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1.
Plasma testosterone increases during breeding in many male vertebrates and has long been implicated in the promotion of aggressive behaviors relating to territory and mate defense. Males of some species also defend territories outside of the breeding period. For example, the European nuthatch (Sitta europaea) defends an all-purpose territory throughout the year. To contribute to the growing literature regarding the hormonal correlates of non-breeding territoriality, we investigated the seasonal testosterone and corticosterone profile of male (and female) nuthatches and determined how observed hormone patterns relate to expression of territorial aggression. Given that non-breeding territoriality in the nuthatch relates to the reproductive context (i.e., defense of a future breeding site), we predicted that males would exhibit surges in plasma testosterone throughout the year. However, we found that males showed elevated testosterone levels only during breeding. Thus, testosterone of gonadal origin does not appear to be involved in the expression of non-breeding territoriality. Interestingly, territorial behaviors of male nuthatches were stronger in spring than in autumn, suggesting that in year-round territorial species, breeding-related testosterone elevations may upregulate male-male aggression above non-breeding levels. In females, plasma testosterone was largely undetectable. We also examined effects of simulated territorial intrusions (STIs) on testosterone and corticosterone levels of breeding males. We found that STIs did not elicit a testosterone response, but caused a dramatic increase in plasma corticosterone. These data support the hypothesis that corticosterone rather than testosterone may play a role in the support of behavior and/or physiology during acute territorial encounters in single-brooded species.  相似文献   
2.
2019年2和3月,在西藏自治区墨脱县记录到8种鸟类的新分布,分别是冠鱼狗(Megaceryle lugubris)、黄冠啄木鸟(Picus chlorolophus)、白腹凤鹛(Erpornis zantholeuca)、棕腹 鹛(Pteruthius rufiventer)、小盘尾(Dicrurus remifer)、冕雀(Melanochlora sultanea)、丽?(Sitta formosa)、丽星鹩鹛(Elachura formosa)。  相似文献   
3.
山地次生林冬季鸟类集群的初步研究   总被引:3,自引:0,他引:3  
高玮  冯贺林 《动物学报》1993,39(4):385-391
通过山地次生林两冬季鸟类集群的研究表明,集群的鸟类主要是由大山雀、沼泽山雀和普通Shi组成;每群个体数为7.41-10.63只;据群的行为(单种群、多种集群和单独个体)分析,大多数种类是单独个体活动,冬季鸟类集群大小和组成有空间的变化。气候因子影响群的形成和行为。  相似文献   
4.
Capsule Woodland birds were significantly less likely to occur in gardens in years of high beechmast crop.

Aim To test the hypothesis that woodland species that feed on beechmast will have significantly lower occurrence rates at garden feeders in mast years.

Methods Weekly winter occurrence rates at garden feeders between 1970/71 and 1999/2000 for 40 species were analysed in relation to annual beechmast abundance, classified into low, medium and high years. A repeated-measures logistic regression model was used to assess whether beechmast abundance explained further significant variation additional to underlying seasonal and annual trends.

Results Seven species that commonly feed on beechmast showed significantly lower occurrence in gardens in years of highest beechmast abundance: Great Spotted Woodpecker Dendrocopos major, Woodpigeon Columba palumbus, Great Tit Parus major, Coal Tit Periparus ater, Nuthatch Sitta europaea, Jay Garrulus glandarius and Chaffinch Fringilla coelebs. Blackbird Turdus merula and Siskin Carduelis spinus, which showed similar significant patterns, are likely to take beechmast as elements of their diet. Pied Wagtail Motacilla alba was the only insectivorous species to show significant effects, but occurrence was lowest in years of intermediate beechmast abundance. For the latter species, this may have been due to confounding effects of temperature, but there were no such confounding effects of either temperature, or the number of bird feeders provided in gardens, for the other nine species.

Conclusion Use of artificial food sources by birds in gardens is influenced by resources in the surrounding countryside, suggesting that food provided in gardens may play a significant part in the population dynamics of these species, that population monitoring without consideration of the garden habitat may be deficient, and that volunteer-based garden bird recording may provide data that can be used as an indicator of changes in the wider countryside.  相似文献   
5.
Habitat fragmentation has often been implicated in the decline of many species. For habitat specialists and/or sedentary species, loss of habitat can result in population isolation and lead to negative genetic effects. However, factors other than fragmentation can often be important and also need to be considered when assessing the genetic structure of a species. We genotyped individuals from 13 populations of the cooperatively breeding Brown‐headed Nuthatch Sitta pusilla in Florida to test three alternative hypotheses regarding the effects that habitat fragmentation might have on genetic structure. A map of potential habitat developed from recent satellite imagery suggested that Brown‐headed Nuthatch populations in southern Florida occupied smaller and more isolated habitat patches (i.e. were more fragmented) than populations in northern Florida. We also genotyped individuals from a small, isolated Brown‐headed Nuthatch population on Grand Bahama Island. We found that populations associated with more fragmented habitat in southern Florida had lower allelic richness than populations in northern Florida (P = 0.02), although there were no differences in heterozygosity. Although pairwise estimates of FST were low overall, values among southern populations were generally higher than northern populations. Population assignment tests identified K = 3 clusters corresponding to a northern cluster, a southern cluster and a unique population in southeast Florida; using sampling localities as prior information revealed K = 7 clusters, with greater structure only among southern Florida populations. The Bahamas population showed moderate to high differentiation compared with Florida populations. Overall, our results suggest that fragmentation could affect gene flow in Brown‐headed Nuthatch populations and is likely to become more pronounced over time.  相似文献   
6.
Capsule Nuthatches used holes with strong walls, typically in live trees with entrances reduced by plastering, and ‘oversized’ interiors filled with bark flakes.

