April - What's In A Nestbox?

April was a very hectic month for the AmerenUE/WBS nest box study. In the month of April I counted eggs, banded babies and some fledglings have even left the nest already, probably because of the very early spring!

 Black-capped Chickadee nest

The study has been a success in all of the three habitats I am monitoring, and the data is pouring in. The numbers can be overwhelming, so I wanted to hit on the key points of my findings thus far.

Each area is prescribed a different treatment for maintaining the vegetation under the power lines within power line right-of-ways, and these prescriptions make different habitats. The three habitats that are being monitored are mow, spray, and a combination of the two; mow/spray. Each habitat has 80 nest boxes for a total of 240 for the whole study.

Before I give you the data, I want to explain two key things to remember. When looking at the fledged numbers one must bear in mind that there are still birds that haven’t decided to leave the nest yet. Also, not every egg is going to be successful, and the trend that I have noticed is that about half will hatch.

Habitat 1 (mow area) has been the most productive line so far with a total of 106 eggs. Of those 106 eggs 67 hatched, 45 have been banded and 31 have fledged so far.

Habitat 2 (spray area) is the second most productive area with a total of 101 eggs. From the 101 eggs 66 hatched, 63 were banded, and 26 have fledged to date. This area has been a surprise so far because all 80 boxes were installed in early March.

Habitat 3 (mow/spray) has been the least productive area with only 98 eggs. Of the 98 eggs 60 hatched, 50 were banded, and 13 have fledged so far. The most shocking finding on this line is that 80 of the 98 eggs were bluebirds! There were a few Black-capped Chickadees, too.

Overall for the month of April I have had 305 eggs, 203 babies, 141 birds banded, and 80 have fledged. This is only the beginning of what can be a very busy/great nesting season!

Submitted by Adam Triska, World Bird Sanctuary Field Studies Coordinator