ScienceDaily (Nov. 21, 2012) — A new strain of avian pox is taking its toll on garden birds in Britain, reports new research published this week in PLOS ONE.
Scientists from the Zoological Society of London (ZSL), University of Oxford, the British Trust for Ornithology (BTO) and RSPB report on the impact avian pox is having on great tit populations.
Avian pox has been recorded in British bird species such as house sparrows and wood pigeons for a number of years. However, the emergence of a new strain of this viral disease in great tits is causing concern amongst vets and ornithologists.
Wildlife vet Dr Becki Lawson from ZSL says: "Infection leads to warty, tumour-like growths on different parts of a bird's body, particularly on the head around the eyes and beak.
"Although the disease can be relatively mild in some species, great tits suffer severe growths that can prevent them from feeding and increase their susceptibility to predation," Dr Lawson added.
Whilst a range of tit species are susceptible to this novel form of the disease, detailed monitoring of birds in Wytham Woods by scientists at the University of Oxford show that great tits are by far the most susceptible.
Great tits 'more susceptible' to new avian pox than other British birds
Great tits are being severely affected by a new strain of avian pox in Britain that "significantly reduces" the birds' chance of survival, new research published on Wednesday shows.
Avian pox is a viral disease that has been present in British garden birds such as dunnocks, house sparrows, starlings and wood pigeons since the 1950s. However it was unknown among species in the tit family before 2006, when sightings of infected birds were first reported by members of the public in south-east England.
While all tit species are affected by the new form of the disease, great tits (Parus major) are "by far the most susceptible", shows one of three new papers by the Zoological Society of London (ZSL), the University of Oxford, the British Trust for Ornithology (BTO) and the RSPB, published in the journal PLOS ONE.
Affected birds develop warty, tumour-like growths and lesions, mainly on the head and neck and at the base of the wings. Infection is thought to be spread by biting insects, direct bird-to-bird contact or indirect contact from contaminated surfaces.
Although the disease has a relatively mild affect on some species, it causes severe and large growths on great tits that can prevent them from seeing, feeding or moving around, thereby increasing their risk of predation, starvation and other infections.
Increasing incidents of pox reported by the public between 2006-10 showed the disease spreading further west and north, and in 2011 it reached south-west England, Wales and as far north as Merseyside and the Humber.