Whales are an amazing species that have evolved from land-dwelling creatures millions of years ago (through ancestral bloodlines) to the marine mammals we know today. Over the course of their evolution, whales have made many adaptations towards their oceanic lifestyle to survive and thrive in the underwater world.
To help them adapt to the ocean, whales developed echolocation, thick layers of blubber, modified lungs, better hearing, and larger arteries, among other things, to ensure their survival and prosperity.
Blubber
Blubber plays a significant role in whales’ life. Having blubber allows whales to maintain their body heat and survive in frigid environments that would otherwise be uninhabitable.
Some whales can also use their blubber for energy when food is scarce or during long trips. During migration periods, the blue whale will go without food for up to four months while they migrate and live primarily off of the body fat and calories stored within its blubber.
Echolocation
In addition to having ears toothed whales also use a method known as echolocation to help them navigate the ocean, find food and avoid potential threats.
By using echolocation toothed whales can determine many factors about their environment, such as how far an object is, how fast it is moving, whether it is above or below them, what direction it is traveling in, how large it is, and whether it is a hollow or solid object.
Echolocation is extremely useful in areas where visibility is low and helps whales avoid colliding with other objects when they cannot see what is around them.
Lungs
To survive in the ocean, whales have had to adapt their lungs to breathe easily and hold their breath for extended amounts of time when submerged underwater.
While whales aren’t born with massively large lungs, they can exchange as much as 90% of the oxygen they inhale compared to humans, who only exchange 10 %- 15%.
Larger red blood cells allow whales to transfer oxygen more effectively than humans and other land mammals. When submerged underwater, their diving reflex allows them to distribute oxygen and blood to vital organs while restricting it in other non-essential areas. In addition to all of this, whales can fill their lungs with oxygen in just 2 seconds.
Conscious breathing
Because whales are mammals, they breathe oxygen, and must come to the water’s surface to breathe. Due to this fact, whales are never able to fall completely asleep because if they did, there is a good chance they would drown.
To combat this problem, when a whale needs rest, it goes into a semi-conscious state, and half of its brain shuts down, but the other half of the brain remains conscious, allowing the whale to quickly come up for oxygen and inhale when it needs to.
During periods of rest, whales can often be found logging around (resting motionless) at or near the surface of the water so that they can easily obtain oxygen whenever necessary.
4 Chamber heart & arteries
A big part of a whale’s ability to survive in the ocean has to do with its four-chamber heart & large arteries, which allow blood to quickly pass through the body and effectively move to vital organs.
For example, the blue whale has a heart that can weigh the size of a small car (1,300 pounds), and its arteries are so large that a human could crawl through them.
Excellent hearing
One of the most important senses a whale has is its sense of hearing. Whales have a very acute sense of hearing and can detect sounds made by other whales from miles away, which can be important for mating or locating other whales in a pod.
Having acute hearing when submerged underwater is also extremely important because sound travels 4 times faster in water than on land. Those who have developed good underwater hearing have the best chances of survival, especially species that worry about potential predators.
Survival based adaptations (against predators)
Over the course of evolution, whales (or rather their ancestors) have evolved and adapted their physiology from living and walking on land to living solely in the ocean. These adaptations have played a huge role in their survival in the ocean and, in particular, against other oceanic animals that could do them harm.
Whales have to adapt to a purely aquatic lifestyle. They also had to survive against predators that were already living in the ocean well before them.
So how did they do it? There are a number of specific characteristics or adaptations whales developed as a deterrent or way to protect themselves against predators. As many people know some species of whale have very thick layers of blubber.
This blubber keeps whales warm and acts as a protective barrier against smaller predators such as sharks. In fact some whales can have blubber that measures up to 11 inches thick!
Another adaptation whales developed to protect themselves is related to size. Numerous would-be predators often pass these large marine mammals because they are too large to be successfully attacked. Therefore, attempting to injure and kill a large whale would likely be a huge waste of time and energy.
Speed is also a vital component of their survival. When threatened, some whales can reach speeds of 25 – 30 mph for short bursts to escape potential predators or threats.
Lastly, smaller species of whale and other cetaceans are known to form pods or large communities, which increase social interaction among marine mammals and help deter large predators or minimize the chance of any single animal being harmed as they all belong to the group.
While not always the case, large whales (particularly those that belong to the baleen whale suborder) tend to live more solitary lives and are more likely to travel alone or in small temporary pods.
Unlike smaller species, these whales have a much lower risk of being attacked by a predator and thus do not need to rely on large pods or groups for protection.