15 years ago those who put out bird feeders in their gardens whether they be in the countryside, near woodland or in a town, would be familiar with the greenfinch, a regular visitor to bird feeders across the UK. However, in 2005 the west of England and Wales was the source of an outbreak of the deadly disease, trichomoniasis. The previous population of breeding greenfinches (4.3 million individuals) dropped dramatically by 35% to 2.8 million between 2006 and 2009. Unfortunately, greenfinches are not the only species unlucky enough to be affected by trichomoniasis; chaffinches, pigeons and birds of prey also fall victim to the disease. House sparrows, siskins and dunnocks have also been found with trichomoniasis but it is far less likely to affect these species.
Not all infected individuals show signs of disease but they are still carriers and can affect others. The most common signs include swollen neck, the feathers around the bill will appear to be wet, fluffed up plumage (as if they are cold) and they will look lethargic. The bird will also regurgitate its food as it is unable to swallow it due to the swelling of the neck. Pigeons with the disease will have a cottage cheese like substance in their mouth (known as canker) which prohibits them from eating. The cause of the disease is a protozoan, which doesn’t last long outside its host, but long enough for a bird to eat regurgitated food from the infected individual. Those that don’t show physical signs but are still carriers are able to pass it on to their offspring while feeding them as well as to other birds that visit the table.
A wild bird can’t be treated for trichomoniasis but there are ways to help reduce the spread. Most birds that become affected are those that feed on bird tables and feeders that people put out in their gardens. These attract a high density of birds, allowing for quick and easy transmission. Feeders and tables need to be cleaned regularly, ideally cleared of uneaten food daily before putting fresh out. It is recommended for tables and feeders to be disinfected a minimum of once a fortnight with wildlife safe disinfectants, to prevent build up of diseases. Having feeders spread around is also a way to help reduce the spread as areas will be less crowded and therefore it won’t spread as quickly. If a bird is seen on a feeder or a table showing signs of trichomoniasis (especially regurgitating food), the feeder/s needs to be taken down and cleaned immediately so other birds are not able to eat the contaminated food. It is recommended that no food is put out for a few weeks after seeing signs of the disease to encourage the birds to disperse to a less populated area. But don’t worry about losing the bird from your garden; once food is put out again they are sure to return soon!
If you see sick or dead wildlife then please report it to gardenwildlifehealth.org
For more information visit: https://www.vinehousefarm.co.uk/hygiene/