Abstract
During a radio-tracking study of L. t. tardigradus in Masmullah Proposed Forest Reserve, Sri Lanka, we recorded the animals’ vocalizations and associated behaviors. The 1,720 calls we heard in the field fell into five call types: whistle (97.7%), chitter (2.0%), monosyllabic chitter (0.2%), “krik” and “zic” calls (0.1%). We provide a preliminary account of the contextual use of these vocalizations, with an emphasis on qualitative variation in the loud “whistle” call, by far the most common call type. Whistles vary greatly in their contextual use, structure, and usage frequency. Synchronous calls are uttered by mothers and infants in the context of infant parking and pick up. The average number of calls per hour was highest between 19:00 and 20:00 (1.9 calls/h) and lowest between 6:00 and 7:00 (<0.01 calls/h).
Resume
Au cours d’une étude par radio-pistage de L. t. tardigradus à Masmullah, une zone proposée pour un classement en Réserve Forestière, au Sri Lanka, nous avons construit le répertoire vocal de ces animaux et observé des comportements associés. Les 1720 vocalisations entendues sur le terrain entraient dans cinq [sept] types de cris : sifflement (97.7%), pépiement (2.0%), pépiement monosyllabique (0.2%), «kric» et «zic» (0.1%). Nous proposons un rapport préliminaire des contextes d’utilisation de ces vocalisations, en insistant sur les variations qualitatives observées sur le « sifflement » fort, de loin la plus commune des catégories de cris. Les sifflements montrent de grandes variations de contexte d’utilisation, de structure, et de fréquence d’utilisation. Des cris sont émis en synchronie par les mères et leurs jeunes, dans le contexte de parking et déplacements des jeunes. La fréquence moyenne des cris (1.9 cris par heure) était la plus grande entre 19 :00 et 20 :00 et la plus faible entre 6:00 et 7:00 (< 0.01 cris par heure).
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Acknowledgments
We thank the Departments of Forest, Wildlife Conservation, and Telecommunications for providing permits, A. Beresford and K. Davey for field and laboratory assistance, and Oxford Brookes University, the Primate Society of Great Britain Conservation Working Party, Cleveland Metroparks Zoo, People’s Trust for Endangered Species, National Geographic, Columbus Zoo, and the L.S.B. Leakey Foundation for financial assistance.
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Bernede, L., Davies, R., Nekaris, K.AI., Gunawardene, A., Bearder, S.K. (2012). Vocalizations of Red Slender Lorises (Loris tardigradus tardigradus) in Masmullah Proposed Forest Reserve, Sri Lanka. In: Masters, J., Gamba, M., Génin, F. (eds) Leaping Ahead. Developments in Primatology: Progress and Prospects. Springer, New York, NY. https://doi.org/10.1007/978-1-4614-4511-1_30
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