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Osiecka AN, Briefer EF, Kidawa D, Wojczulanis-Jakubas K. Social calls of the little auk ( Alle alle) reflect body size and possibly partnership, but not sex. ROYAL SOCIETY OPEN SCIENCE 2023; 10:230845. [PMID: 37736531 PMCID: PMC10509585 DOI: 10.1098/rsos.230845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Accepted: 08/21/2023] [Indexed: 09/23/2023]
Abstract
Source-filter theory posits that an individual's size and vocal tract length are reflected in the parameters of their calls. In species that mate assortatively, this could result in vocal similarity. In the context of mate selection, this would mean that animals could listen in to find a partner that sounds-and therefore is-similar to them. We investigated the social calls of the little auk (Alle alle), a highly vocal seabird mating assortatively, using vocalizations produced inside 15 nests by known individuals. Source- and filter-related acoustic parameters were used in linear mixed models testing the possible impact of body size. A principal component analysis followed by a permuted discriminant function analysis tested the effect of sex. Additionally, randomization procedures tested whether partners are more vocally similar than random birds. There was a significant effect of size on the mean fundamental frequency of a simple call, but not on parameters of a multisyllable call with apparent formants. Neither sex nor partnership influenced the calls-there was, however, a tendency to match certain parameters between partners. This indicates that vocal cues are at best weak indicators of size, and other factors likely play a role in mate selection.
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Affiliation(s)
- Anna N. Osiecka
- Department of Vertebrate Ecology and Zoology, Faculty of Biology, University of Gdańsk, 80-308 Gdańsk, Poland
- Behavioural Ecology Group, Section for Ecology and Evolution, Department of Biology, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Elodie F. Briefer
- Behavioural Ecology Group, Section for Ecology and Evolution, Department of Biology, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Dorota Kidawa
- Department of Vertebrate Ecology and Zoology, Faculty of Biology, University of Gdańsk, 80-308 Gdańsk, Poland
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Osiecka AN, Briefer EF, Kidawa D, Wojczulanis-Jakubas K. Seabird's cry: repertoire and vocal expression of contextual valence in the little auk (Alle alle). Sci Rep 2023; 13:8623. [PMID: 37244959 DOI: 10.1038/s41598-023-35857-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Accepted: 05/24/2023] [Indexed: 05/29/2023] Open
Abstract
Many seabird species breed in colonies counting up to hundreds of thousands of individuals. Life in such crowded colonies might require special coding-decoding systems to reliably convey information through acoustic cues. This can include, for example, developing complex vocal repertoires and adjusting the properties of their vocal signals to communicate behavioural contexts, and thus regulate social interactions with their conspecifics. We studied vocalisations produced by the little auk (Alle alle)-a highly vocal, colonial seabird-over mating and incubation periods on the SW coast of Svalbard. Using passive acoustic recordings registered in a breeding colony, we extracted eight vocalisation types: single call, clucking, classic call, low trill, short call, short-trill, terror, and handling vocalisation. Calls were grouped by production context (based on the typically associated behaviour), to which a valence (positive vs negative) was later attributed, when possible, according to fitness threats, i.e. predator or human presence (negative) and promoters, i.e. interaction with a partner (positive). The effect of the putative valence on eight selected frequency and duration variables was then investigated. The putative contextual valence significantly affected the acoustic properties of the calls. Calls assigned positive valence had higher fundamental frequency and spectral centre of gravity as well as shorter sound duration than these assigned negative valence. These results indicate that the little auk's vocal communication system may facilitate expression of complex behavioural contexts, and seems to include vocal plasticity within vocalisation types-however, more data are necessary to better understand this effect and possible interplays of other factors.
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Affiliation(s)
- Anna N Osiecka
- Department of Vertebrate Ecology and Zoology, Faculty of Biology, University of Gdańsk, 80-308, Gdańsk, Poland.
