Individual identification on the basis of the songs of the Asian Stubtail(Urosphena squameiceps)

We analyzed the songs of the Asian Stubtail (Urosphena squameiceps),a migratory passerine that breeds in northeast Asia.The possibility of individual identification of this species by songs was examined in a population in northern China during the breeding season of 2010.Individuality was determined using discriminant function analysis,artificial neural networks and spectrographic cross-correlation.Our results show that,the rate of correct classification is satisfactory in this species,regardless of methods.From an applied perspective,spectrographic cross-correlation is most suitable.Besides its maximum rate of correct classification (89.4％),it does not require measurements of spectrograms,which is a necessity other methods and may introduce artificial errors.We hope that our result of individual identification on the basis of acoustic signals may open up a new research venue for this species.

充分准备 防范危险 增强意识

近年来,我国颁布出台了《3~6岁儿童学习与发展指南》,明确指出：＂教师应把保护幼儿的生命和促进幼儿的健康放在工作的首位。＂在此方针的指导下,幼儿教育工作者尝试着通过户外体育活动提高幼儿的自我保护能力,这可谓是一种十分有益的探索。丰富多彩的户外体育活动,既能够激发幼儿的兴趣爱好,锻炼幼儿体能,又能提高幼儿的自我保护能力。

首次将垂钓之道搬上银屏的人们——记《钓鱼趣谈》摄制组

曾经发生过这样一件事:当电视片《钓鱼趣谈》在中央电视台播出后不久,该台一位工作人员找到这部电视片的导演应红女士,开玩笑地要她赔偿医药费,因为这位同志的老父亲因没能来得及录下其中的某一集,急得心脏病发作,被送进了医院。还有另一件事,某办公室四位渔友,说好轮流请假回家录制《钓鱼趣谈》。

Who＇s your neighbor？ Acoustic cues to individual identity in red squirrel Tamiasciurus hudsonicus rattle calls

North American red squirrels Tamiasciurus hudsonicus often produce a loud territorial rattle call when conspecifics enter or invade a territory. Previous playback experiments suggest that the territorial rattle call may indicate an invader＇s identity as squirrels responded more intensely to calls played from strangers than to calls played from neighbors. This dear-enemy effect is well known in a variety of bird and mammal species and functions to reduce aggressive interactions between known neighbors. However, although previous experiments on red squirrels suggest some form of individual differentiation and thus recognition, detailed acoustic analysis of potential acoustic cues in rattle calls have not been conducted. If calls function to aid in conspecific identifi- cation in order to mitigate aggressive territorial interactions, we would expect that individual recognition cues would be acoustically represented. Our work provides a detailed analysis of acoustic cues to identity within rattle calls. A total of 225 calls across 32 in- dividual squirrels from Sheep River Provincial Park, Kananaskis, AB, Canada, were analyzed with discriminant function analysis for potential acoustic cues to individual identity. Initial analysis of all individuals revealed a reliable acoustic differentiation across individuals. A more detailed analysis of clusters of neighboring squirrels was performed and results again indicated a statistically significant likelihood that calls were assigned correctly to specific squirrels （55%-75% correctly assigned）; in other words squirrels have distinct voices that should allow for individual identification and discrimination by conspecifics [Current Zoology 58 （5）： 758-764, 2012].

Individual consistency and sex differences in migration strategies of Scopoli＇s shearwaters Calonectris diomedea despite year differences

Recently-developed capabilities for tracking the movements of individual birds over the course of a year or longer has provided increasing evidence for consistent individual differences in migration schedules and destinations. This raises questions about the relative importance of individual consistency versus flexibility in the evolution of migration strategies, and has implications for the ability of populations to respond to climatic change. Using geolocators, we tracked the migrations of Scopoli＇s shearwaters Calonectris diomedea breeding in Linosa （Italy） across three years, and analysed timing and spatial aspects of their movements. Birds showed remarkable variation in their main wintering destination along the western coast of Africa. We found significant individual consistency in the total distance traveled, time spent in transit, and time that individuals spent in the win- tering areas. We found extensive sex differences in scheduling, duration, distances and destinations of migratory journeys. We also found sex differences in the degree of individual consistency in aspects of migration behaviour. Despite strong evidence for individual consistency, which indicates that migration journeys from the same bird tended to be more similar than those of dif- ferent birds, there remained substantial intra-individual variation between years. Indeed, we also found clear annual differences in departure dates, return dates, wintering period, the total distance traveled and re^rn routes from wintering grounds back to the colony. These findings show that this population flexibly shifts migration schedules as well as routes between years in response to direct or indirect effects of heterogeneity in the environment, while maintaining consistent individual migration strategies [Current Zoology 60 （5）： 631-641, 2014].

Memory of conspecifics in male salamanders Plethodon cinereus： Implications for territorial defense

We investigated how exposure duration （time that two individuals initially interact） and separation interval （time be- tween the initial interaction and a subsequent interaction） affect recognition memory of conspecifics in male red-backed sala- manders Plethodon cinereus. Previous studies have demonstrated that this species aggressively defends territories. We recorded aggressive behavior to assess recognition memory, because aggression is more intense toward previously unencountered indi- viduals compared to previously encountered individuals in this species. We found that with 15-min exposures and 5-day separa- tion intervals, focal males did not spend significantly more time threatening ＇unfamiliar＇ intruders than ＇familiar＇ intruders. After either 8-hour exposures and 5-day separation intervals and 5-day exposures and 5-day separation intervals, focal males spent sig- nificantly more time threatening unfamiliar intruders than familiar intruders. These results suggest that male red-backed salaman- ders can remember familiar conspecifics （e.g., territorial neighbors） after at least an 8-hour exposure duration and that memory persists at least as long as 5 days. After 5-day exposure and 15-day separation intervals, we found no significant difference in ag- gressive behavior toward familiar and unfamiliar intruders. Long separation intervals （15 days） may lead either to loss of memory of previously familiar individuals or, alternatively, aggressive reassessment of individuals as only a change in behavior indicates positively that memory has occurred. Thus, variance in territorial defense within an individual may depend on its ability to recog- nize conspecific males .

Ontogenetic mechanisms underlying sexual size dimorphism in Urodele amphibians： An across-species approach

Why do two sexes of the same species differ in body size holds a long-standing question of evolutionary biology. While many across-species comparisons have focused on ultimate causes behind sexual size dimorphism （SSD）, only have a few been directed toward elucidating its ontogenetic basis. Urodeles are an amphibian group in which the direction and degree of SSD vary greatly among species. Using demographic data yielded by skeletochronology for 33 urodele species, the current study re- veals a positive across-species correlation between SSD and the sex difference in mean age of adult animals, and the latter in- creases with the corresponding difference in age at maturity; annual growth rate does not differ between the sexes. We conclude that extended longevities in one sex, which is mediated by delayed maturation, would allow it to grow for longer and get larger, with growth rate making a weak contribution to body size. The sex-specific divergence in ontogenetic trajectory might be ex- plained by potentially high growth costs of reproduction to females in association with stronger fecundity selection, and to males that are expected to experience stronger sexual selection [Current Zoology 59 （1）： 142-150, 2013].