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Information on Barn Owl and Barn Owl Houses

BARN OWL

Identification: The barn owl has a white, heart-shaped facial disk, no ear tufts and long legs. The bird appears white from below and golden-brown from above, with black specks all over. The long wings fold beyond the tail and the legs are feathered. The sexes can be distinguished by differences in coloration and weight. Males usually have whiter breasts with fewer and smaller dark specks. Females are typically heavier and have more and larger dark specks. Chicks are covered with down when born, but 8 to 10 weeks later they acquire adult-like plumage.  

Range: The barn owl is found on every continent except Antarctica. The species is considered partly migratory in the northeastern United States, although many individuals remain there throughout the winter. Band recoveries indicate that some northeastern barn owls winter in Texas and the southeastern part of the country. 

Reproduction: Barn owls are monogamous (one mate). They are not aggressive toward other barn owls and can nest within a half mile of other pairs. Barn owls are sexually mature at 1 year of age and, because they have a short lifespan, they breed only once or twice. Both natural and human-made sites are used for nesting and they are generally used repeatedly by other barn owls throughout the years. Nest sites include tree cavities, barns, abandoned and occupied buildings, and chimneys. Males use a courtship call to show the female the nest site. Barn owls do not construct a nest; the eggs are laid in a dark space surrounded by pellets. These brownish-black pellets, which are the regurgitated fur and bone fragments of each meal, average about 2 inches in size and are produced twice a day. 

The 5-11 eggs (average 4-6) are laid every other day. The female incubates the eggs for 30-34 days, starting when the first egg is laid. Hatching occurs in the same order as the eggs were laid, so a gradation of ages and sizes can be observed in a brood. In times of scarce food, the older and stronger young have a better chance of survival. Stronger, first-hatched nestlings have been observed eating and trampling younger, later-hatched owls. The young are fed by both adults for approximately 2 months. The adult male does most of the hunting and feeding. 

Reason for Decline: Land use changes, particularly the decrease in the number of farms, have contributed to the decline of this species. Not only has foraging habitat been reduced, but the increased use of rodent poisons has resulted in a smaller food base. Natural nest sites in hollow trees are often limited, and human disturbance of the nest during incubation may cause nest abandonment. One common cause of mortality is predation of young barn owls by raccoons. Other mortality factors include exposure to harsh weather, electrocution by power lines, predation by dogs and great-horned owls, and accidental entanglement in farm and industrial machinery.

 

Habitat

Open areas, such as grassy fields, old fields, wet meadows and wetland edges, around farms and rural towns. Daytime roost is usually an evergreen tree, belfry or barn.
Weight

Males, 14-19 ounces; females, 17-25 ounces.
Length

Males, 13-15 inches; females, 14-20 inches.

 

Life Expectancy

Few adults live beyond 3-4 years; high mortality the first year.

Food

Meadow voles, mice and shrews; also bats, skunks and various birds; frogs and large insects only if necessary.

Status

State endangered.

 

JCs Wildlife Owl house are modeled after an Original Design by Steve Simmons

JCs Wildlife Barn Owl box has many advantages. It provides optimized protection from predators such as Great Horned Owls and raccoons. This is achieved by use of an ellipse-based entrance hole of unique shape and size and by an interior divider that separates the box into two compartments. The divider provides a safe living area away from the entrance. Should a predator gain access to the entrance hole, it is unlikely that it will fit completely through the hole, and the divider further prevents the predator from reaching around the divider to access the occupants.

Additionally, the placement of the entrance hole is such that younger owlets who congregate near the hole waiting to be fed will not be pushed out of the box by older and larger siblings lunging for food from behind.

The design omits perches or platforms in front of the entrance hole which would enable predators to perch during their attempt to snatch the box’s occupants. Owlets likewise cannot perch outside the box and thus be exposed to predation.

Grooves (grip grooves) below the entrance hole assist adults entering the box.

The design includes one doors for end clean out which provides access to the interior during clean out and monitoring activities

An important attribute about this box is that the design has been tested in use by thousands of owls, an extremely unique situation. Over 10,000 Barn box like this one sold to local ranchers for pest control.

To Paint or Not to Paint

The box will provide many years of use without painting. If the decision is made to paint the box, apply either a white exterior latex based paint or a linseed oil finish. Apply either to the exterior of the box only.

Where to Place the Box

Barn Owl habitat is generally open fields and meadows. A supply of small mammals is of course necessary in this range. The owl’s diet consists primarily of Pocket Gophers, Voles (or Meadow Mice), Deer Mice, House Mice, and small birds. The box should be placed near (not necessarily directly on top of) an area where the latter are readily available. In cropland areas with trees, the rodents are often in the uncultivated area between the trees and cultivated crops and the number of owls that can be supported is determined by that area2. Owl control of small mammals is useful in vineyards and in orchards.

Barn Owls hunt over a range that may have a radius of as much as a mile or more, and the hunting ranges of individual owls may overlap.

The male Barn Owl is territorial, so the boxes should be placed a minimum of 80 yards apart.

Great Horned Owls and Red-tailed Hawks are predators of Barn Owls, so it is wise to avoid their habitat (large forest groves). Vehicles (large trucks and trains) are the number one killer of Barn Owls since the flight path of owls is low. Therefore, box placement should not be near roads or train tracks that have significant night-time traffic.