Fairly close to Bangalore one can find a number of nice nature spots. Driving there does not take long once one has managed to leave behind Bangalore traffic. One very nice spot is Kabini River and Nagarhole. I have been there twice so far, once via a team outing in 2007, and once again in July 2008.
Two resorts exist next to the Kabini River. One is Jungle Lodges, and one is Cicada. Both are very nice. And both organize jeep safaris into the Nagarhole National Park.
Within the national park one can see very many deers - their population also supports tigers, panthers and wild dogs. Also, one can see elephants, both solitary males and groups of elephants with females and cups.
On the way from Bangalore to Kabini River (or on the way back) one can easly put in a stop at the Ranganathittu Bird Sanctuary. As the name suggests one can see many birds. But also crocodiles swim in the waters and can be seen when taking a short boat ride.
In August 2008 our team made an outing to Bheemeshwari in Karnataka. The camp site was right next to the Cauvery river. We were lucky with the weather despite the monsun season.
After arriving there, the food was cooked over the open fire. Afterwards, we sat around the camp fire for a long time. And after a very short night, we got up at the crack of dawn. A small hike up the hill topped off the outing. From there we had a nice view of the Cauvery river.