Vocal negotiation over parental care? Acoustic communication at the nest predicts partners' incubation share

In species with biparental care, individuals adjust their workload to that of their partner to either compensate or match its investment. Communication within a pair might be crucial for achieving this adjustment. Zebra finches, Taeniopygia guttata, form life-long monogamous pair bonds, in which partners are highly coordinated and both incubate the eggs. When relieving each other during incubation, partners perform a structured call duet at the nest. If this duet functions to coordinate incubation workload, disrupting the pair's usual nest-relief pattern by delaying the male's return to the nest should affect the structure of the duet. Using domesticated birds breeding in a large aviary, we found that delaying the male's return induced shorter duets with higher call rates. In addition, we tracked the location of individuals with a transponder at the nest and the feeder, and showed that these accelerated duets were associated with an increased haste of the partners to take turns incubating and foraging. Females also spent less time incubating during their subsequent shift, and females' time off-nest was best predicted by their mate's calling behaviour in the previous duet. Taken together, these results suggest that duets may function as 'vocal negotiation' over parental care.

Vocal communication at the nest between mates in wild zebra finches : a private vocal duet?

Bird vocal duets are joint displays where two individuals, generally a mated pair, produce temporally coordinated vocalizations. Duets may contribute to pair bond maintenance, mate guarding or collaborative defence of resources. The degree of coordination between mates and the variety of vocalizations, however, vary considerably. Although only 3–4.3% of bird species have been reported to duet, this may be because studies have generally focused on conspicuous duets, and more private forms of duet might have been overlooked. We investigated private vocal communication between mates in wild zebra finches, Taeniopygia guttata, a gregarious Australian songbird that forms life-long pair bonds. The partners are inseparable unless nest building, incubating or brooding. Using microphones inside nestboxes, we monitored interactive communication between partners at the nest and its variation during different stages of breeding. After periods of separation, partners performed coordinated mutual vocal displays involving specific soft vocal elements that fulfilled all the criteria used to define duets. In addition, using playback experiments, we obtained preliminary results suggesting that these soft calls could allow mate recognition. Thus, we propose that mutual displays at the nest in zebra finches represent private vocal duets and may function to mediate pair bond maintenance.

Ave 04

Ave 04 is a short vocal performance with a female singer singing Ave.

Deeper than the forest AMBIENT with VOCAL

A short instrumental featuring ethereal female vocals, percussion, bells, synths, mandolin, and sound design.

Vocal mimicry in spotted bowerbirds is associated with an alarming context

Although the presence of vocal mimicry in songbirds is well documented, the function of such impressive copying is poorly understood. One explanation for mimicry in species that predominantly mimic alarm calls and predator vocal isations is that these birds use mimicry to confuse or deter potential threats or intruders, so these vocalisations should therefore be produced when the mimic is alarmed and be uncommon in other contexts. Male bowerbirds construct bowers to display to females and anecdotal reports from the Ptilonorhynchus genus suggest that males mimic alarm sounds when disturbed at their bowers. We quantified and compared the rate of mimicry during disturbance to the bower by a human and in naturally occurring social contexts in a population of spotted bowerbirds Ptilonorhynchus maculatus. Male bowerbirds produced mimicry more than thirty times more frequently in response to bower disturbance than they did in any other context. Neither conspecifics nor heterospecifics were attracted to the bower area by mimicry. These data are consistent with the hypothesis that the production of mimicry is associated with a response to an alarming situation. Additionally, the predominance of alarm mimicry by spotted bowerbirds raises the possibility that the birds learn these sounds when they experience alarming situations and they reproduce them in subsequent alarming situations.

Acoustic features involved in the neighbour-stranger vocal recognition process in male Australian fur seals

Many territorial species have the ability to recognise neighbours from stranger individuals. If the neighbouring individual is assumed to pose less of a threat, the territorial individual responds less and avoids unnecessary confrontations with familiar individuals at established boundaries, thus avoiding the costly energy expenditure associated with fighting. Territorial male Australian fur seals respond more to strangers than to neighbouring males. The present study evaluated which acoustic features were important in the neighbour–stranger recognition process in male Australian fur seals. The results reveal that there was an increase in response strength or intensity from males when they heard more bark units, indicating the importance of repetition to detect a caller. However, lengthening and shortening the inter-unit spaces, (i.e. changing the rhythm of the call) did not appear to significantly affect an animal's response. In addition, the whole frequency spectrum was considered important to recognition with results suggesting that they may vary in their importance. A call containing the dominant and surrounding harmonics was considered important to a male's ability to recognise its neighbour. Furthermore, recognition occurs even with a partial bark, but males need to hear between 25 and 75% of each bark unit from neighbouring seals. Our study highlights which acoustic features induce stronger or weaker responses from territorial males, decoding the important features in neighbour–stranger recognition.

