Effects of artificial feeding on waterfowl were investigated at an artificial pond adjacent to Lake Izunuma-Uchinuma. We recorded the abundance of wintering waterfowl and the quantity of feed provided to the birds from November 2007 to March 2008. The most abundant species was Pintail Anas acuta, and the maximum abundance was 1,400 individuals on 10 January 2008. Second in abundance to Pintail was Whooper Swan Cygnus Cygnus, with a maximum of 110 on 23 January 2008. The number of Tufted Duck Aythya fuligula and Pochard A. ferina were less than that of Pintail and Whooper Swan, but those four species were the most common at the pond. The quantity of waterfowl feed (white rice, brown rice, etc.) increased between November and December and then decreased through March. Based on the Field Metabolic Rate (FMR) and body weight, the monthly energetic requirements were calculated for the four common species. Monthly energetic values of waterfowl feed were also estimated from the amount of feed, the caloric values of each food, and the assimilation efficiency. Percentage (feeding / FMR x 100) of energetic dependence by waterfowl on feed was 102 % in November and 94 % in March. However, the percentage was low (35-40 %) between January and February. This suggests that during the severe period of the wintering season (January-February), the energetic requirement of waterfowl largely exceeds the energy they gain from artificial feeding.

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During the two wintering seasons from 2004 to 2005 and 2006 to 2007, the habitat use of hunting Eastern Marsh Harriers Circus spilonotos was studied at four sites in the Watarase Marsh of central Japan. During both seasons surveyed, the frequency of hunting flights was significantly higher in an artificial reedbed (Site A) with ditches, small ponds and lakes, than in a dry reedbed (Site B). Site A had a significantly greater number of bird species and a larger population of the harriers' potential prey than Site B. For the purpose of analysis, the survey sites were completely divided into a grid with a cell size of 100m by 100m. Cells with ditches and/or ponds had a significantly greater number of hunting flights than those with only tall vegetation. These results suggest that reedbeds with ditches and ponds provide abundant prey for the harrier and also may facilitate the surprise hunting technique in which the harrier is specialized. The conservation or creation of reedbeds with a diverse structure is assumed to be beneficial to the conservation of wintering Eastern Marsh Harriers.

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Tree Sparrows Passer montanus are one of the most common garden birds in Japan. The species' biology, however, is not well known. I have estimated the population size of this species in Japan, using a method of extrapolation based the results of field surveys and land-use data. The areas treated in this study include the five main islands of Japan: Hokkaido, Honshu, Shikoku, Kyushu and the Okinawa Island. The densities of Tree Sparrows' nests in five habitat types (central urban, residential, rural, other possible breeding, and non-breeding areas) were measured by counting the nests within survey plots during the breeding season in 2008. Each of the total area for the five habitat types in Japan was calculated from three different definitions of that habitat type (Table 1) which were applied to a database of Japanese land-use. The sum of the products of the density and the area for each of the five habitat types gave an estimated total number of Tree Sparrows' nests in Japan and its value was about 9,000,000. Assuming monogamy (i.e. two adults per nest), the number of adult Tree Sparrows at the breeding season in 2008 was estimated at about 18,000,000. Considering the roughness of the estimation method, the true population size was expected to lie in the range of two or three (or, one-half or one-third) times the estimated value.

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The moult of remiges and rectrices in adult Carrion and Jungle Crows, Corvus corone and C. macrorhynchos were studied in Tsuru-City, Yamanashi Prefecture, central Japan. From mid-May to mid-October in 2007, we collected remiges and rectrices which had moulted and fallen in the field, and we also recorded the moult condition of crows observed in flight at fixed point observation points. Both species began primary moult from the innermost feather. After the 5-6th primaries moulted, they began the secondary moult. Carrion Crows moulted remiges from the end of May to early September, and Jungle Crows did so from early June to the end of September and early October. Rectricial moult started from the center after the 4th primary was moulted.

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I recorded songs of Dusky Warbler Phylloscopus fuscatus at the Sarobetsu Marsh in Hokkaido on June 12, 2008. Dusky Warblers have been known as migrants or winter residents in Japan, and this is the first record of their songs in the breeding season. Dusky Warblers are difficult to find and identify since they live in bushes. Knowing their songs will make it easier to identify them during the breeding season. I hope this report helps us to confirm their breeding in Japan.

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Research methods for recording nocturnal birds were studied at 24 forests all around Japan, including semi-tropical to cool temperate zones, from mid May to mid June, 2007. We identified and collected data by ear from observation points for songs and calls of nocturnal birds between 19:00 and 04:00 hours. We also recorded the bird sounds with a Hi-MD (SONY MZ-RH1) recorder, and compared the results with the data collected by ear in the field.
The nocturnal bird species, except for Nycticorax nycticorax, were recorded more often during time periods after sunset and before sunrise. Cuculus fugax and Zoothera dauma were frequently recorded only before sunrise, and Otus scops and Strix uralensis were frequently recorded only after sunset. These results suggest that conducting surveys during both time periods is an effective method to record nocturnal avifauna.
Comparisons between direct/listening observations and sound recordings showed no significant differences in recording efficiency between the two methods for any nocturnal bird species. Sound recordings have some advantages over observations, for instance, allowing the possibility of reexamination of the records, including later identification of the sounds with the assistance of a specialist or by comparison to sound recordings. Therefore, sound recordings is recommended as a useful method to study nocturnal avifauna.

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It is reported that a Wind Profiler (WPR), a meteorological radar for wind direction and speed, detects the echoes that are assumed to return from birds. We attempted to determine whether these echoes actually returned from birds at Muroran, northern Japan, which is located on one of the main bird migration routes between Hokkaido and Honshu. We recorded the number of birds migrating over the study site by counting bird flight calls and the number of birds passing across the moon surface at night as well as the number of birds flying past in the early morning for 6 days in the autumn seasons of 2005 and 2006. We also recorded bird echoes using a marine radar for 5 days in the autumn of 2007. We compared these results with the occurrences of "bird echoes" detected by a WPR, which is operated by the Muroran Meteorological Station. The occurrences of WPR bird echoes were significantly correlated with the bird numbers based on the four methods. The time and altitude patterns of "bird echoes" were also highly correlated between the WPR and the marine radar. These suggest that the WPR bird echoes returned from migratory birds. However, the WPR bird echoes underestimated the bird number in the early morning when the birds flew in dense flocks and overestimated the flight altitudes. Although WPR bird echoes have these defects, it was shown that they would make a major contribution toward the nationwide monitoring of bird migration because WPRs collect data at 31 sites across the country throughout the year except winter.

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