成年斑胸草雀在体HVC-RA突触传递的电生理特性

鸣禽高级发声中枢（high vocal center,HVC）至弓状皮质栎核（robust nucleus ofthe arcopallium,RA）的突触传递是鸣唱运动通路中的关键部分.本文运用在体场电位电生理记录的方法,研究了成年雄性斑胸草雀（Taeniopygia guttata）HVC-RA突触的电生理特性.实验结果显示,刺激HVC,在RA内所记录到的诱发场电位幅度较小.配对脉冲检测发现,HVC-RA突触传递具有明显的配对脉冲易化特性.当以强直刺激作用于HVC,RA内诱发场电位随即显著减小,并在15 min内逐渐恢复,表明HVC-RA突触传递在强直刺激过后出现了短时抑制.该通路的突触传递特性可能与其在发声控制中的作用有关.以上的实验结果为进一步研究发声运动过程中的突触可塑性提供了资料.     

雄激素对鸣禽斑胸草雀鸣唱行为和鸣唱控制系统的调控

雄激素对鸣禽鸣唱具有重要影响。国内外近年研究表明,体内雄激素水平不仅影响鸣禽外部形态,而且影响其鸣唱行为。雄激素(包括衍生物)对鸣唱行为和鸣唱系统的影响是多方面的。本文以本研究组近年在斑胸草雀上的工作为主,总结了雄激素对鸣禽鸣唱行为、鸣唱系统投射神经元兴奋性及突触传递的影响及其与脑内其它递质受体的相互作用。     

雌性斑胸草雀发育和成体期发声核团LMAN中神经元数量的高水平维持

鸟类的发声和发声学习涉及处于脑中不同水平的相互联系的一些发声核团。在很多鸟类中, 仅雄性鸣啭, 例如在斑胸草雀(Taeniogygia guttata) 中, 雌雄个体间存在显著的性差异, 雌性发声系统和发声核团中的神经元数量显著少于雄性。推测这种性差异也可能存在于弓状皮质前部大细胞外侧核(LMAN), 但有关这方面的报道还很少。为探讨雌雄鸣禽脑中神经元数量发育的规律, 我们应用半薄切片对斑胸草雀发育不同阶段的神经元数量和密度的变化进行了数量分析。结果表明, 在全部实验组中, 发育10 d和成体雌性LMAN中神经元的密度和神经元数量均无明显变化, 神经元的数量维持在一个较高水平。在雄鸟中, 我们发现在发育早期神经元的数量有极为显著的减少, 这与已有的报道, 即应用非类固醇技术获得的结果相似。LMAN中神经元数量的减少(57%) 一直持续到成体。因此, 成年雌鸟LMAN中的全部神经元数量是雄鸟的4 倍(P<0 001)。推测雌鸟脑中存在较多的神经元数量可能与其在发育和成体期间需维持适当的神经网络有关, 这种神经构筑对于动物种间识别等功能可能具有特殊意义。     

家鸽、斑胸草雀丘间复合核背内侧亚核的传出投射

家鸽、斑胸草雀丘间复合核背内侧亚核的传出投射关键词家鸽，斑胸草雀，丘间复合核鸟类中脑丘间复合核背内侧亚核（ＤＭ，ｔｈｅｄｏｒｓｏｍｅｄｉａｌｎｕｃｌｅｕｓｏｆｔｈｅｉｎｔｅｒｃｏｌｌｉｃｕｌａｒｃｏｍｐｌｅｘ）是鸟类发声运动控制核团。本实验采用免疫组...     

成年雄性斑胸草雀前脑与中脑对习得性发声控制的侧别差异

成年雄性鸣禽的习得性发声信号——长鸣(long call)和鸣唱(song)是由前脑高级发声中枢启动,以及由前脑最后一级输出核团弓状皮质栎核(robust nucleus of the arcopallium,RA)整合输出.RA投射神经元与位于中脑的基本发声中枢丘间复合体背内侧核(dorsomedial nucleus of the intercollicular,DM)形成突触连接.该文采用电损毁与声谱分析相结合的方法,通过依次损毁成年雄性斑胸草雀(Taeniopygia guttata)单侧RA和DM核团,探讨了前脑和中脑对习得性发声的影响.结果提示,RA核团与DM核团共同参与了对雄性斑胸草雀习得性声音的调控,而且这种控制具有右侧优势.     

