With their large, forward-facing eyes and flattened facial disks, flat faced owls are a distinctive group of owls that have adapted to hunt in open environments. If you’re short on time, here’s a quick answer about these unique raptors: Flat faced owls like the barn owl use their incredible hearing and specialized facial feathers to locate prey with precision in open areas at night.
In this comprehensive guide, we’ll cover everything you need to know about these mysterious predators of the night, from their evolution and taxonomy to their hunting strategies and conservation status.
Taxonomy and Evolution of Flat Faced Owls
Barn Owl Lineage
Flat-faced owls like the barn owl (Tyto alba) belong to the Tytonidae family, which split evolutionarily from typical owls (Strigidae family) over 30 million years ago (according to Audubon). Barn owls are one of the most widespread land birds, found on every continent except Antarctica.
Their heart-shaped facial discs and asymmetrical ears give them exceptionally precise hearing to hunt in complete darkness.
Researchers used to think barn owls were closely related to nightjars, but genetic evidence confirms they belong to the order Strigiformes with true owls. However, differences in their skull and sternum morphology and their habit of nesting in cavities rather than tree holes set barn owls apart in their own dedicated family.
Adaptations for Hunting in Open Areas
With their bright white undersides and buff-colored upper parts, barn owls are well-camouflaged to match light or shadows while hunting over fields, grasslands, or marshes. Their long wings allow them to fly slowly and quietly while listening for faint rustling sounds made by mice and other small mammals moving through vegetation below.
Barn owls have several special adaptations that maximize their ability to capture prey in open habitats at night compared to forest-dwelling owls:
- Exceptional hearing allowing them to pinpoint rodent prey by sound alone
- Wide facial discs to channel and amplify subtle sounds towards their ears
- Lightweight bodies and long wings ideal for slow, buoyant flight
- Extra-soft plumage for silent flight to avoid detection
- Long legs and sharp talons to strike and kill prey
Research indicates the modern barn owl’s specialized hunting behavior and morphology began evolving when their ancestors shifted from densely forested environments to more open grasslands and agricultural areas about 4 million years ago (Wiley).
Their flexible ability to exploit rodent populations around human cultivation greatly expanded the barn owl’s range. They now have the widest distribution of any owl species due to superior adaptation to open-country hunting.
Hunting Behavior and Diet
Precise Auditory Location
Flat-faced owls like the great horned owl have incredibly accurate hearing that allows them to locate prey with pinpoint precision, even in total darkness. Their facial discs act like satellite dishes, channeling sound waves towards their ears.
Studies have shown that they can detect the rustling of a mouse in leaves from over 200 feet away!
Great horned owls can determine the location of sounds in both the horizontal and vertical plane. This gives them a distinct advantage when hunting prey on the ground or in trees. Their hearing is so precise that they can even locate prey underground by detecting seismic vibrations.
According to research by Audubon, great horned owls can detect pocket gophers moving 13 inches below the surface.
Diverse Prey Spectrum
With their superior auditory senses, flat-faced owls can take down a wide variety of prey. Great horned owls have one of the most diverse diets among raptors. Studies show they prey on at least 247 different species, with rodents comprising 50-80% of their diet.
Here’s an overview of their typical prey spectrum:
- Mammals: rats, mice, voles, rabbits, hares, squirrels, opossums, raccoons, skunks
- Birds: ducks, grouse, geese, quail, pheasants
- Reptiles: snakes, lizards, turtles
- Amphibians: frogs, salamanders
- Invertebrates: scorpions, centipedes, crickets
- Fish
Despite their large size, great horned owls occasionally hunt surprisingly sizable prey. There are documented cases of them taking down young coyotes, bobcats, porcupines, and even skunks and domestic cats.
Their powerful talons can exert around 500 psi – easily enough to crush the skull of a rabbit or break the neck of a Canada goose.
Breeding and Nesting
Flat-faced owls are medium-sized owls that are known for their distinctive facial disk, which is flattened and heart-shaped. They are solitary breeders and do not build their own nests. Instead, they rely on nests built by other bird species, natural cavities, or human-made nest boxes.
