For marine mammals such as whales blubber plays in important role in a whales ability to survive in the ocean as their blubber supply keeps them warm in the cold arctic and antarctic waters and provides them with a supply of extra calories during food shortages.
When it comes to eating and searching for prey various species of whale are known to travel towards the polar northern and southern hemispheres during their feeding season due to the large abundance of food that is often found in these climates.
The large amounts of calories these marine mammals consume helps build their supply of blubber allowing them to maintain their body heat and store extra calories for emergencies.
Since whales are marine mammals they are warm-blooded animals so they require constant feeding and/or stored calories in order to survive.
As the weather grows colder and various forms of marine life migrate away from the polar hemispheres certain marine mammals begin their preparation to travel off to their mating grounds.
When mating season comes around the whales take their long annual migration trip from their feeding grounds towards the center of the equator where the whether is warmer and provides an ideal place to mate and reproduce.
During the migration trip some species will forgo eating completely and live off of their supply of blubber and stored calories.
This fasting state can last for several months, which helps explain why having a significant amount of blubber is so important for some species as their blubber/fat is all they have to rely on for energy.
The amount of blubber a particular species has can vary significantly from one species to the next.
In fact blubber can range anywhere from 4 inches to over 1 ft. thick; however the bigger factor in determining a whales ability to stay warm in cold climates is the lipid concentration found in the whales blubber.
The higher the concentration of lipids the easier it is to stay warm and whales with less blubber but higher lipid concentrations can maintain more body heat than whales with lower concentrations of lipids but more blubber.
While not always the case larger whales with a thick layer of blubber tend to prefer living in colder environments as their body is better adapted for dealing with cold/freezing temperatures while smaller whales (often with thinner/less insulated layers of blubber) tend to prefer warmer climates.
Some whale species with extremely thick and well insulated layers of blubber may even be limited in terms of how close to the equator they can travel as they may face heat exhaustion from the additional insulation their blubber provides.
What about non migratory whale species?
Although whales are known for their long migration trips not all species are known to migrate between the cold icy climates and warm tropical waters.
In fact some whale species are known to inhibit the same environment regardless of the time of year and some species migrate in order to maintain their food supply rather than for mating purposes.
Bowhead whales for instance stay in their arctic/sub arctic environment all year-long and may only migrate within their local habitat.
For these marine mammals having a thick layer of blubber is vital for keeping these marine mammals warm throughout the year.
Killer whales on the other hand (killer whales belong to the dolphin family) have been observed migrating in order to maintain their food supply rather than migrating for mating purposes.
Killer whales may travel between various environments throughout the year or choose to stay in the tropical or polar regions of the world all year long.
Why else is blubber important?
For whales blubber is useful for a number of different things besides keeping them warm.
As stated earlier the whales blubber helps protect their vital organs from the cold/freezing waters.
This blubber is the reason whales are able to remain comfortable in freezing temperatures while other animals (such as humans) would easily freeze to death.
While these attacks are rare they do occur and the thick layer of blubber can provide some defense against these attacks and deter would be predators that are looking for an easy meal.
Blubber also provides whales with additional buoyancy when they are in the water and makes it easier for them to rise to the surface of the water after making a deep dive.
Because whales are such large and heavy animals their ability to remain buoyant allows them to swim more effectively rather than just sinking to the bottom of the ocean like a rock.
Lastly, a whales blubber can be used to store additional calories during times when there are food shortages or when migrating to other areas.
Depending on the thickness of the blubber some marine animals can survive for months without food.
In order to minimize their expenditure of calories whales are very efficient swimmers and will limit their speed and body movements in order to use the least amount of calories during their long trip or during food shortages.
To a lesser degree humans and other animals are also survive for weeks without food by utilizing their body fat for energy and minimizing the amount of physical activities being performed.
What other animals possess blubber?
In addition to whales, dolphins and porpoises there are a number of other marine animals that also possess blubber.
Pinnipeds such as seals, sea lions and walruses are known to possess a thick layer blubber as well as sirenians such as dugongs and mantees.
All of these animals are considered marine mammals and as such are warm-blooded, breathe air and give birth to their young rather than laying eggs.