Nature blogs now have their own toplist: the new Nature Blog Network developed by Mike of 10,000 Birds. Toplist sites rank member blogs according to traffic levels, given an idea of how your site is doing compared to others. The list is similar to other birding toplist sites like Fatbirder 500 or Bird Top 100. The new toplist is limited to blogs and is open to naturalists other than birders. As more people join, the site will help bloggers find out about other bloggers who write on similar themes.
The second site is Birdstack, created by David of Search and Serendipity. This is a bird listing site for world listers. You can add observations of any bird species from anywhere in the world, with a great amount of detail about the birds and locations. It also provides forums and sidebar widgets for websites. Eventually the site will provide an easy way to share sightings from the western hemisphere with eBird. Unfortunately I have been too busy the last two weeks to try it as much as I would like, but the site looks promising.