scholarly journals Population and habitat of wintering Brent Geese Branta bernicla in eastern Oshima Peninsula, Tsugaru Strait and Mutsu Bay

2015 ◽  
Vol 64 (1) ◽  
pp. 77-82 ◽  
Author(s):  
Kazuhiko HIRATA ◽  
Masayuki SENZAKI ◽  
Takanori HORIMOTO ◽  
Yuki OSAFUNE ◽  
Junichi SAKAI ◽  
...  
2012 ◽  
Vol 140 (6) ◽  
pp. 1779-1793 ◽  
Author(s):  
Teruhisa Shimada ◽  
Masahiro Sawada ◽  
Weiming Sha ◽  
Hiroshi Kawamura

Abstract This paper investigates the structures of and diurnal variations in low-level easterly winds blowing through the Tsugaru Strait and Mutsu Bay on 5–10 June 2003 using a numerical weather prediction model. Cool air that accompanies prevailing easterly winds owing to the persistence of the Okhotsk high intrudes into the strait and the bay below 500 m during the nighttime and retreats during the daytime. This cool-air intrusion and retreat induce diurnal variations in the winds in the east inlet of the strait, in Mutsu Bay, and in the west exit of the strait. In the east inlet, a daytime increase in air temperature within the strait produces a large air temperature difference with the inflowing cool air, and the resulting pressure gradient force accelerates the winds. The cool air flowing into Mutsu Bay is heated over land before entering the bay during the daytime. The resulting changes in cool-air depth and in pressure gradient force strengthen the daytime winds. In the west exit, local pressure gradient force perturbations are induced by the air temperature difference between warm air over the Japan Sea and cool air within the strait, and by variations in the depth of low-level cool air. The accelerated winds in the west exit extend southwestward in close to geostrophic balance during the daytime and undergo a slight anticyclonic rotation to westerly during the nighttime owing to the dominance of the Coriolis effect.


2020 ◽  
Vol 19 (2) ◽  
pp. 211
Author(s):  
Yusuke Sawa ◽  
Chieko Tamura ◽  
Toshio Ikeuchi ◽  
Tetsuo Shimada ◽  
Kaoru Fujii ◽  
...  
Keyword(s):  

2019 ◽  
Vol 53 (4) ◽  
pp. 297-312
Author(s):  
Yu. O. Andryushchenko ◽  
V. S. Gavrilenko ◽  
V. A. Kostiushyn ◽  
V. N. Kucherenko ◽  
A. S. Mezinov ◽  
...  

Abstract In the article is analyzed own field data of the authors and scientific publications on the wintering of Anserinae in the Azov-Black Sea region of Ukraine in 1900–2017, but the main data was obtained in frame of international mid-winter counts (IWC) in 2005–2017. It was found that 9 species of Anserinae occur in this region during the different seasons of the year: Anser anser — nesting, wintering and migrating; Rufibrenta ruficollis, A. albifrons, A. erythropus, A. fabalis — migrating and wintering; Branta canadensis, Branta leucopsis, Branta bernicla, Chen caerulescens — vagrant or birds which flew away from captivity (zoo etc.). Eulabeia indica — is possible vagrant species. The most numerous wintering species is A. albifrons, common — Rufibrenta ruficollis, not numerous — Anser anser, the other species are not met annually and registered in a very small number. There was almost tenfold drop in number of wintering geese in the Azov-Black Sea region of Ukraine during the period of counts. The main reasons of such reducing of geese amount are the followwing: weather and climate conditions, changes in the forage acessibility, hunting and poaching pressure, poisoning as a result of deratization of agricultural lands, and from 2014 — the militarization of the Syvash area and stop of water supplying of Crimea through the North Crimean channell. It is likely that the factors mentioned above led to relocating of wintering areas of Anserinae, and resulted in decreasing of their amount in this region.


2001 ◽  
Vol 7 (1) ◽  
pp. 77-86 ◽  
Author(s):  
Mark Hassall ◽  
Simon J. Lane ◽  
Martin Stock ◽  
Steve M. Percival ◽  
Barbara Pohl

2017 ◽  
Vol 10 (4) ◽  
pp. 201-210 ◽  
Author(s):  
Meg C. Gravley ◽  
George K. Sage ◽  
Joel A. Schmutz ◽  
Sandra L. Talbot

The Alaskan population of Emperor Geese ( Chen canagica) nests on the Yukon–Kuskokwim Delta in western Alaska. Numbers of Emperor Geese in Alaska declined from the 1960s to the mid-1980s and since then, their numbers have slowly increased. Low statistical power of microsatellite loci developed in other waterfowl species and used in previous studies of Emperor Geese are unable to confidently assign individual identity. Microsatellite loci for Emperor Goose were therefore developed using shotgun amplification and next-generation sequencing technology. Forty-one microsatellite loci were screened and 14 were found to be polymorphic in Emperor Geese. Only six markers – a combination of four novel loci and two loci developed in other waterfowl species – are needed to identify an individual from among the Alaskan Emperor Goose population. Genetic markers for identifying sex in Emperor Geese were also developed. The 14 novel variable loci and 15 monomorphic loci were screened for polymorphism in four other Arctic-nesting goose species, Black Brant ( Branta bernicla nigricans), Greater White-fronted ( Anser albifrons), Canada ( B. canadensis) and Cackling ( B. hutchinsii) Goose. Emperor Goose exhibited the smallest average number of alleles (3.3) and the lowest expected heterozygosity (0.467). Greater White-fronted Geese exhibited the highest average number of alleles (4.7) and Cackling Geese the highest expected heterozygosity (0.599). Six of the monomorphic loci were variable and able to be characterised in the other goose species assayed, a predicted outcome of reverse ascertainment bias. These findings fail to support the hypothesis of ascertainment bias due to selection of microsatellite markers.


2020 ◽  
Author(s):  
Tyler L. Lewis ◽  
David H. Ward ◽  
James S. Sedinger ◽  
Austin Reed ◽  
Dirk V. Derksen ◽  
...  
Keyword(s):  

2020 ◽  
Author(s):  
Masahide Wakita ◽  
Ken'ichi Sasaki ◽  
Akira Nagano ◽  
Hiroto Abe ◽  
Takahiro Tanaka ◽  
...  

2021 ◽  
Author(s):  
Hitoshi Kaneko ◽  
Ken'ichi Sasaki ◽  
Hiroto Abe ◽  
Shuichi Watanabe ◽  
Yoshiaki Sato

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