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Volume 51 (2002)
- Issue 2 Pages 101-
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Volume 51, Issue 2
Displaying 1-5 of 5 articles from this issue
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Hiroshi HASHIMOTO, Takashi KAMIJYO, Hiroyoshi HIGUCHI2002 Volume 51 Issue 2 Pages 101-107
Published: 2002
Released on J-STAGE: September 28, 2007
JOURNAL FREE ACCESSDispersal of Styrax japonica (a deciduous tree) seeds by Varied Tits Parus varius was observed on Miyake-jima, Izu Islands. Seven sample trees were monitored for 65-780 min. to examine seed consumption by birds. Varied Tits visited all the sample trees and carried off some of the fruits. The tits removed the toxic pulp and testae from the S. japonica fruits using their bills, and ate only the seed albumen. The tits stored some of the seeds close to the trees, but carried many others out of sight. Half of the stored seeds were placed on the ground, and these seeds presumably hadchance of germination, thus the Varied Tit may be an important seed disperser of S. japonica on Miyake-jima.View full abstractDownload PDF (80K) -
Kenichi ISEKI, Yutaka WATANUKI2002 Volume 51 Issue 2 Pages 108-115
Published: 2002
Released on J-STAGE: September 28, 2007
JOURNAL FREE ACCESSTo examine the effects of brood size on chick growth and survival, we manipulated the brood size of early and late breeding Black-tailed Gulls (Larus crassirostris) that usually lay two eggs, in two years of different environmental conditions at Rishiri Island, Hokkaido. Early breeders produced more chicks that grew faster than late ones, though there were no significant interactions between the effects of laying period and brood size. In 2000, the parents of enlarged 3-chick-broods produced greater number of 25-day-old chicks than those of reduced 1-chick-broods. In 2001 with heavy rain, however, the effects of brood size on the number of 25-day-old chicks were not significant because the survival of 3-chick-broods was small. This indicated that the parents might not be able to care three chicks during bad weather. Body mass of chicks at 25-day-old was smaller for larger broods in both early and late breeders and in both years. In our study, parents might not have enough ability to provision three chicks.View full abstractDownload PDF (75K) -
Michio FUKUDA2002 Volume 51 Issue 2 Pages 116-121
Published: 2002
Released on J-STAGE: September 28, 2007
JOURNAL FREE ACCESSGreat Cormorants Phalacrocorax carbo breed year round in Japan, though there are variations between colonies in the timing and duration of breeding. Males bring more nesting material than females do. The clutch consists of 2-3 eggs and both male and female parents alternate incubation duties for a month. At the Shinobazu Pond colony, Tokyo, the chicks of nests on trees fledged in 31-59 days (average 45 days). Although essentially monogamous the cormorants often mate with other partners even during the same breeding season. At the Shinobazu Pond colony, males start to breed at a younger age (1-6 years-old, average 2.1 years) than females (1-8 years-old, average 2.6 years).View full abstractDownload PDF (53K) -
Satoshi TOKOROZAKI, Kaori TOKOROZAKI, Eiki SUNAGAWA2002 Volume 51 Issue 2 Pages 122-124
Published: 2002
Released on J-STAGE: September 28, 2007
JOURNAL FREE ACCESSA first-winter Rose-coloured Starling S. roseus was observed on Miyako-jima, Okinawa Pref. on 27 December 2000, which was the first record of this species from the prefecture. At least three Rose-coloured Starlings (two in adult-winter plumage and one in firstwinter plumage) were observed also on Ishigaki-jima, Okinawa Pref. between 19 March and 10 April 2001, among about 500 Red-billed S. sericeus and Whiteshouldered starlings S. sinensis.View full abstractDownload PDF (134K) -
Shigeru MATSUOKA2002 Volume 51 Issue 2 Pages 125-128
Published: 2002
Released on J-STAGE: September 28, 2007
JOURNAL FREE ACCESS
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