Degree of social contact affects the emission of food calls in the common marmoset (Callithrix jacchus)

The aim of this study was to investigate whether the emission of food calls in common marmosets (Callithrix jacchus) is influenced by different social contexts. Food calls are emitted by this species only in the presence of preferred food. If these calls have any communicative function, it may be that individuals produce food calls in order to call family mates toward the food source. If this is the case, the number of calls produced should vary in accordance with the number of family mates present at the moment of the discovery of the food, i.e., the fewer family mates nearby, the more food calls are emitted. This hypothesis was tested with five pairs of common marmosets, by recording the number of food calls emitted in four experimental conditions: 1). isolation: completely isolated from the family mates; 2). visual isolation: separated by a wooden panel from the family mates; 3). visual contact: separated by a wire-mesh from the family mates; and 4). physical interaction: together with the family mates. The results show that the proportion of intervals during which food calls were produced by the pairs was significantly different in the four experimental conditions. It decreased from the isolation and visual isolation condition, through the visual contact condition, reaching the lowest value in the physical interaction condition. The variation observed in the proportion of intervals during which food calls were emitted, in relation to different social contexts, is an indication in favor of the communicative function of this vocalization.     

中国43种蛙类鸣声特征数据集

无尾两栖动物的鸣声通常具有物种特异性,了解其鸣声特征信息,是利用生物声学进行物种多样性调查及物种监测的前提。本文汇总、整理了2012–2020年间利用高保真录音设备在野外记录的43种(隶属于7科26属)无尾两栖动物的鸣声数据,以及相应的鸣声采集信息。对音频文件进行降噪处理后,提供了由61个鸣声的波形图及语图组成的鸣声特征数据集。本数据集展示了鸣声的多种时域和频域信息,如单音节或多音节、音节数、音节时长、音节间隔、鸣声时长、主频、基频、谐波等,为我国无尾两栖类的声学研究、物种多样性调查及鸣声监测提供了数据支持。     

Ignorant hooded crows follow knowledgeable roost-mates to food: support for the information centre hypothesis

Communal roosting in birds may function to enhance foraging efficiency as explained by the information centre hypothesis, which predicts that successful foragers return from the roost to the rewarding food patch and that birds ignorant of this food follow knowledgeable roost-mates. We tested these predictions by exposing 34 radio-tagged, free-ranging, flock-living hooded crows (Corvus corone cornix) to a novel experimental set-up mimicking a superfluous food patch with maximum temporal and spatial unpredictability Each replicate lasted two days and was located on a new site. Data were collected during ten replicates over three years. First, a crow was more likely to visit the experimental food patch on the second day when it had been there on the first day. Second, when a crow had not been at this food patch on the first day, it was more likely to visit it on the second day if it had roosted together with a crow that had been there on the first day, but only if this knowledgeable roost-mate returned to the food patch on the second day. Our results support the information centre hypothesis and suggest that communal roosting might function to enhance foraging efficiency in hooded crows.     

Bioacoustic analysis of frog calls from northeast India

Mating calls of three frog species abundant in northeast IndiaRana tigerina,Rana cyanophlyctis andRana limnocharis were recorded in the fields of Assam and Meghalaya during their breeding season (July-August, 1991). The calls were analysed for their temporal and spectral characters. They were species specific, with distinct call duration and call period, number of pulses per call and interpulse interval, and dominant frequency and frequency domain. A comparison of the mating calls ofRana cyanophlyctis with those of the siblingRana ehrenbergi from Yemen showed differences in their temporal and spectral characters, supporting the suggestion that these two species are distinct species, rather than subspecies of the same species. Differences in the temporal and spectral pattern were found in the mating calls of morphologically alike specimens ofRana limnocharis, indicating that the present morphotypeRana limnocharis in northeast India is composed of several species.     

