Gray Whale Enemy Number One

Photo Mike Hawe
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Orcas (Killer whales) are one of the dangers on the whales' journey north. Sightings of Orcas increase during the migration season. Here's what Marine Biologist Caitlyn Toropova told Journey North about the connection between gray whales and Killer whales:

What do you think happened to this whale's tail? (enlarge)

Orcas As Hunters
"Although killer whales can and do eat gray whales occasionally, there is a lot more to it than that. Killer whales are the gray whales' main predator. Killer whales are amazingly good and adaptable hunters. That means they can eat many different kinds of food using many different techniques. (Not many animals can do that!)

"When killer whales do attack a gray whale, several things happen:

  • The victim is almost always a calf. This means the orcas usually have to separate the calf from its mother. Doing this takes coordination, skill, and communication among many killer whales. (This can take up to 6 hours.)
  • After the calf is separated, the killer whales attack in very deliberate ways. They often teach the youngest of the killer whale pack how to make the kill. Usually, just the victim's tongue and lower jaw are eaten. This is a bit of a mystery, considering there is a lot more meat on the whale and the kill took extraordinary amounts of energy.
  • When attacks on gray whales do happen, the entire process is rarely seen from start to finish. Killer whales are like wolves in that a pack works together with strategy to make a kill."

Transients and Residents: Different Killer Whale Pods

Photo Mike Hawe

Photo Lindescom
Resident Orcas feed on fish—but NOT usually on marine mammals. Transient Orcas feed on marine mammals. How can you tell them apart? Look at the top of the DORSAL fin. If it is rounded, the orca is a resident. If it is pointed, the orca is a transient.

How would you identify the Orcas in these photos?

Try This! Journaling Questions

  • Imagine you are a gray whale mother taking your calf on its first migration. Describe your hopes and your fears for the long journey north. (Also see Literature Link: Whale Journey)
  • Think of a "journey" that you have made in your life. It can be a trip OR a series of events in order to meet a goal. What were the dangers or scary parts? How did you face and overcome them?

National Science Education Standards

  • Organisms have basic needs.
  • All animals depend on plants. Some animals eat plants for food. Others eat animals that eat plants