Individual, ecological, and anthropogenic influences on activity budgets of long-finned pilot whales

• Published in: Ecosphere
• Main Authors: Isojunno, Saana, Sadykova, Dina, de Ruiter, Stacy, Cure, Charlotte, Visser, Fleur, Thomas, Len, Miller, Patrick James O'malley, Harris, Catriona M.
• Other Authors: University of St Andrews Scotland, School of Biological Sciences Aberdeen, University of Aberdeen, Calvin College Burton, Unité Mixte de Recherche en Acoustique Environnementale (UMRAE ), Centre d'Etudes et d'Expertise sur les Risques, l'Environnement, la Mobilité et l'Aménagement (Cerema)-Université Gustave Eiffel, Leiden University
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2017
• Subjects: ACLI; NAVAL SONAR; ANTHROPOGENIC NOISE; DTAG; GLOBICEPHALA MELAS; ACTIVITY SYNCHRONY; BENTHIC HABITAT; DEEP-DIVING MAMMAL; ETHOGRAM; HIDDEN MARKOV MODEL; CEREMA; IMPACT; INTERNATIONAL; SONAR; NAVIGATION; FAUNE; [SDE]Environmental Sciences; Killer Whale; Killer whale
• Online Access: https://hal.archives-ouvertes.fr/hal-02915533; https://doi.org/10.1002/ecs2.2044

Time allocation to different activities and habitats enables individuals to modulate their perceived risks and access to resources and can reveal important trade?offs between fitness?enhancing activities (e.g., feeding vs. social behavior). Species with long reproductive cycles and high parental investment, such as marine mammals, rely on such behavioral plasticity to cope with rapid environmental change, including anthropogenic stressors. We quantified activity budgets of free?ranging long?finned pilot whales in order to assess individual time trade?offs between foraging and other behaviors in different individual and ecological contexts, and during experimental sound exposures. The experiments included 1-2 and 6-7 kHz naval sonar exposures (a potential anthropogenic stressor), playback of killer whale (a potential predator/competitor) vocalizations, and negative controls. We combined multiple time series data from digital acoustic recording tags (DTAG) as well as group?level social behavior data from visual observations of tagged whales at the surface. The data were classified into near?surface behaviors and dive types (using a hidden Markov model for dive transitions) and aggregated into time budgets. On average, individuals (N = 19) spent most of their time (69%) resting and transiting near surface, 21% in shallow dives (depth