WWF-Canada Blog:
Homepage


Five marine mothers and the incredible ways they care for their young

It’s WWF Water Wednesday, when Love Nature television explores the unique characteristics, natural history, environmental challenges and threats facing waters and aquatic species in Canada and around the world, hosted by WWF-Canada president and CEO David Miller. Tonight at 9 p.m. ET/PT watch Glowing Seas, and below read on about some of the most extraordinary examples of motherhood in our oceans.

For many animals, the relationship between mother and child is one of the most vital and important factors of survival. Getting through the early years of life can be perilous for animals in complex and demanding water ecosystems, and often it’s the mother who feeds her young, teaches them to care for themselves and protects them from threats for extended periods of time while they develop and become self-sufficient.

Underwater mothers face challenges and dangers we cannot imagine, including those posed by human activities such as pollution, habitat loss and underwater noise from shipping and development, which can affect the ability of marine animals to communicate and navigate. WWF-Canada is working to better understand the impacts of industrial activity on belugas, orcas and other species and to protect the marine habitats essential for their survival.

Here are a five examples of incredible mothers caring for their young, and of the extraordinary bond forged between mother and child.

Orca whales

Many animals raise their young until they are self-sufficient, and then parent and child part ways. In one variety of orcas, known as Bigg’s killer whales, offspring disperse from their mothers once they reach maturity or have offspring of their own. But another variety, resident killer whales, stay with their groups or pod for life, meaning mother and child stay together their entire lives, even after they have offspring of their own. Mothers have just one calf every five years, and the mortality rate in the first year is extremely high, so mothers have to watch over their young 24/7. For the first month of their lives, the calves don’t sleep, so mothers forgo sleep to stay up with them. Throughout its life, a resident killer whale will only separate from its mother for a few hours at a time: to forage and mate.  

Orca (Orcinus orca), 3 year old female and her cub. © William W. Rossiter / WWF

Orca (Orcinus orca), 3-year-old female and her cub. © William W. Rossiter / WWF

Sea otters

Most marine mammals have a layer of blubber to help them keep warm, but sea otters rely only on dense fur and on generating a lot of energy by eating. When a sea otter is pregnant, she must increase the amount she eats to keep her baby alive, consuming up to 50 per cent of her body weight daily. After giving birth, mother sea otters are weakened, but must forage for themselves and their ravenous young for the first six months of their offspring’s life. By the time her young begins to wean, the mother sea otter’s energy demands have increased by 96 per cent.

Sea otter (Enhydra lutris) swimming on its back. © Alan BURGER / WWF-Canada

Sea otter (Enhydra lutris) swimming on its back. © Alan BURGER / WWF-Canada

Eastern gray whales

Gray whales have the longest known migration of any mammal , swimming a round trip of 16,000 to 19,000 kilometres each year — with young in tow. Some whales even give birth mid-migration. Mother gray whales don’t feed during their months of migration, but they do nurse their calves who drink about 50 gallons of their mother’s fat-rich milk per day. For the Eastern gray whale, rearing a child is an incredible test of endurance.

Grey whale spyhooping with its mouth open. What looks like a row of teeth is actually the whale’s baleen, a row of keratin-rich bristles used for filter-feeding. © James Michael Dorsey

Grey whale spyhooping with its mouth open. What looks like a row of teeth is actually the whale’s baleen, a row of keratin-rich bristles used for filter-feeding. © James Michael Dorsey

Beluga whales

Belugas need to consume 40 to 70 pounds of food daily to survive, and for the first year of her calf’s life, a mother beluga must add to this the responsibility for feeding her calf as well. Calves begin nursing within a few hours of birth and continue to nurse regularly for an entire year — this after a gestation period of 14 to 15 months. After a year, calves supplement their diets with shrimp and fish, but will continue to nurse for another year. Baby belugas are very dependent on their mothers, and so pods are segregated into males and females with young.

Beluga whale (Delphinaptherus leucas). © Andrey Nekrasov / WWF

Beluga whale (Delphinaptherus leucas). © Andrey Nekrasov / WWF

Walruses

By animal standards, walruses spend an extremely long time feeding and raising their young. A baby walrus will nurse for an entire year, and then remain with their mother for two years or more. Mother walruses are very protective of their young. A mother will pick a baby walrus up with her flippers and hold it to her chest if it’s threatened, diving into the water with it to escape predators. Walruses have young fairly infrequently, so it is vital for them to protect their offspring.

A 3-month old Atlantic walrus calf (Odobenus rosmarus) finds refuge on her mother's back in Igloolik, Nunavut, Canada. © Paul Nicklen/National Geographic Stock / WWF-Canada

A 3-month-old Atlantic walrus calf (Odobenus rosmarus) finds refuge on her mother’s back in Igloolik, Nunavut, Canada. © Paul Nicklen/National Geographic Stock / WWF-Canada