HOW TO ATTRACT NESTING TAWNY OWLS
Robert Fuller has put up nearly 200 nestboxes for owls and kestrels. Here are his top tips.
KNOW YOUR AREA
Tawny owls live in open woodland but also large suburban gardens, parks and cemeteries. Your success in attracting local tawnies will depend in part on how many natural nest sites there are in the area.
SAFE AND SECURE
Don’t make the mistake of siting owl boxes where you can get a good view – being looked at is the last thing an owl wants. For breeding success, tawnies need to feel safe: they’re very susceptible to disturbance.
THE RIGHT SPOT
Place the nestbox on a mature deciduous tree at least 3m off the ground, with branches nearby for fledgling chicks to climb onto. It needs to be sheltered from the rain, prevailing winds and sun.
Many commercial tawny owl nestboxes are too small, usually just 25cm2 at the base. They’re too cramped for fledglings to flap or for the adults to sit together during courtship and egg laying. They also tend to have the nest cavity at the bottom of a tall box, making it hard for adults to get in without damaging their tails or landing on their eggs.
AVOID THE TUBE
Tube-shaped nestboxes that are designed to be strapped under a branch, also present problems. Their open tops mean there’s no cover from the rain and if they get too wet, the bases of these boxes often rot.
Tawny owls seem to prefer nestboxes designed for kestrels – they’re bigger than owl boxes but are too easy for owlets to climb out of. My own design (above) is bigger than a typical owl box, with a base that’s at least 30 x 35cm, and an elevated entrance to keep owlets inside until they’re ready to fledge. The lower door lets me add wood chippings for nesting material.
Jackdaws and grey squirrels often colonise owl nestboxes. There is no simple solution to this. You just have to clear out any material these hijackers put in until you have resident owls that will then hopefully chase their rivals away.
A helping hand: with luck, tawny owls will move into your box
You’ll need to add nesting material as tawny owls don’t gather it