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Tuesday, 11 August 2015

Ornithological Science July 2015 (Volume 14, Issue 2): Abstracts

Ornithological Science
Published by: The Ornithological Society of Japan

July 2015 : Volume 14 Issue 2 


Table of Contents


Satellite Telemetry of the Annual Migration of Baikal Teal Anas formosa Wintering at Katano-Kamoike, Ishikawa, Japan 
Hironobu Tajir, Yoshiaki Sakurai, Kikuyo Tagome, Yukiko Nakano, Yoshio Yamamoto, Toyotaka Ikeda, Yoshiyasu Yamamura and Kyohsuke Ohkawara

Baikal Teal were tracked, by satellite telemetry, in order to identify their migration route between their wintering grounds at Katano-kamoike, Ishikawa, Japan and their breeding range in Russia, and to identify the staging sites they use during migration. In the winter of 2012, four Baikal Teal were captured and satellite transmitters were attached to each individual. From 2012 to 2013, we tracked two of the four teal throughout their annual migration. In the spring, they crossed the Sea of Japan in late March and used stopovers in the Khanka Plain and the Three Rivers Plain for about one month. In early June, they reached their Arctic summer sites in the estuaries of the Indigirka and Khroma rivers of the Sakha Republic, Russia. They remained there for about three months and commenced their autumn migration in early September. The autumn migration route as far as the Three Rivers Plain was similar to that in spring, but after leaving the Three Rivers Plain, they moved to the western part of South Korea and stayed at Seomjin River and other rivers for several weeks. Finally, one of them returned to Katano-kamoike in January and spent more than two months of the winter there. In this study, we identified a total of 19 wetlands as important sites for Baikal Teal; three wintering sites, 13 stopover sites, one stopover/wintering site and two summer sites.

Seasonality of the Bird Community in the Ogawa Forest Reserve, an Old-Growth Deciduous Forest in Central Japan
Hitoshi Tojo

The bird community in the Ogawa Forest Reserve (OFR), an old-growth cool-temperate deciduous forest in central Japan, was surveyed monthly using the point count method from September 1996 to August 1997. Of the 61 bird species observed in the OFR during the study, 41 species were recorded in the survey's circular plots. Species richness was lowest (6) in January and peaked (21) in April. Total bird abundance was also lowest (25 birds/10 ha) in January and peaked (138 birds/10 ha) in April. As for the migration status, resident species such as tits (Paridae), longtailed tits (Aegithalidae) and woodpeckers (Picidae), dominated throughout most of the year. During the breeding season (April—August), summer visitors accounted for 20 to 33.3% of species richness and 10 to 27% of abundance, but never reached a level comparable to those of resident species. In non-breeding season (October—February), winter visitors accounted for up to 27% of species richness and up to 72% of abundance. The temporary dominance of winter visitors in December is attributed to waxwing flocks, which were not recorded either January or February. An ordination using non-metric multidimensional scaling showed that the bird community varied more during the non-breeding season than during the breeding season. Compared with the seasonal patterns of bird communities in other types of forest along the migration route, a characteristic of cool-temperate deciduous forests is that they have a highly diverse avifauna during autumn, suggesting that such forests are important stopover sites for migrants.

Hydrological Management in a Restored Wetland Affects Stopover Ecology of Aquatic Warbler: The Case of La Nava Wetland, Northern Spain
Emigdio Jordán Muñoz-Adalia, Fernando Jubete, Carlos Zumalacárregui and Vittorio Baglione

The Aquatic Warbler (Acrocephalus paludicola) is one of the most threatened migratory passerine birds in the world. The species stops over at both European and African wetlands during its migration. Using data from a long-term ringing program in the restored wetland of La Nava (Spain), we describe several aspects of the species' stopover ecology at this site with special focus on juveniles: (1) timing of migration, (2) population size, (3) fuel reposition rate, (4) stopover duration and (5) site fidelity. We elaborated two Multiple Linear Regressions and a Generalized Linear Model to estimate the determinants of migration phenology, daily fattening rate and abundance of captures in addition to minimum observed stopover duration. Finally, we calculated return rates to estimate stopover site fidelity. We determined that: this stopover site belongs to an Atlantic migration route; juveniles experience delayed migration; and that reduced captures are associated with more restrictive hydrological management. Return rate results suggested that there is stopover site fidelity is low. Our results may indicate that this stopover site serves primarily as a resting place rather than a refuelling habitat for this species.

Nest Site Characteristics of the Newly Established Eurasian Magpie Pica pica Population in Hokkaido, Japan
Toru Nakahara, Misako Kuroe, Osamu Hasegawa, Yuko Hayashi, Sayaka Mori and Kazuhiro Eguchi

Nest site availability is an important factor promoting the establishment of introduced bird species. Since the 1990s, the Eurasian Magpie Pica pica has colonized an area of southwestern Hokkaido, in northern Japan. In this study, we investigated the characteristics of magpie nest sites in Tomakomai, Hokkaido, at multiple spatial scales: home range, territory, and microhabitat, in order to understand the environmental factors that have supported the magpie's successful establishment. We found 67 nests (49 on trees; 18 on artificial structures) in May 2011. We analysed nest locations and surrounding land use, using nest presence/absence data and a logistic regression analysis, in order to reveal preferable environments for magpies. At the home range scale, the urban environment positively influenced nest presence. We also revealed by territory scale analysis that magpies used tree-dense patches when nesting on trees, while magpies built nests on artificial structures when tree density was relatively low. At the microhabitat scale we found that magpies preferred to nest at higher positions in nesting substrates. These results suggest that magpies are flexible in their nest site selection in the urban environment, depending on the complexity of the surrounding land use, tree density and substrate heights, at each spatial scale. This conclusion provides new insight into the successful establishment of magpies in Hokkaido.


Breeding Ecology of the Japanese Bush Warbler in the Ogasawara Islands
Shoji Hamao and Masahiro Hayama

Island and mainland populations of birds often differ in their breeding biology because of differences in ecological conditions. We studied the breeding biology of Japanese Bush Warblers Cettia diphone on Hahajima in the Ogasawara (Bonin) Islands group. Based on observations of four nesting attempts, clutches consisted of three or four eggs, which is smaller than on the mainland. Males fed the chicks, although the frequency was fairly low. Brood sizes declined during the nestling period due to starvation. Neither such male behavior nor starvation, have been reported on the main islands of Japan or on their small peripheral islands. These features of their breeding biology may have resulted from food scarcity and strong intraspecific competition on the island.

Nest Failure Owing to Intraspecific Agonistic Behaviour in Dupont's Lark Chersophilus duponti 
Cristian Pérez-Granados and Germán M. López-Iborra

Intraspecific nest aggression in a diverse array of passerine species is usually explained in the context of competition for nesting sites among cavity nesters, or as parental investment among polygynous species, but has been reported only rarely in monogamous, open ground-nesting species such as larks. We video-monitored ten Dupont's Lark nests. This declining species has a patchy and restricted distribution in Iberia and northern Africa. We detected aggression toward one nest, during which a female deserted her clutch after being attacked by another Dupont's Lark. This is the first record of nest abandonment resulting from intraspecific agonistic behaviour in the Alaudidae family. The high density and proximity of territories of Dupont’s Lark in the study area seems a likely explanation for such agonistic behaviour, which may be a neglected cause of nest failure in shrinking Dupont’s Lark populations living in small habitat patches.

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