Gray Whales (Eshrichtius robustus) are baleen whales reaching 40-50 feet in length and weighing in at up to 40 tons. Their slate gray skin bears the colorful pattern of scars left behind by parasites and two
blowholes on top of their head. An average whale’s life span is between 55 and 70 years.
Gray whales feed primarily on crustaceans, which they scoop with sediment off of the sea floor. This is unique among whales,
and makes them particularly suited to coastal habitats. They do also skim plankton from the surface waters, especially in their
northern feeding grounds. In place of a dorsal fin, gray whales have a characteristic series of bumpy “knuckles” along their
Gray whales migrate each winter from the frigid Arctic waters to mate and calf their young in the protected lagoons of Baja
California Sur. San Ignacio lagoon is one of the last undeveloped gray hale birthing sites on the planet, and has been designated
a UNESCO Heritage Site.
Each October, as ice begins to push southwards in their Arctic feeding grounds, the gray whales embark on a 5-6,000 mile trip
south to Baja California. This incredible journey is believed to be the longest annual migration of all mammals.
The first whales to arrive in San Ignacio are the pregnant females who seek a safe birthing location for their calves. Gestation
period clocks in at 13 months, and most calves are born in the sheltered lagoons of Baja California around January. They seem
to choose these protected bays with shallow water to protect their young from predators such as sharks and orcas.
Newborn gray whales are about 15 ft in length, weighing about 2000 lbs! Most females birth a single calf every 2 years starting
around the age of 8-9 years. The calves nurse for 7 months.
Gray whales were previously subjected to whaling, especially in Magdalena Bay in the mid 1800’s. Since 1949, they have been
protected from whaling by the International Whaling Commission and are no longer hunted on a commercial basis. The current
Western Pacific population has recovered to about 18,000 individuals and is stable, being removed from the Endangered
Species List in 1994. The Eastern Pacific whales number only about 150 individuals and are considered critically endangered
and threatened by fishing and oil and gas exploration.
Gray Whale Behavior Identification Guide
How many will you spot?
A whale leaps out of the water head
first, Usually, they roll in the air to land
on their side, creating a big splash!
A whale at the surface rolls onto its
side, raises a flipper out of the water,
and then hits the surface with it.
A whale lifts its upper body with at
least one eye out of the water. This
behavior allows the whale to look
around and see what is happening
above the water surface. Cetaceans
have an excellent vision in as well as
out of the water.
This refers to when a whale dives down
but leaves its tail out of the water, then
slaps the surface of the water with its
fluke, sometimes repeatedly. The
sound can be very loud and may be
heard for some distance.
A whale lifts its tail out of the water
before diving. It flukes in order to
descend steeply beneath the surface
to greater depths.
When a cetacean comes to the surface
to breathe, it releases a lot of air, called
its spout (or blow), when it exhales.
The breath is made of warm air and
water droplets. The gray whale blow
is typically low and wide, reaching up
3-4 m in height, and is often described