Nesting Suprise

This season is all about nesting as far as I am concerned, and yet I was surprised yesterday while at the Salem Audubon Reserve when some of the other volunteers reported a Bushtit nest. I was taken to the location at this drooping Indian Plum shrub where we observed the pair busily constructing a nest. I took some photos, which didn’t turn out that good when looked at closely on the computer, and had to make a second trip in the afternoon to get this photo with a Bushtit working with a long piece of material at the nest.  They make a very interesting, sock-shaped hanging nest of up to twelve inches in length with an opening at the top. These are very small birds, only about four inches in length from beak to end of tail. The question came up, which I had to research to find the answer, how small are the eggs? The average size is 13.7 x 10.1 mm, which strikes me as enormous given the size of the bird.   I think only some hummingbirds have smaller eggs. They normally produce 5-7 eggs.  I was most surprised because I have only seen Bushtits on three occasions on the 24 observation lists I’ve made at the Reserve since the first of the year. This is the first known nest at the Reserve this season that I’m aware of, and unfortunately not by a species that would take advantage of the ten artificial cavities that we have constructed.