Does the ring species concept predict vocal variation in the crimson rosella, Platycercus elegans, complex?

Vocal variation may be important in population divergence. We studied geographical variation in contact calls of parrots of the crimson rosella, Platycercus elegans, complex, which is characterized by striking geographical plumage coloration variation. This complex has long been considered a rare example of a ring species (where two divergent forms coexist in sympatry but are connected by a chain of intermediate populations forming a geographical ring). We tested whether contact call variation is consistent with the ring species hypothesis. We recorded calls throughout the ring, including several sites from the three main population groups forming the ring and interfaces between them. We analysed duration, peak frequency, fundamental frequency and frequency modulation. We found significant differences, particularly in fundamental frequency and frequency modulation, at multiple biogeographical scales ranging from local populations to subspecies level. Discriminant function analyses showed some populations could be reliably discriminated from call structure. However, our results provided little support for three key predictions of the ring species hypothesis: (1) calls of the terminal, most divergent forms were not significantly different in three of the four acoustic variables, and differences did not appear to be maintained in sympatry, (2) phenotypically/geographically intermediate populations were not characterized by intermediate calls, and (3) call variation was not concordant with geographical sequence around the ring from one terminal form to the other. Our results underscore the emerging view that the evolutionary histories and phenotypic variability of many long-held ring species may be inadequately described by the ring species hypothesis and require alternative explanations. (C) 2008 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.

Vocal mimicry in songbirds

Baylis (1982, Acoustic Communication in Birds, Academic Press) decried the serious lack of experimental verification for the various hypotheses proposed to explain vocal mimicry in songbirds. With few exceptions, our understanding of the function and acquisition of this fascinating behaviour seems to have scarcely progressed. We examine the proposed functional explanations and supporting evidence, and summarize advances made since Baylis's (1982) review. We conclude that there is no compelling evidence to support any of the functional hypotheses but, rather, that almost all of the data concerning song mimicry are consistent with the learning mistakes hypothesis, whereby birds learn simple and common sounds, frequently using them in inappropriate contexts. Additionally, many apparently mimicked sounds are calls, not songs, which themselves may not be learned by the models. It is plausible that many examples of call mimicry are, in fact, due to evolutionary convergence.

Vocal mimicry in male bowerbirds : who learns from whom?

Vocal mimicry is one of the more striking aspects of avian vocalization and is widespread across songbirds. However, little is known about how mimics acquire heterospecific and environmental sounds. We investigated geographical and individual variation in the mimetic repertoires of males of a proficient mimic, the spotted bowerbird Ptilonorhynchus maculatus. Male bower owners shared more of their mimetic repertoires with neighbouring bower owners than with more distant males. However, interbower distance did not explain variation in the highly repeatable renditions given by bower owners of two commonly mimicked species. From the similarity between model and mimic vocalizations and the patterns of repertoire sharing among males, we suggest that the bowerbirds are learning their mimetic repertoire from heterospecifics and not from each other.

Vocal mimicry

What is vocal mimicry? Vocal mimicry occurs when an individual learns a sound from another species or the environment. It differs from other animal vocalisations such as bird song or human speech, as these are learned from members of the same species (conspecifics). Parrots are the most renowned mimics, with reports of their talents dating back at least to the early 1500s with Henry VIII of England's pet African grey parrot, Psittacus erithacus, which mimicked his servants' voices.

Halloween witches and monsters with bell SFX

A sound effect of vocal recordings and sound design depicting halloween styled monsters, witches, ghouls and a bell striking to midnight.

Allelujah (female vocal led dreamy)

Allelujah is a cinematic and New Age piece that also fits well with projects of a religious or spiritual theme; Christmas and Easter included. It centers on a female vocal singing Alleluia, with violin, cello, piano, harp and 2 synths and bells at the very end.

Ave (piano and vocal) DREAMY

This audio features vocals, piano, strings, synth and bells a curious and unique piece with a light feel.