Dr. Clara and Mandrake
and me have had a rough couple of days. After they sucessfully fledged four babies, the couple disappeared as usual to show the babies the world. They did come back occasionally to feed and check on the box. One day, however, a House Sparrow took a liking to the box. This was a first, it has never happened in five years. I use a Gilbertson box, which they usually do not like, with fishing line around the entrance, and the sparrow spooker also was still up. Shooing and spooking the sparrow did not deter him and his lady. One day, I was not home for one hour, and the sparrows had started a nest in the Bluebird box. House sparrows are invasive to the US and can have negative effects on the breeding success of native species like the Bluebirds. I will not let them nest in my boxes.
Eventually, I took the Gilbertson down. After one day, the sparrows moved on. I was very upset about this whole situation and decided to be proactive. I researched and built another box, a slotted style called Troyer. The slot and its relatively small volume are something that HOSP are usually not fond of. The slot lets in lots of light, and they like it dark and deep. The slot opening also enables the female to escape if a House sparrow should go in there to attack her. I also updated the camera in the same step. Now the BBs have brought their baby (it looks like possibly one one of the four has survived this far (- update - actually, two!! Just saw another one :D) to the backyard yesterday, and they have been checking out the new box already too. I hope this all works out, I did not like changing things like that mid-season but I did not want to keep the old box up that the sparrows ended up liking. This is a weird spring.
For more information on how to help Bluebirds and other native cavity nesting birds, check out sialis.org.