麻雀身体大小的性二态和基于身体量度的性别判定

身体大小的性二态是鸟类中较为普遍的现象。性二态的研究是理解性选择的关键,也能为性二态鸟类的野外快速性别判定提供依据。麻雀Passer montanus通常被认为是一种性单态鸟类,野外很难通过外在特征识别性别,有关麻雀性二态和性别判定的研究很少。2017—2018年每年的1—3月,在甘肃省庆阳市陇东学院校园内用雾网捕捉到67只麻雀成鸟,并测量了这些麻雀的10个身体量度。通过观察生殖腺鉴定了性别,确定为31只雄鸟和36只雌鸟。结果发现,总体上麻雀身体量度存在显著的两性差异(MANOVA:Pillai's Trace=0.492,F_(10,56)=5.426,P0.001),雄鸟的全长、尾长、翅长、跗跖长和中趾长显著大于雌鸟(t-test:P0.05)。利用这5个身体量度变量构建判别方程来判定麻雀性别,发现:在所有的单变量判别方程中,翅长构建的判别方程具有最高的性别判定准确率,达77.6%;由5个身体量度变量构建的典型判别方程,性别判定准确率为82.1%;而由全长和翅长构建的逐步判别方程,性别判定准确率为79.1%。麻雀存在身体大小的性二态,而这使得野外通过测量身体量度构建判别方程能较容易、准确地判定麻雀的性别。     

黄喉鹀的羽色与雄鸟质量相关性分析

在国内首次利用光纤光谱仪对鸟类的羽色进行量化和分析.对黄喉鹀Emberiza elegans雌、雄鸟羽色的差异以及雄鸟羽色与雄鸟质量的相关性分析结果表明,黄喉鹀雌、雄鸟在人眼看来相同的黄色羽和白色羽部分,在紫外光色度上却存在显著差异,雄鸟紫外光色度高于雌鸟;雄鸟的质量与脸部黑色羽的亮度、可见光色度和色调呈显著正相关,雌...     

鸟类的求偶行为及其生物学意义

鸟类的繁殖具有明显的季节性。每当进入繁殖季节以后 ,随着鸟类性腺的发育 ,会出现一系列的繁殖活动。其中第一步常常是通过求偶行为而形成一定的配偶关系。求偶行为是鸟类通过婉转鸣唱 ,展示华丽多彩的婚羽或色彩斑斓的冠囊、角、裙等附属物 ,进行婚飞、戏飞或其它行为姿态吸引异性的一种活动。1　求偶行为的主动性雌鸟和雄鸟由谁先出现求偶行为呢 ?谁在求偶行为中表现主动呢 ?这是由鸟类的外貌决定的。我们知道 ,多数鸟类的雌雄鸟外貌之间存在着明显的差别。一般雄鸟具有色彩艳丽的羽毛或“婚装” ,而雌鸟的羽色较为平淡。所以 ,大多数鸟…     

鸟类的饰羽与求偶

达尔的性选择理论解释了为何某些鸟类具有华丽羽衣,他认为,雄鸟的饰羽是雌鸟基于抽象美感择偶的结果,正如饲养通过有意识的人工选择生产出品种珍奇的各种雄鸽。华莱士提出另一种可能性的解释：身体越强壮的雄鸟饰羽越华丽,因而能够在竞争配偶时获胜。同时,赫克胥指出：雄鸟的饰羽有助于建立其在雌鸟中的支配地位：饰羽还起到了恐吓其它雄鸟从而减少了争夺的必要。     

云南普洱发现家麻雀

<正>2014年10月,在云南省普洱市思茅区、宁洱县等地多次发现集群的家麻雀(Passer domesticus),雌雄混群。雄鸟羽色与麻雀(P.montanus)相似,眼先、颏、喉部黑色,颊部灰白色,后颈部和颈侧栗褐色,翅上具两道淡色翼斑,下体棕白色。但家麻雀的雄鸟额部、头顶及枕部灰色,耳部无黑色斑块,上胸部黑色,与麻雀明显不同。     

