Gray Whales: A Brief Analysis
Gray Whale: Scientific Classification
Common Name: Gray Whale
Binomial Name: Eschrichtius robustus
Species: E. robustus
Conservation Status (IUCN): “Least Concern” (Eastern North Pacific Population); “Endangered” (Western North Pacific Population)
Synonyms: Balaena gibbosa (Erxleben, 1777); Agaphelus glaucus (Cope, 1868); Rhachianectes glaucus (Cope, 1869); Eschrichtius gibbosus (Van Deinse and Junge, 1937); E. glaucus (Maher, 1961)
Gray Whale: Quick Facts
The Gray Whale is one of the largest animals in the world. Measuring approximately forty-nine feet (Fifteen Meters) in length, and weighing approximately 80,000 pounds (35,000 kilograms), the Gray Whale is a truly magnificent creature. As its name implies, the whale’s body is a mottled gray coloration. It also possesses a slightly arched mouth, with approximately 130 to 180 cream-colored scales per side, along with two to five creases along the underside of its massive head. Unlike other sea animals, the Gray Whale has no dorsal fin, but rather a large hump that is followed by approximately six to twelve smaller humps along its long back.
When diving, the Gray Whale’s mottled flukes are frequently raised, allowing the creature to dive to extraordinary depths for relatively long periods of time. When surfacing, the whale’s blow is either bushy or columnar in shape.
Like most mysticetes, the Gray Whale is not known to form lasting associations and relationships with other whales. Preferring a solitary life, they are often observed alone or in small groups (that rarely last longer than a few days, at most). The Gray Whale is also migratory, and often journeys more than 5,000 miles annually to feeding grounds in the south. Curious by nature, the Gray Whale is also known to raise its head out of water on a regular basis, particularly when boats and other small craft cross near its path.
Habitat and Geographical Distribution
The Gray Whale is found primarily along shallow coastal waters, and is endemic to the Eastern and Western coasts of the North Pacific Ocean. Remaining in the north for much of the summer, the Gray Whale migrates south with the approach of winter, embarking on trips of 5,000-6,800 miles from the Bering Sea to the warm waters of Mexico and the Gulf of California. Due to their abundance in December and early January, whale watching has become a major tourist attraction around San Diego and the surrounding area, as the wandering whales appear on a regular basis during these months.
"We owe it to our children to be better stewards of the environment. The alternative? - a world without whales. It's too terrible to imagine."— Pierce Brosnan
Prey and Predators
The Gray Whale’s primary source of food is benthic amphipods, which are found along the bottom of coastal waters in the Pacific. Using filters to consume their food, the Gray Whale often forages along the ocean floor, leaving a long trail of mud and debris as they search for food. Gray Whales also prey on a variety of midwater animals. Similar to the Humpback Whale, Gray Whales typically do most of their feeding during the summer months, while using fat reserves to survive throughout the winter months (eating only opportunistically, and not actively during these months).
Due to the whale’s tremendous size, predators are few in number for the Gray Whale. Recent evidence, however, indicates that large sharks and Killer Whales (orcas) may pose a threat to the whale, particularly juvenile whales. Attacking in groups of three to four, Killer Whales have been observed ramming calves in an attempt to separate it from the mother. Despite facing great resistance by the mother, attacks such as these are often successful, making the Killer Whale a formidable threat to the Gray Whale.
Although little is known about the reproductive habits of the Gray Whale, current research indicates that breeding is strongly correlated with the animal’s migratory habits, and occurs predominantly during the winter months while the whale is in warmer waters. It is also believed that females give birth every two to three years, with a long gestational period of approximately twelve to thirteen months. Calves are typically born during the winter (mid-January), and are fully independent by the age of seven to nine months, just before the traditional fall migration south. Calves are almost always born tail-first, and are nearly thirteen feet in length at birth. Despite their large size, mothers often keep their young along coastal (shallow) waters to protect newborns from both orcas and sharks.
During the early parts of the Nineteenth Century, the Gray Whales were heavily exploited by fishers and whalers, prompting government action in the 1930s to protect the animal from extinction. Following these conservation laws, the Gray Whale’s population recovered significantly over the ensuing decades; prompting the United States to remove the whale from its endangered species list in 1994. Present population figures are believed to be around 26,000 whales. Western Gray Whales, on the contrary, are far fewer in number as whaling efforts have dropped their population to an estimated 100 animals.
Despite a large number of conservation laws in place to protect the Gray Whale, the animal continues to face numerous threats from human encroachment. This includes aboriginal whaling, entanglement in fishing gear, collisions with boats, as well as the destruction of natural environments by offshore drilling and exploration.
Before reading this article, how familiar were you with the Gray Whale?
In closing, the Gray Whale is one of the most fascinating sea animals in the world due to its tremendous size, behavioral patterns, and natural beauty. Despite being one of the largest animals in the world, there is still much to be learned about this amazing creature. This is due, in part, because of the tremendous difficulty in observing the Gray Whale in its natural habitat. With new research on the whale already underway in many parts of the world, however, it will be interesting to see what new forms of information can be learned about this extraordinary animal in the years and decades that lie ahead.
Suggestions For Further Reading:
Hogan, Linda and Brenda Peterson. Sightings: The Gray Whales' Mysterious Journey. New York, New York: National Geographic, 2003.
Sumich, James. E. robustus: The Biology and Human History of Gray Whales. New York, New York: Whale Cove Marine Education, 2014.
Articles / Books:
Reeves, Randall R. and Brent S. Stewart. Guide to Marine Mammals of the World. New York, New York: Chanticleer Press Inc., 2002.
Schultz, Ken. Field Guide to Saltwater Fish. Hoboken, New Jersey: John Wiley & Sons Inc., 2004.
Images / Photographs:
Wikipedia contributors, "Gray whale," Wikipedia, The Free Encyclopedia, https://en.wikipedia.org/w/index.php?title=Gray_whale&oldid=909055657 (accessed August 8, 2019).
© 2019 Larry Slawson