Fun with owl pellets, part 1

Today I submitted the Big Grant Proposal that I’ve been working on for a while. To celebrate this, because I am a normal person, I dissected some owl pellets.

Now that's what I call a party.

Now that’s what I call a party.

These particular owl pellets were from Great Horned Owls—these ones, in fact:

owlpellets_owls_scratchingWhen an owl eats something, it doesn’t digest the whole thing. The hard-to-digest parts—bones, fur, exoskeleton—get smooshed into a pellet in the gizzard and then regurgitated. These pellets are a record of what the bird has eaten.

This is my "How is it your business what I've eaten?" look.

This is my “How is it your business what I’ve eaten?” look.

I can guess that the pellets were from these particular owls because I found the pellets underneath the owls. There were a lot of pellets: clearly the owls have been using this roost for a while.

owlpellets_pellets

owlpellets_pellets2owlpellets_skull

 

Yeah, we eat a lot.

We eat a lot.

I collected three pellets to dissect. I was curious to see what these owls were eating, and owl pellets are hard to resist, with their mystery and tiny bones.

This one is kind of a half-pellet. You can see rodent teeth in it.

This one is more of a half-pellet really. You can see rodent teeth sticking out of it.

Ribs,

Dissected: ribs, vertebrae, a cranium and a jaw, and lots of fur.

Yep, we ate that.

Yep, we ate that.

Dissecting a pellet just means pulling the matted fur apart and pulling bones out. Mostly the bones are disarticulated, but some vertebrae were still together.

owlpellets_vertebrae

Two vertebrae (and some fur).

The pellets weren’t all the same. Pellet #2, unlike the others, had a lot of little larvae in it. Sorry I messed up your home, larvae.

 

Larva

Annoyed larva

Pulling wriggling grubs out of skull eye sockets felt like Halloween come early.

Pellet #1 had some plant matter: grass, a few spiky little seeds. All of the pellets had a lot of dirt and tiny stones. I suppose if you’re eating rodents whole, you can expect to eat some dirt too.

owlpellets_pellet1

 

owlpellets_pellet1_done

 

I had seen seagull feathers scattered around the roost and was hoping to find some bird bones, but everything I could identify looked like rodent to me.

Rodent cranium, with one tooth removed to show how big it is.

Rodent cranium, with one tooth removed to show how big it is.

I found 8 skulls in my pellets. Two were very small, while the rest were maybe gopher or squirrel-sized—certainly not the largest prey these big owls can eat.

owlpellets_skulls

That big foot is a serious weapon.

That foot is a serious weapon.

Because bones, especially mammal bones, are not my area of expertise, I’m going to see if I can get some friends to help identify the owl pellet bones, and will let you know the results.

Lots of bones!

Lots of bones!

Pssh. Who cares about bones when I can make this weird face?

Pssh. Who cares about bones when I can make this weird face?

Elegant owl.

Elegant owl.

Just-woke-up owl.

Just-woke-up owl.

Great-Horned-but-no-head-Owl.

Great-Horned-but-no-head owl.

 

 

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4 thoughts on “Fun with owl pellets, part 1

  1. Really enjoyed this normal post. It’s a bizarre way of eating but it sure is efficient on the front end. I would really enjoy the access you got to those beautiful birds.

  2. I’m so jealous! (Does that make me weird? lol)
    By the way, I have a photo of some pellet-like things that I am wondering about, maybe they are pellets (or droppings) from some kind of bird. They are made of fiber and are smaller than the ones in your photos. I’m the one who sent you the photos of the deformed junco a couple of years ago. Hope you don’t mind but I’m going to send you a photo over email, thanks :)

  3. Pingback: Old owl and falcon pellets, new research | Dear Kitty. Some blog

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