食鱼蝙蝠形态和行为特化研究

总结了食鱼蝙蝠种类、分布 ,及其形态结构、回声定位功能和捕食行为的研究成果。比较食鱼蝙蝠与近水面“拖网式”食虫蝙蝠在形态、回声定位信号及捕食行为方面的异、同 ,推测食鱼蝙蝠起源于“拖网式”食虫蝙蝠类 ;体形和回声定位信号的几种特异性是捕食行为进化压力 ,而环境是决定因素。     

同一山洞中五种蝙蝠的回声定位比较及生态位的分化

对同一山洞中5种蝙蝠的回声定位叫声和外部形态作了比较分析,根据蝙蝠回声定位叫声,形态特征与捕食策略之间的联系,并结合部分的野外观察研究,推断其捕食生境及捕食策略,并对洞中5种共栖蝙蝠的生态位分化进行了分析;研究结果如下：（1）南蝠（Ia io)在地面或树冠中间的开阔空间捕食个体较大的昆虫;（2）大鼠耳蝠（Myotis myotis)主要以掠食性方式（gleaning) 捕食森林或草地地表面的昆虫;（3）黄大蹄幅（Hipposideros pratti)主要在树冠周围或树冠上方进行捕蝇器式（Fly-catching)（即倒挂于一固定枝条或地点,探索周围飞行或接近的昆虫,探索到后捕捉回原倒挂地点再进食）或飞行捕食,它主要捕食个体较大的甲虫;（4）角菊头蝠（Rhinolophus cornutus)主要在较密集树木中（枝叶间）,农田及树木周围捕食型较小的翼拍动昆虫;（5）三叶蹄幅（Aselliscus wheeleri)是在树木,灌丛或在其周围空间内捕食较小的翼拍动昆虫,但其食性可能菊头蝠不同,根据以上研究结果,认为这5种蝙蝠的取食生态位存在着明显的分化。     

Adaptive mechanisms underlying the bat biosonar behavior

For survival, bats of the suborder Microchiropetra emit intense ultrasonic pulses and analyze the weak returning echoes to extract the direction, distance, velocity, size, and shape of the prey. Although these bats and other mammals share the common layout of the auditory pathway and sound coding mechanism, they have highly developed auditory systems to process biologically relevant pulses at the expense of a reduced visual system. During this active biosonar behavior, they progressively shorten the pulse duration, decrease the amplitude and pulse-echo gap as they search, approach and finally intercept the prey. Presumably, these changes in multiple pulse parameters throughout the entire course of hunting enable them to extract maximal information about localized prey from the returning echoes. To hunt successfully, the auditory system of these bats must be less sensitive to intense emitted pulses but highly sensitive to weak returning echoes. They also need to recognize and differentiate the echoes of their emitted pulses from echoes of pulses emitted by other conspecifics. Past studies have shown the following mechanical and neural adaptive mechanisms underlying the successful bat biosonar behavior: (1) Forward orienting and highly mobile pinnae for effective scanning, signal reception, sound pressure transformation and mobile auditory sensitivity; (2) Avoiding and detecting moving targets more successfully than stationary ones; (3) Coordinated activity of highly developed laryngeal and middle ear muscles during pulse emission and reception; (4) Mechanical and neural attenuation of intense emitted pulses to prepare for better reception of weak returning echoes; (5) Increasing pulse repetition rate to improve multiple-parametric selectivity to echoes; (6) Dynamic variation of duration selectivity and recovery cycle of auditory neurons with hunting phase for better echo analysis; (7) Maximal multiple-parametric selectivity to expected echoes returning within a time window after pulse emission; (8) Pulse-echo delaysensitive neurons in higher auditory centers for echo ranging; (9) Corticofugal modulation to improve on-going multiple-parametric signal processing and reorganize signal representation, and (10) A large area of the superior colliculus, pontine nuclei and cerebellum that is sensitive to sound for sensori-motor integration. All these adaptive mechanisms facilitate the bat to effectively extract prey features for successful hunting.     

Mother-cub relationships in giant pandas in the Qinling Mountains,China, with comment on rescuing abandoned cubs

Six cases of mother-cub relationships in wild giant pandas (Ailuropoda melanoleuca) were observed in the Qinling Mountains, China. It was found that panda cubs are normally left alone in the den for 4–8 h while mothers forage. The mother's absence during bouts of foraging should be considered when rescuing abandoned cubs in order to avoid adding to the decline of the wild population. © 1994 Wiley-Liss, Inc.     

Why should bats be protected? A challenge for conservation

In Britain, the distribution of a few bat species appears to have declined over the past century. Generally, the documentary evidence is sparse, but improving knowledge of how bats exploit their roost and foraging habitats, combined with investigations into their prey selection suggests causes that will have affected them. Reduction in insect diversity and abundance resulting from much less grazed pasture and the loss of over 300000 km of hedgerow is considered to have had the most impact on bats. In addition, loss of, or damage to, roosts is known to have had deleterious consequences. Large scale management of landscape to create shelter and an abundance of insects is considered necessary if bat populations, especially of die rarest species, are to flourish.     