不同生长发育期的虎皮鹦鹉发声行为与发声控制神经核团的研究

鸟类的鸣叫依赖于发育完善的鸣管并接受各级发声中枢组成的机能控制系统的调控,善鸣唱的鸟类前脑控制发声的神经核团发达.用石蜡切片法和生物信号采集处理系统对不同生长发育期的虎皮鹦鹉的发声控制神经核团的体积和声音进行了比较性研究.结果发现:(1)随着虎皮鹦鹉的成长,核团体积逐渐增大,核团轮廓逐渐清晰,而且雄鸟的核团明显大于雌鸟;(2)在鸟类成长的过程中,鸟的叫声越来越复杂,幅度越来越高,雄鸟的叫声比雌鸟更复杂,雌鸟的叫声比雄鸟的叫声幅度更高;(3)鸟类鸣叫的复杂程度和发声控制神经核团的体积呈相关性.     

灰椋鸟身体大小和内脏器官形态的两性差异

鸟类性二态现象广泛存在,比如身体大小、羽色等,性二态很可能是自然选择和性选择共同作用的结果。为了探索和更好地了解雀形目鸟类身体大小性二态的进化,在2019年繁殖季节早期研究了灰椋鸟(Sturnus cineraceus)野外种群身体大小和内脏器官形态的两性差异。结果表明,除嘴宽外,其他身体特征参数均雄性显著大于雌性,表现出雄性偏向的身体大小二态性。内脏器官大小两性间无显著差异。灰椋鸟是聚群生活的鸟类,雌雄鸟常一起觅食,食性相似,雌雄鸟内脏器官和消化道形态差异不显著,暗示食性分化在灰椋鸟身体大小性二态进化中的作用并不明显;雄鸟体型较大的原因可能是其在巢址竞争、配偶保护中适应进化的结果。本研究明确了灰椋鸟身体大小的两性差异,对于该物种身体大小性二态进化的确切原因,尚需更多研究。     

灰胸薮鹛活动区的无线电遥测研究

2016年1—2月和6—8月,分别在四川省峨眉山和四川老君山国家级自然保护区,利用无线电遥测技术对灰胸薮鹛Liocichla omeiensis非繁殖季和繁殖季活动区进行了初步研究。结果表明:灰胸薮鹛非繁殖季的平均活动区面积为9 659 m2±975 m2(95%FK),平均核心区面积为2 542 m~2±263 m~2(60%FK)(n=4);繁殖季的平均活动区面积为13 040 m~2±6 003 m2(95%FK),平均核心区面积为1 581 m~2±1 362 m~2(60%FK)(n=2)。非繁殖季遥测个体间的活动区重叠百分率基本在50%以上;而配偶间的活动区重叠面积在70%以上。该现象可能与是否配对、领域行为及栖息地质量有关。此外,还发现灰胸薮鹛的日活动具有节律性,雌鸟和雄鸟分别在早、晚和早、中、晚各有1个活动高峰期。     

虎皮鹦鹉

正虎皮鹦鹉(Melopsittacus undulatus)是鹦型目的小型鸟类,属于攀禽。原产澳大利亚,被世界各地人民广泛养殖。野生型羽毛以绿、黄、黑为主要色调,成体长18 cm左右,体重30～40 g,成年雄鸟蜡膜(喙上鼻孔周围)为蓝色,成年雌鸟为白色或褐色。培养品种羽色多变,体形也差异较大。全年可繁殖,营洞巢,窝卵数4～8枚(笼养条件下也有更大窝卵     

