Mother goose laid her first egg in the Decorah Eagle nest on Thursday, March 24, at around 8:30 AM. After laying the egg, she concealed it under dirt, leaves, and sticks, burying it so completely that I initially wondered where the egg went! Covering her egg helps protect it from predators and lets her delay incubation until she’s laid the full clutch. She will most likely lay egg #2 some time on March 25, or about 35 hours after egg #1.
You’ve been wondering about these three things:
- Mother goose isn’t spending enough time on her eggs
- The goslings will starve when they hatch
- The goslings will die when they jump from the nest
So let’s talk about them!
Incubating the Eggs
Mother goose won’t begin full incubation until around the time her last egg is laid. Embryonic growth and development is a fast-paced chemical process that requires heat. By delaying incubation, mother goose delays the onset of embryonic development and assures the synchronous hatching of fertilized eggs. Synchronous (closely-timed) hatching is especially important in the case of Canada geese and similar birds, which leave the nest roughly 24 hours after hatching. Unhatched eggs or birds too young to follow their parents die.
I used to think that eggs would die if birds stopped sitting on them for even brief periods of time. Not true! Embryos are less sensitive to cold than to heat, particularly before incubation has started, and few birds incubate continuously. Mother Goose regulates the temperature of her eggs by varying the amount of time she sits on them and the tightness of her sit. If the weather is warm and sunny, she may spend a great deal of time off the eggs. We also might see her cover the eggs with soft nesting material.
Feeding the Goslings
Canada geese are precocial – that is, the young are relatively mature and mobile from the moment they hatch. They are born with their eyes open and can swim, run, and jump shortly after leaving the egg. This is important, since precocial species are normally nidifugous, meaning they leave the nest shortly after birth or hatching. You can read more about precocial versus altricial here: https://www.raptorresource.org/2022/03/25/canada-geese-precocial-versus-altricial/.
Just before hatching, the goslings will consume whatever yolk and albumen remains in their eggs. This provides enough food energy for the next 24 to 48 hours. Once they’ve jumped from the nest, their parents will lead them to water and protect them from predators. Parents do not need to provide food in the nest and the goslings will find food (mostly) on their own once they reach the water.
Roughly 24 hours after hatching, Mother goose will leave the nest and the goslings will jump after her. While this seems scary, it is very normal for geese. Canada geese have been documented nesting on heron nests, osprey nests, cliffs, and man made structures. Nesting in high places helps protect eggs and very young babies from ground-bound predators including raccoon, coyotes, opossums, cats, and dogs.
The jump is over quickly. Dad will be waiting on the ground below to help protect his family. Mom will fly down from the nest and honk for the goslings, who will follow her out of the nest. Their light weight and downy bodies will help protect them from injuries when they land on the soft grassy surface below the nest. Once the goslings have landed, their parents will lead them directly to the pond, honking and hissing all the way.
Remember, the birds wouldn’t have these behaviors if they didn’t work for most individuals. Geese that are good at synchronous incubation will have better offspring survival rates than those that aren’t. Geese that nest high will lose fewer eggs and young to ground-based predators, offsetting potential losses caused by landing injuries. Whatever we might think, the geese are following a way of life that has produced more winners than losers. Mama (goose) knows best!
Did you know?
The giant Canada goose (Branta canadensis maxima) was once believed to be extinct, but thanks to the Mayo Brothers of Mayo Clinic fame, a relict population survived in Rochester, Minnesota’s Silver Lake. I remember my Dad taking me to see them when I was very young! You can learn more about their fascinating story here: https://www.atlasobscura.com/articles/a-minnesota-towns-love-hate-relationship-with-giant-geese.