Early birds

Concern is growing about the impact of climate change on organisms but there's much uncertainty about its effects. A new European study of two bird species does not provide good news.     

中国特有鸟类

特有种(endemicspecies)是有关物种的地理分布和起源进化研究的一个名词术语,指“在地理分布上只局限于某一特定地区,而不见于其他地区的物种”(Darlington,1957;Brown&Gibson,1985;张荣祖,1999)。在有关动物类群的起源、进化和分布的研究中,人们所关注的是特有种、特有属和特有科的起源中心、扩散格局以及分布区的扩散、退缩、断裂,直至灭绝的历史进程,以从中探究自然历史事件以及人类活动对动物分布所造成的积极和消极影响。特有动物的分布规律研究是以自然地理要素为基本着眼点,严格按照“特有(endemic)”的定义进行的。例如新大陆、澳…     

Head-bobbing of walking birds

Many birds show a rhythmic forward and backward movement of their heads when they walk on the ground. This so-called “head-bobbing” is characterized by a rapid forward movement (thrust phase) which is followed by a phase where the head keeps its position with regard to the environment but moves backward with regard to the body (hold phase). These head movements are synchronized with the leg movements. The functional interpretations of head-bobbing are reviewed. Furthermore, it is discussed why some birds do bob their head and others do not.     

Aging in birds

Rodents are the most commonly used model organisms in studies of aging in vertebrates. However, there are species that may suit this role much better. Most birds (Aves), having higher rate of metabolism, live two-to-three times longer than mammals of the same size. This mini-review briefly covers several evolutionary, ecological, and physiological aspects that may contribute to the phenomenon of birds’ longevity. The role of different molecular mechanisms known to take part in the process of aging according to various existing theories, e.g. telomere shortening, protection against reactive oxygen species, and formation of advanced glycation end-products is discussed. We also address some features of birds’ aging that make this group unique and perspective model organisms in longevity studies.     

Rhythmic birds show a better social integration than arrhythmic birds

The activity rhythms of Japanese quail vary from one individual to another. Performing a divergent selection, we obtained one line of quail expressing a robust circadian rhythmicity of feeding activity (R) and one line of quail expressing circadian arrhythmicity of feeding activity (A). We questioned whether the endogenous rhythmicity of an individual could predict its integration in a group. For that, we introduced either an R- or an A-line chick into stable groups of standard chicks. First, we evaluated proximity and synchronization of the introduced chicks on the activities of the other group members. R-chicks remained spatially and temporally closer to other group members than did A-chicks. Second, we evaluated interactions of the introduced chicks and the level of their acceptance by the other group members. R-chicks were more competent to gain access to food than were A-chicks, and separation from their group stressed R-chicks more than A-chicks. Last, successive introductions assessed age effects: before, around, and after dispersal time (～11th day of chicks' life). Most differences between R- and A-chicks were observed between their 7th and 15th day of life. In conclusion, individual endogenous rhythms predict social integration.     

鸟类对城市化的适应

城市生态系统是以人为主导的复杂系统,当前的高速城市化进程对包括鸟类在内的城市区域动物施加了广泛的选择压力。从鸟类对城市环境的主动适应角度,归纳了国内外城市鸟类生态学研究中有关鸟类对城市化的适应研究,探讨了城市化进程中城市鸟类行为、生理指标以及种群基因结构的适应性变化。基于遗传的数量效应,研究认为某些鸟种对城市环境的适应已经上升到进化层次,同时还对城市化导致鸟类新物种形成的可能性进行了探讨。最后,对鸟类对城市化适应的研究前景提出了展望。