These mounting brackets are designed to attach to a farm T post.  I use the 7 ft post available at most farm supply stores.  when driven in the ground past the spade on the bottom, they offer good support for the bird house and can be placed in the  yard or garden wherever you like and moved in minutes.  These brackets come in pairs and are anchored to the bird house with 1 1/4 inch screws that will not penetrate into the nesting area.  You will have to measure your post and place the mounts according to the flat places on the post as all post are somewhat different.

Item #3000
Price:  $2.00 pair Click here for ordering information