Vocal cues to male androgen levels in giant pandas

Little is known about the potential of non-human mammal vocalizations to signal information on the hormonal status of the caller. In the current study, we used endocrine data and acoustic analyses to determine whether male giant panda bleats provide reliable information about the caller''s current androgen levels. Our results revealed significant relationships between acoustic features of male giant panda bleats and the caller''s faecal androgen metabolite concentrations. To our knowledge, this constitutes the first demonstration that the acoustic structure of a non-human mammal call has the potential to yield information about the caller''s current androgen levels. We go on to discuss the anatomical basis for our findings and the potential functional relevance of signalling information on male androgen levels in giant panda sexual communication.     

Are men better than women at acoustic size judgements?

Formants are important phonetic elements of human speech that are also used by humans and non-human mammals to assess the body size of potential mates and rivals. As a consequence, it has been suggested that formant perception, which is crucial for speech perception, may have evolved through sexual selection. Somewhat surprisingly, though, no previous studies have examined whether sexes differ in their ability to use formants for size evaluation. Here, we investigated whether men and women differ in their ability to use the formant frequency spacing of synthetic vocal stimuli to make auditory size judgements over a wide range of fundamental frequencies (the main determinant of vocal pitch). Our results reveal that men are significantly better than women at comparing the apparent size of stimuli, and that lower pitch improves the ability of both men and women to perform these acoustic size judgements. These findings constitute the first demonstration of a sex difference in formant perception, and lend support to the idea that acoustic size normalization, a crucial prerequisite for speech perception, may have been sexually selected through male competition. We also provide the first evidence that vocalizations with relatively low pitch improve the perception of size-related formant information.     

Female red deer prefer the roars of larger males

Surprisingly little is known about the role of acoustic cues in mammal female mate choice. Here, we examine the response of female red deer (Cervus elaphus) to male roars in which an acoustic cue to body size, the formants, has been re-scaled to simulate different size callers. Our results show that oestrous red deer hinds prefer roars simulating larger callers and constitute the first evidence that female mammals use an acoustic cue to body size in a mate choice context. We go on to suggest that sexual selection through female mating preferences may have provided an additional selection pressure along with male-male competition for broadcasting size-related information in red deer and other mammals.     

Individual acoustic monitoring of the European Eagle Owl Bubo bubo

The Eagle Owl Bubo bubo is cited in Annex I of the Birds Directive of the European Union. Europe's biggest owl is extremely sensitive to human presence and needs special conservation measures. The present paper aims to show that monitoring of individuals by bioacoustic methods can be relevant to understanding population dynamics. Our study investigates the possibility of identifying a vocal signature in the wild-recorded calls of male and female Eagle Owls, and assesses the potential use of these signatures for long-term monitoring of individuals in the field. We show that both males and females of a given population can be identified individually on the basis of their calls. Our results also show that, regardless of the sex, most of the individuals recorded in the first year of the investigation may be identical to those recorded in the same places the year after. This bioacoustic approach could thus be used in studies of site fidelity.     

Individuals in foraging groups may use vocal cues when assessing their need for anti-predator vigilance

Many studies of social species have reported variation in the anti-predator vigilance behaviour of foraging individuals depending on the presence and relative position of other group members. However, little attention has focused on how foragers assess these variables. It is commonly assumed that they do so visually, but many social species produce frequent calls while foraging, and these 'close' calls might provide valuable spatial information. Here, we show that foraging pied babblers (Turdoides bicolor) are less vigilant when in larger groups, in the centre of a group and in closer proximity to another group member. We then show that foragers are less vigilant during playbacks of close calling by more individuals and individuals on either side of them when compared with calls of fewer individuals and calls on one side of them. These results suggest that foragers can use vocal cues to gain information on group size and their spatial position within a group. Future studies of anti-predator vigilance should consider the relative importance of both visual and vocal monitoring of group members.     

Are dogs able to recognize their handler's voice? A preliminary study

Abstract

A number of studies have dealt with the ability of dogs to rely on olfactory cues to recognize their owner or handler. However, in the absence of these cues (e.g., when working at a distance from their owner) dogs have to use other senses to interact with their owner. Considering the high sensitivity of their auditory system, we can hypothesize that dogs are able to use vocal cues for this purpose. Certainly, it is commonly assumed that dogs can discriminate between people on the basis of their voice, and yet there is a clear lack of empirical data on this subject. The present study assesses the importance of the handler's olfactory and visual cues versus the importance of his/her vocal cues to the working behavior of dogs. I compare the ability of working dogs to obey different vocal commands issued either by their handler (HV) or by a stranger (SV) via loudspeakers in different olfactory contexts: presence of their handler (H) or of a stranger (S). The dogs' performance (percentage of correct responses) decreased when the acoustic cues were modified (H+HV tended to differ from the H+SV—p = 0.09—and differed from the S+SV conditions—p = 0.05) but not when only the olfactory cues were changed (no difference between H+HV and S+HV conditions—p > 0.1). Consequently, we can assume that dogs rely, at least in part, on acoustic parameters of voices to recognize and cooperate with their handler.     

