Clustering of sperm whales recorded by a single hydrophone

Orcinus orcais a cosmopolitan species and the most widely distributed marine mammal. Its diet includes over 140 species of fish, cephalopods, sea birds and marine mammals. However, many populations are specialised on certain specific prey items. Three genetically distinct populations have been described in the North Atlantic. Population A (that includes the Icelandic and Norwegian sub-populations) is believed to be piscivorous, as is population C, which includes fish-eating killer whales from the Strait of Gibraltar. In contrast, population B feeds on both fish and marine mammals. Norwegian killer whales follow the Norwegian spring spawning herring stock. The only description in the literature of Norwegian killer whales feeding on another cetacean species is a predation event on northern bottlenose whales in 1968. Daily land-based surveys targeting sperm whales were conducted from the Andenes lighthouse using BigEyes®binoculars (25×, 80 mm). The location of animals at sea was approximated through the use of an internal reticule system and a graduated wheel. On 24 June 2012 at 3:12 am, an opportunistic sighting of 11 killer whales was made off Andenes harbour. The whales hunted and fed on a harbour porpoise. Despite these species having overlapping distributions in Norwegian waters, this is the first predatory event reported in the literature.

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Severity Scoring of Behavioral Responses of Sperm Whales (Physeter macrocephalus) to Novel Continuous versus Conventional Pulsed Active Sonar

Journal of Marine Science and Engineering ◽

10.3390/jmse9040444 ◽

2021 ◽

Vol 9 (4) ◽

pp. 444

Author(s):

Charlotte Curé ◽

Saana Isojunno ◽

Marije L. Siemensma ◽

Paul J. Wensveen ◽

Célia Buisson ◽

...

Keyword(s):

Behavioral Responses ◽

Physeter Macrocephalus ◽

Vital Rates ◽

Sperm Whales ◽

Experimental Conditions ◽

Active Sonar ◽

Lower Amplitude ◽

Pilot Whales ◽

New Generation ◽

Free Ranging

Controlled exposure experiments (CEEs) have demonstrated that naval pulsed active sonar (PAS) can induce costly behavioral responses in cetaceans similar to antipredator responses. New generation continuous active sonars (CAS) emit lower amplitude levels but more continuous signals. We conducted CEEs with PAS, CAS and no-sonar control on free-ranging sperm whales in Norway. Two panels blind to experimental conditions concurrently inspected acoustic-and-movement-tag data and visual observations of tagged whales and used an established severity scale (0–9) to assign scores to putative responses. Only half of the exposures elicited a response, indicating overall low responsiveness in sperm whales. Responding whales (10 of 12) showed more, and more severe responses to sonar compared to no-sonar. Moreover, the probability of response increased when whales were previously exposed to presence of predatory and/or competing killer or long-finned pilot whales. Various behavioral change types occurred over a broad range of severities (1–6) during CAS and PAS. When combining all behavioral types, the proportion of responses to CAS was significantly higher than no-sonar but not different from PAS. Responses potentially impacting vital rates i.e., with severity ≥4, were initiated at received cumulative sound exposure levels (dB re 1 μPa2 s) of 137–177 during CAS and 143–181 during PAS.

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Cetacean strandings along the Pacific and Caribbean coasts of Nicaragua from 2014 to 2021

Marine Biodiversity Records ◽

10.1186/s41200-021-00209-5 ◽

2021 ◽

Vol 14 (1) ◽

Author(s):

Joëlle De Weerdt ◽

Eric Angel Ramos ◽

Etienne Pouplard ◽

Marc Kochzius ◽

Phillip Clapham

Keyword(s):

Marine Mammals ◽

Sperm Whale ◽

Distribution Patterns ◽

Sperm Whales ◽

The Pacific ◽

Toothed Whale ◽

Beaked Whales ◽

Causes Of Mortality ◽

Cuvier’S Beaked Whale ◽

Stenella Attenuata

AbstractDocumenting marine mammal strandings provides important information needed to understand the occurrence and distribution patterns of species. Here, we report on strandings of cetaceans on the Pacific (n = 11) and Caribbean (n = 2) coasts of Nicaragua, documented opportunistically from 2014 to 2021. Strandings included three species of baleen whale (blue whale Balaenoptera musculus, Bryde’s whale Balaenoptera edeni, humpback whale Megaptera novaeangliae) and five species of toothed whale (dwarf sperm whale Kogia sima, Guiana dolphin Sotalia guianensis, pantropical spotted dolphin Stenella attenuata, spinner dolphin Stenella longirostris, Cuvier’s beaked whale Ziphius cavirostris). These are the first published accounts of blue whales, Bryde’s whales, dwarf sperm whales, and Cuvier’s beaked whales in Nicaraguan waters. Limited resources and the advanced decomposition of animals prevented necropsies in most cases, the identification of the causes of mortality in all cases, and the species identification of two dolphins. Information derived from these stranding events offers new insights into the occurrence of marine mammals on the Pacific and Caribbean coasts of Nicaragua and Central America.

