My Bluebird Project

 Spring is coming, and with it comes nesting birds! This is a very exciting time, as we get to watch the migrating species return and move North to their breeding grounds. Some people will put out wren houses or maybe bluebird boxes, but not everyone will have birds utilizing them. This year I am going to be establishing a bluebird nesting box trail at the Eddyville Sand Prairie. With this trail I hope to be able to study Eastern Bluebirds nesting patterns. I'm planning to work with a local biology teacher and her STEM class to monitor and maintain boxes and collect data.

My trail will consist of ten boxes that will either be facing South, East, or Southeast as these are the directions that current literature suggests facing your boxes. This orientation makes sense because it allows the birds to use radiant heat from the sun to help incubate their eggs. East and Southeast facing boxes will likely capture more of the morning sun which will help warm the bird and the nest after cooler evening temperatures. South facing boxes will likely stay warmer during the day because in the Northern Hemisphere the sun is always slightly in the Southern half of the sky. With even distribution of boxes facing in these directions, I plan to test whether bluebirds prefer a box facing a particular direction.

Male Eastern Bluebird (Sialia sialis) perching on a fence.

Current literature also has differing opinions on the spacing of boxes. Some say that boxes should be individual and spaced at least 100 yards apart. Others state that having boxes in pairs with the individuals within the pair spaced at least 15 feet apart and groupings spaced at least 100 yards apart is beneficial. Bluebirds are fairly territorial when it comes to their nesting and don't like to be over-crowded. This makes sense that they would then select nesting sites with plenty of room (individuals 100 yards apart). That being said, there is an argument to be made for nesting in groups. This provides more security for the nesting birds as there are more eyes watching for predators. If one mother is out collecting food for her nestlings, there might be another nearby that can sound the alarm if a nest predator comes near. To test which spacing is preferred, I will have four individual boxes that don't have another box within 100 yards, and three sets of pairs with 15-20 feet between them.

Eastern Bluebird perching on a twig.

Another factor that I would like to monitor is the nesting success rate of Eastern Bluebirds. This will be determined based on whether or not nestlings fledge. Students will do occasional nest checks to monitor the progression of eggs and nestlings. Many factors will likely play into the success or failure of nests including; box direction, habitat structure around nest, nest spacing, or effort of parent. There may be many other factors that play into the success or failure of bluebird nests, and with this small scale study I hope to add to the list of causes.

Possible female Eastern Bluebird taking rest before coming to the feeder.

Finally, I am hoping to become sub-permitted to band birds, specifically bluebirds, for this project. I believe that being able to band these birds, both parents and fledglings, will help us to determine whether or not bluebirds return to their same nesting areas each year. Returning to the same nesting site year after year is called site fidelity and many species display this behavior. It will also be interesting to note whether site fidelity has anything to do with success or failure in nesting attempts.