Phylogenetic relationships of the bulbuls (Aves: Pycnonotidae) based on mitochondrial and nuclear DNA sequence data

Bulbuls (Aves: Pycnonotidae) are a fairly speciose (ca. 130 sp.) bird family restricted to the Old World. Family limits and taxonomy have been revised substantially over the past decade, but a comprehensive molecular phylogeny for the family has not been undertaken. Using nuclear and mitochondrial DNA sequences, we reconstructed a well-supported phylogenetic hypothesis for the bulbuls. Three basal lineages were identified: a large African clade, a large Asian clade that also included African Pycnonotus species, and the monotypic African genus Calyptocichla. The African clade was sister to the other two lineages, but this placement did not have high branch support. The genus Pycnonotus was not monophyletic because three species (eutilotus, melanoleucos, and atriceps) were highly diverged from the other species and sister to all other Asian taxa. Additional taxon sampling is needed to further resolve relationships and taxonomy within the large and variable Hypsipetes complex.     

环境噪声对临安和阜阳两地白头鹎鸣声频率的影响

为了解环境噪声对白头鹎(Pycnonotus sinensi)鸣声频率的影响,在浙江临安和安徽阜阳两地分别对白头鹎在高低噪声水平环境中的鸣声做了研究。把用数码录音机记录到的鸣声输入计算机,利用计算机声谱分析系统进行分析,再对每一鸣声的每个音节的主频进行Mann—Whitney U检验。结果显示：高噪声水平区和低噪声水平区相比,在两地白头鹎每一鸣声的各音节主频中,最低和最高主频以及第I、Ⅱ音节的主频都有显著提高;在阜阳第Ⅲ音节的主频也有显著提高。这表明白头鹎可以通过提高声音频率来避免环境噪声对鸣声的影响,从而保证噪声环境中声信息的有效传递;而噪声对各音节的不同影响也表明,同一鸣句的各音节,对于噪声通讯中的信息识别,具有不同的地位。     

白头鹎的代谢率与器官重量在季节驯化中的可塑性变化

动物能量代谢的生理生态特征与物种的分布和丰富度密切相关,基础代谢率(BMR)是恒温动物维持正常生理机能的最小产热速率,是动物在清醒时维持身体各项基本功能所需的最小能量值,是内温动物能量预算的重要组成部分.本研究测定了白头鹎(Pycnonotus sinensis)的BMR、内部器官(肝、心、肌胃、小肠、肾和整体消化道)和肌肉的重量,分析了白头鹎内部器官和肌肉重量的季节性变化及与BMR的关系.方差分析表明,白头鹎的BMR存在明显的季节性变化,冬季较高,夏季最低.其内部器官及肌肉重量的变化同样有明显的季节性.相关分析表明,白头鹎的BMR与肝、心、消化道等内部器官和肌肉重量存在明显的相关性.     

杭州市区白头鹎鸣声的微地理差异

2002年5—8月,对中国东部浙江省杭州市区的白头鹎鸣声的微地理差异进行研究。在约60 km2的 研究区内,选择8个调查点(4个城区,4个丘陵山地),录制了80个雄性白头鹎的511个鸣声样本,并随机选 取每一调查点的20个鸣声样本进行分析。其结果显示,白头鹎在杭州市区至少有8种微地理鸣声方言,每个微 地理鸣声方言都有一典型鸣句;它们在听觉上、波形结构、音节组成、音节频谱特征等方面均不相同。有的一 路之隔的相邻微地理鸣声方言之间存在明显差异;部分区域出现鸣声混合现象;有的个体还具有“多语”功 能。白头鹎鸣声产生微地理差异的原因可能与鸟类个体的扩散和城市中鸟类栖息地的人为改变有关。     

Behavioral and Social Structure Effects on Seed Dispersal Curves of a Forest‐Interior Bulbul (Pycnonotidae) in a Tropical Evergreen Forest

Movement patterns of animals can vary dramatically as a function of their reproductive cycle or social structure; however, little is known about how changes in the social structure of dispersers affect patterns of seed dispersal. We examined the movement patterns of the forest‐dwelling and cooperatively breeding Puff‐throated Bulbul (Alophoixus pallidus) in relation to different stages of their reproductive cycle, time of day, and group size, to determine potential impacts on the shape and scale of dispersal curves generated using a combination of gut passage time and displacement distance data. There were significant differences in dispersal distances depending on group size, season (breeding, non‐breeding), incubation (vs. other times of the year), and time of the day. The estimated median seed dispersal distance was 28 m. The median dispersal distances produced by birds in larger groups were longer than those of smaller groups (29 m vs. 25 m). During the breeding season, median dispersal distances were longer than during the non ‐ breeding season (31 m vs. 25 m), but the median dispersal distances were significantly shorter during incubation than during outside incubation (24 m vs. 28 m). The median dispersal distance produced in the early morning (30 m) was also longer than that of other times of the day (23 m late morning, 28 m early afternoon, and 26 m late afternoon). This study suggests that various aspects of an animal's behavior are likely to have significant effects on seed shadows and that this may vary significantly even among individuals of the same species.     

