Nesting boxes

In late fall while we humans are staying home and cozying up, the male Barn Owl is hard at work searching for a nest site in which to raise a family.
Barn Owls are cavity nesters and most often use tree hollows as natural nest sites, as well as dark crevices, ledges in abandoned buildings, palm trees, attics (if they find a way in), between hay bales and in old barns, as their name suggests.

 Luckily, Barn Owls will readily accept a nest box as an artificial cavity, making it easy to attract them to a desired location to help control rodent populations. Once the little light-colored male Barn Owl finds a suitable nest site, he calls to a female enticing her to inspect the new home. He uses a series of unearthly metallic clicks irresistible to a female owl. The female takes her time going in and out of the possible nest site, inspecting it thoroughly before she makes up her mind to move in. Installing nest boxes before November helps ensure an owl family might move in before the next breeding season, which runs from January to March the following year.

Once an owl family has accepted a nest box, they will often return to the same nest box for several years. Sometimes the owls will have two broods in one year. Here in Ca, five to seven owlets per four-month breeding cycle is most common. Not all of the owlets always survive to fledge, but most of them do.  Some makers continually learn and make improvements to their boxes, and offer updated information on installation and placement, always with the safety of the owls in mind.

 Barn Owls can be attracted to many different types of barn owl nesting boxes, and many owl boxes and owl box plans are available on the internet. Unfortunately,  number of young owls have had to be rescued from nest boxes that are not safe, and can even pose a danger to an owl family because the boxes were badly designed, improperly placed or not maintained.
These unfortunate babies often end up dead, or if they are lucky, they are brought to WildCare.

 They're a wide variety of issues, but two of the greatest and most common problems concern heat and accessibility. High temperatures can turn an owl box into an oven. The owlets will jump out prematurely if temperatures inside the box become unbearable, or the owlets can die from dehydration inside the box if they are too young to jump out. Heat will build up inside the box if it: - has inadequate ventilation - is badly placed (little or no shade or no sunroof) - was built with wood that is too thin (under ½”) - is too small - is so full of debris there is little room for air flow - is placed facing SW, directly towards afternoon sun with no shade - is likely to have increased heat from the afternoon sun shining directly into the box through the entrance hole.

HOP’s (Hungry Owl Project)
is one whose box design replaces ventilation holes with gaps on the left and right sides, to allow increased airflow. They are now painting the boxes a much lighter color to help reflect heat and enlarged the cleaning flap for easier use, and to encourage annual cleaning. Annual cleaning will help maintain better ventilation and help keep owlets safely in the box.
 All of their boxes now come with sunroofs attached, and additional side shade-panels can easily be added.



Nesting boxes WITHOUT sunroofs were found to have an internal temperature of eight to fifteen degrees Fahrenheit above the ambient temperature. They ask that careful consideration be taken when choosing locations for boxes. Temperature should be a major consideration. Accessibility  often encounter problems with owl boxes installed too high to be accessible for maintenance. This makes cleaning and other maintenance very difficult, and makes monitoring the box impossible. Should an owlet fall out of the box it’s more likely to get injured and having a box too high makes it that much harder to return an owlet to the box.

  Lowering existing boxes installed in trees (in October before breeding season begins) to ten to twelve feet high, or installing boxes on posts no higher than nine feet above the ground.

A box at an accessible height also encourages cleaning not exceeding twelve feet. Occupancy at lower heights also has had great results . There are certain situations that do require the box to be higher, such as in parks when having a higher box helps avoid human interference.
 Reminder for all current box owners: October and November are the safest months to check on your box and do any needed maintenance inside or out! Thoroughly clean boxes that were occupied this year. 

Owning an owl box is a responsibility and it is important to consider it carefully before buying and installing one. It is well worth the time and research it takes to be sure the owls will be safe and will be able to successfully raise a family. Having owls is not only beneficial, highly-rewarding and educational,
“It is a wonderful and magical experience, the owls are just so beautiful!”