Birds have two choices when it comes to eggs - larger eggs take more effort upfront, while smaller eggs need more parental protection once they hatch.
Welcome to this week’s edition of Something Wild. I’m Rosemary Conroy for the Society for the Protection of New Hampshire Forests.
As we speak, millions of birds are flapping their way north. And the ones that are already here are busy setting up shop. The product? More birds, of course!
The evolutionary strategy of producing young by laying eggs is a pretty cool trick. It allows a female bird to reproduce without being weighed down - literally. And while incubating eggs has its risks, it also has advantages. If the eggs are lost to a predator or inclement weather, for example, the parents often do escape to reproduce again.
So birds basically have two choices when it comes to making babies. They can lay large eggs that result in large chicks that are born ready to rock and roll - or at least to follow their parents around pretty much from the get-go. These well-developed chicks are known as precocial. Ducks, shorebirds, geese and birds like grouse and turkey follow this game plan.
Smaller birds tend to go the other route. They produce much smaller eggs that result in helpless chicks that are born naked and blind. These chicks are called altricial.
Which strategy is better? Well, female ducks, on the one hand, have to invest a lot more up front to produce those better-developed hatchlings. Their eggs contain almost twice the calories per weight than those of altritial birds. That's why humans eat chicken eggs and not robin eggs.
On the other hand, robins have to put more energy into feeding and protecting their chicks after they hatch - not before. And most songbirds tend to share the burden of raising their babies between both the male and female. Turkey or mallard hens are pretty much on their own once the initial courtship is over.
Either way, it's a fascinating subject to study. And soon, we'll be able to see it happen all around us.
Something Wild is a joint production of the Society for the Protection of New Hampshire Forests, New Hampshire Audubon, and New Hampshire Public Radio.
For Something Wild, I’m Rosemary Conroy.
