A Humpback Whale calf is between 10 and 15 feet in length when born and weighs up to 1 ton. The characteristic barnacles under the chin are, of course, not there so a newborn calf is a perfect specimen.
The calf is brought to the surface by the female for it’s first breath of air and from then on begins to swim and begins the learning process. It is not long before the calf is head lunging and taking it’s first look around.
In this stage of life the Humpback Whale calf is vunerable to predators and also to damage from male Humpback Whales trying to mate with it’s mother.
Humpback Whale calves soon accumulate scarring from male Humpbacks pushing it out of the way to mate with it’s mother.
It’s not easy being a baby Humpback Whale.
Humpback Whales are mammals so the calf must drink it’s mothers milk from birth. The female Humpback Whales milk is rich in fat with up to 60% of the milk being fat. This ensures the calf puts on weight quickly for it’s long migration back to Antartica.
A baby Humpback whale will consume around 200+ litres of milk per day. You can identify a feeding calf because the female Humpback usually stays underwater while the calf returns to the surface every few minutes to breath between feeding.
A baby Humpback will usually surface 4-6 times before you see the mother surface to breath. There are exceptions to this rule as a few females will feed their calves by remaining motionless in an upright position with their tail in the air while the calf feeds under water though this type of feeding position is relatively rare.
Humpback Whale calves are usually positioned over their mothers head when swimming. This protects the baby from a predators attack from below.
I have observed Humpback whale calves crossing the mothers head when a male Humpback whale approaches. The female Humpback will usually place herself between the approaching male and her calf.
A female Humpback whale can also display the same behaviour when approached by a vessel.
Some female Humpbacks prefer to stay away from whale watching vessels with their calves while others appear to enjoy showing off their calf to the boat. I have actually seen a female Humpback seemingly lift her calf out of the water on her head and back right in front of a boat.
A calf will generally stay with it's mother for around 12 months before becoming a juvenile whale and heading off to make it's own life.