Mothers are renowned for doing all that they can for their kids. In the animal kingdom some go to extreme lengths – including some devious tricks – to get the very best outcomes for their precious offspring.
To celebrate Mother’s Day, we asked University of Melbourne experts from the School of BioSciences, Professor Raoul Mulder and Dr Kath Handasyde, and aquarium curator and diving officer John Ahern, to nominate their top seven “super mums”.
1. The HELICOPTER MUM
If you think human babies are the most dependent in the animal kingdom, think again. At least human mothers can let go of their babies every now and then. For the first four months the mother orang-utan is constantly carrying around its baby. And what’s more, for the next two years the baby orang-utan will be completely dependent on mum. At five it will still be breastfed, so it’s no wonder most female orang-utans don’t have another baby until their young one is around eight! “If you want helicopter parenting, the orang-utan is probably the most extreme example, though by necessity rather than choice,” Professor Mulder says.
2. The FINICKY MUM
The strawberry poison-dart frog of Central America wants the very best for its tadpoles, even to the extent of giving each tadpole its own personalised pond. This tiny frog is only about 2cm long and lays just three-to-five eggs at a time. But each egg gets royal treatment. Once they hatch the mother carries each tadpole one at a time up to 30m up a tree in search of isolated pools of water among the leaves and tree branches for the tadpoles to grow up in. The mother will keep visiting each in turn providing unfertilised eggs for them to eat. Thanks mum!
3. The Foster Mum
The cuckoo is the ultimate outsourcing mum. Rather than rearing her chicks herself the cuckoo instead lays her egg in the nest of a completely different species of bird, turfing out one of the original eggs so as not to raise suspicion. The cuckoo has also evolved to lay eggs that mimic those of the new unsuspecting host, which is tricked into thinking the cuckoo egg is one of her own darlings. The cuckoo egg then hatches early and evicts the host’s own eggs before they hatch, leaving the cuckoo chick as the precious only-child of the unknowing foster mum. “It makes perfect sense for the cuckoo because raising offspring is costly and if you can get another species to do that for you, you are ahead. But for the host it’s very costly,” Professor Mulder says. “They end up working themselves into the ground to feed these chicks that are from an entirely different species. They are the ultimate foster mums.”
4. The Conscientious Mum
A crying baby always puts everyone on edge and some of us will run a mile from the noise, but for a mother koala the cry of any koala baby is virtually impossible to ignore. “They have a deeply innate response to cries of their babies, and they will even pick up a baby that isn’t their own if it is making a distress call,” Dr Handasyde says. Even when the babies are weaned, as long as the mother hasn’t got a new baby in her pouch, she will happily continue to carry the baby around on her back even when ‘junior’ is large enough to be off fending for itself. Dr Handasyde recalls during one long-term field project, a mother who was still carrying a 4kg “baby” around when she herself weighed only 7.5kg.
5. The Mouthy Mum
Some mothers are so good they will even starve themselves for their children’s sake. African cichlid fish don’t just lay their eggs and forget about them, they actually carry them around with them … in their mouths. This is a pretty effective way to protect them from predators, but it comes at a cost. It is hard to eat when your mouth is full of scores of developing fry! While some species of cichlid mothers can manage to eat something, and there are cases of cannibalism, many don’t eat at all for up to four weeks until the fry are independent. Even then the cichlid mother will be on hand to protect their free-swimming babies, opening their mouths as portable hiding places when danger threatens. “It is amazing to watch,” Mr Ahern says. “The female will be sitting there with her mouth open and the young will be swimming around her mouth, and if there is a threat the young will all dive in and she will snap it shut.”
6. The Selfless Mum
The octopus mother goes even one better than the cichlid – she starves herself to death. Octopuses lay their precious eggs in safe places like caves or even discarded bottles, and then the mother stays constantly with them protecting and caring for them. She cleans them of parasites and keeps them oxygenated by gently passing a small current of water over them and moving them around. It gives her no time to go hunting for crustaceans to eat, and by the time the eggs hatch she is so weakened she is at death’s door. In one famous incident scientists monitored a mother octopus in Monterey Bay off California who brooded her eggs for over four years while she wasted away. “They live short lives, grow quickly and then they reproduce once, and then that is pretty much it,” Mr Ahern says.
7. The Mum who gives it all
Starving yourself to death is one thing. What about offering yourself as a first meal for your young? That is what the crab spider mother does in what is a truly ghastly fate. It is a phenomenon known as matriphagy, where a mother is consumed by her young. In the case of the crab spiders, it starts with the tiny spiderlings swarming over her and sucking out the liquid from her leg joints. Eventually the mother weakens and becomes decrepit, at which point the spiderlings just eat her. “They literally suck her dry and then start cannibalising her,” Professor Mulder says. Happy Mother’s Day!
Banner Image: Michael Gwyther-Jones/Flickr
Multi-media research: Aidan Western