The Birth of a Gray Whale in Monterey Bay, California
By Nancy Black and Richard Ternullo
Gray Whale Calf
The highlight of this Gray Whale season was the unexpected and spectacular
birth of a Gray Whale calf during one of our whale watching
trips. On January 15 we were aboard the Pt. Sur Clipper on a Monterey Bay
Whale Watch trip. There was light to moderate rain with strong southerly winds
west of Pt. Pinos. These conditions forced us to seek the shelter of the Bay
and search for whales migrating inside the protection of the Bay.
observing a single large Gray Whale at about 11:35 about 1 mile north of Pt.
Pinos. The whale was slowly swimming in a wide circle, frequently surfacing.
The whale would periodically make a high arch as if to begin a fluke-up dive,
but then submerged with no visible flukes above the surface. The whale then
began swimming in ever tightening circles and surfacing even more often.
At this point, Captain Richard Ternullo made an offhand comment to Biologist
Nancy Black that this whale seemed as if she was about to give birth. This was
partly in jest and partly to account for its unusual behavior. The whale was
on the starboard (right) side of our boat when it unexpectedly surfaced close
by and a newborn calf popped right out of the water next to the mother for
its first breath at 11:57. A large dark cloud of blood appeared around the
posterior portion of the mother. The infant whale had clearly folded flukes.
It swam awkwardly and would jut its head above the surface and then throw
its flukes high in the air and submerge. After about five minutes, the calf
calmed down into a more regular and normal surfacing motion.
We made every effort to avoid any activity that would disturb the mother or newborn calf. After the calf
seemed stabilized, we left the whales and began observing other whales that
had entered the area. Along with us, there were about 25 passengers who were
truly amazed at what we had just witnessed. The was a remarkable encounter and
nothing like this has ever been witnessed in the Bay before.
Thirty-nine mother/calf pairs were recorded for Monterey Bay during the 1998 southbound
migration. Although Gray Whale mother/calf pairs are sighted each year, with 27
noted two years ago, this year's number was the most ever documented since we
began noting them four years ago. Other Gray Whale shore census stations also
recorded a record number of mother/calf pairs. The Gray Whale Census Station at
Granite Creek (south of Monterey), operated by the National Marine Mammal Lab
(NMFS), recorded over forty mother/calf sightings. Over 100 observations of such
pairs were recorded farther south at the Pt. Vincente (Palos Verdes Peninsula)
Observation Station, manned by volunteers from the Los Angeles Chapter of the
American Cetacean Society.
Most Gray Whale calves
are born in a relatively narrow period of a few weeks spanning the last week
of December and the first two weeks of January. Since Monterey Bay is a
relatively short swim (10 to 14 days) to the lagoons in Baja California, it is
not surprising that calves are born during the southbound migration. However,
increased observations of calves indicate that something else may have
influenced pregnant females to migrate a bit later than usual.
Wayne Perryman (Southwest Fisheries Science Center, NMFS) suggested that due
to the warmer ocean temperatures related to El Nino, the whales may have
stayed longer in their Alaskan feeding regions. Normally the ice moves south
and covers the feeding areas, but this season the ice moved south a bit later than usual,
allowing the whales to spend more time feeding. This could provide an
advantage for pregnant females as they need to gain as much weight as possible
to increase their chances of giving birth to healthy calves and having enough energy
reserves to nurse the calves for many months.
Wayne Perryman, who presented
his research at the Marine Mammal Conference in Monaco this past January,
found that during years when the ice moves in late, Gray Whales are more
successful at producing healthy calves with higher survival rates through the
northern migration. His group monitors the mother/calf pairs during their
northern migration at his census station at Pt. Piedras Blancas
(north of Morro Bay) and predicts
that this year there is likely to be a relatively large proportion of
Few births are witnessed, even with over 23,000 Gray Whales in the population.
Alisa Schulman-Janiger, director of the census station at Pt. Vincente, knows
of only 6 other reports of observed births either on migration in southern
California or in the lagoons. Researchers such as Marilyn Dahlheim of the
National Marine Mammal Lab, who has spent over 5 years studying Gray Whales in
their breeding lagoons of Mexico, have never seen a birth. Therefore, the birth
we witnessed in Monterey Bay on January 15 was a very rare event that will be
remembered for a long time!
Note: The Gray Whale calf in the photograph is not the one born on January 15. Unfortunately no photos of that calf were available, so another photo was used to illustrate the story.