabird species in autumn. To understand the distribution of seabirds, in the shelf, slope and basin off eastern Hokkaido, ship-based censuses were carried out over three days from 27 to 29 September, 2003, on board the T/S Oshoro Maru (Hokkaido University, Fisheries Science). The warm (>19°C) Tsugaru Current affects the western area off Cape Erimo, while cold (<14°C) Oyashio Current affects the eastern area off the same cape. The density of seabirds sitting on the sea was high in the shelf and slope (including frontal area) areas influenced by the cold current where the primary productivity is usually high. Within these areas, densities of diving seabirds (Rhinoceros Auklet Cerorhinca monocerata and Puffinus spp) were high in the shelf area, whereas densities of surface feeders (Streaked Shearwater Calonectris leucomelas and Laysan Albatrosses Diomedea immutabilis) were high in the slope area.

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In order to understand the environmental factors affecting the distribution of Rhinoceros Auklets at sea, ship-based censuses were carried out in the northern Sea of Japan off Hokkaido, during late May and early June 2005. Potential prey density was surveyed using acoustics: 38 kHz for pelagic fish and 200 kHz for plankton. Multiple regression analyses did not show any linear effects of prey density index, sea surface temperature, depth of the sea (water depth), or slope of the sea bottom, on the density index of Rhinoceros Auklets on the sea at any spatial scale (0.3–10 km). The density index for auklets was higher than expected around Teuri Island, Rebun Island, Ishikari basin and Musashi bank where the strength of marine currents seemed to be weaker than elsewhere, although differences were not statistically significant.

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