Short-eared owls (Asio flammeus) are medium-sized owls that are found throughout North America, Europe, Asia, and parts of South America and Australia. As their name suggests, short-eared owls have distinctive short feather tufts on the top of their heads that resemble ears. But why are these tufts referred to as “ears” and how did the short-eared owl get its name?
The appearance of short-eared owls
Short-eared owls have brown and buff colored plumage that provides good camouflage in open habitats like grasslands, meadows, and marshes. Their underparts are buff colored with brown spotting and streaking. The upperparts are mottled brown, buff, and black. Short-eared owls have large wings that allow them to fly slowly and methodically over open areas when hunting.
The heads of short-eared owls are rounded without any obvious ear tufts until the owl is alarmed. When alerted, the owl raises its short, black-edged feather tufts that sit close to the head. These tufts appear to look like small ears sticking up from the top of the head, leading to the owl’s common name.
However, the tufts are not actually ears at all. An owl’s true ears are small openings located asymmetrically on each side of the head behind the eyes. The distinctive tufts are thought to have several functions:
- They may help camouflage the owl by breaking up the round outline of the head
- They may serve as a visual signal to communicate with other owls
- They may help collect sound, but this is not confirmed
So while the feather tufts superficially resemble ears, they are not physically the owl’s ears. But their appearance when raised up led to the descriptive name “short-eared owl.”
Origin of the name
The origins of the name “short-eared owl” can be traced back hundreds of years to early European naturalists and ornithologists (scientists who study birds). Some key references include:
- English naturalist Francis Willughby first used the term “short-eared owl” in his 1678 book Ornithologiae to distinguish between owls with differing lengths of ear tufts.
- Swedish naturalist Carl Linnaeus retained the name in the 1758 10th edition of Systema Naturae, which formally named the short-eared owl Strix flammea.
- In 1788, John Latham used the common name “short-eared owl” in his book A General Synopsis of Birds.
The specific epithet flammeus means “flame-colored” in Latin, referring to the owl’s bright orange-yellow eyes. The current scientific name, Asio flammeus, recognizes the short-eared owl’s placement in the Asio genus.
Over time, the descriptive term “short-eared owl” became the established common name used by ornithologists, naturalists, and birders as the species was described in more detail. The unique feather tufts remain the most recognizable feature of the short-eared owl and inspired its enduring common name.
Habitat and hunting behavior
Understanding more about the habitat and hunting strategies of short-eared owls provides insight into the usefulness of their shortened ear tufts.
Short-eared owls favor open areas with relatively low vegetation, including:
- Grasslands
- Prairies
- Meadows
- Marshes
- Agricultural fields
They tend to hunt while flying low over these open areas in daylight, using their exceptional hearing and vision to locate small mammal prey like voles, mice, rabbits, and other rodents. Their wing beats are buoyant but purposeful, with slow flaps interspersed by brief glides.
The short feather tufts are useful while hunting in open environments because they enhance the owl’s camouflage by breaking up its outline when viewed from below against the sky. The mottled brown plumage also provides camouflage. Short-eared owls sometimes perch on low poles or small mounds, remaining perfectly still until prey is detected.
If alarmed, the tufts may help signal other owls while the short-eared owl is on the ground or in flight. When interacting with conspecifics (members of the same species), the feather tufts can be raised tall and lowered, which may aid communication. However, the tufts serve less purpose for owls that hunt in forests and woodlands.
Physical adaptations
In addition to their shortened ear tufts, short-eared owls possess other physical adaptations that aid their hunting in open habitats:
- Large wings – Short-eared owls have broad wings that can span up to 50 inches across. Their large wing area provides the lift needed to fly slowly while hunting.
- Keen eyesight – Their vision is optimized for crepuscular (dawn and dusk) hunting. Short-eared owls may have some color vision and can detect ultraviolet light, helping them spot prey.
- Acute hearing – Their true ears buried under feathers are lopsided and asymmetrically placed to enhance sound localization. The facial disc (concave face) also helps direct sound to the ears.
- Muffled flight feathers – The edges of primary flight feathers have soft fringes that dampen noise while the owl is in flight, improving hunting stealth.
- Downy body – Dense, soft down feathers help insulate the owl in open environments and cold weather.
These adaptations allow short-eared owls to keenly hunt by sight and sound over open terrain in low light. Their short ear tufts complement their habitat and behavior.
Comparison to long-eared owls
The traits of short-eared owls stand out more clearly when compared to their close relative, the long-eared owl (Asio otus). As their names suggest, long-eared owls possess two long, conspicuous feather tufts on the crown of their head that can exceed 2 inches in length.
Some key comparisons between long-eared and short-eared owls:
| Trait | Short-eared owl | Long-eared owl |
|---|---|---|
| Plumage color | Buff, brown, black, white | Brown, black, buff, white |
| Ear tuft length | Less than 1 inch when raised | Over 2 inches when raised |
| Wingspan | Up to 50 inches | Up to 42 inches |
| Preferred habitat | Open areas like grasslands | Woodland edges |
| Hunting strategy | Flies low over open ground | Perches and pounces on prey |
The longer ear tufts of long-eared owls likely help enhance their camouflage when roosting in dense vegetation associated with forests and woodland edges. In these settings, long tufts help break up the owl’s outline. However, short-eared owls do not require lengthy tufts in open environments.
Conclusion
Short-eared owls get their name from the small, shortened feather tufts on the top of their heads that superficially resemble mammalian ears. These tufts are raised when the owl is alert and contribute to camouflaging the owl in open habitats like grasslands where it primarily hunts. The ear-like tufts are not physically the owl’s true ears, yet they inspired early ornithologists to coin the descriptive name that remains today. While not literal ears, the shortened tufts of the short-eared owl suit its lifestyle and habitat perfectly.
