Some animal mothers do some admittedly horrible things to their young, from abandoning them to letting an older sibling beat them up to outright killing them. As a lawyer might put it, there are usually “extenuating circumstances” behind these behaviors. Animal mothers want to increase the chances of their strongest, fittest offspring surviving — even if it means disposing of a weaker juvenile.
Neglect/Abandonment with the Worst Animal Mothers
Some animal mothers apparently just don’t take very good care of their kids. Pandas, for instance, only take care of one cub — even if they have two. The mother panda feeds and cares for one cub, and leaves the other one to its fate. It takes eight or nine months for panda babies to get fully weaned, and it’s doubtful that the mother could successfully nurse them both. Pandas live on bamboo, which is not the most nutritious of foods. From the mother panda’s perspective, it’s better to have one strong and robust cub rather than two weak ones.
The hooded grebe outright abandons younger chicks. She will lay two eggs and take good care of the first one that hatches. The second egg is simply insurance in case there’s something wrong with the first egg. Once the mother grebe is satisfied that her first chick is perfect, she has no interest in the second chick and abandons it.
Some of the worst animal mothers that engage in brood parasitism can’t even be bothered to raise the kids themselves, but foist the job on someone else. The European Cuckoo, for example, lays her eggs in another bird’s nest. Generally, she lays one egg per nest, and her eggs resemble those of her victim. The cuckoo mother will ensure there’s room for her egg by disposing of at least one of the other eggs. The young cuckoo typically hatches before its host’s chicks do and will quickly shove their eggs over the side of the nest, thus ensuring that its hosts feed it and only it.
Brood parasitism is generally associated with birds, but has been seen in fish and insects. Cuckoo bees and wasps lays their eggs in the nests of other insect species, and they will often kill any host larvae they find to ensure their young get taken care of.
The Worst Animal Mothers and Siblicide
Siblicide means one sibling kills another sibling. It happens a lot in the animal world, and the worst animal mothers generally don’t do anything to stop it. In fact, in a lot of cases, the mother just watches as one juvenile kills another.
Birds, especially birds of prey, are notorious for this. The black eagle mother, for instance, will just sit and watch while her oldest chick kills its sibling. Bird species that practice siblicide often show hatching asynchrony, in which the eggs hatch at different times. The chicks that hatch first quickly gain an advantage over their younger siblings in terms of size and strength. Since there are often more chicks than the mother can really feed, the younger, weaker chicks either starve or get killed by their older siblings.
The black eagle is a case of “obligate siblicide,” for the older chick always kills the younger one even when there’s plenty of food. The black eagle mother had never planned on raising both chicks, but had laid the second egg as an insurance policy in case something happened to the first egg. Once it becomes obvious that the first chick is going to be fine, the second chick or egg is considered superfluous and treated accordingly.
Siblicide does occur in non-avian species. Spotted hyenas are an example of “facultative siblicide,” which means the siblings don’t always kill one another. Hyena siblings do, however, always fight each other for dominance within the litter, and the winning sibling gets the lion’s share of the milk and meat. When there’s plenty of food, all of the siblings may live, but when times are hard the weaker siblings starve to death, for the dominant sibling bullies them away from any food.
Or Maybe Cannibals Might be The Worst Animal Mothers
Quite a few of the worst animal mothers will kill and eat their own young. One example is the burying beetle, which owes its name to its habit of burying a mouse carcass that it then lays its eggs on. The mother beetle eats the meat and regurgitates it to feed her larvae who crowd around her begging. She can only regurgitate so much meat at a time which often means not everybody gets fed. The first larvae do indeed get fed, but any stragglers that are still begging after the mother runs out of meat get eaten.
The reason is that burying beetles often have more young that a mouse carcass can support, so she periodically culls the numbers to get her brood down to a manageable size. Doing so increases the chances of survival for the others by making sure that there is enough food to feed them until they’re old enough to get their own food.
Hamsters may be a lot cuddlier than beetles, but hamster mothers also produce more young than they can realistically raise, and they also eat some of them. Hamsters can’t predict how much food will be available, so they tend to have large litters in the hopes there will be plenty for them. A large litter also serves as an insurance policy. If some of the young have birth defects, the mother will eat them and concentrate on raising the healthy babies.
Animal mothers are plainly much less sentimental than human mothers. So in a sense can we talk about worst animal mothers. It does imply a scale f comparison. In their eyes, the strongest juveniles have the best chance of survival, especially in tough times, so they will devote most of their time and energy on caring for them. An animal mother might spare a weaker juvenile if there are plenty of resources, but she won’t do so if they’re scarce.
Here you you will find more about Mother Bear.