The response of willow grouse chicks to auditory stimuli 2. Synthesized brooding calls attract machine-incubated chicks

Willow grouse (Lagopus l. lagopus) chicks appear to possess a ‘template’ of the hen's brooding call. Chicks newly hatched from machine-incubated eggs were therefore exposed to a number of electronically synthesized approximations to brooding calls. These sounds were either paired with a recording of a grouse hen's brooding call, or were played alone. Some of the synthesized calls (repetitive, low-frequency) attracted chicks, while others appeared to be aversive. None of the synthesized calls drew chicks away from the recorded hen call. These results suggest that grouse chicks will approach a wide range of attraction calls which have certain minimum features.     

On the responses of laughing gull chicks (Larus atricilla) to the calls of adults II. Age changes and responses to different types of call

Three age-groups of laughing gull chicks were tested with playback of recordings of calls of their parents and calls of neighbouring adults. The chicks in each group showed response to the playback calls, and recognition of the voices of their parents. The chicks in the early group (1 to 3 days post-hatching) showed the least evidence of parent recognition: the chicks of the late group (12 to 28 days post-hatching) showed the lowest levels of response in general.Evidence of relationships between variation in the behaviour in the tests and variation in the test recordings was found from correlation analysis, the type of call initiating positive response, and analysis of temporal association. This evidence, and the results of tests which allowed responses to the parents' crooning and responses to the parents' ke-hah calls to be compared for chicks in the late group, indicate that whereas the filial approach behaviour of very young chicks is stimulated by crooning but suppressed by ke-hah and long-calls, this behaviour in older chicks requires the occurrence of ke-hah calls or long-calls for its elicitation. However the ke-hah calls and long-calls of adults other than the parents continue to have negative effects on the behaviour of older chicks.It is argued that this progression in discrimination of the voices of the parents and the changes in responsiveness to the different types of adult calls are consistent with functional requirements, both from the point of view of changes in a growing chick's social situation and from the point of view of the characteristics of the calls. The changes are also discussed from a developmental point of view.     

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。     

Parent-offspring recognition in bank swallows (Riparia riparia): II. Development and acoustic basis

In study 1, bank swallow (Riparia riparia) chicks were exchanged with like-aged chicks from other broods. Parents accepted chicks that were transferred into their nests at age 15 days or younger; rejection began to occur at 16 to 17 days. In study 2, chicks' vocalizations were recorded in the burrow. We found that an immature begging call given by young chicks is replaced by a ‘signature’ call at 15 to 17 days of age. An acoustic analysis suggested that these calls are individually distinctive. Study 3 was a playback experiment designed to test whether the chicks' signature calls are a sufficient cue for parental recognition. We found that parents would approach a speaker broadcasting the calls of their chicks in preference to one simultaneously broadcasting the calls of alien chicks. The pattern of results suggests that parental recognition is based on the chicks' signature calls and that development of recognition is dependent on the development of the call.     

Individual recognition of parental calls by bank swallow chicks (Riparia riparia)

Antiphonal responses of newly fledged bank swallows (Riparia riparia) to the calls of their parents during the joined flights to and from the home burrow suggest that recognition of parents by offspring is a mechanism promoting family cohesion, a necessary condition for the adequate provisioning of chicks in this highly colonial species. Paternal and maternal calls used while leading chicks revealed higher inter-than intra-individual variability in temporal and frequency parameters, indicating that these calls could reliably identify individuals. When tested in the field at the onset of the fledging period, chicks answered significantly more playbacks of parent calls than of alien adult calls. Quantified observations of the rearing activity of the parents suggest that chick-parent recognition is based on familiarity, because of the chicks' differential exposure to the parental calls prior to fledging. During the development of the chicks in the burrow, both parents (which share the rearing activities equally) often call before feeding the chicks.     

Vocalizations of chicks and juveniles and the development of adult calls in the Aldabra White-throated rail Dryolimnas cuvieri aldabranus (Aves: Rallidae)

Calls were recorded from eggs, chicks and juveniles of the Aldabra White-throated rail Dryolimnas cuvieri aldabranus. A sonagraphic analysis was made of these calls, their behavioural contexts described and probable functions suggested. Three calls, the twitter, tiuu and contented peep were produced by chicks in the egg. All three calls may be derived from the basic peep first recorded some 36 hours before hatching. Shortly after hatching two more calls, the distress call and the alarm call, can be elicited from the rail chicks. Contented peeps and twitters are restricted to the repertoire of young rails. Song was first heard from wild rail chicks at the age of ten days and may develop from the contented peep. Three adult calls, the 'mp yeah, 'mptiuu and 'mpclick appear at the age of three months and six months later the adult vocal repertoire is completed by the appearance of 'mps, toks, purrs and nest-defence squeals. With the exception of the 'mp, all adult calls can be derived from the vocalizations of chicks and juveniles.     

