Eastern Screech Owl Facts (With Owl Banding Video)
What Are Eastern Screech Owls Like?
Screech Owls are a very small type of owl, only 8-10 inches in height. They are generally a mottled grey color, which helps them to blend in with the trees that they perch in during the day. However, they can range in color from grey to red. There are two varieties of Screech Owls in the United States: Eastern and Western.
Eastern Screech Owls live in Central Texas, where I live. Our family was invited by the top expert on this species to watch a baby owl banding. Banding the owls is how scientists keep track of them and learn about their movements and habits.
What Do They Eat?
One of the reasons Eastern Screech Owls are successful is that they are not picky eaters. They are remarkable predators who eat a variety of insects, small mammals, reptiles, and even small birds. In fact, one of the birds they frequently eat is the cardinal, which is still up and active when they start hunting at twilight, and then is also one of the first birds awake and moving around when the owls are returning at dawn from their nightly hunt. They can even pick birds off of their roosting spot on a branch. Since our family loves the cardinals that regularly nest in our yard, that made my children sad.
Luckily, the research by the scientist who invited us to the owl banding, Dr. Fred Gehlbach, shows that even if the Eastern Screech Owls do eat other birds, they don't have a negative impact on species in their range, which is generally 10 acres during the summer and 20 acres during the winter season.
Eastern Screech Owl Call
Successful Adaptation to Human Habitats
What surprised us is learning that these owls are becoming more and more common because they find suburban neighborhoods like ours an excellent environment. Over the 40 plus years Dr. Gehlbach studied them (the longest-running study of any bird), he has watched their habitat in Central Texas move from being rural to suburban. During that time, his banding and tracking of the birds has shown that they have done very well, adapting nicely to box nests put up by humans when the naturally hollowed out trees were cut down. Dr. Gehlbach has found that currently, the owls in suburban areas do better than those in the wild in Central Texas because they have more food, more water, and fewer enemies to worry about.
Screech Owls and Blind Snakes: An Unusual Relationship
For most bird boxes, the policy is to clean them out yearly. However, the screech owls have their own system to clean out their boxes. According to research done by Dr. Gehlbach, and reported in Audubon magazine in 2002 by Kenn Kaufmann, screech owls have an interesting relationship with blind snakes. They take these snakes, which look like large earthworms, into their nests. Dr. Gehlbach speculates that they probably bring them as food for their babies, but these snakes have skin that is rather slimy and slippery. It seems that the snakes often slip away from the owl babies and burrow into the mass of rotting debris in the nest.
While at the bottom of the nest, the snakes eat the fly and ant larva which are feeding on the leftover baby owl food. For example, the snakes might eat bits of mice bones and beetles. Amazingly, the nests where the blind snakes clean out the rotting material have healthier owlets and more of them fledge out of the nest successfully. Dr. Gehlbach calls this relationship "mutualism." Eventually, when the owlets leave the nest, the snake gets out and goes back to its normal underground life.
We see these snakes regularly in our backyard. They are about the size of a pencil in thickness and length. They vary in color from brown to silver, like the one pictured above. They mostly live in the soil and only come out to feed or when it rains and they are flooded out. Even though our whole family had seen these snakes, we had never heard of this symbiotic relationship, which we found fascinating!
Baby Owlet Banding
My husband, my three girls, and I were invited by Dr. Gehlbach, an Emeritus Professor of the Biology Department at Baylor University, and the world authority on screech owls, to participate in a baby screech owl banding. We were very excited to have this opportunity to see the baby owlets up close.
Dr. Gehlbach has researched the owls in the Central Texas area for many years and has helped homeowners put up Screech Owl boxes for the owls to nest in. Every spring, he opens the boxes and takes out the baby owls to put an identifying band on their leg so that they can be tracked and their locations and movements pinpointed for study.
We arrived at four when the light was still up and the owls would still be asleep. My husband and daughters attended a screech owl banding the previous year, but this was my first opportunity. I was very surprised to have them point out the father owl sleeping on a branch a few feet away from the babies. It was late afternoon and, apparently, the father sleeps there all day. He was hidden in the branches and I would not have seen him if they had not pointed him out.
How Are Owls Banded?
As the video shows, Dr. Gehlbach held the baby screech owls one by one as he attached a numbered tag to each one's leg with a clamp. The tags are documented through the Department of Wildlife and will help Dr. Gehlbach and others track and research the birds throughout their lives. Although the metal bands are put on securely, they are loose enough to not bind the bird's legs as they grow.
Our Owl Banding Experience
There were four baby owls in the box, and they were bigger than I had expected. The homeowners said they had been peeking out of the box, and Dr. Gehlbach said that was a sign they were ready to leave the nest soon. They were wide awake as he pulled them up and put them gently in a paper sack. I expected them to squawk, but they actually made clicking noises most of the time, or else were silent.
Unfortunately, the homeowners said they had found the mother owl dead. They were not sure what had killed her. However, the father owl had continued to feed the babies, even though we imagined that feeding four large birds and himself every night must be quite a challenge.
Although rarely noticed by humans because they are awake at night, screech owls are not afraid of living in areas where there are people. However, they have trouble finding nesting sites even in neighborhoods where there are plenty of Oak and other trees that they like. That is because screech owls normally nest in the hollows of dead trees which humans cut down.
Through his research, documented in his book that I found fascinating, Dr. Gehlbach developed the ideal screech owl nest, a box about 8 inches square and 10 inches deep. The box needs to be 12 to 20 feet from the ground for the owls to be comfortable with it. See the video for instructions. If you aren't handy, you can also buy a pre-made owl box from Amazon.
Do you have an owl box or owls in your neighborhood? I'd love to have you share your own owl experiences in the comments!