城里鸟儿起得早睡得少
与乡村生活相比,城市生活往往意味着节奏更快、压力更大。不仅人如此,鸟也这样。科学家发现,城里的鸟比野外的鸟“起得更早,睡得更少”。
英国格拉斯哥大学和德国马普鸟类学研究所的研究人员在新一期《皇家学会学报B》上报告说,他们研究了德国南部一些乌鸫的生物周期节律。他们先给捕获于慕尼黑城中和附近森林中的鸟佩戴轻量无线电发射器,放归原捕获地点10天后,重新捉回这些鸟,并将其置于避光、隔音的室内,在无外界干扰的环境下测试其生物周期节律,同时研究无线电发射器记录的相关数据。
研究人员发现,生活在城市里的鸟与森林中的鸟作息规律有所不同,前者“起床”时间平均要早半小时,而晚上休息的时间要晚约9分钟,即一天中要多“忙碌”约40分钟。此外,生活在商业区等嘈杂环境的鸟,生物钟也较紊乱。
格拉斯哥大学研究人员芭芭拉·赫尔姆说,这项研究再次证明,城市化对环境的改变的确会影响到鸟类等生物。它们会像人类一样,随着城市生活的需要改变生活节奏和规律,但这些变化是否与健康问题增加有关,仍需进一步研究。(来源:新华社 刘石磊)来源:《皇家学会学报B》A tropical bird can use the equatorial change in sunrise and sunset times to synchronize its circannual clockAt higher latitudes, most organisms use the periodic changes in day length to time their annual life cycle. At the equator, changes in day length are minimal, and it is unknown which cues organisms use to synchronize their underlying circannual rhythms to environmental conditions. Here, we demonstrate that the African stonechat (Saxicola torquatus axillaris)—an equatorial songbird—can use subtle solar cues for the annual timing of postnuptial moult, a reliable marker of the circannual cycle. We compared four groups that were kept over more than 3 years: (i) a control group maintained under constant equatorial day length, (ii) a 12-month solar time group maintained under equatorial day length, but including a simulation of the annual periodic change in sunrise and sunset times (solar time), (iii) a 14-month solar time group similar to the previous group but with an extended solar time cycle and (iv) a group maintained under a European temperate photoperiod. Within all 3 years, 12-month solar time birds were significantly more synchronized than controls and 14-month solar time birds. Furthermore, the moult of 12-month solar time birds occurred during the same time of the year as that of free-living Kenyan conspecifics. Thus, our data indicate that stonechats may use the subtle periodic pattern of sunrise and sunset at the equator to synchronize their circannual clock.
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