Two pilot whales that washed up on Massachusetts beaches this week were rare visitors from the South, members of a species that had never been documented in the state, animal welfare officials said.
The animals, which both died, were identified as short-finned pilot whales, a species that is rare in the Northern Atlantic, according to the International Fund for Animal Welfare.
Short-finned pilot whales typically frequent warmer waters such as the Gulf of Mexico and the ocean off Florida and are distinctly different from long-finned pilot whales, whose range includes Massachusetts waters.
“To put it in perspective, a household dog and a gray wolf actually have more in common genetically than these two types of whales,’’ said Brian Sharp, stranding coordinator for the fund.
A short-finned pilot whale was recorded stranded in Rhode Island in 2001 by the National Oceanic and Atmospheric Administration, the only other documented case of the animal inhabiting waters north of New Jersey, officials said.
One of the cetaceans died on a Duxbury beach Monday, the other on a Truro beach Tuesday.
“This may have been a simple case of being in the wrong place at the wrong time, as other pilot whales were sighted just offshore when it stranded,’’ Sharp said of the whale in Truro. “This whale’s unfortunate death at least will provide an opportunity for us to learn more about another whale species through [a necropsy] and CT scans.’’
Biologists are unsure why the pilot whales traveled so far north, but speculate it could be because of warmer-than-usual weather or because the mammals are extending their habitat range.
Short-finned pilot whales are smaller than long-finned pilot whales, have deeper chests and shorter pectoral flippers, fewer teeth, different markings, and a taller dorsal fin, according to the fund.
Marine mammals stranded south of Plymouth through Rhode Island should be reported to the fund’s emergency hotline at 508-743-9548. Strandings from Plymouth to Maine can be reported to the New England Aquarium at 617-973-5247.Amanda Cedrone can be reached at firstname.lastname@example.org.