红腹锦鸡鸣声声谱分析

本文对笼养红腹锦鸡的啼叫,求偶,炫耀,恐惧,惊叫等鸣叫声进行了声谱分析,探索不同呜声特征与行为的关系,并将该雄体繁殖期的主要鸣声－蹄叫声与白腹锦鸡进行了比较。     

Imperfect mimicry of host begging calls by a brood parasitic cuckoo: a cue for nestling rejection by hosts?

Coevolutionary interactions between avian brood parasites and their hosts often lead to the evolution of discrimination and rejection of parasite eggs or chicks by hosts based on visual cues, and the evolution of visual mimicry of host eggs or chicks by brood parasites. Hosts may also base rejection of brood parasite nestlings on vocal cues, which would in turn select for mimicry of host begging calls in brood parasite chicks. In cuckoos that exploit multiple hosts with different begging calls, call structure may be plastic, allowing nestlings to modify their calls to match those of their various hosts, or fixed, in which case we would predict either imperfect mimicry or divergence of the species into host-specific lineages. In our study of the little bronze-cuckoo (LBC) Chalcites minutillus and its primary host, the large-billed gerygone Gerygone magnirostris, we tested whether: (1) hosts use nestling vocalizations as a cue to discriminate cuckoo chicks; (2) cuckoo nestlings mimic the host begging calls throughout the nestling period; and (3) the cuckoo begging calls are plastic, thereby facilitating mimicry of the calls of different hosts. We found that the begging calls of LBCs are most similar to their gerygone hosts shortly after hatching (when rejection by hosts typically occurs) but become less similar as cuckoo chicks get older. Begging call structure may be used as a cue for rejection by hosts, and these results are consistent with gerygone defenses selecting for age-specific vocal mimicry in cuckoo chicks. We found no evidence that LBC begging calls were plastic.     

Signals for Parent-Offspring Recognition: Strong Sib-Sib Call Similarity in Cliff Swallows but not Barn Swallows

We tested the prediction that the calls of sibling cliff swallow (Hirundo pyrrhonota) chicks are more similar than those of sibling barn swallow (Hirundo rustica) chicks. This prediction was derived from the hypothesis that the call of the colonial cliff swallow, but not the call of the noncolonial barn swallow, has been selected for signature function (i.e., for individual distinctiveness). In Study 1 we examined the calls of 22 cliff swallow sibling pairs and 23 barn swallow sibling pairs. The intraclass correlations for 4 of the 5 cliff swallow variables were significantly different from zero, and each of the 4 was approximately 0.5. Only one of the 4 barn swallow call variables was significantly different from zero. In a discriminant-function analysis of these data, cliff swallow chick calls were correctly identified as to sibship in 82 % of the cases, barn swallow chick calls in only 46 % of the cases. In Study 2 we cross-fostered eggs between cliff swallow nests to create foster sibships (all chicks in a nest were unrelated). We found no similarities among foster sib calls, and thus no evidence for call imitation of the calls of sibs or parents, suggesting that genetic differences are the main source of variance in cliff swallow chick calls.     

Adult chicken alarm calls enhance tonic immobility in chicks

An experimenter induced tonic immobility (TI) in parentally naive chicks (G. gallus domesticus). The chicks remained in TI longer when they were exposed to a conspecific adult fear squawk alarm call than when exposed to an equally novel attraction call or white noise. In a second experiment, both aerial-predator and ground-predator alarm calls enhanced TI similarly to the fear squawk call which is elicited by capture. These results support the hypotheses that TI is an antipredator defense mechanism and that alarm calls evolved through kin-selection.     

Sibling Recognition in Bank Swallows (Riparia riparia)

Observations of the behavior of newly-fledged bank swallows suggest that sibling recognition may be a mechanism promoting location of the home burrow in their large, dense colonies and of cohesion of family groups following departure from the burrow. We tested for sibling recognition in the field by comparing the antiphonal response of sibling groups to the recorded calls of own vs. unrelated sibling groups. Birds responded more to the calls of their own groups. In a laboratory experiment we raised chicks in isolation from 8–10 to 20 days of age and exposed them to a call of an unrelated chick. When tested in a choice situation at 15–20 days, chicks approached the familiar call in preference to a different call which they had not previously heard. We suggest that sibling recognition is based on familiarity, i.e., that it requires a period in which the calls of siblings are learned.     

