Oh, spring. Everything starts to get green and fresh and new. And now the first chicks start hatching as well. But in a nest full of hungry beaks, which baby bird will get the most food from the parents?
Finding a partner, making a nest and guarding the eggs is one thing. Keeping all the young chicks fed is a harder challenge for the parents. With all those tiny, hungry creatures, parents will have to work extremely hard to come up with enough food. But who will get the next bit? Is it the chick that screams loudest, or the one that is silently sitting in a corner?
Passing on Genes
Let’s start at the beginning. Basically, the ultimate goal in nature is to get your genes passed on to the next generation. In that respect, for a parent, every offspring is equally important. They all carry (more or less) the same amount of genes from the parent. But, for a young chick, it is a bit different. Naturally, he is a hundred percent related to himself, and wants to pass those genes on in the future. So even though he also shares genes with his siblings, they will never be completely the same. Thus, it is more favourable for him to pass on his own genes, instead of helping his siblings do so.
And that is where the conflict starts. The chicks all want to have the best chances of survival for themselves, while the parents just want to raise as much healthy chicks as possible.
The tactics from the chicks are quite simple. Just beg as much as possible. That involves screaming, showing a big, hungry beak, and raising your head as high as you can, hopefully to do better than the others. Because this form of begging is costly for the chicks, they will only do it if they are either really hungry or just very strong. Weaker birds will be pushed aside by their siblings, making them less visible for the parents.
So how do the parents react to this? Do they support the weak, pushed-aside chicks? Well, no. Generally, they give food to the best “competitor”. The chick that begs the most. That might sound a bit strange, seeing as they could try to save their weak, starving young. But then remember it is all about selection in nature. What if they would use their costly food on those weak chicks and let the strong ones be hungry? Then they would end up with a lot of half-starved young. The young could get a decreased growth and all kinds of illnesses. Eventually, all of them might even die, in which case the parents have no chicks passing on their genes at all. So that is why they favour the strong ones. Feed those, make them strong and healthy, so that they can become big adults and successfully pass on the genes to the next generation. That a few chicks with less-favourable genes might not survive, well, that’s the way it is.
See if you can hear or see any baby birds already in your area!