Date: 1/4/19 6:27 pm From: Joe Roller <jroller9...> Subject: [cobirds] Retraction on usefulness of leg and foot size for swan ID
I looked at myriad photos of both species by googling"Tundra Swan on ice" or "Trumpeter Swan on Ice." That eliminates photos of swans aswimming, their legs hidden from view.
When feet are visible, smaller feet are seen on photos of Tundras, but not on Trumpeters.
BUT *leg thickness* is not too helpful. I saw many photos of Tundra Swans with thin legs, which no Trumpeters seem to have; BUT some Tundras have thick legs too.
So pending more input, I would say that an ancillary field mark may be "thin legs, think Tundra." Thick legs could be either species. Foot size, which is usually hard to see, seems to be more reliable, with Trumpeters shopping for size EEE's, and Tundra's for size C.
Note that Sibley draws both species with rather thick legs. And on Swan ID sites, I saw NO mention of all this as useful for sorting them out. So it's probably not!
My next step (ouch) is to go to the Collections Department at the Denver Museum of Nature and Science, toting one of those hefty metal shoe size measurers used by salesmen. In the meantime, look at your own photos and look for swans walking on ice.
NOT the first time I've been wrong! Expert opinions are welcome. Joe Roller, Denver