Sunday, April 14, 2024

NOTES FROM THE FALLEN TREE: Great Horned Owl’s Call a Treat for Nature Lovers – Caution Advised if Using Rodenticide

Great horned owl (Bubo virginianus)

The great horned owl. Photo by J. Correa-Kruegel, 2023.

One call that can radiate through an otherwise quiet winter forest is the “hoot, hoo, hoo” of the great horned owl. 

I was pleasantly woken up early this morning by a pair trying to find each other in the dark. Even under the covers and through closed windows, I could hear their communications with each other. 

These nocturnal creatures will eat squirrels, rabbits or even skunks. Great horned owls have the ability to eat smaller prey, like mice, whole. Later on, they will regurgitate the indigestible fur and bones into pellets. Multiple owl pellets can be found under the same tree. 

If they are seen during the day, it is often because crows and other birds will perceive them as a threat and mob them where the owls are trying to quietly roost. You won’t hear them in flight because their serrated wings allow the air to go through so they can sneak up on their prey undetected. 

Owls also have this amazing adaptation for hearing. One side of the ear opening is slightly higher than the other, allowing the owl to determine the distance and location of prey more easily in the dark. In addition, their round, disc-like faces direct sounds toward their ears to enhance the quality. 

Owls have seemingly giant eyes, but they are fixed. This is an advantage for catching prey but can leave a blind spot behind them.

Humans can stare straight and move eyes up, down, left or right. If owls possessed the same muscles humans have to move eyes around, they would weigh too much for flight. Instead, they have additional bones in their neck to be able to turn their head halfway around fairly quickly. 

Great horned owls begin nesting this time of year and they will typically use the old nests of hawks, other large birds or return to the same nesting site year after year. They can lay anywhere from one to four eggs and will begin incubation before all the eggs are laid due to the cold weather. 

Great horned owls are fairly common in our area but not often seen. One negative impact on all our birds of prey is the use of rodenticide to control the mice populations in our homes. 

Unfortunately, the mice do not always die immediately and if they are able to exit your home, they can seem like easy prey to an owl. An owl that has consumed a mouse filled with rodenticide can die painfully as it passes through their digestive tract. It is recommended to use spring or snap traps to remove mice from your homes. 

Make sure to keep an eye and ear out for great horned owls on your next venture outside. 

Jennifer Correa-Kruegel, Warren County Naturalist
Jennifer Correa-Kruegel, Warren County Naturalist

Jennifer has a Masters in Parks and Resource Management from Slippery Rock University. She worked as a Park Naturalist for Hunterdon County Park System from 2003-2006 and then at the NJSOC full-time from 2006 - 2020, starting as the Program Coordinator and evolving to an Environmental Educator. Jen is a New Jersey native and has lived in Warren County with her family since 2004. She is excited to be offering programs to this community she has grown to love.