I'm weighing in late, here, but I'd like to respectfully disagree with Arthur and add my views...
You can achieve a very much finer, more detailed result by sharpening first, THEN downsizing. You can add a touch more sharpening to the downsized (web) version afterward to crisp it up and overcome both the softening effects of downsampling and also pre-compensate for blurring on some monitors (but watch out for that latter; lots of folks have nice sharp LCDs nowadays).
ESPECIALLY with nature and animals, it's all about details and the perception of details.
And all sharpening methods are not created equal.
Deconvolution (e.g., Richardson-Lucy) can be a very good means to sharpen certain images, and others simply fall apart with it. It's worth noting that astrophotographers use all kinds of deconvolution to overcome the limitations of seeing and optics.
I'm not saying it's impossible to work with images at the size posted on the web. Here, for example, is what I could make of the posted image above. The process I used involved upsampling, sharpening, then re-downsampling back to original size. Compare this to Arthur's version. You simply cannot achieve sharpening this fine without working at a higher resolution. Grace, I hope you don't mind my reposting your image; if you do please let me know and I'll take it down.
As the author of what I'd like to think are best-in-show sharpening tools myself I'd like to see the full-sized image as well.
-Noel
Edit: I just read through Roger's info. He's quite clearly (sorry for the pun) an expert in image processing.