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Flight behaviour and observability in human-disturbed sika deer

100%

Borkowski J.

Acta Theriologica

2001

tom 46

nr 2

Sika deer Cervus nippon Temminck, 1838 observability and flight behaviour were studied in an area with a high level of human disturbance (Tanzawa Mts, Japan). Deer observation rate was positively affected by habitat-related food conditions, while it was negatively correlated with the number of tourists in the study area. Flight frequency in April-September was lower than in October-February. It was also influenced by period of day, behaviour of investigator and deer group size. Group composition, deer activity and habitat condition had no effect on flight frequency. Thus, only 317 (48%) of the deer groups encountered were caused to flee and among them as many as 86% fled for a distance shorter than 40 m. It was concluded that deer in Tanzawa Mts learned to tolerate people, what is known for the populations which are unhunted or under low hunting pressure.

Biomechanic consequences of differences in wing morphology between Tadarida brasiliensis and Myotis chiloensis

84%

Iriarte-Diaz J., Novoa F. F., Canals M.

Acta Theriologica

2002

tom 47

nr 2

The wing morphology of bats is very diverse, and may correlate with energetic, behavioural, and ecological demands. If these demands conflict, wing shape may reflect compromise solutions. In this study, we compared the wing morphology of two bats, Tadarida brasiliensis (Geoffroy, 1824) and Myotis chiloensis (Waterhouse, 1828), that differ in body size, habitat, and foraging behaviour. We analyzed features of bio- mechanical and energetic relevance, and sought evidence of compromise solutions to energetic, ecological, and behavioural demands. We found that wing span of both species conformed to expectations based on allometric relationships, but that although the wing area of M. chiloensis did not differ from predictions, the wing area of T. brasiliensis was lower. M. chiloensis possessed an unusually low second moment of area of the humerus. Wing form of M. chiloensis is consistent with highly maneuverable flight needed to live between shrubs and wooded habitats, and its low aspect ratio and low wing loading indicate a high energetic cost and a low flight speed, respectively. The low humeral second moment of area may be related to a reduction of wing mass and may result in decreased inertial power. In contrast, T. brasiliensis showed high aspect ratio and wing loading, characteristic of high speed, energetically economic flight.

Ograniczanie wyników

2 Acta Theriologica

1 Borkowski J.

1 Canals M.

1 Iriarte-Diaz J.

1 Novoa F. F.

1 2002

1 2001

Wyniki wyszukiwania

Flight behaviour and observability in human-disturbed sika deer

Biomechanic consequences of differences in wing morphology between Tadarida brasiliensis and Myotis chiloensis