Cuvier's beaked whale
Cuvier’s beaked whales are the most commonly stranded beaked whale along the outer coasts of Oregon and Washington. Although typically a creature of deep water, beaked whales have been documented in the Salish Sea at least once in the last fifty years, although which species was swimming in Puget Sound was not clear.
Species description
The species is one of the more frequently sighted beaked whales, although it should be noted that most beaked whales are seen very rarely, and even when seen are difficult to identify to species. Sometimes called the goose-beaked whale, adult Cuvier’s beaked whales grow to between 4.5 to 7 meters and weigh more than 3,000 kilograms. Females and males are roughly the same size, but males have two small teeth sticking out from the end of the lower jaw, likely for use during competitive scuffles. Adults are variably colored, ranging from reddish-brown to dark gray or even whitish around the head. They tend to lighten as they age. In part this is due to the fact that their bodies are frequently pocked with disc-shaped divots, thought to be from cookie-cutter shark or lamprey bites, as well as scars from interspecific fights.
Behavior and ecology
Like other beaked whale species, the Cuvier’s beaked whale are noted both for their cryptic behavior and their diving capabilities. They can dive more than 1,000 meters and spend 20 to 40 minutes at depth, and sometimes as long as 90 minutes or more. The deepest known dive was nearly 3,000 meters and lasted for almost four hours. Even when they are on the surface, their blow is only about a meter tall, and so difficult for observers to see. Cuvier’s beaked whales feed mostly on cephalopods, perhaps vacuuming them up through their beak, but are also known to eat fish and crustaceans. They travel alone or in small groups, but pods of around 25 individuals have been seen.
Range and population status
Cuvier’s beaked whales are the most widely distributed of the beaked whales. Their range includes temperate, subtropical, and tropical waters, and as such they are found in most oceans and seas all over the world. In U.S. waters, federal managers divide the species into seven stocks, including a California-Oregon-Washington stock. The species is difficult to survey, and abundance estimates tend to have a high degree of uncertainty. Per the most recent population estimate in 2016, based on a combination of ship-based line transect counts and passive acoustic monitoring, the CA-OR-WA stock has roughly 5,400 whales (Barlow et al. 2021). Although, like all marine mammals, Cuvier’s beaked whales are subject to the Marine Mammal Protection Act, the species is not considered threatened or endangered in any part of its range.
Threats
Cuvier’s beaked whales have received a fair amount of public attention for being particularly vulnerable to mid-frequency active (MFA) sonar, especially after a number of notable strandings following naval exercises (Tyack et al. 2011, DeRuiter et al. 2013, Falcone et al. 2017). They are also vulnerable to ocean noise pollution more generally (e.g., from seismic surveys), entanglement in gear from the California swordfish drift gillnet fishery, and vessel strikes.
In the Salish Sea
Cuvier’s beaked whales are the most commonly stranded beaked whale along the outer coasts of Oregon and Washington. Although typically a creature of deep water, beaked whales have been documented in the Salish Sea at least once in the last fifty years, although which species was swimming in Puget Sound was not clear (Gaydos and Pearson 2011).
Works cited
Barlow J, Moore JE, McCullough JLK, and Griffiths ET. 2021. Acoustic-based estimates of Cuvier's beaked whale (Ziphius cavirostris) density and abundance along the U.S. West Coast from drifting hydrophone recorders. Marine Mammal Science 2021:1-22.
DeRuiter SL, Southall BL, Calambokidis J, Zimmer WM, Sadykova D, Falcone EA, Friedlaender AS, Joseph JE, Moretti D, Schorr GS, Thomas L. 2013. First direct measurements of behavioural responses by Cuvier's beaked whales to mid-frequency active sonar. Biology Letters 9(4):20130223.
Falcone EA, Schorr GS, Watwood SL, DeRuiter SL, Zerbini AN, Andrews RD, Morrissey RP, Moretti DJ. 2017. Diving behaviour of Cuvier's beaked whales exposed to two types of military sonar. Royal Society Open Science 4(8):170629.
Gaydos JK, Pearson SF. 2011. Birds and mammals that depend on the Salish Sea: a compilation. Northwestern Naturalist 92(2):79-94.
Tyack PL, Zimmer WM, Moretti D, Southall BL, Claridge DE, Durban JW, Clark CW, D'amico A, DiMarzio N, Jarvis S, McCarthy E. 2011. Beaked whales respond to simulated and actual navy sonar. PLOS ONE 6(3):e17009.