Parenting in the animal kingdom is a matter of survival, so sometimes the methods of parenting can seem a little... extreme. Whether it's the guillemot chick's perilous leap of faith, the panda mother's brutal favouritism, or the sand tiger shark's internal cannibalism, parents raise their young in unconventional ways.
Worst animal parents
Common guillemots
When a chick leaves the nest for the first time, it’s always a scary moment as it flaps its young wings and starts to fly. However, common guillemots (known as common murres in North America) take this a step further. First by not bothering to build a nest at all, instead eggs are laid on the bare rock of cliff ledges – and its thought that the shape of the egg prevents it from rolling off the ledges.
Second, guillemot chicks leap from the cliff ledges – leading to the name, ‘jumplings’ – before their wings are developed enough for flight, accompanied by their father. This foolhardy parenting strategy has a reason though, as it seems that they can be fed more at sea than if they’d stayed at home.
Harp seals
The female harp seal gestation period is actually longer than a human’s, lasting about 11.5 months albeit some of that consists of a delayed implantation. A very quick birth, sometimes as short as 15 seconds, takes place on pack ice and the pup is suddenly exposed to cold temperatures with minimal blubber layers.
During the following 12 days of nursing, the pup rapidly gains weight and thickens it blubbery layer. After the 12 days though, the pup is abruptly abandoned by its mother on the ice, unable to hunt for itself or even swim yet, leaving it incredibly vulnerable to both the environment and predators such as polar bears or orcas, especially as the pack ice begins to melt…
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Common cuckoo
Neither the female nor the male common cuckoo bother with looking after their eggs or chicks. Instead, the female lays eggs in the nests of other birds. Cleverly, she removes an egg from the nest before laying her own, so the new parent doesn’t spot that there is a new addition.
This is a risky strategy, as despite the female cuckoo’s hard work and similarly coloured and patterned eggs, the potential host may identify that the egg is an imposter, make a hole in the shell and eject it from the nest. However, if not, the cuckoo chick will hatch, push out the other eggs, and then demand food from its parents – even when it is much bigger than them.
Brown-headed cowbirds
This brood parasitism behaviour is also particularly well-known in the cowbirds, and in North America, the most widespread species is the brown-headed cowbird – named for the males’ brown heads contrasting with the iridescent black body. More than 200 host species’ nests have been documented containing a brown-headed cowbird egg.
However, the brown-headed cowbird’s eggs do not necessarily match the host’s eggs in pattern and size, meaning they get rejected. Or the cowbird may lay her egg in the nest of a host species with the wrong diet, meaning the chick normally dies.
Giant pandas
While the male giant panda plays no part at all in raising his offspring, a female giant panda is a very good parent – as long as she has given birth to just one cub.
If she has given birth to twins, which occurs about 50 per cent of the time, she will end up focusing on the stronger one cub at a time. The weaker cub is ignored, and will die. In captivity, keepers will regularly swap the cubs around to ensure that both receive her attention.
- Red panda vs giant panda: what's the difference between these adorable, furry animals?
- Do pandas only eat bamboo?
Hamsters
A stressed female hamster can be a fatal situation for her pups, as she may turn on them, killing and even eating them – not an ideal situation if said female hamster is a pet belonging to young children!
Whilst it is a well-known behaviour in captive hamsters, this can also occur in the wild, thought to be caused by a poor diet. A study in France replicating the corn diet of wild hamsters in farmland found that they were suffering from pellagra.
Nazca boobies
If a female Nazca booby lays two eggs, the older chick will push its younger sibling out the nest and cause its death from exposure or predation. Such siblicides have also been seen in other booby species, but adult Nazca boobies have actually been seen to contribute to this, including pecking at and stamping on the younger chick.
Why bother laying the second egg if the resulting chick is going to be killed by a sibling or parent? It’s basically an insurance policy, in case the first egg doesn’t hatch or the first chick doesn’t survive long after hatching.
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Hoopoes
Hoopoes take the idea of laying extra eggs a step further. Recent studies have found that female hoopoes will produce extra eggs when food is abundant, which initially seems sensible as a method to produce more fledglings later in the season.
However, it seems that the hoopoes are actually using the available resources to produce extra eggs, and those chicks that will act as a larder – and they will feed these extra chicks to the older chicks in their nest.
We named the hoopoe as one of the weirdest birds in the world.
Sand tiger sharks
Female sand tiger sharks are either brilliant mothers, or really awful ones, and which opinion you have depends on which of her young you’re considering. Similarly to the hoopoe and the ladybirds, they provide a larder of young – albeit whilst still within her body.
After mating, she produces up to 50 embryos in each of her two uterine horns. The first one to reach 10cm in length begins to eat all of the other smaller embryos until it is the only one left, a form of intrauterine cannibalism called ‘adelphophagy’ (eating one’s brother), and then goes onto feed on the unfertilised eggs, called ‘oophagy’.
The sand tiger shark is one of the rarest sharks in the world.
Barn owls
The beautiful barn owl is a deadly hunter, preying mainly on small mammals – but occasionally it will eat its own family. The chicks hatch in the order that the eggs were laid, and if food is scarce, the older and larger chicks may turn on their younger, smaller and weaker siblings and eat them.
Sometimes this behaviour can extend to the parents as well. If the weather is very poor, or there are other reasons for them being unable to hunt, they can also kill and eat their own chicks.
