Other Whale and Dolphin Species seen on Jeffreys Ledge

Atlantic white-beaked dolphin (Lagenorhynchus albirostris): A close relative of the White-sided dolphin, White-beaked dolphins are typically found in colder water. They are common as far north as northern Canada and Greenland. When seen on the ledge, it is usually in late winter or early spring. They tend to occur in smaller groups (often 5-10) than white-sided dolphins, and much more elusive. They are easily distinguished by their huskier body than the White-sided dolphins and a white stripe across both the top of the mouth and, more prominently, the top of the tail stock.

For more information: http://www.cetacea.org/wbeaked.htm, or http://nat.is/Whales/white_beaked_dolphin.htm

Killer whales (Orcinus orca): A rare visitor to inshore waters of the Gulf of Maine, there have been several sporadic, but reliable, reports of orcas on Jeffreys Ledge and in nearby Ipswich Bay. Orcas are actually the largest members of the dolphin family, reaching lengths of up to 30 feet and weights of 9 tons in males (which are significantly larger than females). They often live in groups comprising mothers and their male and female offspring, and use these related groups to hunt cooperatively. There are reports of orcas on the Ledge feeding on bluefin tuna, and attacking both minke and fin whales! Orcas are much more common in colder waters of the North Atlantic (they are common off Iceland and Norway), but have been seen as far south as the equator.

For more information: http://www.omplace.com/omsites/discover/ORCA/index.html, or http://www.killerwhale.org/fieldnotes/field.html.

Sperm whales (Physeter catadon): The most famous of whales, sperm whales are best known for their rounded head and underslung lower jaw. Males can reach lengths of 60 feet and weights of 35 tons; smaller females only reach 40 feet and 18 tons. They are abundant worldwide, but are usually found in deep waters. They are commonly seen of the contiental shelf of the US, where depths are up to 5,000 feet. In the fall of 1995, however, several sperm whales (mainly females) spent September and October on the Ledge! In all of the years that whale watching boats have been working in New England, this is the only time that sperm whales have ever been seen for more than a single day inshore.

For more information: http://www.pbs.org/wnet/nature/spermwhales/html/home.html or http://www.omplace.com/omsites/discover/SPERM/index.html

Long-Finned Pilot Whales (Globicephala malaena): The second largest member of the dolphin family, males can reach lengths of 20 feet and 3.5 tons, while females reach 18 feet and 3 tons. They usually occur in groups of 10-50 animals, which are generally comprised of related females and males which move between groups. Pilot whales are squid feeders and are usually found far offshore in New England. In some years, however, pilot whales tend to move inshore in the late summer and early fall. We think that these whales may be feeding on herring, which are spawning when pilot whales are present. At times groups can be residential for up to several months. In 1998, we even saw an albino pilot whale calf on the Ledge!

For more information: http://animaldiversity.ummz.umich.edu/accounts/globicephala/g._melas$narrative.html, or http://www.nfld.com/nfld/other/whales/pilotinfo.html

Risso's Dolphin (Grampus griseus): Risso's dolphins are offshore residents which will travle inshore infrequently. They reach lengths of 14 feet and weights of 1500 pounds. Risso dolphin bodies are often covered with tooth scratches and scars which are believed to be caused by the teeth of other Risso's dolphins. In the past several decades, groups have been seen on the Ledge in only two years - 1985 and 1998. In both cases, the groups were repeatedly sighted over one to two months. In 1998, several group members may have died, as several Risso's dolphin strandings took place at the same time on nearby beaches.

For more information: http://www.acsonline.org/factpack/RissosDolphin.htm or http://www.nsrl.ttu.edu/tmot1/gramgris.htm