温州地区冬季北红尾鸲的代谢特征及体温调节

为探讨北方迁徙性鸟类北红尾鸲(Phoenicurus auroreus)在越冬环境的代谢特征及体温调节,本文采用开放式氧气分析仪和数字式温度测量仪测定了在环境温度(Ta) 5、10、15、20、25、27.5、30、32.5、35、37.5、40℃条件下的代谢率(MR)和体温(Tb),并计算不同温度的热传导(C)。结果表明:在Ta为5~35℃范围内,北红尾鸲的Tb基本维持恒定,平均为40.3±0.1℃;热中性区(TNZ)为25~35℃;基础代谢率(BMR)为50.25±1.35 mL O2·h^-1,是Londo1o等(2015)体重预期值的151%;在Ta为5~25℃范围内,MR随Ta的降低而显著增加,回归方程为:MR (m L O2·h^-1)=99.65-1.93Ta(r=-0.707,P<0.001);高于35℃时,MR随Ta升高增加;当Ta为40℃时,MR达到59.78±1.31 mL O2·h^-1;在Ta为5~25℃范围内,北红尾鸲的C最低且基本保持恒定,为0.17±0.01 mL O2·g^-1·h^-1·℃^-1,是Aschoff(1981)体重预测值的111%;北红尾鸲的基本热生物学特征为较高的Tb、BMR和C以及较宽的TNZ,具有北方地区小型鸟类的代谢特点。     

The biogeographic history of Phoenicurus redstarts reveals an allopatric mode of speciation and an out-of-Himalayas colonization pattern

Montane areas host high levels of diversity and endemism, and these features are tied to habitat stratification along an elevational gradient. As such, montane areas are often thought of as model systems in which sympatric speciation can occur. To test this idea, we selected Phoenicurus redstarts, an avian genus with an extensive distribution across Eurasia, as well as Northwest Africa; nine of the 14 species in the genus have distributions which include the Himalayas. We used sequences of the mtDNA ND2 and cytochrome-b genes and intron 9 of the Z chromosome specific ACO1 gene to reconstruct a phylogeny of the genus. The resulting trees were used to reconstruct a biogeographic history of Phoenicurus, and to date diversification events. We also analysed the relationship between node age and sympatry to determine the geographic mode of speciation in the genus. Our data suggest a very late Miocene, Himalayan origin for Phoenicurus. Diversification and colonization of other parts of Eurasia, as well as Northwest Africa, continued through the Pleistocene, with a rapid pulse of speciation in the late Pliocene. Allopatric speciation was the dominant mode of speciation in Phoenicurus, despite extensive distributional overlaps in the Himalayas where ecological conditions are amenable to speciation in sympatry. Our results, along with several other studies, suggest an emerging pattern where the Himalayas served as a source area for montane specialist avian lineages that subsequently colonized other Palaearctic regions.     

Circadian flight schedules in night-migrating birds caught on migration

Many species of migratory birds migrate in a series of solitary nocturnal flights. Between flights, they stop to rest and refuel for the next segment of their journey. The mechanism controlling this behaviour has long remained elusive. Here, we show that wild-caught migratory redstarts (Phoenicurus phoenicurus) are consistent in their flight scheduling. An advanced videographic system enabled us to determine the precise timing of flight activity in redstarts caught at a northern European stopover site during their return trip from Africa. Birds were held captive for three days in the absence of photoperiodic cues (constant dim light) and under permanent food availability. Despite the absence of external temporal cues, birds showed clear bimodal activity patterns: intense nocturnal activity alternating with diurnal foraging and resting periods. The onset of their migratory activity coincided with the time of local sunset and was individually consistent on consecutive nights. The data demonstrate that night-migrating birds are driven by autonomous circadian clocks entrained by sunset cues. This timekeeping system is probably the key factor in the overall control of nocturnal songbird migration.     

青海门源赭红尾鸲鸣唱方言的时间稳定性

鸟类的鸣唱方言是研究非人类文化进化及其与种群遗传分化相互作用的理想素材。该研究通过比较跨度8年的2001年和2009年青海门源赭红尾鸲(Phoenicurus ochruros rufiventris)鸣唱,研究结果显示,青海门源赭红尾鸲的种特异性音节、经典唱段中的部分音节、典型唱段结构和鸣唱方言的基本形式都具有较高的时间稳定性。2009年赭红尾鸲唱段曲目多于2001年,共享唱段出现了一定的分化,唱段的共享程度和鸣唱的相似性与个体领域间的距离相关,相邻个体的鸣唱相似性程度高于较远距离的个体。     

Hybridization between two insectivorous bird species and the effect on prey-handling efficiency

Gene flow between closely related species is not always impeded by hybrid inviability or sterility but may be limited by behavioural or ecological factors. European common redstarts, Phoenicurus phoenicurus, and black redstarts, P. ochruros, are insectivorous passerine bird species which regularly interbreed in the wild and produce viable and fertile progeny. Yet, the isolation barriers, which prevent extensive gene flow between these distinct species, are unknown. I studied prey-handling time and efficiency in both species and the F₁-hybrids in captivity. All birds changed prey-handling mode from a single pick to more complex behaviour with increasing prey length and their handling time was a positive function of prey length. Common redstarts tended to handle their prey quicker than black redstarts. Hybrids appeared to be intermediate. However, individual differences were significant, but group membership was not. Handling efficiency decreased with increasing prey length and was determined by individual and family effects. Hybrid females handled their prey as efficient as hybrid males. Small differences in beak morphology could not explain individual differences in prey-handling behaviour. The results of this study suggest that prey-handling in F₁-hybrids is not a postzygotic barrier which prevent gene flow between common and black redstarts in the wild.     

