Yes, owls regurgitate.
Owls swallow their prey whole or in large pieces, but they cannot digest fur, teeth, bones, or feathers.
Because of this, the indigestible parts of the prey are formed into a pellet that is regurgitated by the owl
. The process of pellet formation begins in the owl’s gizzard, which grinds down hard structures and squeezes the digestible food into the intestines.
The remaining, indigestible fur, bones, and teeth are compacted into a pellet which the owl spits out. Owls typically cast one pellet per day, often from the same roosting spot, so you may find large numbers of owl pellets on the ground in a single place. Owls regurgitate pellets several hours after eating, and the pellet cycle is regular, regurgitating the remains when the digestive system has finished extracting the nutrition from the food.
What Is The Purpose Of Regurgitation In Owls And How Does It Benefit Them?
The purpose of regurgitation in owls is to remove indigestible material from their digestive system, specifically the gizzard.
Here is how regurgitation benefits owls:
- Sorting Operation: Owls often swallow their prey whole, including bones, fur, and feathers.
The owl’s gizzard performs a sorting operation, allowing soft tissues to pass through for digestion while forming indigestible parts into an oval mass. - Pellet Formation: The indigestible parts, such as teeth, bones, and feathers, are compressed into a pellet in the gizzard.
This pellet remains in the proventriculus for up to 10 hours before being regurgitated.
The pellet partially blocks the owl’s digestive system, preventing the ingestion of new prey until it is ejected. - Ready to Eat Again: Regurgitation often signifies that an owl is ready to eat again.
Once the pellet is expelled, the owl can resume hunting and consuming new prey. - Health Benefits: The regurgitation of pellets serves the health of birds of prey, including owls, by “scouring” parts of the digestive tract, including the gullet.
This helps to keep the digestive system clean and functioning properly.
Overall, regurgitation in owls allows them to effectively digest their prey while removing indigestible material from their digestive system, enabling them to continue hunting and consuming new prey.
Are There Any Specific Circumstances Or Behaviors That Trigger Regurgitation In Owls?
Owls regurgitate pellets that contain undigested parts of their prey, such as fur, bones, teeth, and feathers, several hours after eating.
The pellet cycle is regular, and the remains are regurgitated when the digestive system has finished extracting the nutrition from the food.
This is often done at a favorite roost.
The pellet partially blocks the owl’s digestive system, so new prey cannot be swallowed until the pellet is ejected.
Owls often regurgitate one pellet per mouse-size prey animal eaten, and they will rarely attempt to hunt again until that happens.
When an owl is about to produce a pellet, it will take on a pained expression, the eyes are closed, the facial disc narrow, and the bird will be reluctant to fly.
At the moment of expulsion, the neck is stretched up and forward, the beak is opened, and the pellet simply drops out without any retching or spitting.
There are no specific circumstances or behaviors that trigger regurgitation in owls, as it is a natural part of their digestive process.
Are There Any Other Bird Species Besides Owls That Exhibit Regurgitation As A Natural Behavior?
While many bird species regurgitate pellets, large owl species are especially suited for study because their pellets are big enough to be examined.
However, there are other bird species besides owls that exhibit regurgitation as a natural behavior.
Helpful Resources
- https://www.audubon.org/news/what-owl-pellet
- https://www.barnowltrust.org.uk/owl-facts-for-kids/owl-pellets/
- https://www.washingtonpost.com/lifestyle/style/ever-wondered-what-owl-pellets-are/2013/05/10/677fcc90-1b86-11e1-a1c9-d8aff05dec82_story.html
- https://www.allaboutbirds.org/news/what-are-owl-pellets/
- https://www.owlpages.com/owls/articles.php?a=4
- https://knowledge.carolina.com/discipline/life-science/biology/all-about-owl-pellets/