Episode 180 – Eastern Screech Owl: Snakes in the Nest

“…and today we’re talking about an owl with an eye for allies. But more on that later.”

Small things slithering across the woodlands know to watch the skies. A killer approaches silently as it glides from high perches. For most small mammals and invertebrates that meet this aerial doom, it’s time to say goodbye to this mortal coil. But when a particular snake comes face-to-beak with the eastern screech owl, they have one more chance to prove their worth. But sometimes, combating deadly predators is a matter of being worth more alive than dead in Life, Death, and Taxonomy. 


  • Like most owls, they are imposing birds of prey with seemingly large, neckless heads and a puffed-out chest.
  • They have flat, walnut-shaped faces with short, hooked beaks, enormous yellow eyes, and two larger horned tufts for ears.
  • Their feathers are greyish-brown with black streaks along the belly and wings, and a black line outlining the face. Though there is a “red” or “rufous” variant. Not really red, just reddish-brown.
  • There are five different subspecies (or morphs): 
    • Asio
    • Maxwelliae
    • Hasbroucki
    • Mccallii
    • Florianus

Measure Up

Welcome to the beloved Measure Up segment. The official listener’s favorite part of the show! The part of the show when we present the animal’s size and dimension in relatable terms through a quiz that’s fun for the whole family. It’s also the part of the show that’s introduced by you when you send in audio of yourself saying, singing, or chittering the words Measure Up into ldtaxonomy at gmail dot com. We do have a Measure Up intro this week from Alex. See if you can tell where Alex is from…


  • 16 to 25 cm (6.5 to 10 in)
  • How many screech owls go into the world’s largest pair of cowboy boots?
  • Hint: They aren’t real cowboy boots, but they are a piece of art created by Bob “Daddy-O” Wade. Wade is known for creating huge art and he’s also made a giant iguana in New York. The boots are in San Antonio.
  • 42 owls. The boots are 35 feet high.


  • 121–244 g (4–8 oz)
  • How many owls go into the weight of the largest drum in Texas?
  • Hint: The drum is known as Big Bertha and lives at The University of Texas at Austin. She’s also called the “Sweetheart of the Longhorn Band.” Bertha is played after each touchdown and also sees action at pep rallies and other events. She’s moved on a cart on and off the field. 
  • 1000 owls. Big Bertha is 500 pounds (230 kg).

Fast Facts

  • Range: Most of Eastern North America from Florida to Newfoundland and extending as far inland as Texas and Mexico. They love forests, meadows, marshes, basically anywhere there are pine trees. They are also pretty common in areas with lots of humans.
  • Diet: Insects, lizards, rodents, snails, crayfish, spiders, worms, squirrels, bats, small birds, turtles, fish, snakes, frogs, salamanders, and much much more! Basically anything it can fly off with.
  • Behavior:
    • It’s a pretty avid hunter that swoops down on prey from a concealed perch
    • It has insane hearing and can even hear prey digging around under heavy snow.
    • While it has ear tufts, like we said, its actual ears are asymmetrically placid, so it can use the difference in sound to triangulate the position of prey.
    • It also has the same stealth feathers that the barn owl has.
  • As we mentioned, it is well-adapted to living near humans and will often live in little bird houses made for them or some other bird. In many cases, they’ll kill and eat the birds living there.

Major Fact: Snake Guards

Eastern screech owls are adept hunters and go after all manner of small prey species in the woodlands they patrol. But like every good hunter, they spare those who are better left alive. 

When the owls find a particular snake called the Texas blind snakes, they scoop them up without killing them. These snakes are small and worm-like in appearance. They aren’t completely blind, but they’re close to it, preferring to spend their days burrowed beneath the soil. 

Owls that catch the snakes bring them back to their nest of hungry owlets and drop them in. Some eager owl babies gobble up these non-seeing noodles on sight. But many snakes are able to burrow into the foliage, feathers, and soil in the bottom of the nest where no baby beaks come after them. 

At this point, you may be thinking, “This isn’t something the owl is doing. The snakes are just lucky enough to be able to burrow for their lives.” But, like most owls, screech owls kill their prey quickly, often by biting off their heads, and these snakes make it to the nest in one piece.   

The snakes that live in owl nests gobble up insects and other tiny nest invaders that might act as parasites to young owls. 

Research found that owlets that grow up with noddle nannies tended to grow bigger and faster than their kin with no scaly roommates. The snake gets a steady diet of food while the owls get a housekeeper.

This is a clear example of symbiosis and a debatable example of mutualism. Mutualism is when two species work together in a mutually beneficial relationship. Under ideal circumstances, that’s what happens, but the snake clearly gets the short end of the stick. 

They have to make it through a gauntlet of tiny sharp beaks and when those beaks grow up and leave, the snakes usually don’t maintain a viable food source in the nest. It’s thought that insects are accidentally brought into the nest by hitching a ride on Big Momma like rats on an old frigate. Other insects may be attracted to other aspects of owl life like dropped food and feces.

Ending: So keep your head on a swivel, swoop in at the opportune moment, and always keep a couple snakes handy because you never know when you need snakes like the eastern screech owl here in Life, Death, and Taxonomy.