Owls in Iowa
Iowa has 4 owl species in our range data, 3 of them resident all year. Here is when each one is around, when it nests, what it sounds like at night and which ones will use a nest box.
- Owl species
- 4
- Resident all year
- Eastern Screech-Owl, Barred Owl, Great Horned Owl
- Winter visitors
- Northern Saw-whet Owl
- First to nest
- Barred Owl, January
- Use nest boxes
- Eastern Screech-Owl, Barred Owl
The owls of Iowa, one by one
Eastern Screech-Owl
Megascops asio · 6.3–9.8 in
Year-round resident, nests March–May.
Look for: small owl with ear tufts; grey or rufous morph; yellow eyes.
Call: Descending whinny and a long even trill.
Eats: Insects, mice, small birds and crayfish.
Barred Owl
Strix varia · 16.9–19.7 in
Year-round resident, nests January–May.
Look for: round head with dark eyes and no ear tufts; horizontal barring on the chest, vertical streaks on the belly; mottled brown-grey overall.
Call: The classic 'Who cooks for you? Who cooks for you-all?' hoot.
Eats: Small mammals, birds, amphibians and crayfish, hunted at night.
Great Horned Owl
Bubo virginianus · 18.1–24.8 in
Year-round resident, nests January–April.
Look for: large owl with prominent ear tufts ('horns'); white throat patch and heavy barring below; yellow eyes.
Call: Deep, booming 'hoo-hoo hoooo hoo-hoo' duets in winter.
Eats: Powerful generalist — rabbits, skunks, other owls, ducks and rodents.
Northern Saw-whet Owl
Aegolius acadicus · 7.1–8.3 in
Winter visitor.
Look for: tiny owl with a big round head and no ear tufts; white y between the yellow eyes; rusty streaks on a white breast.
Call: An endless, mechanical, evenly spaced 'too-too-too'.
Eats: Deer mice and other small rodents, hunted at night.
Owl nesting calendar for Iowa
Owls nest earlier than most backyard birds, which is why winter is the best time to hear them calling. In Iowa the order runs:
- Barred Owl: January–May, clutch of 1–5 eggs, incubation 28–33 days.
- Great Horned Owl: January–April, clutch of 1–4 eggs, incubation 28–37 days.
- Eastern Screech-Owl: March–May, clutch of 2–6 eggs, incubation 26–34 days.
Owl boxes in Iowa
2 owls here take to nest boxes. Sizes matter more than style:
- Eastern Screech-Owl: 3 in entrance, 8 × 8 in floor, mounted 10–30 ft. Mount by February.
- Barred Owl: 7–8 in entrance, 13 × 13 in floor, mounted 12–20 ft. Mount by January.
Add 2 to 3 inches of wood shavings, since owls bring no nest material. Skip rodent poison anywhere near the box: owls eat the poisoned rodents.
Hearing owls without disturbing them
- Listen on still, dry nights in the weeks before nesting starts; that is when pairs call most.
- Avoid playing recorded calls, which pulls owls off territory and away from eggs.
- Keep outdoor lights off near tree lines; owls hunt by sound and low light.
Owl eggs
Frequently asked
What owls live in Iowa?
We have range data placing 4 owl species in Iowa: Eastern Screech-Owl, Barred Owl, Great Horned Owl, Northern Saw-whet Owl.
Which owls stay in Iowa all year?
Eastern Screech-Owl, Barred Owl, Great Horned Owl are resident in Iowa year-round.
Which owls only visit Iowa in winter?
Northern Saw-whet Owl is mainly a winter visitor in Iowa.
When do owls nest in Iowa?
The earliest nester is the Barred Owl, starting around January. Eastern Screech-Owl: March–May; Barred Owl: January–May; Great Horned Owl: January–April.
Can I put up an owl box in Iowa?
Eastern Screech-Owl: 3 in entrance, 8 × 8 in floor, mounted 10–30 ft. Barred Owl: 7–8 in entrance, 13 × 13 in floor, mounted 12–20 ft. Have it up a month before nesting starts.
How do I tell owl calls apart in Iowa?
Eastern Screech-Owl: Descending whinny and a long even trill. Barred Owl: The classic 'Who cooks for you? Who cooks for you-all?' hoot. Great Horned Owl: Deep, booming 'hoo-hoo hoooo hoo-hoo' duets in winter. Northern Saw-whet Owl: An endless, mechanical, evenly spaced 'too-too-too'.
Sources
- Eastern Screech-Owl — All About Birds, Cornell Lab of Ornithology
- Eastern Screech-Owl life history — Cornell Lab of Ornithology
- Eastern Screech-Owl — Audubon Guide to North American Birds
- NestWatch nest box plans and species requirements — Cornell Lab
- Barred Owl — All About Birds, Cornell Lab of Ornithology
- Barred Owl life history — Cornell Lab of Ornithology
Timing reflects typical patterns for the region as a whole; local dates vary with elevation and year. Check the linked eBird bar charts for your county.