Reliable Information Content and Ontogenetic Shift in Begging Calls of Grey Warbler Nestlings

The most critical assumption of communication models regarding parent–offspring conflict is that food solicitation displays of genetic offspring are honest signals to elicit beneficial parental care. A critical requirement of honesty is the reliable change of perceivable aspects of begging calls with physiological needs. We experimentally tested whether and how the acoustic structure and begging call rate of individual Grey Warbler Gerygone igata nestlings change with hunger level and age. We also examined a rarely documented component of chick begging calls, namely the temporal dynamics of acoustic modulation after nestlings heard parental feeding calls. Begging call structure narrowed in frequency range and, surprisingly, decreased in amplitude as chick hunger levels increased. We also found that begging calls changed with chick age, with the frequency increasing and the duration decreasing for older chicks. These results indicate that the acoustic properties of nestling Grey Warbler begging calls are complex and may be used to signal several aspects of nestling traits, including hunger level and age (or size, a correlate of age). Overall, begging calls of Grey Warbler chicks appear to be honest, implying that parents are likely to benefit from relying on the acoustic features of their progeny’s calls which predict chick need. Our results have important implications regarding the reliability and information content of nestling solicitation signals for the brood parasite shining cuckoo Chrysococcyx lucidus exploiting Grey Warbler parental care, in that these begging‐call mimetic specialist cuckoos might also need to match closely the dynamics of acoustic features of their host chicks’ calls.     

Comparative study of predator avoidance behaviour of pheasants (<Emphasis Type="Italic">Phasianus colchicus</Emphasis>) of different genetic origin

The aim of the study was to determine differences in the behaviour of chicks of three different pheasant subspecies. The timidity of the pheasant chicks was of special interest, therefore behaviour traits were analysed using an open-field test and a tonic immobility test. In total, 137 pheasant chicks were tested including the copper pheasant (Ph. c. colchicus; n = 87), the green pheasant (Ph. c. versicolor; n = 12) and the melanistic pheasant (Ph. c. tenebrosus; n = 38). In both tests, the chicks of the versicolor group showed the highest timidity, whereas the other two groups were similar in timidity. In the open-field test, the chicks of the colchicus group showed the lowest timidity, and in the tonic immobility test, the tenebrosus group showed the lowest values. Assuming a relationship between the test results and predator avoidance behaviour, it can be concluded that the chicks of the versicolor group show the best predator avoidance behaviour. Further investigations are needed to find out whether the differences in the analysed behaviour traits result in higher survival rates after releasing to the wild.     

Sex-specific responses to vocal convergence and divergence of contact calls in orange-fronted conures (Aratinga canicularis)

We investigated the signal function of vocal imitation of contact calls in orange-fronted conures (OFCs; Aratinga canicularis) in Costa Rica. OFCs live in dynamic social systems with frequent flock fusions and fissions. Exchanges of contact calls precede these flock changes. During call exchanges, the similarity between the contact calls of different individuals may either increase (converge) or decrease (diverge). We conducted a playback experiment on wild-caught captive birds in which we simulated convergent, divergent and no-change interaction series with male and female contact calls. OFCs responded differently to convergent and divergent series of contact calls, but only when we considered the sex of the test birds. Males called most in response to convergent series, whereas females demonstrated high calling rates in response to both convergent and divergent interactions. Both sexes responded most to contact calls from the opposite sex, but overall females produced more calls and had shorter latencies to calling than males. These results demonstrate that OFCs can discriminate between male and female contact calls and that subtle changes in contact call structure during interactions have signal function. The stronger overall response to convergent series suggests that convergence of contact calls is an affiliative signal.     

Acoustic systems are adapted to breeding ecologies: individual recognition in nesting penguins

In all species of penguins studied to date, the display call, or parental call, has been demonstrated experimentally to facilitate identification between mates and between chicks and parents. We investigated parent-chick recognition in two nesting species, the Adélie penguin, Pygoscelis adeliae, and the gentoo penguin, P. papua. Through playback experiments, we tested the capacity of chicks to recognize the parental call at varying levels of background noise. By using modified calls, we found that chicks of neither species used temporal characteristics of the parental call (variations in frequency or amplitude with time) for individual recognition, but that both species used a simpler parameter, the pitch of the call. This finding contrasts with the more sophisticated use of acoustic cues by chicks of two non-nesting species, identified in earlier work. These differences in auditory processing of parental calls may have evolved because of different ecological constraints, particularly whether recognition of a nest site supports mutual identification of parent and offspring. Copyright 2002 The Association for the Study of Animal Behaviour. Published by Elsevier Science Ltd. All rights reserved.     

