Call characteristic of High-Double Trill Leopard Seal (Hydrurga leptonyx) vocalizations from three Antarctic locations

• Main Authors: Kreiß, Cornelia, Boebel, Olaf, Bornemann, Horst, Kindermann, Lars, Klinck, Holger, Klinck, Karolin, Plötz, Joachim, Rogers, Tracey L., Opzeeland, Ilse van
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2014
• Subjects: Text; ddc:590; Antarctic; Austral; Atka; Hydrurga; Davis Sea; Antarc*; Hydrurga leptonyx; Leopard Seal; Leopard Seals; Polarforschung
• Online Access: https://doi.org/10.2312/polarforschung.83.2.63; https://www.openagrar.de/receive/openagrar_mods_00024670; https://www.openagrar.de/servlets/MCRFileNodeServlet/openagrar_derivate_00001616/dn058133.pdf; https://www.tib.eu/de/suchen/id/awi%3Adoi~10.2312%252Fpolarforschung.83.2.63/

Leopard seals (Hydrurga leptonyx) produce underwater vocalizations during the breeding season in austral summer. Due to their solitary occurrence and remote habitat, hydroacoustic observations are an important technique to investigate this species regarding their population structure and acoustic ecology. This study examines, whether the acoustic characteristics of leopard seal high double trills (HDT) differed among three Antarctic locations (DI Drescher Inlet (72 degrees 52’ S, 19 degrees 26’ W), AB Atka Bay (70 degreees 31’ S, 8 degrees 13’ W) and DS Davis Sea (65 degrees S, 90 degrees E). Overall the observed pattern reflects a remarkable similarity in the acoustic characteristics of leopard seal HDTs across the three recording locations. Interestingly, differences in call characteristics were strongest between the closest sites DI and AB (500 km along-shelfice distance). HDTs recorded at DI had lower pulse repetition rates and narrower bandwidths than HDTs recorded at both, AB and DS (4300 km along-shelfice distance). Principal Component Analysis clearly separated HDTs recorded at DI from HDTs recorded at both, AB and DS. Calls from AB and DS were less separable and showed partly overlapping clusters. Previous genetic studies suggested that there is sufficient exchange of individuals between leopard seal breeding groups to prevent the development of genetically isolated populations. Our results support this notion as they demonstrate a high level of similarity in leopard seal vocalizations recorded at disparate locations. Subtle site variation in calls from recording locations within close proximity might be attributed to differences in local social factors including reproductive character displacement or environmental factors. Während der Aufzuchts- und Paarungszeit im polaren Sommer zeigt der Seeleopard (Hydrurga leptonyx) eine hohe akustische Aktivität. Aufgrund ihres schwer zugänglichen Lebensraums und der solitären Lebensweise, stellen hydroakustische Untersuchungen eine wichtige Methode zur ...