@article {58467, title = {Temporal occurrence of three blue whale populations in New Zealand waters from passive acoustic monitoring}, journal = {Journal of Mammalogy}, year = {2022}, abstract = {

Describing spatial and temporal occurrence patterns of wild animal populations is important for understanding their evolutionary trajectories, population connectivity, and ecological niche specialization, with relevance for effective management. Throughout the world, blue whales produce stereotyped songs that enable identification of separate acoustic populations. We harnessed continuous acoustic recordings from five hydrophones deployed in the South Taranaki Bight (STB) region of Aotearoa New Zealand from January 2016 to February 2018. We examined hourly presence of songs from three different blue whale populations to investigate their contrasting ecological use of New Zealand waters. The New Zealand song was detected year-round with a seasonal cycle in intensity (peak February\–July), demonstrating the importance of the region to the New Zealand population as both a foraging ground and potential breeding area. The Antarctic song was present in two distinct peaks each year (June\–July; September\–October) and predominantly at the offshore recording locations, suggesting northbound and southbound migration between feeding and wintering grounds. The Australian song was only detected during a 10-day period in January 2017, implying a rare vagrant occurrence. We therefore infer that the STB region is the primary niche of the New Zealand population, a migratory corridor for the Antarctic population, and outside the typical range of the Australian population.

}, keywords = {bioacoustics, blue whale, distribution, ecology, marine mammals, New Zealand, passive acoustic monitoring, populations, vocalizations}, doi = {10.1093/jmammal/gyac106}, url = {https://doi.org/10.1093/jmammal/gyac106}, author = {Dawn R Barlow and Holger Klinck and Dimitri Ponirakis and Mattea Holt Colberg and Leigh G. Torres} } @article {58394, title = {Bioacoustic monitoring of animal vocal behavior for conservation}, year = {2019}, abstract = {

The popularity of bioacoustics for threatened species monitoring has surged. Large volumes of acoustic data can be collected autonomously and remotely with minimal human effort. The approach is commonly used to detect cryptic species and, more recently, to estimate abundance or density. However, the potential for conservation- relevant information to be derived from acoustic signatures associated with particular behavior is less well-exploited. Animal vocal behavior can reveal important informa- tion about critical life history events. In this study, we argue that the overlap of the disciplines of bioacoustics, vocal communication, and conservation behavior\—thus, \“acoustic conservation behavior\”\—has much to offer threatened species monitoring. In particular, vocalizations can serve as indicators of behavioral states and contexts that provide insight into populations as it relates to their conservation. We explore the information available from monitoring species\&$\#$39; vocalizations that relate to repro- duction and recruitment, alarm and defense, and social behavior, and how this infor- mation could translate into potential conservation benefits. While there are still challenges to processing acoustic data, we conclude that acoustic conservation behavior may improve threatened species monitoring where vocalizations reveal behaviors that are informative for management and decision-making.

}, keywords = {bioacoustics, conservation behavior, monitoring, vocal behavior, vocalizations}, doi = {10.1111/csp2.72}, author = {Teixeira, Daniella and Maron, Martine and Rensburg, Berndt J.} } @article {58197, title = {Acoustically advertising male harbour seals in southeast Alaska do not make biologically relevant acoustic adjustments in the presence of vessel noise}, year = {2020}, abstract = {

Aquatically breeding harbour seal (Phoca vitulina) males use underwater vocalizations during the breeding season to establish underwater territories, defend territories against intruder males, and possibly to attract females. Vessel noise overlaps in frequency with these vocalizations and could negatively impact breeding success by limiting communication space. In this study, we investigated whether harbour seals employed anti-masking strategies to maintain communication in the presence of vessel noise in Glacier Bay National Park and Preserve, Alaska. Harbour seals in this location did not sufficiently adjust source levels or acoustic parameters of vocalizations to compensate for acoustic masking. Instead, for every 1 dB increase in ambient noise, signal excess decreased by 0.84 dB, indicating a reduction in communication space when vessels passed. We suggest that harbour seals may already be acoustically advertising at or near a biologically maximal sound level and therefore lack the ability to increase call amplitude to adjust to changes in their acoustic environment. This may have significant implications for this aquatically breeding pinniped, particularly for populations in high noise regions.