Bonobos extract meaning from call sequences

Studies on language-trained bonobos have revealed their remarkable abilities in representational and communication tasks. Surprisingly, however, corresponding research into their natural communication has largely been neglected. We address this issue with a first playback study on the natural vocal behaviour of bonobos. Bonobos produce five acoustically distinct call types when finding food, which they regularly mix together into longer call sequences. We found that individual call types were relatively poor indicators of food quality, while context specificity was much greater at the call sequence level. We therefore investigated whether receivers could extract meaning about the quality of food encountered by the caller by integrating across different call sequences. We first trained four captive individuals to find two types of foods, kiwi (preferred) and apples (less preferred) at two different locations. We then conducted naturalistic playback experiments during which we broadcasted sequences of four calls, originally produced by a familiar individual responding to either kiwi or apples. All sequences contained the same number of calls but varied in the composition of call types. Following playbacks, we found that subjects devoted significantly more search effort to the field indicated by the call sequence. Rather than attending to individual calls, bonobos attended to the entire sequences to make inferences about the food encountered by a caller. These results provide the first empirical evidence that bonobos are able to extract information about external events by attending to vocal sequences of other individuals and highlight the importance of call combinations in their natural communication system.     

白腹锦鸡鸣声的声谱分析

1986年1月—8月,12月及翌年1月,我们在云南省昆明市西部山区进行白腹锦鸡野外生态观察期间,录制了白腹锦鸡的鸣声。本文就啼叫声、呼唤声、惊叫声、恐惧叫声、威胁叫声及召唤雏鸟声等6种意义比较明确的鸣声进行了声谱分析,探讨各种鸣声与其相应的行为关系。     

Female Preferences for Call Traits and Male Mating Success in the Neotropical Frog Physalaemus enesefae

Female preferences for male call traits may affect male mating success and the evolution of exaggerated secondary sexual traits. We used phonotaxis experiments to examine female preferences in the frog Physalaemus enesefae in relation to variation in male call duration, dominant frequency, intercall interval and amplitude (dB SPL). Females preferred long calls, low and average dominant frequency calls, short intercall intervals and more intense calls. We compared the patterns of female preferences with those of acoustic variation among males to test the prediction that properties with low within‐male variation are associated with stabilizing or weakly directional female preferences, whereas properties with high within‐male variation are associated with directional preferences. Females had weakly directional preferences for the dominant frequency of the call and strongly directional preferences for call duration and call rate. We also determined whether the temporal relationship between calls influenced preferences based on the dominant frequency of the call. Preferences for low‐frequency over high‐frequency calls disappeared when calls partially overlapped. Females preferred the leading call regardless of its dominant frequency. We also investigated mating patterns in the field. There was size‐assortative mating, as male and female body sizes snout‐vent length (SVL) were positively correlated. In addition, differences in the frequency distributions of body length (SVL) between mated and unmated males approached significance; lower SVL classes were underrepresented among mated males. These patterns may reflect female preferences for lower dominant frequency calls, as there is a negative correlation between male mass and the dominant frequency of the call.     

Crepuscular Changes in Emission Rate and Parameters of the Boatwhistle Advertisement Call of the Gulf Toadfish, Opsanus Beta

We quantified crepuscular variation in the emission rate and call properties of the boatwhistle advertisement call of Gulf toadfish, Opsanus beta, from a field recording of a natural population of nesting males in the Florida Keys. Their calls are more variable and complex than previously reported. A call typically starts with a grunt followed by one to five tonal boop notes (typically two or three) and lasts for over a second. The first boop is considerably longer than later ones, and intervals between boops are relatively constant until the final interval, which approximately doubles in duration. Positions of fish are fixed and calls are sufficiently variable that we could discern individual callers in field recordings. Calling rate increases after sunset when males tend to produce shorter calls with fewer notes. Analysis by number of notes per call indicates some individuals decrease the number of initial grunts and the duration of the first note, but most of the decrease results from fewer notes. To our knowledge this sort of call plasticity has not been demonstrated before in fishes. We suggest that call shortening lowers the chances of overlapping calls of other males and that the small amount of time actually spent producing sound (total on time) is an adaptation to prevent fatigue in sonic muscles adapted for speed but not endurance.     