青藏高原白腰雪雀鸣声结构的复杂性

本文以SAS Lab鸟类声谱分析软件对采自青藏高原黑马河、玛多与花石峡、沱沱河的白腰雪雀不同地方种群的鸣叫与鸣唱的复杂性进行了分析 ,发现白腰雪雀的鸣叫相对变化率随着采样量的增加由 0 5 2 2迅速降低到 0 1 2 7和 0 1 1 9,表明其鸣叫声组成中音节类型较少。同时发现其声谱图结构比较简单 ,表现出高度的音节重复并多有谐波的现象。鸣唱结构相对复杂 ,不同鸣唱音节数随鸣唱曲目的增加 ,开始有明显的增加 ,当鸣唱曲目增加到一定值时 ,不同音节数的增加趋于平缓 ,几乎保持稳定 ;野外未发现任何相同的鸣唱型 ,但在不同鸣唱型之间具有不同程度的音节共享现象。依据雷富民等 (2 0 0 3)对鸟类鸣唱多样性和复杂性的评述 ,白腰雪雀鸣唱的结构模式符合“多音节序列不稳定变化型” ,其鸣唱曲目中音节的转换形式为“序列鸣唱”。然而 ,鸣唱模式中音节类型的有限性和鸣唱型的高度多样化表明 :白腰雪雀鸣唱的复杂性不仅体现在鸣唱型内较丰富的音节组成 ,而且更重要的还在于不同鸣唱型间具有多变的音节序列组合形式     

鼻优草螽和苍白优草螽鸣声和发声器的研究

鼻优草螽[Euconocephalus nasutus(Thunberg)]和苍白优草螽[Euconocephalus pallidus (Redtenbacher)]外形相似,但其鸣声特征和发声器的结构明显不同。鼻优草螽鸣声的每个脉冲组由4个脉冲串构成。脉冲组持续时间4．5ms脉冲组间隔为1．8ms,主能峰频率为11．37kHz。苍白优草螽鸣声的每个脉冲组仅由1个脉冲串构成,脉冲组持续时间1．6ms,脉冲组间隔为4．3ms,主能峰频率为11．03kHz,鼻优草螽发声锉较弯曲,中部稍粗壮,两端稍细,苍白优草螽发声锉较直,呈棒状。     

四种草螽雄性鸣声的研究

对分布于我国的长瓣草螽Conocephalus(Anisoptera)gladiatus,中华草螽C.(Amurocephalus)chinensis,悦鸣草螽 C.(Anisoptera)melaenus和斑翅草螽C.(Anisoptera)maculatus雄性鸣声进行了分析.研究结果表明,这4种草螽雄性鸣声的时域波形较简单,鸣声均由1种类型的脉冲组序列构成.长瓣草螽雄性鸣声每个脉冲组持续时间约0.13 s,脉冲组间隔约0.12 s,每个脉冲组通常由8脉冲构成,鸣声的频率范围5～20 kHz.中华草螽雄性的鸣声脉冲组由2个脉冲构成,每次鸣叫持续时间约为3.3 s,两次连续鸣叫间隔约10.5 s,鸣声频率范围为20 Hz～20 kHz.斑翅草螽雄性鸣声的脉冲组由10～13个脉冲构成,脉冲组持续时间2.1～2.5 s,两次连续鸣叫间隔时间约为3 s;鸣声频率从5.5 kHz到高于20 kHz.悦鸣草螽雄性鸣声由单一规则的重复脉冲组序列构成,每个鸣声脉冲组持续时间约0.035 s,脉冲组间隔约0.023 s,每个脉冲组由3个脉冲构成,脉冲组重复率20/s,鸣声频率6.0～20.0 kHz.     

瓦屋山国家森林公园锄足蟾科6种的繁殖鸣声特性

在地处四川省洪雅县的瓦屋山国家森林公园录取了锄足蟾科 6种的繁殖期求偶鸣叫声。它们分隶 4属 ,即角蟾属 (Megophrys)、齿蟾属 (Oreolalax)、齿突蟾属 (Scutiger)和掌突蟾属 (Leptolalax)。在IBMPC上用“SIGNAL”软件 (EngineeringDesign ,USA)对获取的鸣声资料进行分析 ,分析的频率范围设置为 0～ 10kHz。声学分析结果表明 :峨山掌突蟾 (L oshanensi) ,小角蟾 (M minorr) ,角蟾 1种 (M sp) ,金顶齿突蟾[S (S )chintingensis],峨眉齿蟾 (O omeimontis)和无蹼齿蟾 (O schmidti)的主能峰频率平均值分别是45 2 1 9、 34 5 6 4、 2 2 93 8、 10 76 5、 10 71 0和 1849 4Hz ,每声持续时间的平均值分别是 46 2、 90 8、 99 6、72 2、 78 8和 110 3ms ,声距的平均值分别是 140 4、 2 5 3 0、 6 81 4、 15 17 7、 46 1 3和 6 19 5ms。单因子方差分析结果表明主能峰频率、每声持续时间和各声距在 6个种间差异极显著 (P <0 0 1)。LSD法多重比较的结果指出金顶齿突蟾和峨眉齿蟾间的主能峰频率无显著差异 (P =0 917>0 0 5 ) ;在每声持续时间上 ,只有峨山掌突蟾与小角蟾、角蟾 1种、峨眉齿蟾、无蹼齿蟾间差异极显著 (P <0 0 1) ;在声距上 ,峨山掌突蟾与小角蟾间无显著差异 ,角蟾 1种与无蹼齿蟾之间、峨     

