On May 7th, 2006, bird ringer Erkki Lamsa stumbled across an occupied raptor's nest in Ylivieska, C Finland, when monitoring his study area. An adult female Common Buzzard Buteo buteo was seen by the nest, while the attending male was a Rough-legged Buzzard B. lagopus. The nest was then subsequently visited on a regular basis to follow up the nesting. The pair managed to rear three young to ringing age and on the last visit on 30th of July two fledglings and both adults were seen near the nest.

This is only the second time ever hybridisation between these two species of birds of prey has been documented. A similar case was reported and later published from Norway in 2005, where a male Common Buzzard and a female Rough-leg reared also three young.

This current case will be published elsewhere.

The breeding female Common Buzzard. All photos by Erkki Lamsa.

Well-grown young still in the nest

The tarsi of the hybrid young where feathered, but not down to the toes as in Rough-legged Buzzard. In Common Buzzard the tarsus is unfeathered and bare.

Hybrid young giving an overall impression similar to a young Rough-legged Buzzard

Hybrid young. Note the Common Buzzard-like tail, with dense barring, while the uppertail coverts are pale as in Rough-legged Buzzard. Also the extensive pale edges to the mantle and upperwing coverts are similar to young Rough-legged Buzzard. The upperparts are very similar to the Norwegian hybrids, whereas the underparts were a bit more Common Buzzard-like on the Norwegian birds.