Garden birds at risk

It has been reported that virulent virus is now affecting Norfolks wild birds, it was first seen in British finch species in the summer of 2005. An epidemic of disease caused by this parasite occurred in 2006, peaking in the late summer/ autumn months, affecting birds over a wide geographical area across Britain. In early summer 2007, the number of finch mortality reports caused by the disease has again begun to increase only this time there are reports of the disease affecting garden birds in Norfolk. The virus causes birds throats to swell thereby preventing them from eating so that they effectively starve to death.

The deadly parasite Trichomonas gallinae, which has been common amongst pigeons and game birds for a number of years and is treatable for captive birds with drugs, however it has now also affecting garden birds such as Blackbirds, Sparrows and Finches.

Trichomonas gallinae causes “canker” in domestic pigeons, and “frounce” in birds of prey. The disease can be mild and birds that survive appear to have some immunity to further infection but some strains cause a high death rate. Infected birds develop large yellowish masses in their mouths and crops and in fatal cases; the parasite spreads to the liver and lungs. It is characterized by raised lesions in the mouth, esophagus, and crop, infected birds appear to have trouble closing their mouth.

What to look out for

In addition to showing signs of general illness, for example lethargy and fluffed-up plumage, affected birds may drool saliva, regurgitate food, have difficulty in swallowing or show laboured breathing. Finches are frequently seen to have matted wet plumage around the face and beak. In some cases, swelling of the neck may be visible from a distance. The disease may progress over several days or even weeks, consequently affected birds are often emaciated.

It can be spread among wild birds at feeders and bird baths and and bird lovers are advised to take action to avoid spreading this and other diseases especially where they have created habitat that brings wild birds into closer contact with other wild birds than they would normally experience, for example feeders and bird baths.

Because T. gallinae cannot survive long outside of a host there are very few ways in which it is able to effectively spread amongst wild birds as they tend to have less contact with each other but commonly it is passed from one to another as follows…

* Between mother and young when feeding regurgitated food.
* To Birds of prey when eating infected birds.
* Infected birds can contaminate water containers (bird baths) with their oral secretions, which can, in turn, expose many other birds to the disease. Mortality from this disease varies, but it can be quite high.

Further information:

Best feeding practices should be followed at all times to help ensure that the birds visiting your garden remain healthy. More information can be found in the GBHi booklet “Feeding Garden Birds – Best Practice Guidelines” and in the accompanying GBHi leaflet. Details of how to obtain these publications are available on the GBHi page of the UFAW website www.ufaw.org.uk. Tel: 01582 831818

If you wish to report finding dead garden birds, or signs of disease in garden birds, please call the Garden Bird Health initiative on 0207 449 6685.