I have no experience of using birding or astronomical scopes, but excessive experience using quite big medium format cameras.
A wooden tripod is often lighter than an equally rigid aluminum tripod, wood also dampens vibrations better than aluminum and are nice to hold in cold weather.
Carbon fiber tripods have the same properties, maybe they are a little more like aluminum to hold. They are also often more expensive.
May I introduce tripods from a little Swedish company that makes their tripods from Oak wood. I have no personal connection with the company, but I use one of their tripods and find it to be very good in practical usage.
Take a look at:
http://www.stabil.nu/english/index.html
There are tripods with two or three leg sections, I own the short version of the Stabil Speed (with two leg sections) and use it with quite heavy medium format cameras with very small vibration problems that almost always were present with my Manfrotto 055 aluminum tripod.
On the Speed model, the leg lock moves together with the leg so this tripod is very fast to set up. What makes these tripods interesting is that the lowest leg is made of dural aluminum, this makes it resistant against damp and water if you place it in wet grass or something similar. Just as the site states, the cup shaped ends of the legs gives a very good grip, the plastic ends of the otherwise excellent Gitzo and Manfrotto are actually less than adequate in comparison.
This is not an advertisment for the Stabil just because they are Swedish, it is the resulting impression after years of searching for a tripod that, except for being light-weight and sturdy, also have to be nice to carry over the shoulder. I carry my camera attached to the tripod head and carry the whole setup with the tripod legs extracted on my shoulder just as you probably would do when carrying a scope. You can even comfortably place the tripod head on your shoulder with one leg in front of you and the other legs pointing backwards, the tripod head is flat against your shoulder.
What seems to be missing in the information on the site is that you can spread the legs at any angle you wish. There is a tension screw for each leg joint with the tripod head that is easily adjusted, see the picture of the macro tripod, you can see the lock handle just above the right leg:
http://www.stabil.nu/english/makro.html
In this picture you can also see the leg cups a little better.
If you plan to contact the company I recommend mail, since this is a partial time business.
They are well-known at least in Sweden and probably also in Scandinavia, but perhaps not in the UK.
There is also an American maker of wood tripods, Ries, that looks good from specifications, you can find these at:
http://www.riestripod.com/
I have never seen them so I cannot give any first-hand comments.
There is also a German maker, Berlebach, they have both light-weight but also some very heavy and sturdy models if that is what you are looking for:
http://www.berlebach.de/
I have just seen these tripods once and they looked, well, good, but I found nothing special with their lighter models, the heavy UNI models are impressive but did not suit me.
