Learn about these intense animal sibling rivalries

Siblings share a lifelong bond and often spend their lives loving and supporting each other. Siblings can also have some really vicious fights.

However, as you will learn today, none of our sibling fights are as cutthroat as some that we see in the animal world.

In the wild and competitive world of nature, survival strategies extend beyond simply being the fittest; they include being the cleverest and sometimes the most ruthless.

Various species across the animal and plant kingdoms have evolved to adopt harsh methods to ensure that their offspring survive by sometimes eliminating their siblings. These survival tactics are not just fascinating; they are critical to the continuation of these species.

Let’s take a look at some of the extreme sibling rivalries that often end poorly for one or more.

More room in the nest

Among birds, behaviors such as siblicide (the act of killing one's own siblings, often observed in animal species as a behavior driven by competition for resources such as food or parental attention) and brood parasitism (a behavior in which one species lays its eggs in the nest of another species, leaving the host to incubate the eggs and raise the resultant offspring) are particularly interesting and effective for their species.

Nazca boobies, for instance, are known for their brutal sibling rivalry. In environments where food is scarce, the older chick will often push its younger sibling out of the nest soon after birth.

This act of siblicide ensures the surviving chick receives all the nutritional resources and parental care available, significantly increasing its chances of survival.

Another harsh tactic is employed by the common cuckoo, which practices brood parasitism. Instead of raising their own young, cuckoos lay their eggs in the nests of other bird species. The hatched cuckoo chick then pushes the host’s eggs or chicks out of the nest. This ensures the cuckoo chick receives undivided attention and resources from the unsuspecting foster parents.

Mammal jealousy

Mammals also exhibit some harsh survival strategies.

In the world of lions, for instance, a new male taking over a pride will often commit infanticide, killing cubs sired by the previous leader. This tragic strategy brings the lionesses back into heat sooner, allowing the new male to sire his own offspring and thus spread his genes.

Spotted hyenas display a similar ruthless behavior. In some cases, the firstborn hyena cub may kill its sibling to eliminate competition for their mother’s milk and care, securing itself a greater share of resources.

Plant bullies

Plants are not innocent in their survival strategies either. Black walnut trees, for instance, employ a method known as allelopathy. They release a chemical compound called juglone, which inhibits the growth of surrounding plants, thus reducing competition for water and nutrients.

Sugar maples exhibit a behavior known as self-thinning, where weaker seedlings naturally die off. This reduces competition among the remaining seedlings for sunlight and nutrients, allowing the fittest to thrive.

Even the dreaded invasive honeysuckle gets in on the bullying action by outcompeting and shading out the seedlings of other plants until they can no longer survive. This creates large areas dominated only with honeysuckle.

Each adaptation, even when it seems super aggressive to us, has evolved to maximize the reproductive success and survival of species under specific environmental pressures. It is not just about being the fittest, but also about adopting any means necessary to ensure the continuation of one's genetic legacy.

While it may seem cruel to us, nature is just doing what it does to be as strong as possible for the health of the entire system.

Mike Szydlowski is a science teacher and zoo facilitator at Jefferson STEAM School.

TIME FOR A POP QUIZ

What is siblicide, and why do some animals engage in this behavior? 

What is brood parasitism, and how do common cuckoos use this strategy? 

How does infanticide benefit a new male lion when taking over a pride? 

Describe how black walnut trees use allelopathy as a survival strategy. 

What is self-thinning in plants, and how do sugar maples demonstrate this behavior?

LAST WEEK'S QUIZ ANSWERS

What unique method do wolf spider moms use to care for their eggs? 

Wolf spider moms wrap each egg in silk, then carry them on their back. They continue to carry their young on their back for a week after the eggs hatch.

How do octopus moms ensure the survival of their eggs? 

Octopus moms lay their eggs in a safe spot, wrap them in a protective coating, and guard them against predators. They also clean and aerate the eggs by waving water over them with their tentacles.

What are some of the roles elephant moms assume within their herds? 

Elephant moms act as the central support structure for their herd, leading them to water sources and safe migratory paths, mediating conflicts, teaching social skills, and passing on essential knowledge to ensure the herd's survival and social cohesion.

Why do many insects and arachnids lay a large number of eggs — and what happens to most of these eggs? 

Many insects and arachnids lay a large number of eggs because only a small percentage of the hatchlings survive to adulthood. Most of the eggs are eaten or do not survive due to various environmental challenges.

Compare the parental investment of octopus moms with that of most marine creatures. 

Unlike many marine creatures that lay eggs and abandon them, octopus moms invest heavily in the survival of their offspring. They guard and maintain their eggs until they hatch, sacrificing their own health and ultimately their lives to ensure their young have the best start possible.

This article originally appeared on Columbia Daily Tribune: Learn about these intense animal sibling rivalries