Nestbox Surprise

On the outside of my bluebird box I noticed a paper wasp (aka umbrella wasps)that appeared to be gathering wood to be used as nest building material. Wasps of this species are very aggressive when approached whether on their nest or not. As I walked towards the house I got its undivided attention immediately as it glared at me. I eventually spooked it off and opened the side panel of the box to reveal a nice sized nest dangling from the center of the ceiling- and it was loaded.

Bluebirds have to deal with several types of nest site competitors such as- English sparrows, tree swallows, wrens, but one competitor, the paper wasp, known as a “non-avian” competitor can become a problem not only for the bluebirds, but also for the landlord.

Checking for wasp nests is one of the duties of a bluebird landlord, because the presence of these can prevent bluebirds from using that particular box and even lead to nest abandonment for obvious reasons. One way to keep them from building inside your house is to rub a bar of ivory soap on the wood (inside and outside- i.e. eaves) which prevents the stem or “pedicel” of the wasp nest from sticking. Vaseline applied with a paint brush has also been used as a preventive measure. Some have resorted to stapling insecticide strips inside housing, but having these chemicals near the birds is really not a good thing. I had applied soap in the past, but it eventually degrades, so after removing the "competitors" I re-soaped.