Spring Training!
Contributed by Naturalist Tom Lewis

While many gray whales start heading back to the Arctic, mothers and calves are busy with spring training. The peak number of mothers and calves heading north is usually about six weeks after the peak of other northbound grays. Naturalist Tom Lewis describes his observations of mothers and calves in Laguna San Ignacio:
Newborn Whale
Photo Linda Lewis

"When we see a brand new baby gray whale, its flukes and flippers are very floppy. They have not yet become rigid. It is very difficult for these newborns to swim fast enough to keep up with an adult, so the mothers move very slowly. They are very protective of their young. Once a calf's fluke (tail) and flippers have gained strength, the calf begins to explore the lagoon. Mothers carefully swim with their babies around the lagoon, gradually teaching them how to swim. However, they do this in a very specific manner.

"The majority of the whales, and particularly the mothers with calves, swim in a predictable pattern while inside the lagoon. The tidal current inside San Ignacio can be very strong — as much as 2 or 3 knots. The mothers and calves swim against the tidal current. That means if there is an incoming tide, they will swim toward the mouth of the lagoon. If there is an outgoing tide, they swim toward the upper end of the lagoon. This pattern helps to protect the young calves from an accident, and prepares the calves for their life in the open ocean."

Photo Keith Jones

Try This! Discussion or Journaling Questions
  • How could swimming against the tidal current help a calf?
  • What kind of "accidents" might Tom be referring to in the last sentence of his report?
  • How fast are tidal currents of 2-3 knots? (One knot is 1 nautical mile per hour. A nautical mile is 1.15 statute miles.)
  • Why do you think mothers and calves remain in the lagoons for several weeks longer than the other whales?

National Science Education Standards

  • The behavior of individual organisms is influenced by internal cues (such as hunger) and by external cues (such as a change in the environment).
  • An organism's behavior patterns are related to the nature of that organism's environment