著者

Benvenuti Silvano Dall'Antonia Luigi

出版者

国立極地研究所

雑誌

Memoirs of National Institute of Polar Research. Special issue (ISSN:03860744)

巻号頁・発行日

vol.58, pp.110-117, 2004-03

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Our research group has devised and manufactured a data logger, which, glued on the back of a bird, can detect and memorise the direction in which the bird is heading during a flight. Given the birds' constant cruising speed, the memorised data can be used to reconstruct the whole flight path. Subsequent versions of this direction recorder, equipped with new sensors (depth meter and flight sensor), were used to investigate the foraging behaviour of several species of breeding marine birds (Balearic shearwater, Brunnich's guillemot, common guillemot, razorbill, black-legged kittiwake, Audouin's gull, northern gannet, blue-footed booby). The data recorded at different colony sites allowed us to identify the birds' feeding grounds and record the most relevant events occurring in the foraging trips, including the duration of the trips, total flight time, number and duration of the stops where feeding actually occurred, dive profiles and diving behaviour. Differences in the foraging strategies between sexes and between incubating and brooding birds were also investigated.

著者

Holdsworth Gerald

出版者

国立極地研究所

雑誌

Memoirs of National Institute of Polar Research. Special issue (ISSN:03860744)

巻号頁・発行日

vol.54, pp.161-168, 2001-03

被引用文献数

1

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Cross correlation between time series of (1) total precipitation for a combined four-station network in northern Japan and of (2) the net snow accumulation determined from an ice core obtained from Mount Logan (60.5°N, 5340m) situated in the Saint Elias Mountains, Yukon, reveals high, statistically significant, cross correlation coefficients of +0.38 for annual data increasing up to +0.71 for seven point smoothing of the two 89 year series. The distance between sites is about 7000km spanning the complete Pacific Ocean between latitudes of about 40°N and 60°N. A review of the extensive literature of oceanology and climatology for the North Pacific Ocean region indicates that a strong coupling exists between the ocean and the atmosphere especially up to and associated with the Polar Front Zone along which major cyclogenesis occurs during most months of the year. Cyclones track generally from west to east with a strong northerly component especially in the eastern (Gulf of Alaska) sector. Examination of these cyclones on GOES satellite images shows that weather systems can transport moisture from mid latitude ocean sources (<40°N) to high on Mount Logan over the top of the warm front zone and high above intervening coastal topography. Thus, the positive correlation between the two time series can be physically justified and qualifies the link as a genuine teleconnection.

著者

Afanasyev Vsevolod

出版者

国立極地研究所

雑誌

Memoirs of National Institute of Polar Research. Special issue (ISSN:03860744)

巻号頁・発行日

vol.58, pp.227-233, 2004-03

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The device has a sensor that periodically measures and records the ambient light level. Following retrieval of the device, the light level records are converted into latitudes and longitudes, which allows the geographic position of the animal to be estimated twice daily. The instrument is also configured to detect and record the history of time spent in water against time spent flying or on land. For seabirds, this can provide time-budget data related to activity and feeding behaviour. Small size, a low profile and robust packaging are crucial for effective deployments on flying birds and diving animals. Long battery life is often essential (e.g. after fledging, juvenile wandering albatrosses Diomedea exulans usually remain at sea for at least five to seven years). Low unit and operation costs are also very desirable, together with simplicity of operation. Dimensions of the instrument are 22x19x12 mm. Weight is 9 g in air and 4 g in water. The device is pressure tested to 800 m depth of water, and can log data for up to eight years. The total cost of components is less than $70. The principles, design specification and circuit description of the device are presented here, together with a representative migration track, obtained during field tests on grey-headed albatrosses Thalassarche chrysostoma, to illustrate performance.