不同生境大熊猫源肠球菌耐药性分析

目的 为了了解大熊猫源肠球菌耐药性发展和流行现状,为大熊猫源细菌耐药性监测体系的建立和大熊猫细菌性疾病的控制奠定基础,同时为临床合理选用抗菌药物提供参考。方法 本试验采用临床实验室标准化协会推荐的纸片法,对从不同生境来源的254份大熊猫粪便样品分离鉴定出的11种大熊猫源肠球菌共计381株进行21种抗生素的药物敏感试验。结果 在381株大熊猫源肠球菌中,对青霉素、先锋霉素V、链霉素耐药率均在10%以上,其余抗生素的耐药率均低于10%,未发现有对恩诺沙星、复方新诺明、万古霉素、庆大霉素、替考拉宁耐药的菌株;不同种类的大熊猫源肠球菌对同一种抗生素的耐药率不同;同一种大熊猫源肠球菌对不同抗生素的耐药率也有差异;不同生存方式来源的大熊猫源肠球菌耐药情况各有不同,但耐药最严重的均为粪肠球菌;多重耐药主要以1~3重耐药为主。结论 大熊猫源肠球菌对大部分抗生素产生了耐药性,整体和多重耐药情况较轻微,耐药性差异主要体现在肠球菌的种类上,大熊猫的生存环境和方式等对其影响相对较小,尤其是圈养大熊猫、野化大熊猫和野生大熊猫之间只有很细微的差别,可以从侧面反映出目前给予圈养大熊猫使用的抗菌药物较为科学合理,提示在治疗肠球菌感染时, 应根据分离株的耐药特点和药敏试验结果合理选用或及时更换抗生素, 以减少耐药菌株的产生和耐药基因的传播。     

圈养大熊猫妊娠期行为变化及活动节律研究

: 由于环境条件与自身生理状况的变化,动物往往会做出相应的反应,从而形成特定条件下的活动节律模式。大熊猫有效配种后即进入妊娠期,但亦有假孕现象出现,而其激素变化与妊娠个体无异,因此,分析2种妊娠类型个体在妊娠期行为的异同,有助于其饲养管理措施的实施。2013年3—8月,采用瞬时扫描取样法和全事件记录法对成都大熊猫繁育研究基地的6只受配大熊猫进行行为和活动节律研究。结果表明:休息是大熊猫妊娠期最主要的行为方式,其次是摄食和运动,而妊娠行为则较少,主要表现为假妊娠个体与妊娠个体在反应期的求适和妊娠行为时间上差异有统计学意义(P<0.05)。因此,通过对妊娠期大熊猫行为的研究,将为其饲养与管理提供行为学方面的技术依据。     

Wild squirrel monkey (Saimiri sciureus) “caregiver” calls: Contexts and acoustic structure

A field study of the vocal behavior of 22 wild adult female squirrel monkeys (Saimiri sciureus) in Parque Nacional del Manu, Peru, found that 21% of vocalizations were “caregiver” calls. Caregiver calls are brief, low frequency calls, often with numerous harmonics, that are addressed by caregivers to their own infants in three contexts: 1) prenurse, signalling the caregiver's location and willingness to nurse; 2) nurse, while nursing; and 3) end nurse, indicating the end of the nursing bout. Three measures (start, end, and peak frequency) of the acoustic structure of the fundamental frequency of the caregiver calls significantly differed across the contexts. Duration of caregiver calls, however, was not distinguished by context. Compared to other primate taxa, the specificity and importance of caregiver calls in squirrel monkey vocal behavior appears unusual, if not unique. That S. sciureus caregiver calls are highly developed and employed so extensively probably follows from an unusual combination of ecological and life history factors. These factors include delayed weaning and large infant body size, high levels of indirect foraging competition which encourages spatial separation, susceptibility to predation, and specialization on a densely foliated, branch-end microhabitat in which visual contact is often impeded. © 1995 Wiley-Liss, Inc.     

秦岭大熊猫栖息地巴山木竹生物量

巴山木竹是秦岭大熊猫冬、春季食物的主要来源,其生长状况、数量和空间分布格局与大熊猫的生存与活动有着密切的关系。为了探讨不同立地因子对巴山木竹生物量的影响,确定巴山木竹生长的主导因子和适宜立地条件,在秦岭大熊猫栖息地内选取54块样地,对不同立地条件下巴山木竹生物量进行了测定。通过统计分析,结果表明:由于不同地区气候和土壤条件的差异,导致了巴山木竹生物量亦存在较大差别;巴山木竹生物量在其分布区内随海拔的升高而呈规律性变化,1500—1700 m为最适分布区域,其生物量最大;坡度越大生物量越小,陡坡不适宜竹林的生长;上坡位不利于竹林生长,而中、下坡位生物量没有显著差异;坡向对生物量的影响不明显,均适宜巴山木竹生长;在落叶阔叶和针阔混交林中,当林冠郁闭度>0.6时,竹林生长减弱。在这些立地因子中,影响巴山木竹生物量积累的主导因子是坡位和林冠郁闭度。