鹰鹃对白腹短翅鸲的巢寄生

2015年4~8月,在贵州宽阔水国家级自然保护区,记录到1巢白腹短翅鸲(Hodgsonius phaenicuroides)被鹰鹃(Cuculus sparverioides)寄生,寄生率为1/16(n=16)。发现时白腹短翅鸲巢内有1枚白色的寄生卵和2枚蓝色的寄主卵,且卵已凉,疑为亲鸟弃巢。鹰鹃卵重6.09 g,卵大小20.20 mm×27.73 mm;两枚白腹短翅鸲的卵重分别为2.34 g和2.40 g,大小分别为20.05 mm×14.94 mm和19.95 mm×15.09 mm。鹰鹃的卵重量(6.09 g)和大小(27.73 mm×20.20 mm)均明显大于白腹短翅鸲的卵。卵色光谱测量结果表明,鹰鹃和白腹短翅鸲卵色的反射光谱图差别明显,鹰鹃卵在色度和色调上明显低于白腹短翅鸲,但卵色亮度却明显比白腹短翅鸲卵高,为典型的非模拟寄生卵。     

中国中西部五大山系间社鼠头骨形态的地理分化

种群分化是物种形成过程中的关键一步,通过形态特征进行种内变异的探讨对揭示微进化过程具有积极
意义。本文以社鼠头骨为材料,通过SPSS 统计分析软件对采集自我国中西部5 大山系的250 号标本头骨形态变
量进行了判别函数分析,结果表明秦岭与四川各山系之间社鼠头骨已发生完全分化,而在四川各山系之间,除
邛崃和相岭山系外,其余各山系社鼠头骨形态已分化明显。腭长、上颌齿隙长等变量是各山系社鼠头骨样本发
生分化的主要变量,暗示上述山系之间社鼠头骨形态的分化可能主要来自于局部种群在食物资源及觅食习性等
方面的差异。除此之外,本文研究结果尚揭示了在对具有广泛分布的小型兽类进行种下阶元(如亚种) 的划分
时,需充分考虑形态特征可能存在的地理差异。     

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。     

Phylogenetic relationships in the Niviventer-Chiromyscus complex (Rodentia,Muridae) inferred from molecular data,with description of a new species

Based on molecular data for mitochondrial (Cyt b, COI) and nuclear (IRBP, GHR) genes, and morphological examinations of museum specimens, we examined diversity, species boundaries, and relationships within and between the murine genera Chiromyscus and Niviventer. Phylogenetic patterns recovered demonstrate that Niviventer sensu lato is not monophyletic but instead includes Chiromyscus chiropus, the only previously recognized species of Chiropus. To maintain the genera Niviventer and Chiropus as monophyletic lineages, the scope and definition of the genus Chiromyscus is revised to include at least three distinct species: Chiromyscus chiropus (the type species of Chiromyscus), Chiromyscus langbianis (previously regarded as a species of Niviventer), and a new species, described in this paper under the name Chiromyscus thomasi sp. n.     

The use of spatial concepts as a basis for designing a viable-habitat network: Conserving redstart (Phoenicurus phoenicurus) populations in Sherwood Forest, England

This paper presents a method for the design of a habitat network in a fragmented landscape. It employs metapopulation dynamics and connectivity to develop spatial rules which, together with the requirements of a target species, can be used to guide the creation of a network to improve population persistence. Using these guidelines, two conservation strategies of patch enlargement and corridor creation are developed. The spatial models used to produce the habitat network are described. The resulting maps show the network consisting of the source patches that could be occupied by stable populations and a number of patches, which could support viable local populations, situated in the proximity of the sources or linked to them. The approach could be used to inform decision-making in nature conservation and landscape planning.     