东北地区北红尾鸲巢址选择及繁殖成效

北红尾鸲(Phoenicurus auroreus)是一种分布广泛的小型雀形目鸟类,主要分布于南亚东北部,东南亚北部、东亚及俄罗斯等地区,我国东北、华北、华中至西南等地也均有分布,是重要的食虫益鸟。为探究北红尾鸲巢址选择的影响因素,找到影响北红尾鸲繁殖成功率的主要巢址因子,于2017年4—7月,在辽宁仙人洞国家级自然保护区开展系统研究。共发现北红尾鸲自然巢44个,其中29巢繁殖成功,15巢繁殖失败。北红尾鸲主要筑巢于石墙缝、空心砖墙缝及废旧电表箱中。巢址参数的主成分分析结果表明:巢口因子(27.738%)、巢位因子(14.195%)、光照因子(12.145%)、人为干扰因子(10.440%)、安全因子(9.266%)和隐蔽因子(7.187%)是影响北红尾鸲巢址选择的重要因子。采用二元逻辑斯蒂回归分析繁殖成功巢与失败巢参数发现,成功巢的巢口最大高度显著小于失败巢(P=0.047),且其距顶的距离更近(P=0.043)。多元线性回归分析表明,巢上方盖度对繁殖成功率有极显著影响(t=2.883,P=0.009)。总的来说,北红尾鸲虽偏爱筑巢于人为干扰较大的村庄房屋附近,但较小的巢口能有效避免巢捕食者的捕食,更近的距顶距离和更大的巢上方盖度能有效降低巢上方的可视程度和降水等不利因素的影响,从而提高繁殖成功率。     

Repeated vicariance of Eurasian songbird lineages since the Late Miocene

Aim The evolution of avian speciation patterns across much of Eurasia is under‐explored. Excepting phylogeographic patterns of single species, or speciation involving the Himalayas, there has been no attempt to understand the evolution of avian distributional patterns across the rest of the continent. Within many genera there is a pattern of (presumed) sister species occurring in adjacent areas (western, eastern or southern Eurasia), yet this pattern cannot be explained by existing biogeographic barriers. My aim was to examine the possible role of climate‐driven vicariance events in generating avian distributions. Location Eurasia. Methods I constructed a molecular phylogeny of Phoenicurus redstarts, and assembled phylogenetic data from published studies of seven other Eurasian bird genera. On each phylogeny, I assessed the distributional patterns of species and clades relative to refugial areas in western, eastern and southern Eurasia. I also estimated the timing of lineage divergences via a molecular clock, to determine whether distributional patterns can be explained by well‐defined periods of climate change in Eurasia that are recorded from dated sediments in the Chinese Loess Plateau. Results Species relationships in a well‐supported phylogeny of Phoenicurus show a pattern of distributions consistent with repeated speciation in major refugial areas, where one lineage is isolated in a single area of Eurasia relative to its sister lineage. This same pattern is evident in Eurasian Turdus thrushes, and six additional avian genera distributed across Eurasia. Molecular clock dating indicates that divergences within each genus are the result of multiple rounds of speciation in refugia through time, during major climate‐driven episodes of vicariance. Main conclusions Analyses revealed substantial evidence supporting a repeated, non‐random pattern of speciation within and across eight songbird lineages since the Late Miocene. The pattern of speciation supports a model of isolation in refugia during major episodes of vicariance, specifically periods of either intensified desertification of Central Asia or Eurasian glacial cycles. The densely sampled clades used here preclude inter‐continental dispersal as an alternative explanation for distributions. The signature of climate‐driven vicariance across epochs is, given the absence of extant biogeographic barriers, a suitable hypothesis to explain major lineage divergences in widely distributed Eurasian songbird lineages.     

Small-scale spatial variation in the interactions between Prunus mahaleb and fruit-eating birds

We studied fleshy fruit consumption by birds on individualPrunus mahaleb trees in four plots in northwestern Spain.We found large variation among trees in the relative contribution of differentbird species to fruit removal. This variation, which occurred on a scale ofmeters, was correlated with the distance from the tree to nests ofPhoenicurus ochruros, a major fruit consumer, and with thekind of microhabitat surrounding each tree. In the four plots studied, treeslocated farther away from P. ochruros nests receivedrelatively fewer visits by this species, and relatively more byTurdusmerula and Sylvia atricapilla. These three mainconsumer species differed in the kinds of microhabitats (rocks, loose stones,bare or grassy soil, and woody vegetation) where they flew after visitingP. mahaleb, and thus they probably created differentpatterns of seedfall. This study adds to the evidence that environmentalfactorsextrinsic to plants, and acting at different spatial scales, greatly influencethe identity of the fruit consumers visiting individual trees. This influenceundermines the chances that fruit traits become evolutionary modified so as toattract those consumers providing the best seed dispersalservicesto the plants.     

大杜鹃对北红尾鸲的放牧行为

在宿主的寄生防御压力下,鸟类巢寄生者通常会进化出一系列有效的寄生行为以提高其自身的繁殖适合度。以往研究发现,部分巢寄生者可能具有类似人类的"放牧"行为,即通过破坏或捕食不适合寄生的宿主巢,促使其重新筑巢以获取新的寄生机会。然而,对于其野外行为事件的报道并不多见。2018年5至8月,在贵州六枝地区,通过对宿主北红尾鸲(Phoenicurusauroreus)的巢进行录像监控,首次记录到大杜鹃(Cuculus canorus)对正在孵卵的北红尾鸲的放牧行为。进一步查阅了大杜鹃寄生系统中已有的放牧案例,说明放牧行为很可能是大杜鹃普遍采用的一种寄生策略。