by Corinne Daniel

Gray Whale
(Eschrictius robustus)

The gray whale is a baleen whale. The gray whale used to be known among the whalers as the devilfish due to the fierce fight they put up to defend themselves against the hunters. A full-grown gray whale can be up to forty-five to fifty feet long, and weigh approximately thirty-six tons. As is common with all baleen whales, female gray whales are typically larger than the males of this species. The coloration of the gray whale is usually gray with white, blotchy spots. The gray whale is equipped with two to four throat grooves, which are each about five feet long. The purpose of these throat grooves is to enable the throat to expand in preparation of the huge intakes of water necessary in filter feeding. Although lacking a dorsal fin, the gray whale does have two broad flippers and a series of little ridges are stationed along its back near the flukes (tail).

Gray whales are bottom feeders. They typically feed on their right side and they eat by sucking up mouthfuls of mud and their baleen filters pick out the food and they spit the rest of the mud back into the water. Gray whales eat mostly small crustaceans, plankton and mollusks. The gray whale eats very little during certain times of the year including the duration of migrations and while in the warm breeding waters (about 3-5 months). The gray whale can have up to a 10-inch layer of blubber during these times they are forced to live off this fat.

The estimated worldwide population of gray whales is about 15,000 – 20,000. Gray whales usually congregate in small pods of about three whales, but these pods can have as many as sixteen members. In feeding waters larger groups (up to hundreds of whales) are formed, these are temporary bonds and they do not establish long-term relationships. Gray whales may communicate with each other with sounds but we cannot be sure. For instance, noises such as forceful spouts might signal aggravation or slapping pectoral flippers of flukes may indicate arousal, excitement, or aggression.

As their surroundings require, gray whales are very agile swimmers. Gray whales have the ability to dive for up to 30 minutes and can safely go 500 feet deep. They also breach, which is when they jump out of the water a little bit and re-enter at an angle. When they do this they make huge splashes and loud noise. It is possibly a means of communicating with other whales as well. Also gray whales also do something called “spyhopping”. When spyhopping the whale pokes its head up to 10 feet out top the water, and has a look around by turning slowly. Although the gray whale does live underwater it has to breathe air by coming up to the surface of the water and breathing through two blowholes near the top of the head. When they are at rest, the gray whale breathes about 2-3 times a minute, but when they are diving they can go for 3-5 minutes with out coming to the surface to breathe.

The most common habitat for gray whales is the surface of the ocean near the coastline, but they dive to the bottom for food. Gray whales migrate approximately 12,500 miles each year, beginning in the Arctic Ocean (northwest of Alaska in the Chukchi Sea), and ending off of the Baja Peninsula of Mexico. Throughout the whole journey the gray whales stay near the coast. The whales feed in the cold water and in the warmer water calving and mating take place.

Mature females give birth every other year in the warm water off of the Baja Peninsula. Ten seconds after its birth the calf instinctively swims to the surface (with much help from its mother) for its first breath. After as long as 30 minutes the baby whale can swim without assistance. A newborn gray whale is usually about 15 feet long and weighs about 1-1.5 ton, but like with humans, this can vary. Twins are extremely rare and only one out of every hundred births is twins. A calf can consume up to 50-80 pounds of its mother’s fatty milk per day, and is weaned at the age of 7-8 months after its birth. Gray whales reach maturity at 8 years and the growth stops when the whale is 40. Gray whales typically live to be between 50 and 60 years old.

The biggest predators of gray whales are killer whales. The gray whales are much larger than the killer whales and the killer whales have to team up to take down a full-grown gray whale. Large sharks may prey on gray whales but they tend to target the gray whales that are injured, ill or young. The small cookie cutter sharks, which are only about 38cm, are also threats to the lives of gray whales. Using suction, they attach themselves to the whales, and then they carve out a core of flesh with their large triangular teeth. Humans are also dangerous to gray whales.

The gray whale has many parasites, and their bodies are covered with hundreds of pounds of barnacles and whale lice. Interestingly enough, little or no parasites are found on the right side of the whales because of the way that it rubs against the ocean floor while feeding. Skin parasites attach themselves to the head area, back, and blowhole area also.

I have really enjoyed learning more about the gray whale, I think that they are stunning creatures and I hope that this paper will inspire readers to appreciate them more fully, as I have through doing this research.