- Behavioural Ecology Group, Section for Ecology and Evolution, Department of Biology, University of Copenhagen, 2100, Copenhagen, Denmark.
| | - Elodie F Briefer
- Behavioural Ecology Group, Section for Ecology and Evolution, Department of Biology, University of Copenhagen, 2100, Copenhagen, Denmark
| | - Dorota Kidawa
- Department of Vertebrate Ecology and Zoology, Faculty of Biology, University of Gdańsk, 80-308, Gdańsk, Poland
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Martin M, Gridley T, Elwen S, Charrier I. Early onset of postnatal individual vocal recognition in a highly colonial mammal species. Proc Biol Sci 2022; 289:20221769. [PMID: 36475443 PMCID: PMC9727656 DOI: 10.1098/rspb.2022.1769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Mother-young vocal recognition is widespread in mammals. The features of vocal recognition are known to be shaped by the ecological constraints faced by each species. In some species, a rapid establishment of mother-young vocal recognition is crucial for offspring's survival. However, knowledge of the precise features of this recognition system, especially the timing of the onset in the first hours after birth, is often lacking. Here we show that Cape fur seal females can recognize their pup's voice 2-4 h after parturition and that pups develop this aptitude 4-6 h after birth. This study is the first to investigate this mechanism in a wild and free-ranging mammal from only 2 h after birth. We report the fastest establishment of mother-young vocal recognition for any mammalian species, including humans, described to date. Such early vocal identification in pups suggests an in utero vocal imprinting. These findings highlight the synergistic role of environmental constraints and biological traits in optimizing the timing of individual vocal recognition onset in vertebrates.
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Affiliation(s)
- Mathilde Martin
- Institut des Neurosciences Paris-Saclay, CNRS, Université Paris-Saclay, UMR 9197, 91400 Saclay, France,Sea Search Research and Conservation NPC, 4 Bath Road, Muizenberg, Cape Town 7945, South Africa
| | - Tess Gridley
- Sea Search Research and Conservation NPC, 4 Bath Road, Muizenberg, Cape Town 7945, South Africa,Department of Botany and Zoology, Faculty of Science, Stellenbosch University, Stellenbosch 7605, South Africa
| | - Simon Elwen
- Sea Search Research and Conservation NPC, 4 Bath Road, Muizenberg, Cape Town 7945, South Africa,Department of Botany and Zoology, Faculty of Science, Stellenbosch University, Stellenbosch 7605, South Africa
| | - Isabelle Charrier
- Institut des Neurosciences Paris-Saclay, CNRS, Université Paris-Saclay, UMR 9197, 91400 Saclay, France
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Selection levels on vocal individuality: strategic use or byproduct. Curr Opin Behav Sci 2022. [DOI: 10.1016/j.cobeha.2022.101140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Mutual mother-pup vocal recognition in the highly colonial Cape fur seal: evidence of discrimination of calls with a high acoustic similarity. Anim Cogn 2022; 25:1461-1472. [PMID: 35507204 DOI: 10.1007/s10071-022-01627-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Revised: 04/09/2022] [Accepted: 04/13/2022] [Indexed: 11/01/2022]
Abstract
The Cape fur seal (Arctocephalus pusillus pusillus) is one of the most colonial mammal species in the world. Females exclusively nurse their pups for 9 to 11 months, during which they alternate frequent foraging trips at sea with suckling periods ashore. The survival of the pup thus depends on the ability of the mother-pup pair to relocate each other among thousands of individuals. Previous work has demonstrated identity information encoded in pup-attraction (PAC) and female-attraction (FAC) calls. Here, we investigated vocal recognition between mother and pup using playbacks of PAC and FAC performed during the breeding season at Pelican Point, Namibia. Both females and pups were able to specifically discriminate the voice of their pup or their mother from non-affiliated pup or mother. Females were able to memorize previous versions of their pup's calls (evidence of recognition up to 73 days after pup's calls recording). Vocal recognition was demonstrated in pups from 1- to 13-weeks old age. Females and pups did not respond differently to the non-filial or non-mother (for pups) stimulus even if it had a strong acoustic similarity with the filial or mother stimulus. This suggested that Cape fur seal mother-pup pairs have high perceptual and cognitive abilities, allowing individuals to identify kin's vocalizations in a very noisy and confusing environment.