青海海北高寒草甸黄嘴朱顶雀亲鸟递食率

中国科学院海北高寒草甸生态系统定位站的黄嘴朱顶雀（Acanthis flavirostris)雌雄亲鸟的育幼行为数据收集于1999－2001年的3个繁殖季节（5－8月）。观察使用了一个闭路电视系统,包括放在鸟巢附近5－10cm处的摄像头和35－40m外的监视器。数据分析表明：亲鸟的递食率无年间变化;雌、雄鸟递食率没有差异;总递食率不随雏鸟日龄和日间不同时段改变,但雌鸟在傍晚以前的递食率低于雄鸟并在傍晚高于雄鸟。在雏鸟6日龄前,雌鸟总递食率低于雄鸟,且二者逐步逼近,然后稳定在同一水平。此种性别差异与雌鸟在递食以外所承担的,为雏鸟保温、遮阳以及清除雏鸟粪便等事务有关。这些结果与单配制鸟类亲本投资理论一致。     

Extra-pair fertilizations in Tree Sparrows Passer montanus

Females of socially monogamous bird species frequently accept or solicit copulations from males other than their social mates. At the interspecific level, it has been proposed that species with few or no sexual plumage differences have lower levels of extra-pair fertilizations (EPFs) than more dichromatic species. This is because it is easier for females to assess the quality of extra-pair mates in dichromatic than monochromatic species. To test this, by using genetic profiling, we compared the occurrence of extra-pair young in nests of Tree Sparrows Passer montanus , a monochromatic species, in Switzerland and Spain, with published estimates for the House Sparrow Passer domesticus , a closely related dichromatic species. We found that 25% (10/40) of Tree Sparrow broods in Spain and 23% (8/35) in Switzerland had at least one extra-pair offspring, and that 8% (12/151) of nestlings in Spain and 10% (12/114) in Switzerland were sired by extra-pair mates. These proportions did not differ significantly between the two populations. Tree Sparrow EPF rates did not differ significantly from available data for the House Sparrow, either in the proportion of broods with EPF young (24%, 18/75 in Tree vs. 26%, 92/359 in House Sparrows) or the overall proportion of extra-pair young (9%, 24/265 in Tree vs. 11%, 142/1110 in House Sparrows). Our results suggest that a close taxonomic relationship and similarities in behaviour and ecology may be more important in determining levels of EPF in these species than sexual phenotypic differences.     

Reduced sexual dichromatism,mutual ornamentation,and individual quality in the monogamous Zenaida dove Zenaida aurita

Although variation in plumage coloration is known to occur both between and within sexes, its study remains limited to a few bird families. The Zenaida dove Zenaida aurita is a socially monogamous tropical columbid bird species, characterized by an overall cinnamon‐brownish plumage and structural colorations on the head and neck. The species has been described as sexually dichromatic for plumage, although color differences between males and females are not obvious in the field. We investigated variation in the presumably melanin‐based color of the crown, mantle, breast, and belly, in the iridescent dark‐blue streaks on the head, and in the symmetric iridescent patches on the neck, over the whole spectrum visible to birds. Further, unlike most previous studies, we assessed covariation between plumage color and phenotypic traits in both males and females in relation to the putative signaling function of ornaments. Zenaida doves appeared to be slightly sexually dichromatic for the hue of pigment‐based colored areas, with males being on average more reddish than females. However, this difference was not discernible when considering the avian visual system. Conversely, although the reflectance spectra of iridescent plumage did not significantly differ between sexes in brightness, chroma or spectral position of the peaks, color discrimination analyses showed that individuals should be able to perceive between‐ or within‐sex differences in the color of the iridescent patch. In addition, several color parameters of brown and iridescent feathers were significantly related to territorial status, body condition, wing chord, and, albeit weakly, to individual multilocus heterozygosity. Overall, our results thus suggest that plumage color might be a reliable signal of quality in individuals of both sexes in this species. Further studies are needed to test the potential implication of plumage coloration in mate choice and mating patterns in the Zenaida dove.     