白腹短翅鸲雄鸟的羽毛延迟成熟现象

20 0 3年 6月 ,在甘肃省莲花山自然保护区观察到白腹短翅鸲 (Hodgsoniusphaenicuroides)雄鸟的羽毛延迟成熟现象。研究发现 ,亚成体雄鸟体羽暗淡 ,为似雌鸟样的褐色 ,但仍然可以繁殖。声谱分析表明 ,成体雄鸟与亚成体雄鸟的鸣声结构非常相似 ,而且两者在巢址、巢材、窝卵数、卵色、卵大小等巢卵特征上也非常一致。通过对中国科学院动物研究所标本馆 1 1 7只白腹短翅鸲雄鸟标本的测量 ,发现成体雄鸟的翅长和尾长明显大于亚成体 (t 检验 ,P <0. 0 0 1 )。在 1 93 0年北平东陵同一繁殖季节采集的 1 0 8只雄鸟标本中 ,亚成体雄鸟所占的比例为 1 9%。     

实验条件下社鼠个体相遇时的叫声特征

在实验室条件下对捕自杭州市郊的11只社鼠(3♂,8♀)个体相遇时的叫声与行为进行观察和记录,其结果表明,社鼠不同个体相遇后存在4种叫声,即雄性个体相遇打斗时败者的叫声、雌性个体相遇打斗时败者的叫声、异性成体相遇时雌体的叫声和成幼体相遇时幼体的叫声。进一步比较分析显示,各种叫声的主要声学参数之间大多存在着极显著差异。同性个体打斗后,败者的叫声和幼体见到成体时的叫声均呈现为多谐变音的频谱结构,这可能是对强者的惧怕叫声;而异性个体相遇时,雌体的叫声呈现为多谐恒频的频谱结构,这可能是对雄体的拒斥叫声。     

Comparing the precision,accuracy, and efficiency of branch clipping and sweep netting for sampling arthropods in two Jamaican forest types

ABSTRACT Devising methods for sampling arthropods presents many challenges, including understanding possible differences in results obtained by different individuals (precision), investigating differences between estimates and the actual variable of interest (accuracy), and assessing the effort and cost of a given method (efficiency). We assessed the precision, accuracy, and efficiency of sweep netting and branch clipping, two common methods of sampling arthropods, in mangrove and second‐growth scrub forests in Jamaica, West Indies, in 2009. Three individuals used both methods sequentially to sample arthropods in the territories of American Redstarts (Setophaga ruticilla). We found that both branch clipping and sweep netting lacked precision because different individuals produced different estimates of either arthropod abundance (number of individuals per sample) or biomass. In both forests, more arthropods were sampled with sweep netting, in terms of biomass and abundance, and several orders of arthropods were collected that were missed by branch clipping. We also detected the absence of a predictable habitat‐based difference in arthropod biomass with sweep netting, but not with branch clipping. Sweep netting took longer overall (field and processing time combined) and was therefore less efficient. Despite problems with precision and efficiency, our results suggest that sweep netting may be a more accurate method than branch clipping for sampling foliage arthropods in some forest habitats. Our study also reveals the importance of recognizing and controlling for individual bias and of choosing arthropod sampling methods most appropriate to each study species and habitat type.     

Invertebrate availability and vegetation characteristics explain use of nonnesting cover types by mature‐forest songbirds during the postfledging period

ABSTRACT Some species of mature‐forest‐nesting songbirds use regenerating clearcuts and forested wetlands during the postfledging period (between nesting and migration). Relatively dense vegetation structure and abundant food resources in non‐mature‐forest cover types have been hypothesized to explain this phenomenon. We examined the relative importance of vegetation structure and invertebrate availability on use of nonnesting cover types by adult and hatch‐year Ovenbirds (Seiurus aurocapilla) and American Redstarts (Setophaga ruticilla) during the postfledging period of 2009 in northern Minnesota. We used mist nets to sample bird use of forested wetlands and regenerating clearcuts of three age groups: 1–6, 7–12, and 16–19 yr after harvest. We modeled captures of birds using vegetation characteristics and invertebrate availability sampled around nets as explanatory variables. For all birds studied, captures were best explained by food availability and secondarily by vegetation characteristics including litter depth and woody debris for Ovenbirds and canopy height for American Redstarts. Shrub‐level invertebrate availability received a cumulative weight of 0.74–0.99 in Akaike's information criterion corrected ranked models for adult and hatch‐year birds of both species. Vegetation density and variation in vegetation density explained almost no variation in captures of either species. We conclude that both invertebrate availability and some vegetation characteristics influence use of nonnesting cover types by Ovenbirds and American Redstarts during the postfledging period, but that invertebrate availability is generally the stronger predictor of that use.