Some geese have built a nest in the parking lot (annoying) and it has eggs in it.
Why do birds lay eggs? Mainly, it’s for oxygen to the developing baby bird. Another touted theory is the weight, granted that additional materials and nutrients still flow in from outside of an egg after it is laid, thus increasing its weight.
20180607/https://www.livescience.com/32277-why-do-birds-lay-eggs.html