How tawny owls incubate their eggs
It's midwinter, 2021, and Luna the tawny owl is sitting on two eggs. It is minus four degrees centigrade outside and snowing, so it is very important that she keeps them warm. She laid her first egg on January 25th and so these eggs are just two weeks old.
Why it's rare to see wild tawny owl eggs
Every now and then Luna shifts position and we get a fleeting glimpse of her eggs on camera. These views are very brief and this is because tawny owls have a habit of guarding their eggs closely - you rarely get to see them even on nest cameras like these.
Tawny owls don't like to leave their eggs
Female tawny owls sit down tightly on their eggs and barely leave the nest. Luna will leave the nest just three times a night and the longest time we have recorded her away from her nest was 11 minutes.
Why do tawny owls leave their eggs?
Tawny owls like to keep a clean and tidy nest, and so Luna's short trips out are to feed, stretch her wings and 'go'. She doesn't go far, usually only across to the feeding post and back.
Barn owls vs tawny owls brooding
In the video above I have included a clip of a barn owl on eggs for you to compare owl brooding behaviours. Barn owls will get off their eggs, walk around their nest and soil the lining of the nest which is something you never see a tawny owl do. They prefer to do their business outside the nest. This behaviour means when tawny owls are brooding we rarely see the eggs, but when barn owls brood you get good views of their eggs on the nest cameras.
Tawny owl brood patch
Brooding tawny owls have a bald patch on their breasts known as a brooding patch. The feather loss is a hormonal response to egg laying and means that when they sit on their eggs their skin is in direct contact with them. This, coupled with the fact that they can more easily spread the surrounding feathers around the eggs, keeps the eggs warm.
Brooding tawny owls eat their feathers
Watch this clip as Luna pulls at her feathers and then eats them. Tawny owls find the feather loss an irritation on their skin and will tug at them, but they are not actually pulling them out. Watch as Luna then eats them! I've never seen this behaviour before, although I have heard about it, and it is incredible to actually see it on camera.
How long before owlets hatch?
Tawny owls incubate their eggs for approximately 30 days so I am expecting her eggs to hatch at the end of February.
Click here to learn about tawny owl egg laying
Update - tragic loss
Sadly Luna the tawny owl lost this clutch of eggs, possibly because they were laid in the depth of winter. However, it is now a new breeding season and this tawny owl is again sitting on eggs here in my North Yorkshire garden. You can watch her inside Beech Stump nest box live.
