Killer Whales are back in Monterey
It’s that time of the year again when we are getting to the end of the Gray Whale migration north and we are starting to see our summer Humpback Whale coming back into the area. Of course, this also means we are in the time of the year when we start to see more of our Orcas or Killer Whales.
Orcas are the largest member of the dolphin family we see here in Monterey. Males can reach a length of 20 to 26ft (6 to 8m) and weigh as much as 12,000lbs (5443Kg). Females can reach a length of 16 to 23ft (5 to 7m) and weigh as much as 8,400lbs (3,800kgs). Like all dolphin species, Orcas travel in family groups called pods that are usually made up of an average of five individuals with the oldest female being the dominant member of the pod with the other individuals being related females and their offspring. Adult males can be found with pods of unrelated and related females but can also be seen enjoying time by themselves. Females give birth to one calf about every five years and the entire pod comes together to help raise and teach the young calf everything it will need to become a contributing member of the pod. These close-knit communities have been likened to the complex societies that we see in only elephants and higher primates such as humans.
The scientist that have been studying these charismatic animals have found that many of these different family groups exhibit differences in their behaviors, vocalizations, feeding strategies, and even in their morphology, and genetics. Because of these difference scientist have classified Orcas into three major types: Resident pods, Transient pods, and Offshore pods. Resident pods are most commonly sighted in coastal waters of the northeast Pacific and feed mainly on fish and sometimes squid. Offshore pods are found, as their names suggest, mainly offshore and feed mainly on schooling fish but may also feed on marine mammals and sharks. The Offshore pods are some of the least understood of the Orca subpopulations as they were not classified until 1988. The final classification of Orcas, the Transient pods, is what we see here in Monterey Bay. The Transient Orcas that we see here specialize in the hunting of marine mammals and this includes the larger species of baleen whales like the Gray Whale.
During the month April and May we get the privilege of seeing mother Gay Whales and their calves coming through the bay on the calves first northbound migration. The Mother Gray Whale first traveled through Monterey starting in December on her way down to the breeding and calving lagoons in Baja Mexico. While in these warmer waters after a 12 to 13 month gestation period she gave birth to a single 16ft (4.9m) calf weighing 1,500lbs (680kg). Once this calf was strong enough mother and calf left the safety of the lagoons and start the long swim back up the coast in order to the rich feeding ground off of Alaska. When the pair reaches Monterey they must make a choice of crossing the mouth of the bay and over deep water which cuts off about fifty miles of their migration or stays in shallow waters along the coast in hopes to stay off the Orcas raider. Many mother and calf pairs are lucky enough to pass through Monterey without any trouble from the Orcas but a few are unlucky enough to become the target of an Orca hunt.
The main targets of these hunts are the newborn calves as they are much slower than their mothers and do not yet have the strength to put up much of a fight. However, mother Gray Whale is known to defend her calve vigorously during these hunts. She can slam her large tail down on the Orcas and as she can weigh as much as 80,000lbs (35,000kg) this can cause some damage to the Orcas. The mother Gray Whale can also roll over on her belly and support her calf at the surface making it harder to reach by the Orcas. During these hunts, the main strategy of the Orcas is to separate the mother and calf by jumping out of the water and pushing the calf off the mothers back and stomach. Once the mother and calf are separated the Orcas will than jump on the back of the calf wearing it out and eventually drowning it.
These hunts can last for several hours and can be exciting to watch if not a little heart-wrenching. Already this season we have had three confirmed predations on Gray Whales by our Orcas here in Monterey. It looks like it will be a good season to come out and watch our Orcas so book your trip soon and come out early and who knows you might be able to see one of these once in a lifetime evens in person.