The Tawny owl (Strix Aluco)
Family: Strigidae
Habitat: Primarily an owl of deciduous woodland - but can also be found in conifer plantations, large urban parks and mature gardens as long as suitable tree cavities are present.
Diet: Typically consisting of mammals such as field vole, bank vole and wood mouse but have also been found to predate upon beetles, reptiles, birds and even small rabbits.
Predators: Natural predators include other raptors such as Goshawk and Buzzards, as well as predatory mammals including Foxes and even Pine Marten
Biometrics: Body measurements are between 37 – 39cm with a wingspan of up to 1m.
Both the male and females are similar in appearance however the females are slightly larger than the males. Females typically have a body weight in excess of 435g whereas the male is often less than 400g
Features: Classed as a medium sized owl, brown in colouration, with large dark forward-facing eyes. The Tawny owl is predominantly nocturnal and is the commonest owl in Central Europe.
Tawny owls are very vocal at night and are easily distinguishable from other owl species when heard. The male has a characteristic song typically sounding like a ‘twit twoo’, with the female sounding similar but is higher pitched. Both birds will utter a ‘keewik’ call but this is more commonly associated with the female.
Field Signs: Signs of Tawny owl presence can be much harder to spot compared to other owls, as they do not tend to roost in the same spot therefore pellets are often seldom found. Sometimes you may see moulted feathers on the ground but the best field sign would be listening out for them. Vocally they are typically the noisiest of the British owls and can be heard at night on calm conditions all year around.
Breeding & Resting Places:
Tawny owls frequently use hollows of trees which have been formed by snapped branches or decaying sections of the tree, however some woodland habitats such as conifer plantations and urban settings lack these features significantly reducing breeding and resting sites. Erecting artificial nest boxes in habitats that do not tend to provide natural sites can allow the Tawny owl to increase its range in areas where it may find breeding via natural cavities difficult.
Breeding cycle:
Tawny owls are monogamous and will pair for life and maintain a territory all year around.
Breeding typically takes place from February to July.
The pair will create a nest in a hollow of a tree or within an artificial nest box, with the female laying between 1 – 5 eggs. The female will undertake sole incubation which lasts between 28 – 29 days, during this period the male will provide food to the female. The male will continue to provide food when the chicks are very small, however the female will also start to hunt when the chicks are able to begin regulating their own body temperature.
Unlike other owls such as the Barn owl; Tawny owl chicks will often leave the nest around 28-35 days, before they are actually able to fly which is known as branching. When they leave the nest, they often go to the floor and climb up into bushes – it is only when they are around 7 weeks old the chicks begin to fly well and join their parents.
Tawny owls can live up to around 18 – 20 years old in the wild.