Ontogeny of calls of a nonpasserine species: the grey crowned crane Balearica regulorum gibbericeps

This study presents the results of preliminary studies on the ontogeny of two of the three calls of chicks of the grey crowned crane Balearica regulorum gibbericeps. The observed patterns are consistent with those presented in other studies of nonpasserine bird species in that the frequency range decreased in both investigated calls. The duration, however, showed fluctuations in the contact call and no consistent pattern. In the begging call of captive chicks the duration increased as is found in other nonpasserine bird species.     

Vibrational Communication in Two Sympatric Species of Mantophasmatodea (Heelwalkers)

The communication via percussion of the abdomen on the substrate for species recognition and mate location of males and females of two sympatric species of the recently described insect order Mantophasmatodea (Heelwalkers) was investigated. Each sex produced a single and distinctive call. The female call consisted of repeated single pulses, whereas the more complex male call comprised repeated pulse trains. The calls of males and females of the two species were of similar general structure, but differed in most temporal characters such as pulse and pulse train repetition time. In behavioral playback experiments females reacted to the call of conspecific males by calling and decreasing locomotion. When stimulated with the call of the heterospecific, sympatric male, females showed no reaction. Males exhibited abdominal rubbing, high tapping rates, increased activity (both movement and active searching) as well as characteristic searching behavior at branch nodes, when presented with the conspecific female call. Being stimulated with the playback of the heterospecific female call and the conspecific male call respectively, males responded with less intense locomotor and searching behavior. The drumming behavior in the control situation (no playback) suggests that males sometimes call in the absence of other individuals.     

Receivers respond differently to chick-a-dee calls varying in note composition in Carolina chickadees, Poecile carolinensis

The chick-a-dee call of the avian genus Poecile is a structurally complex vocal system because it possesses a set of simple rules that governs how the notes of the call are ordered, and variable numbers of each of the note types strung together can generate an extraordinary number of unique calls. Whereas it has been hypothesized that chick-a-dee calls with different notes may convey different information, no experimental evidence has been offered in support of the hypothesis. Previously published studies suggested that flock members use chick-a-dee calls in the context of moving to or from a feeding site. Here, we tested Carolina chickadees' responses to playbacks of chick-a-dee calls that differed in note composition. Playbacks were conducted in the field in the context of a novel food source. Our pilot data had indicated that chick-a-dee calls with relatively large numbers of ‘C’ notes were given by birds on their first contact with a novel seed stand. In the present study, we found that chickadees flew in close to the playback speaker and subsequently took seed from a seed stand more often during playbacks of chick-a-dee calls containing C notes than chick-a-dee calls not containing C notes or than control playbacks. Vocal responses of chickadees to the playbacks also differed in relation to the particular vocal signal being played back. These results indicate that receivers respond differently to chick-a-dee calls containing different compositions of note types and represent a first step to link variation in note composition and ordering in these calls to possible meanings.Copyright 2002 The Association for the Study of Animal Behaviour. Published by Elsevier Science Ltd. All rights reserved .     

Alarm calls of wintering great tits Parus major: warning of mate,reciprocal altruism or a message to the predator?

When a predator is not an immediate threat, a prey may produce relatively loud alarm calls because the risk is low. Since such calls could nevertheless attract acoustically oriented predators, the cost of predator attraction must be outweighed by factors beneficial to the caller. In this field study we elicited low-risk alarm calls by temporarily catching wintering adult male great tits Parus major at feeders both within and outside their territories. We tested whether the alarm calls of dominant males can be explained in terms of mate warning, reciprocal altruism or notifying the predator of detection. If alarms are intended to warn mates, males accompanied by their mates should give alarm calls both within and outside home range, even if other permanent flock members are absent. If alarms are to be explained by reciprocal altruism, male great tits should give low-risk alarm calls when accompanied by permanent flock members other than mate within and not outside of the home-range. If alarm calling is a message to a predator, males should call when foraging alone. We found that male great tits gave low-risk alarm calls when accompanied by their mates, independent of feeder location. They also gave low-risk alarm calls within home ranges in the presence of other permanent flock members when mates were absent. In contrast, only a few males gave calls when foraging alone within their home ranges, or when in the company of unfamiliar great tits outside their usual home-range. The results suggest that the utterance of alarm calls may be explained as mate protection and reciprocal altruism among familiar individuals.     

Responses of young black skimmers to high-intensity distress notes

The semi-precocial young of the black skimmer (Rynchops niger) rely on cryptic behaviour to avoid detection by predators. After capture most individuals emit loud distress calls, and chicks crouched nearby often run just seconds after these calls begin. Experimental distress calls significantly increase the likelihood of running, regardless of whether a sibling or non-sibling call is used. Since chicks in close proximity are usually siblings, such distress notes could evolve through kin selection, even if disadvantageous to the caller. On the other hand, such calls may startle and distract a predator, providing the captive with an opportunity to escape.