Why do zoos attract crows? A comparative study from Europe and Asia

Crows have successfully colonized many cities, and urban zoos have been important in this process. To evaluate why zoos attract crows, we quantified crow numbers and behavior in three zoos in Europe (Debrecen, Edinburgh, Vienna) and one in Asia (Sapporo). Data were collected in 445 surveys over 297 days in summer 2014 and winter 2014–2015. We found that crow numbers were highest in Vienna, intermediate in Debrecen and Edinburgh and lowest in Sapporo, increased significantly from summer to winter (Debrecen, Edinburgh, Vienna), and from mornings to afternoons (Debrecen, Sapporo, Vienna), and were higher in sunny weather than in cloudy weather with precipitation and when visitor numbers were low (Debrecen, Vienna). The crows' use of natural food was highest in Vienna, intermediate in Edinburgh and Sapporo, and low in Debrecen. The use of anthropogenic food was high in Debrecen and Sapporo, where the availability of open grassy areas typically used by crows for natural foraging was low. In Sapporo, food availability was more limited than in other zoos, resulting in strong territoriality and few crows in summer, which decreased further in winter. Our study indicates that crows are primarily attracted to zoos by food availability and secondarily by breeding opportunities and that the relative importance of natural versus anthropogenic food sources may vary with zoo habitat structure. Our study draws attention to a previously overlooked role of zoos in urban biodiversity conservation. It may also provide useful information for the management of crow populations, if necessary, and for the planning of urban areas.     

Responsiveness of young ring-billed gulls to various natural and manipulated adult gull calls

Individual adult gull calls, call sequences, and artificially manipulated calls were played to parentally naive young Larus delawarensis in the laboratory to assess the effectiveness of calls and call parameters in eliciting filial behaviour. Call duration, the number and rate of calls in a sequence, and absolute intensity (dB) significantly affected chitter vocalization responses. These parameters correlate functionally with the characteristics of actual calls given by adults within the colony. Call frequency (Hz), frequency modulation, and within-call variations in intensity did not. The latter parameters consititute potential physical bases for further differentiation of responses during subsequent development.     

Advertisement calls of Guenther’s frog Hylarana guentheri (Anura: Ranidae) during the breeding season

Acoustic signalling is the most important form of communication in anuran amphibians. Here we recorded and analysed the calls of 18 male Guenther’s frogs (Hylarana guentheri) from the wild during the breeding season. The advertisement calls of H. guentheri were composed of from a single note to five notes, with three-note calls the most recorded. All individuals produced calls around 600 Hz but calls ranged from 470 to 2600 Hz. Comparing the differences between individuals calls, we found within-male coefficients of variation (CV_w) of call intensity, the fundamental frequency, the first formant, the second formant, the third formant and the fourth formant were static (less than 5% variation), whereas those of note duration, call duration, call interval, numbers of pulses and dominant frequency were dynamic (larger than 15% variation). Comparisons of the call characteristics of H. guentheri in this study with other studies from China, Singapore and Vietnam found call characteristics varied greatly between the five different locations.     

Crows cross-modally recognize group members but not non-group members

Recognizing other individuals by integrating different sensory modalities is a crucial ability of social animals, including humans. Although cross-modal individual recognition has been demonstrated in mammals, the extent of its use by birds remains unknown. Herein, we report the first evidence of cross-modal recognition of group members by a highly social bird, the large-billed crow (Corvus macrorhynchos). A cross-modal expectancy violation paradigm was used to test whether crows were sensitive to identity congruence between visual presentation of a group member and the subsequent playback of a contact call. Crows looked more rapidly and for a longer duration when the visual and auditory stimuli were incongruent than when congruent. Moreover, these responses were not observed with non-group member stimuli. These results indicate that crows spontaneously associate visual and auditory information of group members but not of non-group members, which is a demonstration of cross-modal audiovisual recognition of group members in birds.     

