Tuesday 20th March 2018
Ringing Owls & Ring Sizes » Go to: Ring Sizes

Ringing Owls

It is a legal requirement to individually identify European Owls and their sub-species to comply with the Wildlife and Countryside Act 1981, if they are to be used for monetary gain. It is also essential for trace-ability if captive populations of Owls are to be managed successfully in the long term.

The most convenient, economic and readily available method of marking Owls is to place a ring on the leg. For European species an individually identifiable closed ring must be fitted when the bird is young enough for the ring to be slipped over the toes and which cannot then be removed when the Owl becomes fully grown. Other species of Owl can be rung using split rings that can be fitted when they are older; this avoids disturbing the breeding birds when the young are being brooded. At this stage some Owls become very protective of their young, attacking any intruders, this may result in the keeper, the parent birds or the young being injured.

Whether a closed ring or a split ring is used it is important to ensure the correct size is fitted, not only as a legal requirement but also to prevent injury to the bird. If too big, it may become snagged, causing muscle strain or fractures, too small and it could constrict the circulation to the foot causing inflammation and the possibility of infection.

Note: The list of ring sizes for the European species are the sizes that must be fitted to comply with the legislation. The others should be used for guidance only. From our own experience and from consultation with other breeders we have tried to obtain the most accurate estimates of ring sizes for the species listed, but there can be considerable variation within species and certainly between sexes. Always check rings after fitting to ensure freedom of movement.

Ring Sizes

Ring Size & Diameter Common Name Scientific Name
R » 7.1mm Little Owl
Ferruginous Pygmy Owl
Pearl-spotted Owl
Eurasian Scops Owl
Athene noctua
Glaucidium brasilianum
Glaucidium perlatum
Otus s. Scops
S » 7.6mm Saw-wet Owl
Tengmalms Owl
Spotted Little Owl
Eurasian Pygmy Owl
Tropical Screech Owl
Indian Scops Owl
Striated Scops Owl
Sunda Scops Owl
Aegolius acadicus
Aegolius funereus
Athene brama
Glaucidium passerinum
Megascops choliba
Otus bakkamoena
Otus brucei
Otus lempiji cnephaeus
T » 8.7mm Burrowing Owl
African Barred Owlet
Asia Barred Owlet
Western Screech Owl
Southern White-faced Scops Owl
Athene cunicularia
Glaucidium capense
Glaucidium cuculoide
Megascops kennicotti
Ptilopsis granti
U » 9.5mm African Marsh Owl
Short-eared Owl
Long-eared Owl
Southern Boobook Owl
Tawny Owl
Rusty-barred Owl
East African Wood Owl
West African Wood Owl
African Barn Owl
British Barn Owl
European Barn Owl
Ashy-faced Owl
Asio capensis
Asio flammeus
Asio otus
Ninox boobook
Strix aluco sylvatica
Strix hylophila
Strix woodfordii nigricantor
Strix woodfordii nuchalis
Tyto alba affinis
Tyto alba alba
Tyto alba guttata
Tyto glaucops
W » 12.7mm Striped Owl
Greyish Eagle Owl
African Spotted Eagle Owl
Bay Owl
Chaco Owl
Hawk Owl
American Barn Owl
Asio clamator
Bubo cinerascens
Bubo africanus
Phodilus b. badius
Strix chacoensis
Surnia u. ulula
Tyto alba pratincola
X » 14.3mm Pharoah Eagle Owl
Indian Eagle Owl
Mackinder's Eagle Owl
Buffy Fish Owl
South American Horned Owl
Canadian Horned Owl
Great Horned Owl
Brown Fish Owl
Spectacled Owl
Asian Wood Owl
Lapland Owl
Scandinavian Ural Owl
Barred Owl
African Grass Owl
Bubo ascalaphus
Bubo bengalensis
Bubo mackinderi
Bubo ketupa
Bubo v. nacurutu
Bubo v. wapacuthu
Bubo v. virginianus
Bubo zeylonensis
Pulsatrix perspicillata
Strix leptogrammica
Strix nebulosa laponnica
Strix uralensis
Strix varia
Tyto capensis
Y » 15.8mm Aharoni's Eagle Owl Bubo b. interpositus
Z » 19mm Eurasian Eagle Owl
Western Siberian Eagle Owl
Turkmenian Eagle Owl
Eastern Siberian Eagle Owl
Milky Eagle Owl
Snowy Owl
Bubo b. bubo
Bubo b. sibiricus
Bubo b. turkomanus
Bubo b. yeniseensis
Bubo lacteus
Bubo scandiaca