Yes, if you've understood so far you will know my telescope acts the way a Mirror lens does. I'm sure you've seen these on eBay.  Long telephoto lenses for very cheap.  They are based on the same design, and quite poor quality.  Better than not getting the photo.  

The strange thing about this type of lens design is that it produces a weird donut shaped bokeh.  This can result in some pretty ugly backgrounds.  None were visible in the hawk shots, but this wouldn't be a complete article without showing an example with ugly highlights.

As you can see in the background, there was some extreme side lighting on the bushes which produced very ugly bokeh.

Another thing to keep in mind is you won't get auto focus with this setup.  In fact focusing a telescope is not that easy.  I don't mind shooting with manual focus lenses, but the little tiny focusing knob on my telescope can probably turn 20x in the full focusing range.  That is to say focusing is slow and tedious.  It's also not multi-coated or designed to withstand flare.

I personally wouldn't go out and buy a telescope to use as a lens.  I'd rather save up my money for a sharp lens like the Canon 200mm f1.8, or even a MF prime.  You could use those with a teleconvertor to get you closer and the results would be much better than the consumer zoom I used.  I'm sure the results would beat out my telescope.

But if you have a telescope already to play around with.  Buying a $30 adapter certainly doesn't hurt.  Especially when you can dabble with astrophotography as well.  I'll be taking this combo out more often to see if I can find other wildlife to shoot that I can't get close to.