A Lesson Re-Learned:
Missed Opportunity at Crooked Creek Lake

Ken Kostka
Purple Martin Preservation
Alliance
Pittsburgh, PA
www.purple-martin.org
12/11/09

I cannot emphasize how critically important it is to prevent ALL other species of birds from using your martin housing when you are attempting to attract that first breeding pair of Purple Martins. You must diligently and relentlessly prevent ALL other species from nest-building, even the "nice,” native birds like Eastern Bluebirds and Tree Swallows. They are just as good as starlings and House Sparrows at chasing away martins! Discouraging other species is necessary because when a pair of birds builds a nest, they develop what is called “site tenacity,” which causes them to defend the nest and the area around it. In the case of a martin house, non-colonial species tend to claim and defend the entire house, not just the cavity they are using; they will aggressively repulse (harass and chase away) other birds that try to use the house. A pair of inexperienced cavity-hunting martins will usually be repulsed by species that have already claimed the house, because the martins have not yet developed enough of an interest  in the house to stand their ground.

    It was a lack of diligence in keeping non-martin species from using the house that may have cost me the opportunity to establish a new colony site in 2009.

 I’ve tried to attract martins to Crooked Creek State Park in Ford City, PA since 1999. These efforts have included erecting two T-14’s with large gourds, playing the dawnsong, and deploying decoys, among other social attraction techniques. Though it’s a 25 mile drive to the lake, I make it a point to visit at least weekly in May and June to keep the housing free of all other species. (I do not open the housing until May 1st).  In mid-June of 2009, the ranger at the park, Mike Mazzocco, called to report that a martin had been seen on one of the houses. This was not highly unusual since subadult male martins had been spotted on several occasions in the past several years. So I skipped my weekly visit because I was extremely busy that week. When I did visit two weeks later, I found three separate nests in three adjacent gourds – a Tree Swallow nest with eggs, an Eastern Bluebird nest with eggs, and an abandoned Purple Martin nest with dried green leaves. I strongly suspect that the martins abandoned the housing because of harassment from the nesting Tree Swallows and Eastern Bluebirds. Had I made my normal weekly visit, I would have been able to keep these other species from using the housing. Had this pair of martins nested successfully, I might have established only the second Purple Martin colony in all of Armstrong Co., PA. Ten years of effort may have been undone by two weeks of inattentiveness.  This incident underscores the need for VIGILANCE, the PMPA’s mantra -  vigilance against predators, nest site competitors, nest parasites, and poor weather!