An owl hole is a structural entrance built into buildings (such as mills and barns) to allow predatory birds, typically barn owls (Tyto alba), to enter. The birds prey on farm vermin, and therefore benefit the human owner of the structure in a symbiotic relationship.
The barn owl feeds primarily on small vertebrates, particularly rodents. Studies have shown that a barn owl may eat one or more rodents per night; a nesting pair and their young can eat more than 1,000 rodents per year and have been referred to as 'nature's mousetraps'. [1] Locally superabundant rodent species in the weight class of several grams per individual usually make up the single largest proportion of prey. Barn Owls consume more rodents than possibly any other creature. This makes the barn owl one of the most economically valuable wildlife animals to farmers and millers. Farmers and others found these owls effective in keeping down rodent pests, and they encouraged barn owl habitation by providing nest sites. [1] In the few months between hatching and fledging, a clutch of six owlets can consume up to 70 pounds (32 kg) of rodents. [2]
With the advent of modern pesticides the perceived value of biological control has dramatically decreased to the point that few owl holes are still in active use. Many of the holes have been blocked up and landing platforms broken off.
First used at the end of the 17th century, [3] these were often positioned on the gables end of buildings owl holes were usually placed under the eaves. The perch or landing platform was made from stone or wood and usually sloped slightly downward to prevent rain water from entering the building. The entry holes are usually oblong and six to nine inches (152–228 mm) [3] that permits a single bird to enter with space for a safe landing and passage to the interior whilst at the same time excluding larger predators. [1] Owl holes without landing platforms had grooves or rough surfaces beneath the hole to aid grip. On wooden buildings circular examples are sometimes found. [4] The openings usually faced onto open ground so that they could be easily seen by barn owls seeking nesting sites. [1] Owl holes also assisted ventilation within barns and provided for some extra illumination.
Some examples found on the gable ends of wooden barns are very ornate and may be the 'signatures' of the craftsmen who built the barns, coupling this with a practical function of ventilation and as owl holes. Owl holes are sometimes found in association with dovecots as pigeons are not generally a prey species for barn owls.[ citation needed ]
In Scotland owl holes were a common feature of old farms and mills, such as Roughwood Farm and Dalgarven Mill.
Owl holes were found in Wales, a 'triangular' example survives at Llangattock in Glamorgan. [5]
In England an example is to be found on an old pumping mill in Norfolk, old barns in Yorkshire, etc. [6]
In Germany these structures are known as Eulenloch ('owl hole'). [7]
Examples are recorded from Ontario in Canada [5] and the US. [4]
In Hallstatt at the foot of the Echernwand, a trapeze-shaped opening is visible in the rock face. The hole in the cliff has been known as the Eulenloch ('owl hole'). [8]
The common buzzard is a medium-to-large bird of prey which has a large range. It is a member of the genus Buteo in the family Accipitridae. The species lives in most of Europe and extends its breeding range across much of the Palearctic as far as northwestern China, far western Siberia and northwestern Mongolia. Over much of its range, it is a year-round resident. However, buzzards from the colder parts of the Northern Hemisphere as well as those that breed in the eastern part of their range typically migrate south for the northern winter, many journeying as far as South Africa.
Owls are birds from the order Strigiformes, which includes over 200 species of mostly solitary and nocturnal birds of prey typified by an upright stance, a large, broad head, binocular vision, binaural hearing, sharp talons, and feathers adapted for silent flight. Exceptions include the diurnal northern hawk-owl and the gregarious burrowing owl.
Barn-owls are one of the two families of owls, the other being the true owls or typical owls, Strigidae. They are medium to large owls with large heads and characteristic heart-shaped faces. They have long, strong legs with powerful talons. They also differ from the Strigidae in structural details relating in particular to the sternum and feet.
The rough-legged buzzard (Europe) or rough-legged hawk is a medium-large bird of prey. It is found in arctic and subarctic regions of North America, Europe, and Asia during the breeding season, and migrates south for the winter. Historically, it was also known as "rough-legged falcon" in such works as John James Audubon's The Birds of America.
The long-eared owl, also known as the northern long-eared owl or, more informally, as the lesser horned owl or cat owl, is a medium-sized species of owl with an extensive breeding range. The genus name, Asio, is Latin for "horned owl", and the specific epithet, otus, is derived from Greek and refers to a small eared owl. The species breeds in many areas through Europe and the Palearctic, as well as in North America. This species is a part of the larger grouping of owls known as typical owls, of the family Strigidae, which contains most extant species of owl.
The northern hawk-owl or northern hawk owl is a medium-sized true owl of the northern latitudes. It is non-migratory and usually stays within its breeding range, though it sometimes irrupts southward. It is one of the few owls that is neither nocturnal nor crepuscular, being active only during the day. This is the only living species in the genus Surnia of the family Strigidae, the "typical" owls. The species is sometimes called simply the hawk owl; however, many species of owls in the genus Ninox are also called "hawk owls".
The great horned owl, also known as the tiger owl or the hoot owl, is a large owl native to the Americas. It is an extremely adaptable bird with a vast range and is the most widely distributed true owl in the Americas. Its primary diet is rabbits and hares, rats and mice, and voles, although it freely hunts any animal it can overtake, including rodents and other small mammals, larger mid-sized mammals, birds, reptiles, amphibians, and invertebrates.
The barred owl, also known as the northern barred owl, striped owl or, more informally, hoot owl or eight-hooter owl, is a North American large species of owl. A member of the true owl family, Strigidae, they belong to the genus Strix, which is also the origin of the family's name under Linnaean taxonomy. Barred owls are largely native to eastern North America, but have expanded their range to the west coast of North America where they are considered invasive. Mature forests are their preferred habitat, but they can also acclimatise to various gradients of open woodlands. Their diet consists mainly of small mammals, but this species is an opportunistic predator and is known to prey upon other small vertebrates such as birds, reptiles, and amphibians, as well as a variety of invertebrates.
