One of two nesting geese on my pond flies a low level attack to drive off a newly discovered, nesting female trying to establish incubation duties on the pond’s shore. I am slightly above the attacking goose’s altitude because of its low flight path past my position on the lower deck. Then, while writing about this curious nesting event, momma wood duck (small photo below) discovered she could sit on the roof of my hopper feeder and, with her imitation of a giraffe, munch a snack from the lower feeding tray.

CANADA GEESE—
Odd Behavior in Breeding Season

We built our acre and a half pond in 1993 and Canada Geese have bred here ever since.

One aggressive pair will protect the entire pond as their breeding area. The arrival of any interlopers of that species will cause the home pair to launch a furious defense. The water will boil and feathers will fly as the strangers are finally convinced they are truly not welcome.

This went on until several years ago when the breeding pair turned into, well, a trio.

There obviously is a breeding pair because a female always nests on the island where she incubates her brood in about a month. I always speculated the third goose was fledged the previous year here but did not realize it was expected to buzz off and find its own mate somewhere else the following season.

It had to be an offspring of the breeding pair. Otherwise it would not be tolerated.

Then, this year with mother goose firmly established on her island nest and going about her usual incubation duties, the third goose constructed a nest on the pond’s bank near a bench on the stone point.

What I always thought to be a male turned out to be a female. (Individual goose identity is indefinite because they are not banded.) But, who fertilized her eggs? These geese are known to pair for life.

And, almost moments after the second and obviously female goose, attempted nesting activity, the remaining two promptly went on the usual offensive and drove her away from the pond. Whereupon, I checked her nest and, sure enough, it contained one very large goose egg.

A few hours later the goose population went back up from two to three and the non-nesting pair leisured around the pond, paying absolutely no attention to the recently vacated nest.

A case of goose incest?

A case of a female goose returning to her birthplace in a family way from a distant tryst with an unknown suitor?

I have absolutely no idea.