This Shepherd's beaked whale stranded alive near Auckland. The observer assisted in refloating it, and after several hours and multiple attempts the whale eventually was able to head back out to sea. This whale's return to the sea was aided by the New Zealand Department of Conservation.

Sea mystery

Even among the infamously-mysterious beaked whales - deep-diving offshore hunters, low-profile at the surface, and often skittish of boats - Shepherd's beaked whale is poorly known, with the type specimen collected only in 1933. Consulting a few of my cetacean field guides, Lyall Watson reports in Whales of the World (2nd ed., 1985) that the species is known only from eight stranded individuals and one questionable at-sea sighting. Knowledge of this whale had improved somewhat by 2002: compare Pieter Folkens's detailed illustrations of the species in the National Audubon Society Guide To Marine Mammals of the World to Tom Ritchie's simplistic one in Whales of the World. Even so, Randall R Reeves notes that most data on Shepherd's beaked whale is still derived from a small number of carcasses and the reliability of at-sea observations is difficult to establish. While definitive live sightings were less of a rarity by 2015, where the second edition of Marine Mammals of the World includes numerous excellent (at least by beaked whale standards) at-sea photos, the life history of this species remains mysterious, established mainly through examination of carcasses and inference drawn from other beaked whales.

The sole member of the genus Tasmacetus, Shepherd's beaked whale was recognized as an oddity since it was formally named and described in 1937. Its long beak, high somewhat-laterally-compressed melon, and rather bold coloration are all odd features, but its most distinctive character is its dentition. Beaked whales all have a reduced dentition, only two or four teeth in the lower jaw which only erupt as small tusks in mature males - note these little tusks are visible at the tip of the lower jaw in this individual - so females and calves are toothless; vestigial teeth may form in the jaws but do not erupt. Shepherd's beaked whale is unique among the living beaked whales in possessing a full set of functional teeth, between 17-21 pairs in the upper jaw and 18-28 pairs in the lower jaw. Probably because of these teeth, Shepherd's beaked whales eat a significant quantity of fish, whereas other beaked whales feed almost wholly on cephalopods.

On stranded cetaceans

An encounter like this, with such a rarely-seen animal, is remarkable, and is made even more so by the fact that the whale was able to return to sea, apparently safely. Frequently, stranded cetaceans are in serious distress, and the odds of survival are often not in their favor. It is a good idea not to approach stranded cetaceans yourself, and instead contact a stranding network for professional help. Even small cetaceans are powerful animals that could inflict forceful strikes with their flukes or deliver serious bites, and close contact risks the transmission of illness from human to cetacean and vice versa. Attempting to help a struggling cetacean without professional knowledge of what it needs runs the risk of accidentally injuring it further, to say nothing of heightening its distress.

If you are in the United States, NOAA has extensive information and literature on marine mammal rescue, and a section on their website here to report a stranded or injured marine mammal based on your region.

Ref.:

Jefferson, TA, MA Webber, RL Pitman. 2015. Marine Mammals of the World: A Comprehensive Guide To Their Identification 2nd edition (U. Gorter, illustrator). Academic Press.

Reeves, RR, BS Stewart, PJ Clapham, and JA Powell. 2002. National Audubon Society Guide To Marine Mammals of the World (P. Folkens, illustrator). Knopf.