Due to a lack of space, these five live owls are trying to coexist on top of each other.

Poor Box Design:

Poor designs, construction, and materials used to make barn owl boxes lead to a multitude of issues for owls. Owls will often inhabit less than adequate boxes driven by instinct and desperation to nest. It’s tempting to believe that the boxes must be good if a bird is nesting in it, but this isn’t necessarily the case. Since barn owls are cavity nesters who are also facing the additional issue of habitat loss, often the owls have no choice but to inhabit a poorly designed box. This causes a variety of problems, including:

 

Boxes that are too small.

Boxes that are too small will not be able to comfortably accommodate a brood of young birds. Barn Owls have the potential to lay 2–18 eggs, although typically 5–7 is the average number of eggs in a clutch. Since the owlets stay in the box until they are about 9-10 weeks and increase in size, it is imperative that the box be large enough to accommodate multiple owlets with the mother. Ideally, nest boxes should be at least 16” deep, 24" wide and 22"+ tall – minimum. This is because the owlets require ample space to stretch out and engage in activity to strengthen their wings so they can fledge successfully.

 

Boxes without a maintenance hatch.

A family of barn owls, with exception to the male owl and towards the end of the owlets’ development, the female too, will roost in a location near the nest, often in trees and other barn owl boxes close to the nesting box, while their owlets remain in the same box they hatched in for the whole season. This means that the debris from the owls, such as pellets, excrement, even dead remains, etc., stay in the box.

 

Investing in a box with a maintenance hatch should make annual box maintenance safer, faster and easier for the technician doing the work. Boxes that do not give access to the inside for seasonal cleaning, can quickly become filled with waste, possibly causing health concerns for the owls and greatly contributing to the deterioration of the box itself. Owls will return to nest in familiar boxes regardless of debris pileup, which can cause serious health concerns for the whole owl family over time. Choosing boxes that are easy to maintain, will assure the owls a safe and healthy stay during the time they occupy the box and cleaning will be much easier and also ensure your boxes last for many years.

 

Human Safety:

Although last on the list of concerns for owls, human safety is a significant factor that contributes to the well-being of barn owls. If the box is so high off the ground and it puts humans in danger, it is more than likely the barn owl boxes will never be cleaned or maintained. Studies show that barn owls prefer nest boxes at least 10 feet off the ground, but did not show strong preference for heights greater than that. Since maintenance of a barn owl box should be done annually at the end of every nesting season, it is important to have the barn owl box height no higher than 15 feet. We recommend 10 to 15 feet.