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Behaviour and Vocalizations of Two Single Sperm Whales, Physeter macrocephalus, Off Nova Scotia

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f88-205 ◽

1988 ◽

Vol 45 (10) ◽

pp. 1736-1743 ◽

Cited By ~ 34

Author(s):

Julia Mullins ◽

Hal Whitehead ◽

Linda S. Weilgart

Keyword(s):

Nova Scotia ◽

Sound Production ◽

Ocean Floor ◽

Physeter Macrocephalus ◽

Sperm Whales ◽

Scotian Shelf ◽

Male Sperm

During June 1986, two male sperm whales, Physeter macrocephalus, on the Scotian Shelf were tracked by listening for their clicks with a directional hydrophone for periods of 12.5 and 7 h, respectively. Each whale travelled along the edge of the shelf at about 2 kn (3.6 km/h), and one whale, on two occasions at least, dived to the ocean floor. After about 30 min underwater, the whales spent approximately 9 min at the surface breathing. When the whales were visible at the surface, they were silent, except on one occasion when "slow clicking" (mean interclick interval of 4.6 s) was heard from Whale 2. While underwater, most of the sound production consisted of "usual clicks" (mean interclick interval 0.96 and 0.69 s for the two whales) interrupted by frequent short silences (mean durations 21.06 and 27.82 s) and occasional "creaks" (with interclick intervals less than 0.2 s) and "slow clicks." No "codas" (stereotyped patterns of clicks) were heard from these two single whales. These results are consistent with the hypotheses that "usual clicks" and "creaks" are used for echolocation and "codas" for communication.

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Acoustic tracking of sperm whales in the Gulf of Alaska using a two-element vertical array and tags

The Journal of the Acoustical Society of America ◽

10.1121/1.4816565 ◽

2013 ◽

Vol 134 (3) ◽

pp. 2446-2461 ◽

Cited By ~ 19

Author(s):

Delphine Mathias ◽

Aaron M. Thode ◽

Jan Straley ◽

Russel D. Andrews

Keyword(s):

Gulf Of Alaska ◽

Sperm Whales ◽

Vertical Array ◽

Acoustic Tracking

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Foraging dives of sperm whales in the north-western Mediterranean Sea

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315412001087 ◽

2012 ◽

Vol 92 (8) ◽

pp. 1799-1808 ◽

Cited By ~ 5

Author(s):

Alexandre Gannier ◽

Estelle Petiau ◽

Violaine Dulau ◽

Luke Rendell

Keyword(s):

Prey Capture ◽

Sperm Whale ◽

Western Mediterranean ◽

Sperm Whales ◽

The North ◽

Western Mediterranean Sea ◽

Single Animal ◽

Components Analysis ◽

Passive Acoustic ◽

North Western

Oceanic odontocetes rely on echolocation to forage on pelagic or benthic prey, but their feeding ecology is difficult to study. We studied sperm whale foraging dives during summer in the north-western Mediterranean, using visual and passive acoustic observations. Clicking and creaking activities were recorded during dives of focal whales, at distances <3000 m using a towed hydrophone and DAT recorder. A total of 52 sperm whales were recorded over at least one full dive cycle. Data were obtained for 156 complete dives in total, including sequences of up to nine consecutive dives. Various dive and environmental variables were entered in multiple linear regression and principal components analysis, as well as estimated mass of whales. Creak rate was 0.80 creak/minute on average, with moderate variance. Bigger whales tended to dive longer at greater depths (as suggested by ascent durations), and emitted more creaks during a dive: 20.2 creaks/dive on average for individuals <24 tons, compared to 25.6 creaks/dive for animals >24 tons of estimated mass. For individual whales, creak rates did not vary significantly with size (range 0.78–0.80 creak/minute), but decreased with time of the day, and increased for shorter foraging phases. For different dives, higher creak rates were also observed earlier in the day, and linked to shorter foraging phases and surface durations. Although the exact significance of creak emissions (i.e. foraging attempt or prey capture) is not precisely determined, creak rates may be reliably used to quantify sperm whale foraging when single animal dives can be followed acoustically.

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