NEST BOXES FOR OWLS
Some species of owls can be offered additional nest site options by the provision of a wooden nest box or hand-made nesting basket. The details and design of offering this option for wild owls is very important to ensure take-up and importantly to ensure the safety of the fledglings, so please read all the information in this section as a poorly designed or installed box can be a hazard to young owls.
NEST BOXES FOR BARN OWLS
Barn owls are natural hole nesters and will use an artificial box if one is installed in a suitable place close to prey-rich hunting habitats. In fact it is estimated that 75% of Britain’s breeding barn owls are using artificial nest boxes - however in some areas the enthusiasm of volunteers has resulted in more boxes than barn owls and more effort in these areas should directed towards creating and conserving hunting habitats for barn owls too as starvation is a bigger issue for them!
SITING BARN OWL BOXES OUTSIDE
• Boxes should face NE to SE
• Site them on isolated trees in fields, facing out from woodland edge, trees in hedgerows,
on the side of farm buildings or on disused telegraph poles in areas where there are no trees.
• Allow a clear flight path to box entrance (barn owls have a large wingspan)
• Putting boxes up in pairs, within a reasonable distance of each other gives a male barn owl
a place to roost while the female uses the other as the nest site.
SITING BARN OWL BOXES INSIDE
• Install in barn, cow shed or similar farm building
• Make sure the building has at least two entrance/exit points
• Avoid siting boxes where ground predators, such as cats, can reach them.
• Ensure rodenticides are not being used in immediate area of nest box site.
GENERAL ADVICE ON INSTALLING BARN OWL BOXES
Boxes should be sited about 8ft - 15ft off the ground
Owls look for holes not boxes, so make sure that the entrance hole is visible to any passing owls.
Do not site boxes near main roads or within 1/2 mile of motorways or dual carriageways, due to high risk of road fatalities.
Boxes should be installed in open countryside close to areas of suitable vole-rich hunting habitat
Barn owls are a Schedule 1 species and so should not be disturbed in any way during the breeding season - nest box inspection should only be carried out by a licensed person.
Barn owls are generally nervous in the first year of using a new nesting site, and prone to desert the site if disturbed - once they have successfully bred, they are less likely to desert.
They will tolerate general activity around the nest box during the day (farm vehicles, dogs, children playing etc). but they don’t like surprises!
If jackdaws begin to nest in box entrance corridor, this should be cleared immediately to avoid adults or young being trapped in box (applies to certain box designs)
Ensure there is an area for young fledglings to exercise (shelf built into box design, beams, etc)
It can take over two years for a box to be used, so be patient!
The odds of uptake will always increase if there is lots of vole-rich habitat in the immediate area.
NEST BOXES FOR TAWNY OWLS
Tawny owls are natural hole nesters and will use an artificial box if one is installed in a suitable woodland environment or large garden.
The box can be of a very simple design which simulates a tree hollow but it should be installed in a part of a tree where the young will be able to access branches so they can climb higher in the tree once they leave the box.
Click here for tawny owl nest box installation guide
SITING TAWNY OWL BOXES
• Boxes should face NE to SE if exposed to elements
• Height of box should be approx 10ft off ground
• Site them within woodland, in groups of trees, large gardens, churchyards etc.
• In larger woods, more than one box can be sited to give male a roost site.
• Allow a clear flight path to box entrance
• Do not site boxes in places where there is regular human activity (ie. Busy footpaths, near playgrounds, etc)
• Inspection hatch should be tied with wire, not string or cable tie which can be bitten by squirrels.
CAUTIONARY NOTES RE. ACTIVE NEST BOXES
Young tawny owlets will leave the nest box at 3 - 4 weeks old and will climb into the woodland canopy. They will generally not return to the box after leaving, and will be fed by both male and female adult birds as night falls.
These chicks will sometimes fall from the canopy and will spend long periods sat on the ground, even during the day. It is at this time
that, despite constant guarding by the parents, the chicks are vulnerable to attack by foxes, dogs, cats and members of the crow
family, like jays, magpies etc.
Tawny owls are a sedentary woodland species, staying in their territories all year round. They defend these patches from other tawny owls, particularly in the autumn in the run up to the breeding season, when young birds are attempting to set up their own territories.
