The coast of Japan is a migratory corridor for the western stock of the gray whales (Eschrichtius robustus), which was once considered as extinct and remains endangered. According to the historical records, from 1955 ...The coast of Japan is a migratory corridor for the western stock of the gray whales (Eschrichtius robustus), which was once considered as extinct and remains endangered. According to the historical records, from 1955 to 2014, only 21 gray whales occurrence has been recorded in 59 years. However, from 2015 to 2016, intensive occurrence including the seven sightings and the two strandings were noted. In this paper, we found that those sightings were re-sightings of the same individual, which was initially sighted off Sakhalin during August, 2014. On 4 March, 2016, a young female gray whale (8.9 m in body length) was stranded at Wadaura beach, Chiba prefecture. We also conducted research on this animal including taking pictures and external measurements. In addition, we flensed this animal to observe the internal organs and collect a skeletal specimen. The reason for the death of this animal remains unclear;however, from its external characteristics, we identified that this animal was not an identical one, sighted off Sakhalin and the coast of Japan from 2014 to 2016. On 5 April, 2016, another young female gray whale (7 m in body length) was stranded at Arai beach, Shizuoka prefecture. We concluded that from 2015 to 2016, at least three distinct gray whales have migrated along the coast of Japan.展开更多
The lesion of nucleus robustus archistriatalis (RA) has no effect on normal short calls in the bramble finch, but affects significantly the temporal and acoustic features of learned long calls.It causes the principal ...The lesion of nucleus robustus archistriatalis (RA) has no effect on normal short calls in the bramble finch, but affects significantly the temporal and acoustic features of learned long calls.It causes the principal frequency of basic sound in monotone long calls to increase 500 cents, and to lose two upper partials. The lesion of RA not only results in the increased sound length of loud-sound and shortened coda of variable-tone long calls by 13.4%-22.1% and 21.2%-24.2% on average, respectively, but also makes the frequency rising coefficient (FRC) of even order partial tone in loud-sound drop 18.5%-25.8% on an average, and the step-up rate decrease 22.7% -24.0% on an average with the increase of frequencies. These results show that the control of temporal and frequency features of learned calls by RA matches to each other. Moreover, the lesion of bilateral RA can confuse the vocal pattern, and the produced long call has the character of both the mono- and variable-tone long calls. The prelude shows rising frequency, and the loud sound is monotone sound.展开更多
文摘The coast of Japan is a migratory corridor for the western stock of the gray whales (Eschrichtius robustus), which was once considered as extinct and remains endangered. According to the historical records, from 1955 to 2014, only 21 gray whales occurrence has been recorded in 59 years. However, from 2015 to 2016, intensive occurrence including the seven sightings and the two strandings were noted. In this paper, we found that those sightings were re-sightings of the same individual, which was initially sighted off Sakhalin during August, 2014. On 4 March, 2016, a young female gray whale (8.9 m in body length) was stranded at Wadaura beach, Chiba prefecture. We also conducted research on this animal including taking pictures and external measurements. In addition, we flensed this animal to observe the internal organs and collect a skeletal specimen. The reason for the death of this animal remains unclear;however, from its external characteristics, we identified that this animal was not an identical one, sighted off Sakhalin and the coast of Japan from 2014 to 2016. On 5 April, 2016, another young female gray whale (7 m in body length) was stranded at Arai beach, Shizuoka prefecture. We concluded that from 2015 to 2016, at least three distinct gray whales have migrated along the coast of Japan.
基金the National Natural Science Foundation of China (Grant No. 39570195) and Outstanding Youth Foundation of Ministry of Education of China.
文摘The lesion of nucleus robustus archistriatalis (RA) has no effect on normal short calls in the bramble finch, but affects significantly the temporal and acoustic features of learned long calls.It causes the principal frequency of basic sound in monotone long calls to increase 500 cents, and to lose two upper partials. The lesion of RA not only results in the increased sound length of loud-sound and shortened coda of variable-tone long calls by 13.4%-22.1% and 21.2%-24.2% on average, respectively, but also makes the frequency rising coefficient (FRC) of even order partial tone in loud-sound drop 18.5%-25.8% on an average, and the step-up rate decrease 22.7% -24.0% on an average with the increase of frequencies. These results show that the control of temporal and frequency features of learned calls by RA matches to each other. Moreover, the lesion of bilateral RA can confuse the vocal pattern, and the produced long call has the character of both the mono- and variable-tone long calls. The prelude shows rising frequency, and the loud sound is monotone sound.