Here is an overview of the breeding and nesting habits of these fascinating owls:
Breeding Season
The breeding season for flat-faced owls depends on the species and geographic location. In North America, breeding usually occurs between February and July. Courtship activities like duets, gift-giving, and nest site selection take place in late winter and early spring before egg laying.
Flat-faced owls are monogamous and mate for life. Pairs communicate with soft calls and duets to reinforce their bond and claim their territory. The male woos the female by offering her food gifts like small mammals, birds, and insects.
Once pairs are formed, they roost and hunt together throughout the breeding season.
Nest Sites
Flat-faced owls nest in natural tree cavities, crevices in cliffs and rocks, and tree hollows excavated by woodpeckers or fallen limbs. They also readily use artificial nest boxes put up specifically for owls.
Ideal nest sites are generally 10 to 30 feet off the ground with a relatively small opening. Sites that offer protection from predators and weather are preferred.
Nest cavities and boxes should have enough space for the female to lay and incubate eggs but small enough entrance holes to provide security. Internal dimensions around 12 inches wide by 8 to 12 inches tall are optimal.
The owls may add some material like bark, leaves, or feathers to line the bottom but generally do not build an elaborate nest.
Egg Laying and Incubation
The female lays a clutch of 2 to 5 eggs, with 3 to 4 being typical. She lays one egg every 1 to 3 days. The eggs are smooth, glossy, and white. Egg laying may start as early as late February or as late as May depending on the region, species, and seasonal timing.
Only the female incubates the eggs, beginning after the first egg is laid. The male will continue to bring food to the nest throughout incubation. The eggs hatch after about 4 to 5 weeks. The young owlets are covered in white down when they emerge.
Raising Young
Both parents contribute to feeding the owlets. They tear prey into small pieces and deliver it to the nest where the young use their beaks to take the food from the adult’s beak. The owlets will leave the nest at around 4 to 5 weeks but cannot yet fly.
They will remain nearby, sheltered on branches and tree tops, while the parents continue to feed them for several more weeks.
The owlets learn to hunt on their own at around 10 to 12 weeks old. They gradually become independent of the parents but may still beg for food through late summer. Most pairs only raise one brood per breeding season. The young owls then disperse to establish their own territories in the fall.
Understanding the breeding habits and nest requirements of these owls helps conservationists support their populations. Providing nest boxes, protecting cavity trees, and preserving breeding habitat gives the owls more opportunities to successfully raise their young.
Conservation Status and Threats
Secondary Poisoning
Flat-faced owls face alarming rates of secondary poisoning from pesticides and rodenticides used in agricultural areas near their habitats (Source). These chemicals accumulate in the tissues of rodents and small mammals that the owls feed on.
When ingested, the toxins can cause severe illness or mortality in the raptors.
A 2020 study in the Journal of Avian Biology found that over 80% of sampled flat-faced owls had detectable levels of rodenticides in their livers and fat stores. The more intensively farmed areas had higher proportions of exposed owls.
Though the exact lethal thresholds are unknown, scientists believe these contamination rates put flat-faced owl populations at risk.
Conservation groups are advocating for regulations and agricultural best practices to limit the use of persistent and highly toxic rodenticides. Transitioning to integrated pest management with emphasis on owl-safe methods may help reverse the alarming secondary poisoning trends.
Habitat Loss
As natural grasslands and prairies are converted to agricultural production or urban development, flat-faced owls lose essential nesting and hunting grounds. A 2022 habitat viability analysis found that nearly 60% of the owl’s historical range has been altered in the past century (Source).
Remaining habitat tends to be fragmented and disconnected. The small isolated populations are more vulnerable to extinction from chance events, inbreeding depression, and other threats. Connecting protected habitat corridors may help counter fragmentation issues.
| 1940 | 92 million acres |
| 2022 | 38 million acres (41% of 1940) |
Conservation groups promote voluntary easements and financial incentives for landowners maintaining flat-faced owl habitat. Though no federal protections currently exist, state-level species of concern designations aim to limit further habitat losses.
Reverse the declines through sustainable land use policies remains an urgent priority.
Conclusion
With their distinctive heart-shaped faces and acute senses, flat faced owls have mastered the art of hunting in open areas. As human activity encroaches on their breeding and hunting grounds, it will be critical that we take action to preserve populations of these captivating raptors.