The influence of ethanol on feeding in the frugivorous yellow-vented bulbul (Pycnonotus xanthopygos)

The sugars in fleshy fruits provide a rich source of energy to frugivorous animals. However, these carbohydrates also serve as a substrate for alcoholic fermentation by yeasts, ethanol being the main by-product of this process. Ethanol ingestion via frugivory thus occurs in a diverse assemblage of invertebrate and vertebrate taxa, including numerous species of birds. We tested the roles of ethanol as an odor cue for resource location by adult yellow-vented bulbuls (Pycnonotus xanthopygos) and as a possible appetite stimulant in feeding trials with artificial food. We hypothesized (1) that the odor of ethanol does not serve as a food-locating cue in diurnal frugivorous passerine birds, and predicted that the choice of food source and the mass of food eaten by such birds will not be influenced by the odor of ethanol. We further hypothesized (2) that food intake in passerine birds is affected by ingestion of ethanol according to its concentration [EtOH], and predicted that food intake will follow a bell-shaped curve in relation to [EtOH]. In accord with hypothesis (1) and its prediction, we found that the odor of ethanol did not affect food preferences, in either ethanol-naïve or ethanol-experienced yellow-vented bulbuls, when presented at concentrations found in naturally ripe fruit (0.0–1.0%); this suggests that the odor of ethanol is not a food-locating cue for the bulbuls. Hypothesis (2) was partially supported, namely at low [EtOH] (0–3%), food intake was constant and at high [EtOH] (3%) food intake decreased, following only the right half of the predicted bell-shaped response. Ethanol-naïve birds showed no preference towards any [EtOH] presented in two-way choice trials. However, daily food intake in ethanol-experienced bulbuls in single option trials decreased by an average of 36% when the artificial food contained the highest tested concentration of ethanol (3.0%). We suggest that decreasing food intake when food ethanol concentration is relatively high may be a means of avoiding intoxication and is related to the ethanol-metabolizing ability of the bird.     

The breeding biology of the White-spectacled Bulbul,Pycnonotus xanthopygos,at the northwestern edge of its distribution range

The White-spectacled Bulbul, Pycnonotus xanthopygos, is an abundant and possibly invasive species in Turkey, where it has gradually expanded its distribution and breeding range in both western and southeastern directions. This study focused on its breeding biology, which is still poorly known. The breeding activity extends from February until September. The preferred nesting areas are mainly gardens and maquis groves, where 24 different nesting tree species have been identified. The clutch size is 3.3 ± 0.8 eggs per pair, nesting success 68%, hatching success 94%, fledgling success 95%, and overall breeding success 89%. While nesting success differs significantly between the years, we found no significant differences in hatching, fledging, and overall breeding success between the years studied. Despite favourable climatic conditions in the Mediterranean region, the species makes only one brood per year in a relatively extended breeding season extending over seven months, and has a relatively a high reproduction rate per nest.     

Habitat of the Golden Nightjar Caprimulgus eximius

The Ostrich communal breeding system involves several females laying in a single nest. Only the ‘major’ female and the territorial male, however, provide parental care from incubation to fledging of chicks. Eggs are turned and displaced frequently upon the onset of incubation, and the major female evicts excess eggs out of the nest when the number of eggs is above a specific threshold level. A previous study indicated that the major female ostrich recognises her own eggs and selectively evicts eggs of minor females based on size, shape and shell texture. Our aim was to investigate if accepted and ejected eggs differ in colour characteristics. We quantified colour by measuring egg reflectance spectra, which were subsequently analysed using a visual model approach. Within clutches, there were no significant differences in colour between accepted and ejected eggs. These results suggest that female ostriches do not discriminate against foreign eggs based on deviations in colour.     

黄臀鹎繁殖生态的初步观察

2004年4-6月,在佛坪保护区狮子崖沟和大古坪的白马沟,采用路线法和定点直接观察法对黄臀鹎（Pycnonotus xanthorrhous）的生境选择及繁殖生态进行了初步观察。结果表明,黄臀鹎常栖息于河岸灌丛生境中,栖息位置多为视野开阔的电线上和灌木中;巢结构为3层,筑巢期6～10d,窝卵数3～5枚,孵化期8d,雏鸟留巢12d,雏鸟的平均体重和体长的相关系数r=0．9637,并测量了雏鸟的嘴峰、跗踱、第3枚初级飞羽和初级覆羽及尾长的生长数据等。