沼水蛙繁殖期鸣声特征及鸣叫节律

鸣叫对无尾两栖类动物的生存与繁殖起重要作用。蛙类的鸣叫行为受到环境因素影响表现出一定的节律性。2016年8和9月,采用录音机和指向性话筒,在野外录制了57只沼水蛙（Hylarana guentheri）的鸣声并对其鸣声特征进行分析;通过悬挂录音笔和自动温湿度记录仪研究了沼水蛙鸣叫节律（17 d）及其与环境温度、相对湿度的关系。结果显示,沼水蛙的鸣声由1 ~ 4个音节组成,不同类型鸣声间的音节主频、音节时长存在显著差异（P < 0.05）。该物种全天具有鸣叫行为,13:00 ~ 14:00时为鸣叫高峰期。白天单音节鸣声、双音节鸣声、三音节鸣声、总鸣声和总音节的数量较夜晚显著增加（P < 0.01）。鸣声数量和音节数量均与环境温度呈正相关（P < 0.01）。结果表明,沼水蛙通过改变音节数量、音节主频和音节时长改变鸣叫策略。沼水蛙的鸣叫行为具有昼夜节律性且受环境温度的影响。     

Cognitive Processes Associated with Sequential Tool Use in New Caledonian Crows

Background

Using tools to act on non-food objects—for example, to make other tools—is considered to be a hallmark of human intelligence, and may have been a crucial step in our evolution. One form of this behaviour, ‘sequential tool use’, has been observed in a number of non-human primates and even in one bird, the New Caledonian crow (Corvus moneduloides). While sequential tool use has often been interpreted as evidence for advanced cognitive abilities, such as planning and analogical reasoning, the behaviour itself can be underpinned by a range of different cognitive mechanisms, which have never been explicitly examined. Here, we present experiments that not only demonstrate new tool-using capabilities in New Caledonian crows, but allow examination of the extent to which crows understand the physical interactions involved.

Methodology/Principal Findings

In two experiments, we tested seven captive New Caledonian crows in six tasks requiring the use of up to three different tools in a sequence to retrieve food. Our study incorporated several novel features: (i) we tested crows on a three-tool problem (subjects were required to use a tool to retrieve a second tool, then use the second tool to retrieve a third one, and finally use the third one to reach for food); (ii) we presented tasks of different complexity in random rather than progressive order; (iii) we included a number of control conditions to test whether tool retrieval was goal-directed; and (iv) we manipulated the subjects'' pre-testing experience. Five subjects successfully used tools in a sequence (four from their first trial), and four subjects repeatedly solved the three-tool condition. Sequential tool use did not require, but was enhanced by, pre-training on each element in the sequence (‘chaining’), an explanation that could not be ruled out in earlier studies. By analyzing tool choice, tool swapping and improvement over time, we show that successful subjects did not use a random probing strategy. However, we find no firm evidence to support previous claims that sequential tool use demonstrates analogical reasoning or human-like planning.

Conclusions/Significance

While the ability of subjects to use three tools in sequence reveals a competence beyond that observed in any other species, our study also emphasises the importance of parsimony in comparative cognitive science: seemingly intelligent behaviour can be achieved without the involvement of high-level mental faculties, and detailed analyses are necessary before accepting claims for complex cognitive abilities.     

Aprocta matronensis in crows (Corvus corone corone) from northern Italy.

Aprocta matronensis (Nematoda, Spirurida) has been found in the orbital cavities of carrion crows. Hooded crows and crows from the hybrid crow zone in the studied areas were not infected. The parasite population showed the typical morphology described for this species. This is the first record of A. matronensis in crows in Italy and in Corvus corone corone. Some hypotheses about the distribution of the parasites in crow populations are discussed.     

四川山鹧鸪繁殖期的鸣声行为特征

2005年4—12月在四川老君山自然保护区,通过计算机声谱分析技术,对四川山鹧鸪(Arborophilarufipectus)雄性的鸣声行为特征进行了研究,其结果表明,雄性单音节鸣声出现在啼叫、保护领域和求偶中,这些鸣声持续时间差异明显,主峰值差异不明显;雄性双音节鸣声出现在啼叫、保护领域、竞争雌体和求偶中,这些鸣声第一音节时间、第二音节时间、音节间隔时间和主峰值差异极显著,全句时间差异不明显;雄性多音节鸣声出现在保护领域、警戒和惊吓中。雄性亚成体多音节鸣声出现在惊吓和警戒中;雄性成体和亚成体警戒鸣叫的音节持续时间、音节间隔时间和主峰值差异均不明显,全句持续时间差异明显;雄性亚成体和雄性成体的惊吓鸣叫音节持续时间、音节间隔时间、全句持续时间和主峰值差异均不明显。四川山鹧鸪表现出的各种鸣声行为是为了保护配偶和防止天敌,使该种群更好地繁衍。     

