Categorical Rhythms Are Shared between Songbirds and Humans

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Reassessment of the vocal repertoire of a nest-building gladiator frog,Boana pardalis (Anura,Hylidae, Cophomantinae): implications for its diagnosis within the B. faber species group

In this study, we re-describe the advertisement and territorial calls of Boana pardalis, carry out an acoustic comparison between the studied species and the other congeners of the B. faber group, and report for the first time the tympanic amplexus for the studied species. The advertisement call of B. pardalis can be used to supplement its diagnosis in the B. faber group based on temporal call traits, e.g. emission rate and emission pattern, as well as the call envelope.     

The taxonomic status and distribution of Bushbabies in Malawi with emphasis on the significance of vocalizations

The debated identity of a small forest bushbaby in Malawi is resolved by a short-term field study of the animals’ behavior. Locomotor styles, calling patterns, and the structure of advertising calls confirm that the species is Galago zanzibaricusrather than G. demidoffor G. thomasi.A detailed comparison of acoustic structure between the Malawi animals and G. zanzibaricusin Kenya demonstrates a degree of between-population variation, although the calls remain conservative in those parameters expected to aid recognition of conspecifics. Distribution records extend the known geographical range of G. zanzibaricusover most of the northern half of Malawi. Further studies are required to link the animals from this region with either of the previously recognized subspecies: G. z. zanzibaricusfrom East Africa or G. z. grantifrom southern Malawi, Mozambique, and Zimbabwe.     

Can an acoustic observatory contribute to the conservation of threatened species?

Observatories are designed to collect data for a range of uses. The Australian Acoustic Observatory (A2O) was established to collect environmental sound, including audible species calls, from 344 recorders at 86 sites around Australia. We examine the potential of the A2O to monitor near threatened, threatened, endangered and critically endangered species, based on their vocal behaviour, geographic distributions in relation to the sites of the A2O and on some knowledge of habitat use. Using IUCN and EPBC lists of threatened and endangered species, we extracted species that vocalized in the audible range, and using conservative estimates of their geographic ranges, determined whether there was a possibility of hearing them at these sites. We found that it may be possible to detect up to 171 threatened species at sites established for the A2O, and that individual sites have the potential to detect up to 40 threatened species. All 86 sites occurred in locations where threatened species could possibly be detected, and the list of detectable species included birds, amphibians, and mammals. We have incidentally detected one mammal and four bird species in the data during other work. Threatening processes to which potentially detectable species were exposed included all but two IUCN threat categories. We concluded that with applications of technology to search the audio data from the A2O, it could serve as an important tool for monitoring threatened species.     

A PORTABLE DIGITAL SOUND EMITTER FOR INTERACTIVE PLAYBACK OF ANIMAL VOCALISATIONS

ABSTRACT

A new portable digital sound emitter (DSE) for normal and interactive playback of sound signals in the field and in the laboratory is described together with two examples of applications of the DSE in interactive field experiments. The DSE may be loaded with a broad spectrum of digitised sounds, e.g. artificial signals or natural animal vocalisations, and it is controlled via the keyboard of a portable PC running a dedicated program. This program, which can be tailored to support a vast number of different demands, enables the experimenter to start and stop the analog output from the DSE at any time and to choose freely between the available sounds and playback modes. The use of the DSE for interactive playback experiments therefore is only limited by the ability of the operator to perceive the vocalisations of the participating animal and to operate the keyboard of the PC.     

High‐throughput analysis of vocalizations reveals sex‐specific changes in Fmr1 mutant pups

There have been several reports that individuals with Fragile X syndrome (FXS) and animal models of FXS have communication deficits. The present study utilized two different call classification taxonomies to examine the sex‐specificity of ultrasonic vocalization (USV) production on postnatal day (PD8) in the FVB strain of Fmr1 knockout (KO) mice. One classification protocol requires the investigator to score each call by hand, while the other protocol uses an automated algorithm. Results using the hand‐scoring protocol indicated that male Fmr1 KO mice exhibited longer calls (P = .03) than wild types on PD8. Male KOs also produced fewer complex, composite, downward, short and two‐syllable call‐types, as well as more frequency steps and chevron call‐types. Female heterozygotes exhibited no significant changes in acoustic or temporal aspects of calls, yet showed significant changes in call‐type production proportions across two different classification taxonomies (P < .001). They exhibited increased production of harmonic and frequency steps calls, as well as fewer chevron, downward and short calls. According to the second high‐throughput analysis, female heterozygotes produced significantly fewer single‐type and more multiple‐type syllables, unlike male KOs that showed no changes in these aspects of syllable production. Finally, we correlated both scoring methods and found a high level of correlation between the two methods. These results contribute further knowledge of sex differences in USV calling behavior for Fmr1 heterozygote and KO mice and provide a foundation for the use of high‐throughput analysis of neonatal USVs.     

Seasonality of Antarctic minke whale (Balaenoptera bonaerensis) calls off the western Antarctic Peninsula

The Antarctic minke whale (Balaenoptera bonaerensis) is a difficult species to study because of its low visual detectability and preference for living within the sea ice habitat, accessible only by ice‐strengthened vessels. Recent identification of the Antarctic minke whale as the source of the seasonally ubiquitous bio‐duck call has allowed the use of this sound, as well as downsweeps, to investigate seasonality trends and diel patterns in Antarctic minke whale call production, and their relationship to sea ice cover. Passive acoustic data were collected using an autonomous Acoustic Recording Package (ARP) off the western Antarctic Peninsula. Bio‐duck calls were classified into four distinct call variants, with one variant having two subtypes. Bio‐duck calls were detected between April and November, with increasing call duration during the austral winter, indicating a strong seasonality in call production. Downsweeps, which were also attributed to Antarctic minke whales, were present throughout most months during the recording period, with a peak in July, and an absence in March and April. Both bio‐duck and downsweeps were significantly correlated with sea ice cover. No diel patterns were observed in bio‐duck calls or in downsweep call production at this site.     

Behavioral and Cortical Correlates of Self-Suppression,Anticipation, and Ambivalence in Rat Tickling

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Developmental changes in food transfers in cotton-top tamarins (Saguinus oedipus)

We investigated the development of food transfer and independent feeding in cotton-top tamarin (Saguinus oedipus) families. We studied the relationship between infant-directed vocalizations and food transfers on the development of independent feeding in infants. We experimentally tested ten infants (eight twins and two singletons) three times a week for 17 weeks from before weaning through 20 weeks. Food transfers and vocalizations made during tests were recorded and analyzed to determine (1) the role of vocalizations (C- and D- chirps and D-chirp series) in food acquisition, (2) the relationship between food transfers and individual food acquisition, and (3) whether, owing to energetic costs of nursing and carrying twins, food is transferred to twins sooner than to singletons. Infants were more successful in acquiring food via begging when adults produced repeated vocalizations than when adults did not vocalize. Adults emitted more food-related vocalizations in rapid series when in the presence of infants, whereas during feeding in the absence of infants only single unit vocalizations were produced. Begging occurred frequently. Changes over infant age were not significant when all infants were included in analysis. However, when twin data were analyzed alone, begging success changed significantly over months, with successful begging peaking in month 3 (week 12). Begging success rate did not differ between twins and singletons, although twins fed independently sooner and at a higher rate than did singletons.