著者

Wataru Doi Ren Kikuchi Akira Mizutani Hiroyoshi Kohno

出版者

Carcinological Society of Japan

雑誌

Crustacean Research (ISSN:02873478)

巻号頁・発行日

vol.51, pp.137-145, 2022-12-06 (Released:2022-12-06)

参考文献数

36

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To characterize the reproductive behavior of the land crab Cardisoma carnifex, their nighttime activities on the ground surface around their burrows were monitored using infrared-triggered cameras on the Iriomote-jima Island, Japan. Matings of three pairs were recorded near the entrance of the female’s burrow. The results showed that the species shares a common mating pattern of gecarcinids: hard-female mating and short courtship. The males did not exhibit courtship behavior, except for drumming on the surface sediment. The duration of copulation was longer (29, 30, and 49 min) than that in the reference data (1–10 min). After mating, males guarded their mate’s burrow and plugged the opening from the outside. By contrast, the resident crabs sometimes plug their burrows from the inside. Burrow plugging by C. carnifex males is similar to post-copulatory guarding by males of brachyurans, to prevent multiple matings by females. The non-invasive cameras revealed novel features of mating behavior of C. carnifex such as longer copulation, drumming behavior, and burrow plugging by males.

著者

Takashi Yamamoto Hiroyoshi Kohno Akira Mizutani Hanako Sato Hiroki Yamagishi Yutaka Fujii Miku Murakoshi Ken Yoda

出版者

The Ornithological Society of Japan

雑誌

ORNITHOLOGICAL SCIENCE (ISSN:13470558)

巻号頁・発行日

vol.16, no.1, pp.17-22, 2017 (Released:2017-03-01)

参考文献数

42

被引用文献数

14

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There is increasing evidence showing that wind velocity affects the flight and foraging behavior of seabirds; however, few studies have examined these effects on seabirds inhabiting tropical oceans where lighter wind conditions usually prevail. The Brown Booby Sula leucogaster is an example of a tropical seabird with relatively low wing loading; strong wind conditions may be expected to impede the stability of their flight. We examined how different wind conditions affected the duration and flying behavior of Brown Booby fledglings during foraging trips by means of direct observation of nest attendance and by attaching video loggers to birds. The duration of foraging trips by fledglings decreased with increasing wind speed, and during flight, the body rotation of fledglings became greater with increasing wind speed. As expected, fledglings were buffeted by strong winds due to their relative inexperience in flight combined with their low wing loading. Fledglings were probably forced to flap against strong winds in order to adjust the stability of their bodies, offsetting the efficient use of wind for gliding. Furthermore, the height at which fledglings flew fluctuated more at higher wind velocities, which may have constrained their detection and capture of prey. In conclusion, our results indicate that the aerodynamic performance of Brown Booby fledglings is impaired by strong wind conditions, leading to poor flight stability and potentially reduced prey detection.