>When I picked up the Varied Thrush last night, I was surprised at how light the
>bird is relative to my experiences picking up Robins. That's not a very
>scientific weighing, but I had the clear impression that the VATH is a much
>lighter bird. (This was an adult female) Even though the published sizes of the
>two species are very close (+- 1/2") I wonder if the thrush isn't
>typically much
>lighter than the Robin.
>
>Anybody weighed any lately?

Yep.

Not-too-fat Am. Robins weigh in the range of 80-100 grams, Varied Thrush
70-90 grams, so I'd say the VATH averages about 10g lighter than the robin,
or say 10% lighter.

What's amazing to me is Diana Peffer's average weight of 121 g for
Leavenworth thrushes; this is HUGE (or is that the acronym for Hudsonian
Gedwit?)! We have weight recorded for 36 birds, many of which were window
kills in the presumed prime of life, and the *heaviest* was 100.6 grams!!
The explanation perhaps lies in her birds about to head off on migration
and thus being really fat, although our 100.6 g bird was "very fat." We
have only a few weights from east of the Cascades, but those are no larger
than the ones from west. A December bird from near Yakima, for example,
weighted 97 g and was moderately fat. A presumed migrant from Okanogan Co.
in Oct. weighed 80 g, with little fat.

Odd.

Dennis Paulson, Director phone 206-756-3798
Slater Museum of Natural History fax 206-756-3352
University of Puget Sound e-mail dpaulson at ups.edu
Tacoma, WA 98416