The burrowing owl, also called the shoco, is a small, long-legged owl found throughout open landscapes of North and South America. Burrowing owls can be found in grasslands, rangelands, agricultural areas, deserts, or any other open, dry area with low vegetation. They nest and roost in burrows, such as those excavated by prairie dogs. Unlike most owls, burrowing owls are often active during the day, although they tend to avoid the midday heat. Like many other kinds of owls, though, burrowing owls do most of their hunting during dusk and dawn, when they can use their night vision and hearing to their advantage. Living in open grasslands as opposed to forests, the burrowing owl has developed longer legs that enable it to sprint, as well as fly, when hunting.
The eastern screech owl or eastern screech-owl, is a small owl that is relatively common in Eastern North America, from Mexico to Canada. This species resides in most types of woodland habitats across its range, and is relatively adaptable to urban and developed areas compared to other owls. Although it often lives in close proximity to humans, the eastern screech owl frequently avoids detection due to its strictly nocturnal habits.
The red-tailed hawk is a bird of prey that breeds throughout most of North America, from the interior of Alaska and northern Canada to as far south as Panama and the West Indies. It is one of the most common members within the genus of Buteo in North America or worldwide. The red-tailed hawk is one of three species colloquially known in the United States as the "chickenhawk", though it rarely preys on standard-sized chickens. The bird is sometimes also referred to as the red-tail for short, when the meaning is clear in context.
The pearl-spotted owlet is a small bird of prey found in sub-Saharan Africa. They belong to the Strigidae family, otherwise known as the typical owls or the true owls, which contains most species of owl. As part of the genus Glaucidium, or pygmy owls, they are commonly referred to as 'owlets' due to their diminutive size. Pearl-spotted owlets are brownish and heavily spotted white, with two distinct black false 'eyes' at the back of their head. They are often confused with an African barred owlet.
Hawking is a feeding strategy in birds involving catching flying insects in the air. The term usually refers to a technique of sallying out from a perch to snatch an insect and then returning to the same or a different perch, though it also applies to birds that spend almost their entire lives on the wing. This technique is called "flycatching" and some birds known for it are several families of "flycatchers": Old World flycatchers, monarch flycatchers, and tyrant flycatchers; however, some species known as "flycatchers" use other foraging methods, such as the grey tit-flycatcher. Other birds, such as swifts, swallows, and nightjars, also take insects on the wing in continuous aerial feeding. The term "hawking" comes from the similarity of this behavior to the way hawks take prey in flight, although, whereas raptors may catch prey with their feet, hawking is the behavior of catching insects in the bill. Many birds have a combined strategy of both hawking insects and gleaning them from foliage. Mainly founded in the grass lands and from dark oak wood fort trees.
The Tasmanian masked owl is a bird in the barn owl family Tytonidae that is endemic to the island state of Tasmania, Australia. It is the largest subspecies of the Australian masked owl, the largest Tyto owl in the world, and is sometimes considered a full species. The subspecific name castanops, meaning "chestnut-faced", comes from the colouring of the facial disc. It was first described by John Gould, who wrote about it in his Handbook to the Birds of Australia as:
"…a species distinguished from all the other members of its genus by its great size and powerful form. Probably few of the Raptorial birds, with the exception of the Eagles, are more formidable or more sanguinary in disposition."
"Forests of large but thinly scattered trees, skirting plains and open districts, constitute its natural habitat. Strictly nocturnal in its habits, as night approaches it sallies forth from the hollows of the large gum-trees, and flaps slowly and noiselessly over the plains and swamps in search of its prey, which consists of rats and small quadrupeds generally."
A plucking post is a raised structure such as a tree stump which is used regularly by a bird of prey to dismember its prey, removing feathers and various other inedible parts before eating it.
The tawny owl, also called the brown owl, is a stocky, medium-sized owl in the family Strigidae. It is commonly found in woodlands across Europe, as well as western Siberia, and has seven recognized subspecies. The tawny owl's underparts are pale with dark streaks, whilst its upper body may be either brown or grey. The tawny owl typically makes its nest in a tree hole where it can protect its eggs and young against potential predators. It is non-migratory and highly territorial: as a result, when young birds grow up and leave the parental nest, if they cannot find a vacant territory to claim as their own, they will often starve.
Roughwood once Ruchwood is a farm, originally a estate, possessing at one time a small tower castle. Roughwood is situated near to the town of Beith in North Ayrshire, Scotland; the lands lay within the old Lordship of Giffen.
The eastern barn owl is usually considered a subspecies group and together with the American barn owl group, the western barn owl group, and sometimes the Andaman masked owl make up the barn owl. The cosmopolitan barn owl is recognized by most taxonomic authorities. A few separate them into distinct species, as is done here. The eastern barn owl is native to southeastern Asia and Australasia.
The western barn owl is usually considered a subspecies group and together with the American barn owl group, the eastern barn owl group, and sometimes the Andaman masked owl make up the barn owl. The cosmopolitan barn owl is recognized by most taxonomic authorities. A few separate them into distinct species, as is done here. The western barn owl is native to Eurasia and Africa.
The American barn owl is usually considered a subspecies group and together with the western barn owl group, the eastern barn owl group, and sometimes the Andaman masked owl, make up the barn owl, cosmopolitan in range. The barn owl is recognized by most taxonomic authorities. A few separate them into distinct species, as is done here. The American barn owl is native to North and South America, and has been introduced to Hawaii.
