Owl box spring cleaning (and story update)

March 16, 2015

By Mike Coll, Hildacy Farm Preserve Manager

Almost every day this winter our resident female, red phase Screech Owl roosted in the box behind the spring house. This is the continuation of a story that has been ongoing for the past 5 years since I initially placed an owl box in that location (and then replaced it with a box that included a camera). For the first three years a gray phase male Screech Owl roosted in the box. Each spring he called from the entrance of the box but did not successfully attract a mate. This changed last year in early April with the appearance of a red phase female. Following her arrival the pair spent a few days together in the box. About two weeks later the female had laid a clutch of three eggs (laying one egg every other day). For the next 29 days the red female diligently incubated the eggs, leaving the box for only a few minutes each night. During this period her mate did the hunting, constantly bringing mice, frogs and insects to the box and feeding her.

However, for reasons unknown to me, none of the eggs hatched. It appeared that the female owl ate each of the eggs exactly 29 days (the expected incubation time) from the date that the eggs were laid (also eating only one every other day). I can only surmise that she somehow knew that the eggs weren’t viable (maybe they became cold?) and her instinct was to not let an available source of protein go to waste.

After the failure of the eggs, I didn’t see either owl for nearly a month. But at some point the red female began to roost in the box again and since then she has been a fixture there, usually sticking her head out to catch the last few rays of sun each evening before going out for the night.

Photo: Mike Coll

In fact, the presence of the Red Owl has been so consistent that I haven’t wanted to disturb her by cleaning out the box. So when I looked at the camera yesterday and noticed that she was roosting elsewhere, I jumped at the opportunity to clean the box and do some repairs. Some of the metal flashing that prevents squirrels from climbing into the box needed to be reattached and I also added a bungee cord around the trunk to further support of the box itself.

Photo: Mike Coll

The inside of the box was littered with 15-20 owl pellets and the feathers of what appeared to be a Downy Woodpecker, a Blue Jay and possibly some others. I scraped all of this out of the box and then added an inch or so of fresh wood chips. I then replaced a good number of the feathers that were in there because they seemed like an interior design choice that the owls had made. I first noticed feathers in the box just before the eggs were laid and I expect that she may use them as bedding.

This morning I was happy to see the female back in the box. I hope she likes what I did with the place.

Photo: Mike Coll

I expect that the male has remained in the area even though I haven’t seen him. We should know by the first few weeks of April if the pair will make another attempt at breeding.