Siting of boxes should therefore consider this natural behaviour and boxes should not be installed in gardens where there are, in particular, cats or any other domestic animals that may pose a danger to baby owlets.
It should also be noted that female tawny owls will sometimes attack humans in defence of their fledglings if they feel they are in danger, so it is not advisable to encourage this species to breed in areas where there is a lot of human activity, and in particular where children play.
Many of these chicks are picked up by humans as presumed orphans each year.
NEST BOXES FOR LITTLE OWLS
Little owls like to nest in small, dark places and in the absence of an existing site, can be tempted to use a well-placed wooden nest box.
If they have been using an established natural nesting site nearby, putting up a nest box cannot always tempt them to move straight away but it can act as a valuable second option for them and they may start to use it after a while if the original site is lost or sometimes for no apparent reason.
SITING LITTLE OWL BOXES
• Preferred direction of box entrance hole is NE to SE
• Site in hedgerows, orchards, on outside walls of farm buildings, isolated trees in
fields (not in woodland), inside small farm buildings.
• Boxes can be sited at any level from 4ft to 10ft off the ground, depending on
risk of disturbance or vandalism.
• Avoid siting boxes where cats could be a threat to young branching owlets.
NESTING BASKETS FOR LONG-EARED OWLS
LONG-EARED OWLS will often use an abandoned crow’s or magpies nest breed in so artificial nesting baskets can be offered as an option for this species. The basket should be placed about 16ft high on a tree, ideally in coniferous woodland or in hawthorn (field corners are often preferred).
A ready made wicker basket approximately 14 - 18” diameter can be used or a similar sized wire basket lined with twigs, leaves and offcuts of carpet can be used. The basket should be secured firmly to a fork in the tree with wire (cable ties not suitable as they may be nibbled by squirrels) These baskets can offer a nest site for tawny owls and kestrels as well as long-eared owls.
SITING LONG-EARED OWL BASKETS
• Garden-type hanging baskets, lined with twigs and carpet can be used, and secured to tree branch with wire
• Install at the top of trees or on hawthorn bushes
• Large areas of vole-rich habitat should be available nearby. Click here for habitat advice.
• Avoid siting close to any know sparrowhawk or magpie nests (young long-eared are often taken by these predators)
GENERAL ADVICE FOR INSTALLING ARTIFICIAL NESTING SITES FOR OWLS
GENERAL INFORMATION FOR ALL SPECIES
• Hunting habitats are essential to the success of artificial nest sites, and so habitat creation such as field margins and set aside for voles, woodland cover for wood mice, insecticide-free field habitats for invertebrates etc are crucial to the success of these boxes and baskets. Without a reliable source of food, breeding success will be very limited.
• Natural material can be put inside nest boxes to provide material for a scrape e.g., leaf mulch, shredded paper etc - (Nb. Do not use sawdust as this can be harmful to birds if swallowed)
• Boxes may not always be used, but if they remain in place, they can provide a roost for owls during the winter and eventually may be used if an existing natural site is lost.
• Boxes can often be occupied by unwelcome squatters, such as squirrels, jackdaws etc. Once this has been positively established, these unwelcome guests should be evicted asap to ensure the box is available for the target species of owl.
• Owl nest boxes are unlikely to be used for breeding unless there is suitable habitats nearby. Click here for advice on habitats.
• Owls are low-flying birds and nest boxes for barn, tawny and little owls only need to be 6 - 12 ft off the ground. Boxes in danger of being interfered with by vandals should be positioned higher, with this in mind.
• Tawny owl, little owl and long-eared owl chicks all leave the nest at 3 - 4 weeks and will adventure away from the nest - provision should be made for this natural behaviour.
• Barn owl chicks do not ‘branch’ in the same way as the other species, and will only be fed by the parents in the nest, so any chicks found on the floor will need rescuing. Click here for advice on finding chicks.
• To establish if a nest site is being used, it is necessary to observe quietly the box/basket in the breeding season from a non-intrusive distance, and preferably under camouflage. An adult observed bringing food to the nest would either be a male delivering food to a brooding female, or male/female delivering food to chicks - this will be confirmed by loud hissing from the chicks on receiving food (louder as they get older). Branched chicks will call for food from the tree canopy and will be found and fed by the parents.
Look for more information on British owls on Wild Owl Nature Diaries You Tube channel.