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Charrier I, Jeantet L, Maucourt L, Régis S, Lecerf N, Benhalilou A, Chevallier D. First evidence of underwater vocalisations in green sea turtles Chelonia mydas. ENDANGER SPECIES RES 2022. [DOI: 10.3354/esr01185] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Feel the beat: cape fur seal males encode their arousal state in their bark rate. Naturwissenschaften 2021; 109:5. [PMID: 34894271 DOI: 10.1007/s00114-021-01778-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 11/29/2021] [Accepted: 12/03/2021] [Indexed: 10/19/2022]
Abstract
The cape fur seal is one of the most colonial mammal species in the world. Breeding colonies are composed of harems held by mature males (older than 10 years) with up to 30 females and their pups, while roaming subadult males (younger and socially immature) are kept away from bulls' territories. As in other pinnipeds, cape fur seals are highly vocal and use acoustic signals in all their social interactions. Males produce barks-short vocalizations always produced in sequences-for territorial defense, mating behaviors, and agonistic interactions. These calls convey information about the sex, age class, and individual identity. This study investigated whether motivational cues such as the arousal state can be encoded in territorial males' barks and whether these cues are decoded by listening sub-adult males. The rate (number of calls per unit of time) and fundamental frequency of barks were found to significantly increase during high arousal state interactions (i.e., male-male confrontation) compared to spontaneous barks. Playback experiments revealed that subadult males responded with a higher level of vigilance when territorial males' barks had a faster bark rate. This mechanism of decoding the bulls' arousal state from barks will likely constitute an advantage for both bulls and the subadult males, by avoiding or reducing physical conflicts, and thereby reducing energy expenditure and the risk of injury. This study is the first experimental evidence of cape fur seals' using vocal rhythmic patterns to modulate their social interactions.
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Curtis S, Elwen SH, Dreyer N, Gridley T. Entanglement of Cape fur seals (Arctocephalus pusillus pusillus) at colonies in central Namibia. MARINE POLLUTION BULLETIN 2021; 171:112759. [PMID: 34364137 DOI: 10.1016/j.marpolbul.2021.112759] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2021] [Revised: 07/19/2021] [Accepted: 07/20/2021] [Indexed: 06/13/2023]
Abstract
Marine pollution is increasing, and pinnipeds are commonly affected by entanglement in waste. We investigated entanglement rates, common materials, and the demographic profile of Cape fur seals (Arctocephalus pusillus pusillus) affected at two Namibian colonies. Overall, we identified 366 cases of entanglement, and present a global rate of entanglement of 0.17%. Entanglement rates were 0.17% and 0.15% for the Pelican Point and Cape Cross colonies, respectively. We identified 17% more entanglements through photographs than binocular scans. Of the 347 entanglements analysed in detail, juveniles were most commonly affected and fishing materials were the primary cause of entanglements (53%), with 8% of entangled seals exhibiting 'very severe' injuries. Overall, 191 individuals were successfully disentangled, and citizen scientists contributed 51% of total entanglement data. We highlight the negative impact of plastic marine waste among seals and the importance of disentanglement for individual animal welfare.
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Affiliation(s)
- S Curtis
- Sea Search Research and Conservation NPC, 4 Bath Road, Muizenberg, Cape Town 7945, South Africa
| | - S H Elwen
- Sea Search Research and Conservation NPC, 4 Bath Road, Muizenberg, Cape Town 7945, South Africa; Department of Botany and Zoology, Faculty of Science, Stellenbosch University, Stellenbosch 7605, South Africa
| | - N Dreyer
- Department of Botany and Zoology, Faculty of Science, Stellenbosch University, Stellenbosch 7605, South Africa; Ocean Conservation Namibia, Waterfront, Atlantic Street, Walvis Bay, Namibia
| | - T Gridley
- Sea Search Research and Conservation NPC, 4 Bath Road, Muizenberg, Cape Town 7945, South Africa; Department of Botany and Zoology, Faculty of Science, Stellenbosch University, Stellenbosch 7605, South Africa.
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