The European Greenfinch (Carduelis chloris) is one of the more familiar members of the finch family in the UK, along with its relatives such as the Goldfinch and Siskin. It is actually found across Europe, northern Africa and into south-west Asia as well as being introduced into Australia and New Zealand.
Greenfinches are typically 15cm in length with a wingspan of 24-27cm, meaning it is similar in size to the House Sparrow. They are green, as the name says, with yellow on the wings and tail and the female is generally duller with brown shading on the back feathers. They can sing a little like canaries and have distinctive trills in the song. Once you recognise the song of the greenfinch, you will be surprised how often you hear them, even when you can’t see them.
In the wild, they live on the edges of woodlands, farmland hedges and into gardens as long as there is plenty of vegetation. They nest in a tree or bush with typically 3-8 eggs.
In captivity, there have been a number of colour mutations bred including Isabel, cinnamon, agate, lutino and pastel.
The first thing to know is that if you are offered a pair of Greenfinches to buy, they must have a special type of ring on them to be legally sold. This is to prove they have been captive bred and not caught from the wild and is put on the bird at around 5 days after hatching.
Greenfinches will live happily with other birds, mimicking their wild behaviour where they are often found in mixed flocks with other finches and buntings. They can hybridise with canaries and produce infertile chicks, which are called mules. Some people prize these birds as they look like the wild bird but have the distinctive song of the canary. If you don’t want to breed mules, it can be best to keep canaries separate.
Being a native British bird, Greenfinches are hardy to the weather in this country, though it is always best to provide shelter from the extremes. Evergreens plants are also something they will enjoy for perching and even nesting in.
There are specialist mixes available for many of the British birds in captivity and Greenfinches have their own mix. They will also enjoy a general seed mix with the addition of weeds such as dandelion and chickweed and will take egg food. Greens and fruit will be enjoyed, as will insects and germinated seeds. It is always wise to have a supply of grit available for them when needed.
When rearing young, soaked seed is important such as safflower, sunflower, hemp and buckwheat as well as mung beans, boiled egg and peas.
Greenfinches will breed in an aviary or a large cage, depending on what they are used to. They will nest in a canary nesting pan that they will line with hay and coconut fibre then add feathers or animal hair to the inside. The female bird builds the nest and does the incubation of eggs.
The eggs are incubated for 13-15 days and fledge at around two weeks. There is no particular need to remove the young from the parents as the adults don’t see the young as a threat, but it may be necessary once weaned if they are in a cage for space reasons. A fit pair can raise several broods each breeding season.
If you are breeding in a cage, covering the outside of the nest box with evergreen twigs such as conifer or spruce, will help give the illusion of being in a tree for the bird and help her feel more at home.
Greenfinches are one of the species most often associated with the medical condition called ‘going light’. This occurs in young birds when they are puffed up and listless, not moving around and feeding properly. They also show signs of nibbling at food but not being able to swallow it properly and similarly with drinking.
After extensive research in the 1970s and 1980s, it was established that the cause is a parasite called Atoxoplasma. This is a type of coccidian, parasites that affect mammals, birds and reptiles and this is the term most often used to describe the condition.
The parasites lives in adult birds where it causes no problems but when they breed, during the warmer months of the year, the parasites multiply and spread. They often pass the parasites to their young when feeding them in the nest or the young birds may also pick them up when they first start to forage for food when leaving the nest.
Once infected, damage is done to the young bird’s gut lining meaning the bird cannot eat or drink and damage to other organs follows. This means by the time symptoms have presented themselves, it is often too late to do anything for them and they often quickly die.
Because there is no known cure, prevention is the best option. There are a variety of different drugs available that are all ‘sulpha drugs’ which stop the disease from developing. The common method to make use of these drugs is to add 6 drops into a 500ml drinker every day for five days, then off for two days. This is done from the birds leaving to nest until they are through the first moult, at which time they will no longer be susceptible to the parasite in the same manner.
It is entirely possible to keep greenfinches and never encounter problems with going light, however in this scenario prevention is the only option as there is no cure. Otherwise these beautiful birds are easy to keep and feed, simple to breed and are great characters to watch in your aviary. Personally, I love watching a bird in my aviary that I have long watched in my garden and getting close to a bird, which is normally a streak of dark green from one garden feeder to another.