}, keywords = {acoustic communication, harbour seals, marine mammals, Noise, vocalizations}, doi = {10.1098/rsbl.2019.0795}, url = {https://royalsocietypublishing.org/doi/10.1098/rsbl.2019.0795}, author = {Matthews, Leanna P. and Fournet, Michelle E. H. and Gabriele, Christine and Klinck, Holger and Parks, Susan E.} } @article {57914, title = {Molossid unlimited: extraordinary extension of range and unusual vocalization patterns of the bat, Promops centralisAbstract}, year = {2019}, abstract = {

The big crested mastiff bat, Promops centralis, occurs in Central and South America, but knowledge of its ecology is limited due to its open space hunting strategy, making captures extremely challenging. Notwithstanding, members of the species produce echolocation calls that are easy to identify. After recording calls of P. centralis 1,500 km away from its known range in Brazil, we hypothesized that the distribution range of this species was probably greatly underestimated. To improve the accuracy of P. centralis\’ real distribution, we employed acoustic surveys throughout parts of Brazil, conducted after a bibliographic review to gather additional records, and used MaxEnt to model the species\’ potential distribution. We have found that P. centralis has a much wider distribution in South America than previously thought, adding more than 3.8 million km2 to its former known area. We also describe an unusual vocalization pattern of P. centralis, with individuals emitting at least three very distinct but highly variable calls. This study shows that bioacoustic surveys and species distribution models can complement traditional methodologies in studying species that are difficult to capture, such as P. centralis, potentially contributing to more effective conservation and management plans.

}, keywords = {big crested mastiff bat, Chiroptera, duty cycle, echolocation calls, frequency, MaxEnt, Molossidae, Social calls, species distribution modeling, vocalizations}, doi = {10.1093/jmammal/gyz167}, url = {https://academic.oup.com/jmammal/advance-article/doi/10.1093/jmammal/gyz167/5637356}, author = {Hintze, Frederico and Arias-Aguilar, Adriana and Dias-Silva, Leonardo and Delgado-Jaramillo, Mariana and Silva, Carina Rodrigues and Juc{\'a}, Thays and Mischiatti, Francyne Lyrio and Almeida, M{\'a}rcio and Bezerra, Bruna and Aguiar, Ludmilla M S and Ramos Pereira, Maria Jo{\~a}o and Bernard, Enrico}, editor = {Loeb, Susan} } @article {57573, title = {Bioacoustics of Pithecopus rusticus (Anura, Phyllomedusidae): A Rare Species Possibly Threatened with Extinction}, journal = {South American Journal of Herpetology}, volume = {14}, year = {2019}, month = {Jan-12-2019}, pages = {196}, abstract = {

Vocalization is an important means of intra- and interspecific communication in anurans and is essential for reproduction. Here, we describe the advertisement and territorial calls of Pithecopus rusticus and determine the influence of air temperature and morphometric variables on advertisement call parameters. We recorded the vocalizations at the type-locality, in the municipality of \Água Doce, state of Santa Catarina, southern Brazil, from September 2015 to February 2016. The advertisement call was composed of a short note, emitted sporadically, with a duration of 0.023 \± 0.002 ms (0.019\–0.033 ms; n = 244). We recorded two types of territorial calls that were observed during the interaction between males. Territorial call I was composed of two notes and had a duration of 0.095 \± 0.043 ms (0.033\–0.166 ms; n = 27). Territorial call II was a multipulsed note lasting 0.911 \± 0.340 ms (0.504\–1.346 ms; n = 9) composed of 7\–58 pulses emitted after territorial call I. Advertisement call duration was negatively related to air temperature. The duration and number of notes of the advertisement call of P. rusticus were similar to those of phylogenetically close species. Information on vocal repertoires of amphibians and factors influencing acoustic parameters are essential to understand the systematic taxonomy and evolution of groups, especially little-known species such as P. rusticus.

