Ihave several cameras. I have a Nikon D7000 with all the lenses....
I have a Nikon S400 compact....
and I have a Fujifilm HS10 bridge camera. It is a LOT lighter than the D7000 and at 10.3 megapixels it's not too bad.
Upside 30x zoom with a good I S
Downside is lack of [true] manual control. E g, you can't go to a slow shutter and small aperture for a waterfall, but with software, you can twiddle it.
Possibly a D40[ish] with a 18-55 lens may be a better option.
Good luck