Momma is feeling safe with the Bird Guardian installed! She and Daddy are raising their young just fine. Even though I have a baffle and a snake net on the Bluebirds poles. I felt better when I installed the Bird Guardian. They go in and out with no problems.
Martin Colony History: I have been exposed to purple martin sounds in utero when my mother went out to get my father away from his martin colony. I played around the martin colony every summer and watched as my father maintained his colony. In the late 50's until the 70's he did not notice European Starlings in south Texas. When old enough, I helped maintain his colony. My primary task was eliminating English House Sparrows with a 1956 Benjamin 317 .177 air rifle. When I settled into my own home, I started my first colony with an original Trio Castle and Trio Grandpa. When I moved again, I did not put up any martin houses. Frustration with European Starlings in the Southeast US was overwhelming. Found PMCA Forum and learned about modern enlarged compartments and SREHs. Inherited my father's last martin house, a Trio Grandma, modified it to modern specifications and have had good results since then.
I installed these after they were already in the process of building their nest. I was afraid of scaring them off after they had already started building their nest. Luckily I didn't. It took them a while to get use to it, but they did it! I wanted to install these as soon as they were done with their first babies this season, however it took weeks for these items to come in. All is good now. This is the second round of babies they had this season.