From Toadwater Guide
A bird that lives in a birdhouse on a Horse chestnut tree. Once in your inventory (see Birds), you can place the pigeon on an empty ground square to transport yourself back to its home birdhouse. At the same time, the pigeon will fly out of your inventory (and back to its home birdhouse if it has at least one more use).
Pigeons can be kept in your inventory for up to 24 hours. During this time they can be hitched to a Ponderosa pine for an unlimited amount of time. The Ponderosa pine does not need a birdhouse -- just select the pigeon in your inventory then select the Ponderosa pine.
Caution: If you hitch a pigeon to a Ponderosa pine then anyone can feed it a compost worm which will transport the feeder back to the pigeon's home birdhouse (it will also fly back to its home birdhouse if it has at least one more use). You can also transport other players to your base in this manner if you meet at SWI.
Your most recently used pigeon will bring you back to its home birdhouse if you happen to log off.