Synchronized interdigitated calling in the Kuvangu running frog, Kassina kuvangensis

Male Kuvangu frogs show repetitive calling of pulsed advertisement calls in which up to seven calls are repeated in short succession. Recordings of pairwise interactions between males showed that calls were highly synchronized, with individual calls interdigitating with each other. Males frequently switched between the leader and follower role with neither male dominating the interaction. Interactive playback experiments using synthetic calls revealed that males slightly but significantly increased the number of calls per call group with increases in stimulus call number. Males also significantly increased call rate with the number of calls in the playback stimulus. Furthermore, when presented with shortened intercall intervals, males increased their own intercall intervals, thus ‘skipping’ a call and avoiding overlap with the playback. The low degree of call matching suggests that repetitive calling, apart from maintaining a male's attractiveness to females relative to rival males, may mediate male-male competition. In addition, synchronized interdigitated calling may serve to reduce predation, while maintaining species-specific temporal features of advertisement calls important to females. Kuvangu running frogs may have reduced the costs associated with synchrony and alternation by using a signal timing scheme that allows them to do both simultaneously.Copyright 2003 Published by Elsevier Science Ltd on behalf of The Association for the Study of Animal Behaviour.       

Chick Begging Calls Reflect Degree of Hunger in Three Auk Species (Charadriiformes: Alcidae)

Begging behaviour is an important element in the parent-offspring conflict; it has been studied in many avian species. However, the majority of the studies have been entirely based on the call counts, and they agreed that vocal activity was a good indicator of chick’s nutritional need and/or condition. Fewer researches were dedicated to the temporal-frequency variables of the begging calls themselves and they showed contrary results. Here begging behaviour in three burrow nested, uniparous species of auks (Alcidae) was studied. These objects provide an opportunity to study the signalling value of begging calls in the absence of important confounding factors such as nestling competition and predation pressure. I recorded calls of individual chicks in two conditions: during natural feeding and after experimental four-hour food deprivation. I found that almost all measured acoustic variables contain information about the chick’s state in all studied species. The hungry chicks produced calls higher in fundamental frequency and power variables and at higher calling rate compared to naturally feeding chicks. The effect of food deprivation on most acoustic variables exceeded both the effects of individuality and species. In all studied species, the frequency variables were stronger affected by hunger than the calling rate and call durations. I suppose that such strong change of acoustic variables after food deprivation can be explained by absence of vocal individual identification in these birds. As parents do not need to check individuality of the chick in the burrow, which they find visually during the day time, the chicks could use all of the acoustic variables to communicate about their nutritional needs.     

Which Call Parameters Signal Threat to Conspecifics in White‐Throated Magpie‐Jay Mobbing Calls?

Abstract Variation in signals often encodes additional information beyond that provided by the main signal. Many species communicate degree of threat using such signal variation. However, multiple signal parameters often covary with threat level, and it is unclear whether receivers are using variation along one or more parameters when assessing threat level. White-throated magpie-jays ( Calocitta formosa ) vary several call parameters when mobbing, and here I report on an experiment testing whether such variation contains information used by conspecific receivers, and which parameters are salient to receivers. I collected data on natural mobbing sequences in two threat contexts and found that mobbing calls were highly variable in both length and inter-call interval, but on average, both parameters were shorter in high threat contexts, while call frequency did not differ. To determine how jays respond to such between-context variation, I conducted a playback experiment in which call length and inter-call interval were independently varied in a factorial design. This is one of the first studies to my knowledge to deconstruct and independently test covarying signal parameters in an anti-predator signaling system. Magpie-jays responded more often to treatments with either short call lengths or short inter-call intervals, in concordance with the natural calling data. However, the two parameters did not appear to act independently; responses were not additive, and short calls at short inter-call intervals elicited no stronger of a response than short calls at long intervals or long calls at short intervals. Receivers can use either parameter when assessing threat level. These data demonstrate that mobbing can signal threat level, that call length and call rate are redundant, and that receivers need not use both to determine whether to approach.