马铁菊头蝠对同种咀嚼声的反应研究

咀嚼是哺乳动物食物吸收的重要组成部分,对动物的生存和繁殖极其重要。动物咀嚼时会发出低频低强度的咀嚼声,研究表明人类的咀嚼声可以增强自身或他人的食欲和愉悦度。蝙蝠作为哺乳动物中的第二大类群,其咀嚼声的特征和功能仍不清楚。本研究以吉林省集安市治安村的马铁菊头蝠Rhinolophus ferrumequinum为研究对象,通过回放蝙蝠咀嚼声和空白对照实验,同步录制蝙蝠的进食行为和回声定位声波,试图阐明蝙蝠咀嚼声对其进食行为和回声定位声波的影响。结果表明:进食次数在2种回放条件下的差异无统计学意义,但捕食尝试在2种回放条件下的差异有统计学意义。因此,咀嚼声能够显著地提高蝙蝠的进食欲望。此外,在蝙蝠咀嚼声的刺激下,其回声定位声波的频率增加,持续时间延长,脉冲速率减慢。这可能是因为蝙蝠在咀嚼声的影响下改变发声动机,从而改变了其回声定位声波的频谱时间结构。本研究第一次报道了蝙蝠咀嚼声对其进食行为的影响,为进一步阐明蝙蝠咀嚼声的功能和进化具有重要意义。     

亚致死浓度赤藓糖醇对红火蚁工蚁觅食和弃尸行为的影响

红火蚁是国际上最具危险性外来害虫之一,已入侵华南地区并造成严重危害。为弄清潜在杀虫剂赤藓糖醇在亚致死浓度下对红火蚁的影响,本研究使用0.05 g/mL赤藓糖醇水溶液喂食室内蚁群24 h,观察了工蚁的觅食行为和弃尸行为的变化。结果显示,取食赤藓糖醇后工蚁发现食物时间约为5 min,而取食10%蔗糖水后发现食物时间缩短到2 min以内;取食赤藓糖醇后工蚁招募速度和食物搬运效率也显著低于对照。取食赤藓糖醇后工蚁发现尸体时间和弃尸速度变化显著,发现尸体时间由对照的3.45 min延长至8.13 min,开始丢弃尸体时间由20 min延长至37.5 min,丢弃完所有尸体耗时由3.08 h增大至5.37 h。亚致死浓度赤藓糖醇显著降低了红火蚁工蚁觅食和弃尸能力。     

Responses of the parasitoid Cotesia rubecula to its host Pieris rapae in a flight tunnel

Responses of female Cotesia rubecula (Marshall) (Hymenoptera: Braconidae) to larval Pieris rapae (L.) (Lepidoptera: Pieridae) feeding on cabbage leaves were investigated in a flight tunnel. Latency of flight was shorter and the proportion of female wasps flying to leaves was greater when cabbage was infested with hosts. This indicated that wasps detected hosts prior to taking flight and were attracted to them. Wind speed was varied (18, 54, 100 cm/s) to examine its effect on the response of wasps to hosts. Flight was inhibited by increasing wind speed and was accompanied by less frequent but longer bouts of pointing (antennae raised and spread, facing into the wind). The accuracy of landing but not the duration of flight to the plant was affected by increasing wind speed. The results indicated that increasing wind speed will reduce the rate of parasitoid oviposition.

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Résumé Cette étude concerne les réactions des femelles de C. rubecula Marshall (Hyméno., Braconidae) aux chenilles de P. rapae (Lépido, Pieridae) alimentées sur feuilles de choux. Le tunnel fournit un flux laminaire et l'air est recyclé avec désodorisation par circulation sur un filtre de charbon de bois. La période de latence avant l'envol est plus brève et la proportion de femelles volant vers les feuilles plus élevée quand les choux sont contaminés par les chenilles. Ceci montre que les femelles détectent les hôtes avant l'envol et qu'ils les attirent. Le vent peut influer sur la libération de kairomones, sur les caractéristiques du panache d'odeurs et sur l'énergétique du vol; en conséquence, différentes vitesses de vent (18, 54, 100 cm/S) ont été utilisées pour examiner leurs effets sur la réaction des braconides. Le vol a été inhibé par une augmentation de la vitesse du vent et était accompagné par de plus longues, mais moins fréquentes poussées de pointage (antennes dressées et étendues, face au vent). La précision de l'atterrissage a été affectée par l'augmentation de la vitesse du vent, mais non la durée du vol vers la plante. Ces résultats ont montré que l'augmentation de la vitesse du vent peut réduire le taux de ponte du parasitoïde en inhibant le vol. La signification de ces résultats est discutée en relation avec la situation dans la nature.