Among the oceanic dolphin species, they date back eleven million
years or more. Orcas are extremely social animal they are cute, knowledgeable,
alert, active, and sophisticated apex predators. They have emotions, care, and
love for their group members and generations, they even grieve over a deceased
member just like humans, one of the incidents noted in 2018 where an orca named
j35 lost her calf and carried her dead for days through the ocean. They hunt in
packs like wolves and dwell in herds like elephants. They are the largest
members of the dolphin family, averaging 23 to 32 feet in length and 6 tonnes
in weight. They are one of the few mammals to go through menopause. They
possess Bio sonar (echolocation) abilities.
 |
| image: creative commons |
Orca Brain
According to Neuroscientist Lori Marino and a team of researchers, Orca (killer whales) has the second biggest brain among all ocean mammals' weight (15 pounds). They found that orca brains are well-wired for sensing and analysing three-dimensional water environment. They possess Bio sonar (echolocation) abilities because they have evolved immersed in water which is a tremendous transmitter of sound four times faster than air, as a result, they utilize sound to see the world around them.
Cortical thickness (cerebral cortex) cognition
This portion of brain is related with memory, consideration , dialect , thought, and awareness. Additionally, orcas have the thickest corticals. The killer whale has more cortical neurons and gray matter than any other animal, including humans.
Gyrification
Gyrification is the number of wrinkles and folds in the cortex. Gyrification increments the amount of cortical nerve tissue that processes information. Gyrification allows cells to be closer to each other. Due to Gyrification, it requires less time and energy to transmit neural impulses. It increases the speed of brain cell communication.GI for Orca is 5.70. This makes the orcas the most gyrified brain in the world
Brain lobes (Paralimbic system) and Amygdala
This part of the brain is related to memory and navigation.
And this part of the brain is highly developed in orca. Amygdala is associated
with emotional learning and long-term memories.
Orcas have the world's most elaborate insular cortex, which is connected to memory.
The most fascinating part of the orca brain that amazes
scientists is the insular cortex (insula) it is involved in consciousness and
playing diverse functions linked to emotions that include compassion, empathy,
perception, self-awareness, and interpersonal experience.
Matrilineal Family Structure and Menopausal orcas
Orcas have intricated social structures with a female
at the top. The young spend their whole lives with their mothers, mother prepare
them for life through training. They breed primarily in the summer, and their
lengthy (15 to 18 month) gestation period results in the delivery of just one
calf at a time. If a mother is still alive and doesn't have any sons left, she
might be observed swimming with her daughter and grandkids as well. Although
adult daughters who have children of their own may temporarily distance
themselves from their mothers to care for their needs, they are typically seen
traveling close by. Males develop between the ages of 12 and 14, and females
begin to procreate at 11 to 13 years of age. Because they are often larger than
female orcas, male orcas are more reliant on their mother for food.
Menopause occurs in cows (female orcas) around the age of
40, or extremely unusual circumstances, 45. Male orcas live 29 years on
average, to a maximum of 50 or 60 years, whereas female orcas live an average of
50 years in freedom, with some living to 80 or 90. The 1960s, grandma theory
can be used to explain one of the reasons why menopause has evolved in orcas.
According to this theory, grandmothers' assistance allows a younger mother to
have more children and they also share their expertise and experience about how
to care for themselves and their baby.
Orca habitat and what they eat
Orcas are found in every ocean of the world Orcas are
primarily found in cold water due to the availability of food, though they
travel in groups of 3 to 50 or more members they can cover 50 km in an hour and
can even be found in tropical waters. The majority of orcas species are present
in coastal water areas, polar ice caps, the north Pacific Ocean, particularly
the Alaskan coast, and Baja California (Mexico). In the North Atlantic, they
can be found from the waters of Newfoundland and Labrador to Iceland, Norway,
and the British Isles, off the shores of Argentina, South Africa, New Zealand,
and the Galapagos Islands, killer whales can be observed in the Southern
Hemisphere.
There are various ecotypes of orcas, some of them are
Resident orca, Southern Resident orca, and offshore orcas, and depending on
where they dwell, their diets vary. However, some of the components of their diets
include tuna, salmon, and seal. Depending on the availability of food and the
ecology of their habitats, squids, sea lions, penguins, whales, and porpoises
are among the other food sources.
How they attack their prey
They attack in groups and are distinguished by their
apparent communication and high level of group coordination. They snoop up on
their victim from behind, dive beneath it, and then emerge, slicing it into
pieces and sharing it. They are trained for shows despite their unique hunting
methods. Namu, an orca who was kept in captivity at the Seattle Aquarium and
had become completely tame, drowned when he tried to escape in 1967. Two
additional orcas that are trained and kept in captivity are Shamu and Skana. In
1968, a group of killer whales was captured in British Columbia's garden bag
and sold to the Vancouver Public Aquarium. one of the members named Hugo (male
orca) was sold to Seaquarium Miami, Florida, and there he has shown great
interest in people.
