Barn Owl Species Notes, Development Photos and Case Histories

Barn Owls belong to the family Tytonidae, while all the rest of the owls of North America belong to the family Strigidae. It is to be expected, then, that their behavior is quite different in some ways from other owls. For our purposes, the most notable difference is the extreme ferocity of the juveniles, which will be discussed in more detail below. Barn Owls are usually nocturnal hunters, and they specialize in hunting over open fields and pastures, using their long wings to cruise silently just above the grass while locating their prey primarily by their keen hearing. Their preferred prey is small rodents and other small mammals. In times of shortage, they are adaptable, and can make use of whatever prey is most abundant, including birds.

Barn Owls in the southern U.S. can raise as many as three annual broods. In our area the first brood is usually produced in April and May, another in the late summer (July and August), and a third in November. A single clutch usually contains 3 to 8 eggs, but as many as 12 eggs have been found in a single nest. Since the brood size is large, and the young hatch asynchronously, the difference in the size and age of the nestlings may be striking. As long as there is an ample food supply, I have not observed any problems caused by the great disparity in size among members of a brood.

While undisturbed juveniles can coexist peacefully, the same cannot be said if the nest is disturbed. Nestling Barn Owls have powerful talons, and they will attack aggressively if disturbed, even leaping forward with talons outstretched to attack the intruder, meanwhile emitting a piercing scream that is almost deafening. Perhaps the most difficult aspect of handling these aggressive young birds is that once aroused, they attack anything, even their own siblings. Thus it is necessary to keep the birds separate while they are aroused, and allow them to gradually calm down before getting together again. In a nest box or carrying box this is best done by putting each juvenile in a different corner, so that they are out of striking distance of each other. When introducing nestlings into a nest box, it is best to have a box that allows enough space between the entrance and the back of the box so that each new bird placed in the box can calm down before joining the others in the back of the box, while those already there will not feel threatened by the close proximity of the new bird. Usually, if handled gently, it only takes a few minutes for the birds to mingle again as a single group. The young fledge in 55 60 days, but remain dependent on the adults and return to the nest to roost for several more weeks. Since Barn Owls often nest in old buildings, factories, barns, and shooting stands, it is quite common to have to move young barn owls to a nest box to avoid interference. These relocations are well tolerated if properly done. My usual practice is to install the nest box as close as possible to the original nest site, usually within 50 to 100 feet. However, I encountered a case where a shooting stand was moved over a quarter of a mile before it was discovered that it contained a brood of fledgling Barn Owls. In spite of the  extreme distance of the move, the adults were able to locate their brood and continued to provide for them.

 

Barn Owl (Tyto alba)

Development Photos

Hatchlings

 

Young Nestlings

 

Older Nestling

 

Older nestlings almost ready to fledge

 

Fledgling

 

Case Histories

Case History #1

Case History #2

Case History #3

Case History #4

Case History #5

 

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