}, keywords = {Amphibia, Atlantic Forest, Highlands of southern Brazil, vocalizations}, doi = {10.2994/SAJH-D-17-00071.1}, url = {https://bioone.org/journals/south-american-journal-of-herpetology/volume-14/issue-3/SAJH-D-17-00071.1/Bioacoustics-of-Pithecopus-rusticus-Anura-Phyllomedusidae--A-Rare-Species/10.2994/SAJH-D-17-00071.1.full}, author = {Boschetti, Joana Priscilla and De Bastiani, Veluma Ial{\'u} Molinari and Lingnau, Rodrigo and Lucas, Elaine Maria} } @article {57357, title = {Harmonics: Rediscovering Eleutherodactylus Vocalizations}, journal = {Life: The Excitement of Biology}, volume = {5}, year = {2018}, chapter = {173}, abstract = {

There are 17 described species of Eleutherodactylus in Puerto Rico, some more common than others. The use of harmonics as a means of vocalization has been little studied in the Caribbean. As part of a long-term study of the evolution of sonic communication in Puerto Rican Eleutherodactylus frogs, we document the use harmonics in three common but distinct Puerto Rican endemic species: E. coqui, E. antillensis, and E. brittoni. This study focuses only on the description of these vocalizations using computer software not on the behavioral implications of these vocalizations.

}, keywords = {Eleutherodactylus, harmonics, Puerto Rico, vocalizations}, doi = {10.9784/LEB5(4)Rios.01}, author = {Alejandro R{\'\i}os-Franceschi and Rafael L. Joglar} } @article {53414, title = {Behavioral and neural auditory thresholds in a frog}, journal = {Current Zoology}, year = {2018}, abstract = {

Vocalizations play a critical role in mate recognition and mate choice in a number of taxa, especially, but not limited to, orthopterans, frogs, and birds. But receivers can only recognize and prefer sounds that they can hear. Thus a fundamental question linking neurobiology and sexual selection asks\— what is the threshold for detecting acoustic sexual displays? In this study we use three methods to assess such thresholds in t\úngara frogs: behavioral responses, auditory brainstem responses, and multi-unit electrophysiological recordings from the midbrain. We show that thresholds are lowest for multi-unit recordings (ca. 45 dB SPL), and then for behavioral responses (ca. 61 dB SPL), with auditory brainstem responses exhibiting the highest thresholds (ca. 71 dB SPL). We discuss why these estimates differ and why, as with other studies, it is unlikely that they should be the same. Although all of these studies estimate thresholds they are not measuring the same thresholds; behavioral thresholds are based on signal salience while the two neural assays estimate physiological thresholds. All three estimates, however, make it clear that to have an appreciation for detection and salience of acoustic signals we must listen to those signals through the ears of the receivers.

}, keywords = {anurans, auditory brainstem responses, auditory thresholds, mate choice, Physalaemus pustulosus, sexual selection, signal recognition thresholds, t{\'u}ngara frogs, vocalizations}, author = {Ryan, C and Akre, Karin and Wilczynski, Walter and others} } @article {53334, title = {Geographic variation in the advertisement call of Trachycephalus typhonius Anura: Hylidae) based on South American samples}, journal = {Zootaxa}, volume = {4521}, year = {2018}, month = {Feb-11-2019}, pages = {404}, abstract = {

