Camera Body Purchase Advice

[bhowdy]

First let me say that I am new to these forums and look forward to learning and contributing (when I have enough confidence to do so) I have only been taking photos for about 9 months, but I am addicted! My passion has become birds ... any and all. It doesn't matter if they are at the feeders in our backyard, a public park or at a wildlife refuge.

Here's my question:
My current camera is the Canon 40D
Lenses:
Canon EF 70-200mm f/2.8L IS
Canon EF 100-400 f/4.5-5.6L IS  (primary bird lens)
Also a few others such as Canon 100mm macro, Canon 28-135 and a Tamron 17-50

I know that Santa will be bringing me a Canon 500MM f/4L IS this year. (are the dates on the calendar moving backwards?) I would also like to upgrade my camera as well.

Here's where my pondering starts ..... I am debating 3 possible choices
Canon 1D Mark III  (lightly used)
Canon 5D Mark II
or maybe a Canon 50D

A large camera is not a problem as I already typically will shoot my 40D (w/ battery grip) and the 100-400 for an entire day.

Thank you for any opinions or comments

Bob
east Tennessee

[Bob Atkins]

Everything depends on why you want to upgrade the camera body. What do you want to do that the EOS 40D can't do?

If you want to shoot in the rain, then a 1D series body would help.

If you want to shoot movies then you need a 5D MkII.

If you need more pixels in a crop sensor body then it would be the 50D.

Unless there's something that you want to do and you can't do with the 40D, it's tough to say which (if any) would be the right way to go.