I would say that your tripod is probably the most important piece of photo equipment for Nature/Wildlife photography, next to your camera.(and of course at least one lens would be useful)
Oh, if I'd only learned that lesson earlier.
Even though I've owned a tripod since college, I didn't recognize it's importance for a few years. I would, of course use it for my long lenses, but failed to see the difference it would make to all my photography.
Finally, one day I just decided that since I had now invested in a much better tripod system, that I had better start using it. The difference was like night and day.
It was amazing the difference it made in the sharpness of my photos, even with the shorter lenses that I was convinced I could handhold with no problem.
Especially true, with the landscape work. I guess, early on I regarded it as secondary to the wildlife. I was basically just taking snapshots, like an amateur.
Finally, I started to take a lot more care with the landscapes. Once I started using the tripod, the quality improved immensely.
Instead of having to worry about achieving a handholdable shutterspeed, and shooting at f4, or f5.6, this now allows you to shoot using a much smaller aperature.
This helps to improve the image in a couple of different ways. First, the obvious result that more of your image will be sharp due to the small aperature. ( Of course,this is not to say that you should never use a large aperature.)
The second result is the colours will be more saturated due to the longer exposures. The difference can be quite noticeable.
I now use either a tripod or monopod or the window-mount for 99% of my photos.