Bermuda Birds & Guide to Bird Watching
    Watch Hill Park and Devonshire Bay for watching the migration of seabirds from South Shore of Bermuda during summer time.

Bermuda Walking Tours & Hiking
Bermuda Nature Trails (Flexible Time) 
Surprisingly this 21 square mile island has a lot of unspoiled nature and wide diversity of habitat. While the Railway trail does take you through many of such wonderful places, there are a lot more to be explored. With the south and north shore coastlines, reserves, parklands & gardens, forests, caves and pools, Bermuda offers some great nature trails along with native plantations, wide range of birds and array of wildlife. 
Waterville Gardens and Paget Marsh (2 hours guided) 
This guided Bermuda walking tour covers the gardens at Waterville and continues through Paget Marsh, a nature reserve that provides a step back in time to view pre-colonial vegetation over 25 acres of original green. 
Tour of Spittal Pond Nature Reserve (1.5 hours guided) 
This is another guided walking Bermuda tour. Spittal pond provides a diversity of habitats and an amazing variety of birds, especially during the migration seasons. It is Bermuda’s largest bird sanctuary and a nature reserve. 
Bermuda Botanical Gardens Walking Tour (1.5 hours guided) 
This is a 90 minute walking tour of the 35-acre Botanical gardens of Bermuda. 
Quiet and scenic walk in St George (Half Day) 
It's a scenic walk through greenery, beautiful golf courses, beaches, forts and so many other wonderful places. You can also plan for a short snorkel. 
Hiking in Nonsuch Island Bermuda (2 hours) 
Here is something unique. Having been through it, I don't think it's really meant for all. If you have passion to explore unspoiled flora and fauna of Bermuda in an Island that is not too far but still very isolated, and conserved to reflect Bermuda's original vegetation, this is the place for you to go. NOTE: The island is now a restricted area due to its sensitivity towards recently restored habitats for critically endangered species and the national bird Cahow (Bermuda Petrel). You should work through Bermuda's Department of Conservation for such hikes and tours. 

 ( June 2015 
Hi, In Bermuda you won't usually find private or personal walking guides because of low demands. Most individual guides are taxi drivers and offer private taxi tours or van tours. Few others offer guided short walking tours for groups and only on set paths like in St. George's Town where they specialize. Having said that, here are couple of persons/tour companies who offer private walking tours (suggest you call them up and talk instead of sending an email). 
1) Tony (Anthony Young) of Paradise Tours. He conducts walking tours all by himself and also does personalized walking tours. A very knowledgeable man who loves to explore the nooks and crannies of the island. 
Phone: (441) 777 1759. 
2) Ashley Harris of Hidden Gems of Bermuda. While she conducts several set tours of caves and jungles, she herself is a great guide and has other guides in her team. They do private tours as well. You can approach her to find out if they can fit your requirements. Phone: (441) 704 0999; (441) 236 1300. 

Kate Sparrow
 (July 2011) 
... I thought it would be very nice to hike around Bermuda.  Much to my surprise, this was very difficult, if not impossible. 

Bermuda Audubon Society - Bermuda's Birds