Aims To describe patterns of nest-site utilization by Nuthatches in primeval conditions, to examine the influence of various hole attributes on nesting success and to consider the adaptive value of nest-site choice.

Methods Observations of birds living in undisturbed conditions in a strictly protected part of the Bia?owie?a National Park (Poland) during 27 breeding seasons coupled with measurements of hole attributes and observations of nests' fate.

Results Tree species used for breeding differed among habitats. Holes were on average 14.0 m above the ground, in trees with girth at breast height 206 cm; both parameters varied strongly among tree species. They were situated mainly in tree trunks (76%), in living trees (89%), in conical knotholes (51%); woodpecker-made holes constituted 32%. Nuthatches bred in very large (mean bottom area: 325 cm2) holes, the preferred tree species (Maple Acer platanoides, Ash Fraxinus excelsior) had larger holes than other tree species. Nuthatches reduced entrances by ‘plastering’ to a mean size of 2.9 × 3.3 cm. They made the holes substantially shallower by filling them with bark flakes (mean depth to nest level: 10 cm), eggs were laid in depressions among flakes, far from the entrance (mean distance: 21 cm), their ‘nests’ occupied only a fraction of the hole area. Broods in holes with smaller entrances were the most successful. Eggs and small young were covered with bark during the absence of the female. Larger nestlings, when endangered, moved to the rear wall of the hole, where they stayed tightly pressed. These behaviour patterns reduced the risk of predation.

Conclusion The features of holes used by Nuthatches (combination of strong walls, small entrances and large bottoms with copious filling) are probably an evolutionary solution to the need to evade predators while keeping contents of the nest dry.  相似文献   
7.
美丽中国建设时空演变及耦合研究   总被引:3,自引:0,他引:3       下载免费PDF全文
盖美  王秀琪 《生态学报》2021,41(8):2931-2943
美丽中国是党的"十八大"提出的新战略思想,也是生态文明建设发展的延续。本文以2000-2017年为研究时段,选取我国31个省、市、自治区为研究区域,借助GeoDa空间自相关分析及动静态耦合模型,探索我国美丽中国建设的时空分异规律、空间分布格局及系统耦合协调度。结果表明:①研究期内,我国美丽中国的发展呈波动上升趋势,且存在东部>西部>中部的空间分布特征。②我国美丽中国的发展格局稳定,但东西部地区两极分化问题严重;子系统中,除制度体系不显著外,均存在显著正向空间关联,且社会、经济、文化与环境高集聚区空间分布错位。③我国社会、环境、经济、文化、制度的静态耦合协调度呈波动上升趋势,东西部区域发展差异明显;动态耦合不及静态耦合协调水平,部分省市存在社会发展、绿色环境、经济增长、以及文化和制度发展受阻现象。  相似文献   
8.
The Eurasian Nuthatch (Sitta europaea Linnaeus, 1758) is a resident bird in the Alborz and Zagros deciduous forests. We investigated the phylogenetic relationships and the taxonomic position of the Eurasian Nuthatch among other separated lineages of Eurasia with the help of blood samples collected from 19 individuals belonging to four populations in the Eastern and Western Alborz, as well as in the Northern and Southern Zagros forests. Genetic variation was then analysed using complete ND2 gene sequence (1041?bp) and phylogenetic analysis was done using Bayesian and maximum likelihood inference. Additionally, a median-joining algorithm was used to reveal the relationships among haplotypes. The results of the phylogenetic and haplo-type network analyses indicated that Eurasian Nuthatch haplotypes from the Alborz and Zagros Mountains form lineages distinct from the Asian, Caucasian and European haplotypes. Furthermore, an analysis of molecular variance (AMOVA) detected significant (P<0.001) genetic structure among the lineages. The Asian, European, Caucasian and Alborz lineages diverged from one another by an uncorrected genetic distance ranging from 0.029 to 0.039, while the Zagros lineage showed a slightly lower genetic divergence from the Caucasian lineage (0.006), but it did not share any haplotype with the Caucasian lineage. Thus, we suggest considering five Conservation Significant Units (CSU) for the Eurasian Nuthatches as the result of used dataset.  相似文献   
9.
2016年9和10月,在西藏自治区林芝及日喀则开展鸟类多样性调查期间新记录到8种鸟类,包括白胸翡翠指名亚种(Halcyon smyrnensis smyrnensis)、黑冠山雀指名亚种(Periparus rubidiventris rubidiventris)和栗腹?指名亚种(Sitta cinnamoventris cinnamoventris)、斑尾鹃鸠(Macropygia unchall)、红喉姬鹟(Ficedula albicilla)、黄胸柳莺(Phylloscopus cantator)、棕脸鹟莺(Abroscopus albogularis)以及田鹨(Anthus richardi)。  相似文献   
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