Birds

Pellets

Pellets are made from the parts of a bird’s meal that cannot be digested. Raptors, sparrows, herons, and corvids produce pellets when they eat something that contains hard parts such as fur and bone. Pellets are coughed up and expelled though the beak. While many different species of birds cough up pellets, owls are by far the best type of pellet to dissect because they do not digest bones.

What’s in a Pellet?

The image below shows parts of undigestible bits of rodents (mice and rats). The pellet (regurgitated by a barred owl) is the yellowish/white mass at the top. Below the pellet is a piece of bone; below that, part of a rat leg; to the left are bits of fur and bone.

img_4297

Photo Credit: Animal Perspectives

Opening up a pellet is good way to know what a bird has eaten. Claws, vegetation, feathers, parts of insects, and teeth are other undigestible parts that can be found in pellets.

img_4665

Owl Pellet. Image Credit: Animal Perspectives

Why are Pellets Formed?

Pellets are formed because the proventriculus cannot digest the hard parts of a meal along with the ventriculus (the gizzard). The meat, organs, skin, and other tissues are passed along to the intestine from the gizzard. Everything else gets regurgitated.

img_4662

Fur, rodent skull, and lower mandible. Image Credit: Animal Perspectives

How Does it Happen?

Simply: a bird finds food (i.e., an insect, rodent, other bird, etc.) and gobbles it up.

FISH FACE 3

Black-crowned night heron with prey. Image Credit: Animal Perspectives

The meal then goes through to the esophagus, to the crop (the part of the esophagus where some birds store food), then to the stomach. The stomach is made up of two parts, the proventriculus and the gizzard.

BCNH PORTRAIT

Black-crowned night heron with prey in its crop. Image Credit: Animal Perspectives

The gizzard is the part of the stomach where a meal is ground up. The parts of the meal that are not passed on to the rest of the digestive tract form a pellet (or casting) in the gizzard. The rest of the meal is passed through the vent.

img_4668

Rodent skull and jaw with teeth from an owl pellet. Image Credit: Animal Perspectives

Studying pellets helps ornithologists understand avian diets and food sources. Finding pellets in the wild is easy. They can be found in many places at the base of trees where birds may roost.

Pellets can contain contagious diseases, therefore, when handling pellets it’s important to wash hands, wear gloves, and sterilize before handling.

Don’t forget to follow Animal Perspectives on Facebook, Twitter, and Pinterest!

Also read…

Quick Reads: 3 (More) Nature Books for the Young Ones

Review: Three Short Bird-Related Videos to Watch on Amazon Prime

Quick Reads: 3 Nature Books for the Young Ones

Review and Bird Guide: “H is for Hawk”

Sign up for The Animal Perspectives Monthly: http://eepurl.com/cm4z6v

Is there a particular species of bird that you would like to see featured on our website?

Are you a nature writer/blogger and would like to write a guest blog for AnimalPerspectives.Com, or do a blog exchange?

Maybe you snapped a great photo and have a story you’d like to share with it?

Either way, drop us a line! We’d love to hear from you!

Advertisements

Categories: Birds

Tagged as: , , , ,