Previously described calls of Trachycephalus typhonius (Linnaeus, 1758) correspond to several populations from Central and South America, but in general, these descriptions were brief and often based on a single recorded individual. Here, based on an expressive sample, we re-describe the advertisement calls of T. typhonius using recordings from populations in Brazil and Argentina. Additionally, we discuss geographical variation of calls, comment on their frequency band structure and compare calls with those described for other species of Trachycephalus. Calls of 32 males were recorded and temporal and spectral features of 269 calls were measured. To search for discrimination among three populations sampled we used the Random Forest (RF) model, Multidimensional Scaling Analysis (MDS) and Wilcoxon-Mann-Whitney Rank Sum Test. The advertisement calls of T. typhonius consist of a multipulsed note of 343\–540 ms of duration, emitted at regular intervals, with up to three emphasized frequency bands. Dominant frequency ranged between 1705\–2750 Hz. Calls from Rond\ônia (Brazil) were significantly different from those recorded in Argentina and Minas Gerais (Brazil) in relation to pulse rate and dominant frequency. Populations from Minas Gerais and Argentina differed in dominant frequency of calls. Such population differences can be partly attributed to differences in prevalence of calling sites (immersed in water vs. perches on vegetation), but can also hint at the existence of cryptic species diversity under this taxon.

}, keywords = {Amazon Milk Frog, Amphibia, Argentina, Brazil, call structure, differentiation, vocalizations}, issn = {1175-5326}, doi = {10.11646/zootaxa.4521.310.11646/zootaxa.4521.3.6}, url = {https://biotaxa.org/Zootaxa/issue/view/zootaxa.4521.3https://biotaxa.org/Zootaxa/article/view/zootaxa.4521.3.6}, author = {V{\'\i}ctor Hugo Zaracho and Leonardo Dionel Aguiar and Ariovaldo A. Giaretta} } @article {50499, title = {Impact of group size and social composition on group vocal activity and acoustic network in a social songbird}, journal = {Animal Behaviour}, volume = {127}, year = {2017}, month = {Jan-05-2017}, pages = {163 - 178}, abstract = {

In social species individuals living in the same group may synchronize activities such as movements, foraging or antipredator vigilance. Synchronization of activities can also be observed between partners especially during breeding and can be crucial for breeding success. Vocalizations are behaviours that can be coordinated between individuals, but simultaneous vocalizations in groups have mostly been considered as noise that does not bear any information. Indeed, little is known about the structure and function of vocal communications involving a network of individuals. How individual vocal activity forms part of the communal sound and how the group influences individual vocal activity are questions that remain to be studied. Zebra finches, Taeniopygia guttata, are social, monogamous songbirds that form lifelong pair bonds. In the wild, they are typically found in small groups, with the pair as the primary social unit, and they gather in \‘social\’ trees where both females and males produce vocalizations. Here we investigated in the laboratory the influence of group size and composition on general vocal activity and synchrony, as well as the influence of pair bond and spatial location on the finer characteristics of dyads\&$\#$39; vocal interactions. We used a set-up that locked the birds at fixed spatial positions of our choosing to control the proximity network and allowed us to match most of the vocalizations with specific individuals. We used an in-house software suite that automatically detects vocalizations from hours of passive recording. We found that zebra finch groups synchronized their general vocal activity with waves of collective vocalizations, which depended on both the size and the composition of the group. The acoustic network was shaped by pair bonds at different timescales. Birds preferentially vocalized close in time to (synchrony) or directly after (turn taking) their partner when it was present and the nearest neighbour when the partner was not available.

