Cygnus columbianus

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IMG_0387TundraSwan_600.JPG

Cygnus columbianus – tundra swan, Walden Ponds, Boulder, Colorado, March, 2014. A single swan, presumably the same one, has been showing up here for the last few years. I looked for the people with the biggest binoculars and the longest focal-length camera lenses and asked how come there was only one? I got several answers, all of which begged the question why the bird is not in a flock: (1) They mate for life, and maybe this one lost its mate. (2) They mate for life, but maybe they don’t always hang around together. (3) Maybe this one is a juvenile, not old enough to have a mate.

8 Comments

I don’t know about tundra swans specifically, but many young male birds, in species in which pair bonds are formed on the wintering grounds, disperse individually and to random places. This could easily be a young bird, as swans tend not to breed until after age 5, and males later than females.

And let’s not ignore the fine mallard, ring-necked duck, and pair of American wigeons also in that picture.

It shouldn’t be hard to figure out at all–why, it’s just the ugly duckling!

John Harshman said:

I don’t know about tundra swans specifically, but many young male birds, in species in which pair bonds are formed on the wintering grounds, disperse individually and to random places. This could easily be a young bird, as swans tend not to breed until after age 5, and males later than females.

And let’s not ignore the fine mallard, ring-necked duck, and pair of American wigeons also in that picture.

While swans normally form monogamous pairs, often when they’re 20 months old, that will last for years, if not the rest of the swans’ lives, I’ve also read that some young adult swans will form short-term pair bonds that only last up to a few breeding seasons (implying that they’re still shopping around for that perfect mate).

apokryltaros said: While swans normally form monogamous pairs, often when they’re 20 months old, that will last for years, if not the rest of the swans’ lives, I’ve also read that some young adult swans will form short-term pair bonds that only last up to a few breeding seasons (implying that they’re still shopping around for that perfect mate).

Which species of swan are you talking about here? Tundra swans do sometimes form pair bonds several years before the first successful breeding attempt, but is that the species you numbers come from?

John Harshman said:

apokryltaros said: While swans normally form monogamous pairs, often when they’re 20 months old, that will last for years, if not the rest of the swans’ lives, I’ve also read that some young adult swans will form short-term pair bonds that only last up to a few breeding seasons (implying that they’re still shopping around for that perfect mate).

Which species of swan are you talking about here? Tundra swans do sometimes form pair bonds several years before the first successful breeding attempt, but is that the species you numbers come from?

From what I remember, it was swan species in general.

apokryltaros said: From what I remember, it was swan species in general.

From what I remember, swan species vary quite a bit. Mute swans in parts of Europe, for example, tend to be semelparous, which strikes me as weird. Mean age at first breeding, from the literature, varies from 2 (C. atratus) to 6 (C. olor) years, depending on species. Now in fact the data are fairly sparse and it’s possible all these differences are just noise. But that’s what I have.

Robert Krulwich on NPR said the other day that swans have a 5 % divorce rate. No suggestion what species.

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This page contains a single entry by Matt Young published on March 17, 2014 12:00 PM.

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