Branta canadensis

Posted 14 April 2014 by Matt Young

Branta canadensis -- Canada goose on nest, Walden Ponds, Boulder, Colorado, 2014. The nest is on a small island in the middle of a pond. The goose sat on her (?) nest for most of the hour or so that we hung around. Then she got up, apparently cleaned the nest, and took off for a tryst or something with her boyfriend. We could see no sign of eggs or babies, but we thought we heard a high-pitched chirping coming from the nest when the parents were gone. The geese came back a little while later, and one of them immediately sat down on the nest. We plan to check on our newfound friends every week or so and will report back if there is anything to report.

4 Comments

John Harshman · 14 April 2014

I'm fairly sure that in all anseriforms only the female incubates the eggs or (briefly) broods the young, even in species with a permanent pair bond. I'm somewhat more sure that this is true for Canada geese.

So yeah, that would have been the mommy.

eamon.knight · 14 April 2014

Meh, I'm a Canada goose curmudgeon (I'm Canadian; I'm allowed). We have way too many of these damn birds around here. A couple of pairs have been nesting on the grassed "islands" in the middle of the parking lot of the place I used to work, every year for years. Which was kind of cool, but it made walking in from the car a little hazardous when the gander was in a protective mood. Sorry to crap on a nice picture, but...well, that's another thing they do a lot of....

jchapman033 · 14 April 2014

John Harshman said: I'm fairly sure that in all anseriforms only the female incubates the eggs or (briefly) broods the young, even in species with a permanent pair bond. I'm somewhat more sure that this is true for Canada geese. So yeah, that would have been the mommy.

That's good to know. I was led to believe otherwise by the Wikipedia article, which said only that "the female spends more time on the nest than the male." I've been watching a nesting pair at Descanso Gardens (near Los Angeles, CA) who I've been told have returned to this site for their 4th consecutive year.

John Harshman · 15 April 2014

jchapman033 said: That's good to know. I was led to believe otherwise by the Wikipedia article, which said only that "the female spends more time on the nest than the male."

Actually, it says "at the nest"; I think they're trying to say that the male hangs out in the near vicinity, not that he sits on the eggs. Checked out their source (10) and it also says "at". However, I have found that male incubation is not completely unknown in anatids. Swans of several species do it, and male black swans, the only species in which males have a brood patch, actually spend more time on the eggs than females do. Male incubation is known in whistling ducks and the closely related white-backed duck. In magpie geese, in which the typical mating group consists of one male and two females, all three share incubation. And I also find that male and female screamers share incubation duties. So shared incubation seems to be primitive within Anseriformes but was lost somewhere in the line leading to ducks and geese. It seems most likely that swans have regained this habit, as I am unable to find any suggestion that their sister group, coscoroba and Cape Barren goose, ever do male incubation.