I can't address the Tamron 18-250mm, but I have a Tamron 17-50 f2.8 for
my Canon 40D that I love. It is very sharp, lightweight, and is simply
more than I could have asked for for $400. I don't have personal
experience with Nikon, but I'm sure it's a fine lens, and VR is a nice
bonus. For a long lens I purchased a Sigma 150-500mm, f5-6.3. It has
Optical Stabilization and I've been very happy with it. It is selling
for about $1000 right now. I will send you a link to some of my bird
photos in a separate e-mail. Most but not all were taken with the Sigma.
I'll see if I have a good link for my Tamron lens.

Tucker, Trileigh wrote:
> Hello Tweets,
>
> I'll be taking a trip to Cali, Colombia in June-July primarily for
> educational purposes, but I'm expecting that there will be organized
> excursions to other parts of Colombia on which I can do some birding.
>
> Could anyone recommend good bird and natural-history guidebooks for
> Colombia?
>
> And also, I'd like to get a single travel lens for my Nikon D90 that I
> could use for birding (so need some zoom capability) as well as
> generic tourist photos. The two I'm considering, and the pros and cons
> that seem to emerge from a few minutes playing with them in the camera
> store, are:
>
> * Nikon 18-200mm zoom (AF-S DX NIKKOR 18-200mm f/3.5-5.6G ED VR II)
> o Pros: Nikon name, more solid ?feel,? seemingly smoother zoom
> o Cons: Nikon price, less zoom capability, no special macro
> capability, heavier
> * Tamron 18-250mm zoom (Tamron 18-250mm F/3.5-6.3 AF Di-II LD
> Aspherical (IF) Macro)
> o Pros: More extended zoom, macro capability, lighter
> weight, lower price
> o Cons: Feels less solid (more plastic vs metal?), off-brand
> name
>
>
> If anyone has experience traveling with either of these ? or has
> recommendations for other lenses -- I?d really appreciate your
> thoughts and perspectives. For instance, is one likely to be more
> durable and reliable than the other? And so on.
>
> And for my favorite birding observation this week, here?s a Pileated
> Woodpecker excavating its nest in Lincoln Park. S/he would hammer for
> a while down deep in the tree, then grab beakfuls of wood scraps and
> toss them out of the hole for a while, then go back down and hammer
> some more. It was interesting to me that s/he seemed to intentionally
> throw the debris in different directions. Every once in a while when a
> nearby eagle called, s/he?d stop throwing sawdust and look up towards
> the eagle. Photos at www.flickr.com/photos/trileigh/4546744926 et seq.
>
> Thanks in advance for your photography advice,
> Trileigh
>
> * * * * *
> Trileigh Tucker
> Lincoln Park, West Seattle
>
> ------------------------------------------------------------------------
>
> _______________________________________________
> Tweeters mailing list
> Tweeters at u.washington.edu
> http://mailman2.u.washington.edu/mailman/listinfo/tweeters
>