I had a great time monitoring two of our bluebird nestbox trails yesterday morning and thought it’d be fun to share some of what I saw and experienced.
The two trails that I monitor are Banshee Reeks and the Dulles Wetlands. While both trails are not too large (10-11 boxes each), I took a good while doing it, and meandered my way through each trail, checking out other birds flying around, spotting butterflies in the grasses and along the forest edges, and just generally enjoying the day, oh yea, and doing frequent checks for ticks – since I didn’t want to take home too many hitch hikers.
I started my morning of monitoring at Banshee Reeks at about 8:30 and after picking up the monitoring log book and perusing the sightings from last week, I went off along the trail. It’s always exciting to peek inside the nest boxes because, while we have an idea of what we’ll see based on the previous week’s observations, stories play out over the course of the week as birds pair up, eggs are laid, boxes are fought over, and so on.
At both Banshee and the Dulles Wetlands, we have a healthy number of both Bluebirds and Tree Swallows, although the Tree Swallows seem to make up the majority of nesters.
Tree Swallows can be a pretty aggressive bird when it comes to defending the nestbox, dive bombing and chittering at our heads. All monitors are given training prior to monitoring at a trail and we always warn new monitors about the Tree Swallow behavior. Our protocol – in general – is to get in, take a peek to gather the data, and then get a good distance way from the box so to put the Tree Swallows (and Bluebirds) back at ease.
At the trail at Banshee, as of May 16, we have 23 Tree Swallow eggs, 10 Bluebird eggs and 9 Bluebird babies. At the Dulles Wetlands, we have 32 Tree Swallow eggs, 5 Bluebird eggs, 4 Bluebird babies and 5 House Wren eggs.
This is the first brood of the year for all of these species. We expect at least 1 more brood as we go through the season and then at the end of the year we’ll tally how many young were fledged from the trails across Loudoun.
Along the trails, I saw some nests that were complete and ready for eggs and some nests where there may have been disputes over box ownership, like the one in this photo which has 2 Tree Swallow eggs and 1 Bluebird egg.
Other boxes show signs of possible predation such as where I saw Tree Swallow eggs ejected from the nestbox and cracked on the ground.
We learn a lot by monitoring, not only about population trends but also about bird behaviors and the whole cycle of life. It’s quite fascinating.
For some additional views inside the nestboxes, I’ve posted a few photos from yesterday in our Facebook album.
Learn more about Bluebird Nestbox Monitoring.