Technology & Science·Q&A

Mother birds get a bad rap, though some deserve it

With Mother’s Day coming up, it’s time to get some inspiration from the animal kingdom. Birds provide the best and worst examples of motherhood from eating their young to sacrificing themselves for the survival of the chicks.

In honour of Mother's Day a look at some avian parents

Bird moms don't get a lot of respect for their skills. Here a baby starling gets a meal (Ferne Williams )

Bird moms have bad reputations in the animal kingdom. Especially when there are so many other doting mothers to choose instead. 

From elephants who have a whopping 22-month gestation and then give birth to a 250-pound baby, to the polar bear who spends eight months fasting to stay close to her cubs and feed them.  

Birds don't quite get their due even though some of them are incredible moms. Here's why.

Where does the bad rap come from?

Bird moms can range from the good to the bad to the ugly.

Cuckoos are famous for laying eggs in other birds' nests. That way they don't have the hassle of raising their own chicks.

But then there are the eclectus parrots who sometimes kill their own young and select for particular sexes.  

So, not all birds deserve a homemade card this Mother's Day.

There must be some good parenthood stories in the bird family, right?

Yes, for starters, they regurgitate their food to feed it to their chicks. If that doesn't score some points, I'm not sure what does. And, there are other examples of really good bird moms. 

A Laysan albatross in flight.

For instance, there's one of the world's oldest wild birds, a Laysan albatross named Wisdom that nests at Midway Atoll. On February 17, she hatched her 41st chick. That's 41 breeding seasons. She's 66. That's an incredible feat of motherhood. 

And there's the least tern. These birds make sure their eggs are just the right temperature: on hot days they'll go for a quick dip in the water and come back to sprinkle cooling droplets over their eggs, or they'll stand there for hours with wings spread shading them from the hot sun. That's dedication.

Is it true if you touch a hatchling the mother bird will abandon their young?

No, in fact, there's no evidence that birds will abandon their hatchlings if touched by someone. Birds generally have a really poor sense of smell and rely much more on eyesight for survival. It takes a lot for a mother bird, or any mother, to abandon her young if she's naturally inclined to rear them.

If the nest has been disturbed, the mother bird has to make a call: she has to decide whether that disturbance represents some sort of threat like if the nest has been discovered by a predator. Then, the mother bird can choose to relocate the nest and the young within — this tends to be for birds that are often very committed to child rearing — or abandon the young and wait it out until next breeding season and try again. 

An osprey soars to its nest. (Submitted by Michael Wilkshire)

But depends on the bird. Ospreys are famous for their terrifying defense of their nests. They will stop at nothing to make sure their chicks are protected. 

Why are there such wildly different behaviours amongst all the different types of birds?

It comes down to something in evolution called trade-offs. There's always a tradeoff in any evolutionary strategy just like in any decision in life.

For some birds — say some whose eggs are at a constant risk of predation by other birds, like robin's eggs by magpies — they generally don't invest as much into their offspring, because there's a chance that it won't survive beyond the first year, or even first few moments of life.  

Whereas an osprey, who has small clutches of eggs, spends a lot of energy defending her nest and her young; she is way less likely to abandon her nest or eggs in danger because she's got way more invested.

Magpies have a fondess for robins' eggs. (Creative Commons)

In evolution you have a limited amount of energy. You can spend it making a lot of young then not really caring for them as they grow up, or you can spend it making few young but making sure they are successful.  

Different birds have evolved different strategies because of their size, ability to defend a nest, presence of predators, lifespan — all of those factors go into what strategy works best for one species over another.

Birds of prey, for instance, need to learn how to hunt and so rely on their parents to provide them with tutelage.

Take the oystercatcher, for example. These coastal birds are black and white with a bright orange beak and feed on — you guessed it — oysters. They will eat lots of other things as well, from worms to insect larvae, but bivalves are their favourite. It takes some experience to crack open a mussel or an oyster, so the mother bird must teach the hatchlings how to access this yummy treat.

Presumably, by spending more time with their offspring, the more likely those offspring are to survive and reproduce.

So maybe bird moms don't deserve Mother of the Year, but some of them rival even the most helicopter-like parents in ensuring their offspring have the greatest chance of survival.

About the Author

Torah Kachur

Science Columnist

Torah Kachur is the syndicated science columnist for CBC Radio One. Torah received her PhD in molecular genetics from the University of Alberta and now teaches at the University of Alberta and MacEwan University. She's the co-creator of scienceinseconds.com.