Last week, when I cleaned out the three birdhouses in my back yard, I discovered that the nests inside of them were different sizes. One had barely been started, the second was 2-3 inches tall and the third almost filled the bird house.
In Part 1 of this series, I showed photos of the bird houses and the nests and questioned why the one was so big. I also wondered why the big one had a flat top; there was no place for a nesting bird and her eggs to lay.
Several people who read my first post told me that the big one was a wren’s nest. One reader thought that the bird houses were too close together and that the wren who made the big nest had chased the two other nest builders away. Another reader joked that the bird who made the big nest must have had OCD! No one speculated about the flat top.
I did some investigation. After looking at photos of wrens’ nests, I realized that the readers were right; the big one was a wren’s nest. From an Audubon Field Guide, I learned that a male wren may build several nests. When the nests are finished, the female wren chooses between them. The guide went on to say that the male may build some incomplete “dummy” nests. After reading that, I realized that it was a good possibility that the same wren had built all three nests.
I took the big nest inside so that I could look at it closer. Once I removed the top layer, I discovered a section that looked like a plug. It was much denser than the rest of the nest.
I wondered what the plug had been plugging. When I looked underneath the plug, I saw this:
It sure looked like an area that could have been meant for the female and her eggs!
The Audubon Guide had mentioned that wrens may puncture the eggs of birds that are nesting nearby. It also said that a female wren may leave the male to take care of her eggs, and go nest with another male. I wondered, partially in a joking way, if the female had not approved of any of the nests her partner had built and had taken off to find another male. If that was the case, had the abandoned male decided to plug the nest and add a solid roof on top so no other bird could use it? How in the world had he built the plug? I was left with another set of questions.
After finding the plug and the place that might have been intended for the female, I went back to examining the whole nest. I discovered it was made up of at least ten different materials.
I separated much of the nest into ten piles. The remainder looked like this.
I took a sample of this conglomeration of substances and looked at it under the microscope. I was mesmerized by what I saw. (Click on the gallery to enlarge the photos.)
I had intended to make this a two-part series but have decided to divide it in three instead. In Part 3, I will show you microscopic images of the ten types of materials I found when I separated the components of the nest!
For last segment go to: A Surprising and Disturbing Discovery- Part 3