Audience Effect Alters Male Mating Preferences in Zebra Finches (Taeniopygia guttata)

The social environment of animals strongly influences the mating preferences of both the choosing and the observing individuals. Notably, there is recent evidence that polygamous males decrease their selectivity when being observed by competitors in order to direct their rivals' attention away from their true interest and, consequently, reduce sperm competition risk. Yet, other mechanisms, whose importance remains unexplored, could induce similar effects. In monogamous species with mutual choice, particularly, if males adjust their selectivity according to the risk of being rejected by their preferred mate, they should as well become less selective when potential rivals are present. Here, we investigated whether the presence of bystanders modifies male mating preferences when the risk of sperm competition is low, by carrying out mate-choice experiments with male zebra finches (Taeniopygia guttata) whose preferences for two females were measured twice: with and without an audience. We found that the presence of potential rivals had no effect on the males' choosiness. However, with an audience, they spent more time with the female that was considered as the less attractive one in the control condition. These findings support the hypothesis that monogamous males alter their mate choice decisions in the presence of a male audience to reduce the risk of remaining unpaired. Thus, our results indicate that several explanations can account for the changes in male preferences due to the presence of competitors and highlight the importance of assessing the relative role of each mechanism potentially involved, to be able to make conclusions about the effect of an audience on signal evolution.     

Survivorship, dispersal and sex ratios of Zebra Finches Taeniopygia guttata in southeast Australia

Membership of three permanent breeding colonies of Zebra Finches Taeniopygia guttata studied in farmland changed continually due to arrival and departure of birds from distant colonies. Sixty-six percent of adults stayed for less than 1 month, and many that stayed longer disappeared for extended periods. Over 78% of adults captured were hatched in other colonies and only 23% made a breeding attempt in their natal colony. There was no sex-biased natal dispersal or philopatry, but there were sex differences in the timing of dispersal. Sex ratios at the end of parental care were variable and may depend on food resources. Adult ratios were slightly male-biased. Annual losses of adults ranged from 72 to 82% across colonies, but mortalities and dispersal were heavily confounded by high adult mobility. The oldest bird was more than 5 years old. A total of 67% of young were lost between fledging and nutritional independence at 35 days of age, and only 20% of fledglings survived to day 80, the age of first breeding. Artificial supplies of seed at baited walk-in traps prolonged the stay of dispersing adults from other colonies, enhanced the survivorship of young hatched in the colony and possibly affected the secondary sex ratio. In this southeast part of their Australia-wide distribution, Zebra Finch populations appear to be highly mobile over a very large home range with extensive free interchange of members among a number of permanent breeding colonies. High mobility may be adaptive for exploiting patches of seed and water in a highly erratic environment.     

The Strength of Species Recognition in Captive Female Zebra Finches (Taeniopygia guttata): A Comparison Across Estrildid Heterospecifics

Conspecific recognition is essential for sexually reproducing species. Captive zebra finches ( Taeniopygia guttata ) are a model system in which the behavioural, ontogenetic and neurobiological bases of own-species (conspecific) recognition have been studied in detail. To assess the potential role of phylogeographic effects on species recognition, we examined the spatial preferences of unmated captive-bred female zebra finches between unfamiliar captive males of conspecific and estrildid heterospecific male stimuli. In accordance with prior studies using domesticated Bengalese finches ( Lonchura striata vars. domestica ), we found significant spatial and behavioural preference for conspecific males by female zebra finches, irrespective of heterospecific male phylogeographic origin mating status, or individual behaviour. This result has ramifications for the interpretation of social and mate preferences in this model species as it implies a consistency of species discrimination by captive female zebra finches.     