Status signalling in male but not in female Eurasian Tree Sparrows Passer montanus

Male ornaments, such as plumage coloration, frequently serve as signals. The signalling function of similar ornaments in females has, however, received much less attention despite the fact that conspicuousness of their ornaments is often comparable to those of males. In this study we tested the signalling function of a plumage trait present in both sexes in the Eurasian Tree Sparrow Passer montanus. The black throat patch has been repeatedly found to have a signal function in the closely related House Sparrow Passer domesticus, where only males bear the ornamental trait. However, the function of the black throat patch in the females of Passer species that have sexually monomorphic ornament expression has never, to our knowledge, been considered. We investigated the outcomes of aggressive encounters in foraging flocks of free‐living Tree Sparrows, and assessed whether throat patch size and measurements of body size predicted fighting success in these flocks. We found that male throat patch size predicted fighting success against both male and female opponents. However, female throat patch size did not correlate with fighting success against either sex. Among the morphological traits studied, wing length was the best predictor of fighting success in females. Our findings suggest a status signalling function of throat patch size in males but not in females, although further experimental studies are necessary to corroborate these correlative results.     

Light matters: testing the “Light Environment Hypothesis” under intra‐ and interspecific contexts

The “Light Environment Hypothesis” (LEH) proposes that evolution of interspecific variation in plumage color is driven by variation in light environments across habitats. If ambient light has the potential to drive interspecific variation, a similar influence should be expected for intraspecific recognition, as color signals are an adaptive response to the change in ambient light levels in different habitats. Using spectrometry, avian‐appropriate models of vision, and phylogenetic comparative methods, I quantified dichromatism and tested the LEH in both intra‐ and interspecific contexts in 33 Amazonian species from the infraorder Furnariides living in environments with different light levels. Although these birds are sexually monochromatic to humans, 81.8% of the species had at least one dichromatic patch in their plumage, mostly from dorsal areas, which provides evidence for a role for dichromatism in sex recognition. Furthermore, birds from habitats with high levels of ambient light had higher dichromatism levels, as well as brighter, more saturated, and more diverse plumages, suggesting that visual communication is less constrained in these habitats. Overall, my results provide support for the LEH and suggest that ambient light plays a major role in the evolution of color signals in this group of birds in both intra‐ and interspecific contexts. Additionally, plumage variation across light environments for these drab birds highlights the importance of considering ambient light and avian‐appropriate models of vision when studying the evolution of color signals in birds.     

Sexual differences in colour and size in the Great Spotted Cuckoo Clamator glandarius

The appearance of plumage in brood parasites represents an evolutionary conflict between sexual selection that favours colourful plumages, and parasite–host coevolution that favours crypsis. In this study we quantified the degree of sexual dimorphism from a sample of 179 Great Spotted Cuckoos and determined which features facilitate accurate sex discrimination. In addition, we collected spectrophotometric measures of two colour patches (the crown and the throat) and ran visual models to test for physical and bird‐perceivable sexual differences in coloration. We found that males are bigger and brighter than females in both colour patches. Using visual modelling techniques we demonstrate for the first time that adult Great Spotted Cuckoos are sexually dichromatic in an avian visual framework.     

Revealing the colourful side of birds: spatial distribution of conspicuous plumage colours on the body of Australian birds

In many species of birds, different body parts often display very different colours. This spatial distribution of coloured plumage patches may be determined, among other factors, by the balance between being cryptic to predators, and conspicuous to intended receivers. If this is the case, ventral and anterior body parts in birds – which are less visible to predators but more prominent to conspecifics – should present more conspicuous and sexually dichromatic plumage colours. Here, I test these predictions using reflectance spectrometric measurements of standardised plumage patches across males and females for nearly an entire avifauna (Australian landbirds, n = 538 species). My data show that, as predicted, conspicuous and sexually dichromatic colours are mainly located near the head, while the plumage of the back is the most cryptic. One clear exception to this pattern is the conspicuous rump coloration. In many species, this patch can be concealed by wings, and therefore exposed only when necessary. In addition, conspicuous rump coloration could deflect or confuse predators in case of attack. However, there is considerable variation across species, and this makes position on the body a very poor predictor of plumage elaboration (R² < 0.02). Future studies should try to determine whether differences between species in the distribution of colours across the plumage are due to variation in ecological factors (predation risk, habitat, etc.).     