}, keywords = {acoustic communication, group collective calling, pair bond, social network, songbirds, turn taking, vocalizations, Zebra Finch}, issn = {00033472}, doi = {10.1016/j.anbehav.2017.03.013}, url = {http://linkinghub.elsevier.com/retrieve/pii/S0003347217300854}, author = {Fernandez, M.S.A. and Vignal, C. and Soula, H.A.} } @article {50487, title = {Hens vary their vocal repertoire and structure when anticipating different types of reward}, journal = {Animal Behaviour}, volume = {130}, year = {2017}, month = {Jan-08-2017}, pages = {79 - 96}, abstract = {The vocalizations of nonhuman animals are considered potential indicators of motivational or internal state. In many species, different call types, and structural variation within call types, encode information about physical characteristics such as age or sex, or about variable traits such as motivation. Domestic chickens, Gallus gallus, have an elaborate vocal repertoire, enabling investigation into whether reward-related arousal is encoded within their call type and structure. Twelve hens were given a Pavlovian conditioning paradigm using sound cues to signal the availability of two food rewards (mealworms, normal food), one nonfood reward (a container of substrate suitable for dustbathing), and a sound-neutral event (sound cue, no reward). A muted-neutral treatment (no sound cue, no reward) provided a baseline for vocal behaviour. Sound cues preceded a 15 s anticipation period during which vocalizations were recorded. Hens produced a {\textquoteleft}Food call{\textquoteright} (previously defined in other studies) in anticipation of all rewards, including the nonfood reward. {\textquoteleft}Food calls{\textquoteright} and {\textquoteleft}Fast clucks{\textquoteright} were more prevalent in anticipation of rewards, and most prevalent following the cue signalling the dustbathing substrate, suggesting that this reward induced the most arousal in hens. The peak frequency of {\textquoteleft}Food calls{\textquoteright} made in anticipation of the dustbathing substrate was significantly lower than those made in anticipation of food rewards, potentially reflecting differences in arousal. Vocalizations that reliably indicate hens{\textquoteright} motivational state could be used as measures of welfare in on-farm assessment situations. Our study is the first to reveal variation in the frequency-related parameters of the {\textquoteleft}Food call{\textquoteright} in different contexts, and to show the prevalence of different call types in reward and nonreward contexts, which may have implications for welfare assessments.}, keywords = {laying hens, motivation, referential, rewards, vocalizations}, issn = {00033472}, doi = {10.1016/j.anbehav.2017.05.025}, url = {http://linkinghub.elsevier.com/retrieve/pii/S0003347217301707}, author = {McGrath, Nicky and Dunlop, Rebecca and Dwyer, Cathy and Burman, Oliver and Phillips, Clive J.C.} } @article {50485, title = {Feeling anxious? The mechanisms of vocal deception in tufted capuchin monkeys}, journal = {Animal Behaviour}, volume = {130}, year = {2017}, month = {Jan-08-2017}, pages = {37 - 46}, abstract = {

An ability to deceive conspeci fi cs is thought to have favoured the evolution of large brains in social animals, but evidence that such behaviours require cognitive complexity is lacking. Tufted capuchin monkeys ( Sapajus spp.) have been documented to use false alarm calls during feeding in a manner that functions to deceive competitors. However, comparative evidence suggests that the production of vo- calizations by nonhuman primates is largely underpinned by emotional mechanisms, calling into question more cognitive interpretations of this behaviour. To determine whether emotional states are plausibly necessary and suf fi cient to proximately explain deceptive alarm call production, we examined the association between self-directed behaviours (SDBs), as a proxy for anxiety, and the production of spontaneous false alarm calls among tufted capuchins. Speci fi cally, we predicted that if anxiety is necessary for the production of false alarms, then individuals that produce spontaneous false alarms should exhibit more SDBs in those contexts in which they call. If anxiety is also suf fi cient to explain the false alarm call production, then we predicted that individuals that call more in a given context would show higher rates of SDBs in that context, and that high rates of calling would be temporally associated with high rates of SDBs. Our results support the contention that states of anxiety are necessary for an individual to spontaneously produce false alarms, but that such states are not suf fi cient to explain patterns of calling. The link between anxiety and deceptive calling thus appears complex, and cognitively based decision-making processes may play some role in call production.

}, keywords = {affect, alarm calls, anxiety, deceptive behaviour, emotions, primates, scratching, self-directed behaviours, vocalizations, within-group contest competition}, issn = {00033472}, doi = {10.1016/j.anbehav.2017.06.008}, url = {http://linkinghub.elsevier.com/retrieve/pii/S0003347217301835}, author = {Kean, Donna and Tiddi, Barbara and Fahy, Martin and Heistermann, Michael and Schino, Gabriele and Wheeler, Brandon C.} }