Song Learning in Bengalese Finches: a Comparison with Zebra Finches

Male Bengalese finches, Lonchura striata var. domestica, learn their song from an adult male conspecific with whom they can interact at 35 to 70 days of age and normally-raised males fail to reproduce song which they have only heard before or after this time. Birds which have been raised by their mother alone and those which have been deprived of a song tutor during the learning phase produce abnormal songs with indistinct elements and little or no phrase structure; this is typical of males which fail to hear adult song during their development. These songs are unstable and are replaced by normal songs, if there is an opportunity to learn from an adult male conspecific. Presumably, this flexibility in the time when young males learn acts as a safeguard to ensure that normal conspecific song is produced. These results bear striking similarity to those on zebra finch song development. Differences between the two species, especially in the learning of call notes by female zebra finches, are discussed.     

Triploid ZZZ Zebra Finches Taeniopygia guttata exhibit abnormal sperm heads and poor reproductive performance

Here we report the first discovery of two viable triploid male Zebra Finches Taeniopygia guttata. We compared the morphology of their sperm with that of normal diploid Zebra Finches and examined eggs resulting from a triploid male and diploid female pairing to investigate whether triploid Zebra Finches can reproduce. The majority (78%) of the triploids' spermatozoa had malformed sperm heads, which were 60% larger, and all examined eggs (n = 42) were infertile. Our results tentatively suggest that triploid ZZZ Zebra Finches cannot reproduce, and thus represent a rare evolutionary dead‐end.     

The Onset of Song Learning and Song Tutor Selection in Fledgling Zebra Finches

We investigated song development in the pre‐independent zebra finch (aged 15–35 d), a period when neural pathways for song learning and production are forming and social influences outside the family are limited. Expt 1 investigated the onset and the minimum duration of tutoring needed for song learning in fledglings. We found most begin to learn song from 25 d of age and need about 10 d contact with the father tutor to make accurate copies. This onset corresponds with major developments in the formation of the neural circuitry implicated in song acquisition. Subsong also begins on day 25 suggesting that the sensory and motor phases of song learning fully overlap in the zebra finch. Our findings support the hypothesis that the song circuitry is fully functional by 35 d of age and the sensitive phase for zebra finches extends therefore from about days 25–65. However, only the first 10 d of this period are necessary to learn a tutor's song with fair accuracy. Expt 2 investigated the role of the paternal bond, spatial proximity and mating status in a fledgling's choice of song tutor where the father was the sole parent. Young chose the father over single unrelated males (expt 2a) or unrelated males in company with their female partners (expt 2b). Given the close spatial proximity of both potential tutors to the fledglings it is probably the filial bond, established via paternal care that is the cause of this preference. Zebra finches sing the same song phrase in two contrasting contexts: female‐directed song during pre‐copulatory courtship and undirected song where no female or display is involved. In expt 3 we tested the song learning preference of pre‐independent young for two categories of non‐paternal tutors: those singing predominantly female‐directed song and those singing exclusively undirected song. There was a small, but significant, preference for fledgling zebra finches to copy songs from males that sang female‐directed song. This preference is consistent with the hypothesis that young males not only learn the acoustic features of their tutor's song but also the visual and dynamic movements that constitute the courtship display.     

Personality and body condition have additive effects on motivation to feed in Zebra Finches Taeniopygia guttata

Several hypotheses have been proposed to account for the adaptive evolution of personality, defined as inter‐individual differences in behaviour that are consistent over time and across situations. For instance, the ‘pace‐of‐life syndrome’ hypothesis suggests that personality evolved as a behavioural correlate of life‐history trajectories that vary within populations. Thus, proactivity, corresponding to higher exploratory tendencies or higher boldness levels, has been linked to higher productivity or mortality rates. However, the extent to which proactivity is associated with a higher motivation to forage remains poorly understood. Moreover, although personality and its effects on foraging behaviour are usually considered to be independent of any motivational or nutritional state, few studies so far have challenged this. Here we show that personality traits, both individually or combined using a principal component analysis, and body condition have additive effects on latency to feed following food deprivation in the Zebra Finch Taeniopygia guttata, with personality accounting for 41% and body condition for about 20% of the total variation in latency to feed. In accordance with the pace‐of‐life syndrome hypothesis, latency to feed was negatively related to the degree of proactivity and positively related to body condition. Thus, proactive individuals and individuals in poorer condition were quicker to start feeding after a period of food deprivation. The absence of a significant interaction between personality and body condition further suggests that the effect of personality was independent of body condition. We discuss the relevance of our results in relation to the different factors influencing foraging in birds. Moreover, we place our results within a life‐history framework by emphasizing the correlated evolution of life‐history traits and personality.