Contributed by Naturalist Tom Lewis
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
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
how to swim. However, they do this in a very specific manner.
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
This! Discussion or Journaling Questions
- How could swimming against the tidal current
help a calf?
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?
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