The cost of living seems to rise steadily every single year, and as a result, parenting is more expensive than it has ever been. The price of college tuition is at an all-time high, and these days it feels like a mandatory destination in terms of competing in the job market. The time and energy that must be invested when caring for a child is also nothing to scoff at. A legitimate cost of parental care is the sacrifice of what could have been done with that time and energy. There are countless instances of parents who were destined for exciting careers and lifestyles and gave it all up for the sedentary ways of family life. For these parents, all decisions are made with the thought of their children in mind.
Animals also demonstrate a considerable amount of sacrifice for their offspring. Just think about the times you’ve witnessed a feral mother putting herself at harm to protect her offspring. I have personally experienced this in my childhood when I witnessed wild turkey chicks roaming on our lawn. The first instinct of me and my siblings was to capture the cute chicks and keep them as pets. I approached the chicks, but before I could catch them, the mother turkey charged at me and I ran away. When I reached the top of my deck and looked back to see the mother guiding her chicks into the forest I reflected on what just happened. Wait a minute, I thought. I’m way bigger, faster, and stronger than that stupid turkey. I could kill her with one swift kick of the foot, yet she still charged at me. That turkey put its own life at risk in order to protect her chicks, and while it was quite dangerous, it was also valiant.
In that case, the cost of raising children extended beyond the loss of resources. It included the mother putting herself in danger, something that is seemingly counter intuitive in the animal kingdom. Is it just plain love, or were there some instinctual reasons behind the action of that turkey? In order to answer this question, we can ask the most ancestral species that engaged in parental care in the animal kingdom, the fish. Fish were busting their butts for their offspring long before man ever walked the earth. They exhibit a primitive type of parental care known as brooding, meaning that they protect, and incubate their eggs before and sometimes even after they hatch. Cichlid fish specifically are known for this type of behavior, and different species engage in different levels of care which come with different degrees of sacrifice. For example some species may hold their eggs in their mouths while others may protect them in caves. Both activities require an increase of resources. Some species have such a difficult time acquiring resources while caring for their eggs, that they recruit other cichlids to care for their offspring. In fact, my buddy was just telling me the other day that his coworker, who happened to be a cichlid fish,sold his house in order to pay for its offspring’s daycare! Joking aside, these fish do in fact relinquish territory as payment for foster care. It’s just one among many costs of parental care.
The cost of resources is the most visible cost of parental care. Oxygen is often a limiting resource in cichlid habitats, just like money or food in human society. There are two ways a cichlid fish can breathe. They can either use their gills and breathe under water, or they can swim to the surface and breathe with their mouths. Under normal circumstances, the former is preferred because staying underwater reduces the chances of encountering an aerial predator. However, when fish are brooding and require more oxygen, they will often take that risk and breathe at the surface.
There is also the need for food. Unsurprisingly, it’s actually quite difficult to forage for food while eggs are brooding in your mouth. So what do these fish do? They partner up and take turns. A mother and father will cycle between who watches the eggs and who goes out in search for food! Cichlids have even been observed fighting over whose turn it is to watch the eggs (spoiler alert, the male usually loses and has to watch the eggs). Increases in stress levels have been measured in fish that go to these lengths to care for their eggs, and sometimes they even die as a result of raising their children.
Lastly, we can’t mention the sacrifices of fish parental care without looking at the opportunity cost of investing time in their children. In fish society, polygamy, or mating with multiple partners, is the standard of success. It’s all about spreading your seed, and brooding fish are off the market. Moreover, after the fish have completed brood care and their eggs have hatched, they become less desirable than they were beforehand. This happens because of two things. First, the stress of parental care often causes cichlid fish to shrink in size. Small fish are less desirable than big fish and have a harder time attracting mates. Small fish are also more likely to be exposed to predators and aggression from other fish. Second, brooding fish often sacrifice their territories in order to search for mates and don’t typically regain territory while brooding. After brood care is complete, they are left in search for territory which they may or may not find. These factors make the process of mating a second time much more difficult.
So why do they do it? It’s not as if the fishes’ offspring appreciate the time and energy their parents invested in them. Although there aren’t any direct benefits of parental care for the parents, there is one major benefit for the offspring. Fish that protect their eggs with brooding decrease the likelihood that predators will find and eat their offspring. In other words, parental care in fish is a behavior that was evolved for the perseverance of their species.
Just as we see in fish, caring for children often drains the time, energy and prospects of human parents. And just like we see in fish, we can’t necessarily expect children to appreciate the sacrifices that parents make. In both fish and humans, parental care is a necessary responsibility that helps ensure the success of our future generations. Offspring may not always appreciate their parents, but biologists do!