Those of us who feed the birds may have noticed over the past month an infection has been passing through the garden bird population. It seems Greenfinches are particularly susceptible but also chaffinches and other birds. Many local people in Assynt have told me about seeing many dead and dying greenfinches in their garden starting in Lochinver in early July and spreading to Clachtoll and Stoer.
The cause is a protozoan organism called Trichomonas gallinae that inhabits the upper digestive tract of certain birds. It is unfortunately very infectious and birds pass it to each other when feeding young and courtship feeding. Food and water may also become contaminated by discharges from infected birds, potentially spreading to other birds.
Although it occasionally occurs in pigeons and doves, birds of prey and budgerigars until recently Trichomonas infection has not been considered a problem in the UK and has never been diagnosed in wild finches. However in 2005 the first case of Trichomonas infection was found in a dead wild chaffinch in Ayrshire. It has started occurring sporadically in many other places since then and maybe developing into something a greater significance.
It seems to most prevalent in July and August. Infected birds look lethargic, are fluffed up and reluctant to fly. They often hang around the bird table but are unable to eat. There is very little one can do for these birds.
If you notice any infected birds in your garden the recommendations are to clean and disinfect all your feeders and consider leaving your birdbaths and drinkers empty for a short period. Consider stopping feeding altogether for two weeks – this rest period will help to reduce levels of contamination. Feeding can then be re-introduced, monitoring for further signs of ill health.
I would be interested in anyone who has found more than a few dead birds in their garden.
Highland Council Ranger Service 01571 844654