The same is to be observed in all birds (except some domestic ones, where plenty of food excuses the cock from feeding, and taking care of the young brood), whose young needing food in the nest, the cock and hen continue mates, till the young are able to use their wing, and provide for themselves.

And herein I think lies the chief, if not the only reason, “why the male and female in mankind are tied to a longer conjunction” than other creatures, viz.