Blue tits are ultraviolet tits

The blue tit (Parus caeruleus) has been classified as sexually monochromatic. This classification is based on human colour perception yet, unlike humans, most birds have four spectrally distinct classes of cone and are visually sensitive to wavelengths in the near-ultraviolet (300 to 400 nm). Reflectance spectrophotometry reveals that blue tit plumage shows considerable reflection of UV light. For example, the blue crest shows peak reflectance at wavelengths around 352 nm. Furthermore, the blue tit is sexually dichromatic for multiple regions of plumage, including the crest. Choice trials performed in the laboratory indicate that females prefer males with the brightest crests. This study has implications for both intra- and interspecific studies of sexual selection, as well as future classification of dichromatism, which should not ignore the possibility of variation in reflectance in the UV.     

Is male plumage reflectance correlated with paternal care in bluethroats?

Although it is now well established that the conspicuous maleplumage colors of many birds have been subject to sexual selectionby female choice, it is still debated whether females matewith colorful males to obtain direct or indirect benefits.In species where males provide substantial parental care, femalesmay obtain direct benefits from mating with the males that are best at providing care. The good parent hypothesis suggeststhat male plumage coloration signals a male's ability to provideparental care. Alternatively, the differential-allocation hypothesissuggests that colorful males reduce their care in responseto increased investment by females mated to attractive males.We tested these hypotheses on the bluethroat (Luscinia s. svecica),a socially monogamous, sexually dichromatic bird, in which males have a colorful throat patch consisting of a structurallyderived blue area surrounding a melanin-based chestnut spot.Male plumage coloration was objectively quantified by use ofreflectance spectrometry. We found no evidence of a relationshipbetween male coloration of either the blue patch or the chestnutspot and the level of paternal care. Nor were there any correlationsbetween male coloration and body size or body condition. Thus, our study does not support the hypothesis that male colorationsignals male parental quality (the good parent hypothesis)or the hypothesis that colorful males reduce their care inresponse to increased investment by females (the differential-allocationhypothesis).     

The ubiquity of avian ultraviolet plumage reflectance

Although several bird species have been shown to reflect ultraviolet (UV) light from their plumages, the incidence of UV reflectance, and therefore the potential for UV or UV-enhanced signals, across the avian tree of life is not known. In this study, we collected reflectance data from the plumages of 312 bird species representing 142 families. Our results demonstrate that all avian families possess plumages that reflect significant amounts of UV light. The ubiquity of UV reflectance indicates that all studies of avian behaviour, ecology and evolution involving plumage coloration would benefit from consideration of plumage reflectance in the UV portion of the electromagnetic spectrum. Additionally, we demonstrate the existence of cryptic UV plumage patches and cryptic dimorphism among birds.     

Bird species in Mediterranean pine plantations exhibit different characteristics to those in natural reforested woodlands

Passive woodland regeneration following cropland abandonment and pine plantations are two major approaches for vegetation restoration in agricultural landscapes in the Mediterranean Basin. We compared the effects of these two contrasting approaches on local bird density in central Spain on the basis of species characteristics, including regional density, habitat breadth, life-history traits and plumage colouration. Local bird density increased with regional density and habitat breadth in both woodland and pine plantation plots following macroecological patterns of bird abundance and distribution. In woodlands, dichromatic species were more abundant than monochromatic species and bird density increased with the intensity of territory defense and as the proportion of plumage colour generated by pheomelanin decreased. Contrary to our prediction, this latter observation suggests that woodlands may induce higher levels of physiological stress in birds than pine plantations even though these represent a novel habitat change. In pine plantations, sedentary species were more abundant than migratory species and bird density was negatively related to body and egg mass. These traits of bird species in pine plantations are characteristic of successful invaders. The variation in bird density explained by phylogeny was twice as high in pine plantations as in woodlands, suggesting that pine plantations limit accessibility to some clades. Our results support, from an evolutionary perspective, the described inability of pine plantations on cropland to maintain or increase bird diversity in Mediterranean agricultural landscapes.