Goldfinch with abnormal plumage

This Goldfinch has been visiting the garden over several weeks. In place of the black heading markings is an area of white, meaning that this bird is suffering from some form of plumage abnormality. The BTO is running an Abnormal Plumage Survey and wants to hear from you if you have seen a bird with unusual plumage, perhaps a Blackbird with some white feathering. You can access the BTO pages on abnormal plumage here.

Goldfinches attain clown-like masks

The garden has been teaming with Goldfinches over the last few months, with the good numbers of young suggesting it has been a successful breeding season for these delightful little birds. Initially, the young Goldfinches could be told from their parents by their lack of the characteristic red and black facial markings. By now, however, they have moulted through into their adult plumage and can no longer be distinguished by eye, as I watch them on the feeders through the kitchen window.


In the hand, when caught during a ringing session, it is possible to identify juvenile Goldfinches by looking at subtle differences in the shape of the tail feathers and the colour of certain wing feathers. Such differences come about because of the way in which these birds renew their feathers during moult. In most small birds that breed and winter here, the adults undergo a complete renewal of their feathers once the breeding season is over. Some species undergo a second, ‘partial’, moult just before the start of the next breeding season. Many of our summer-visiting migrants, however, will not undergo their annual moult until they have reached their wintering grounds, although some start the moult here before interrupting it just ahead of their long journey south. 


Most young birds follow a different strategy, replacing some feathers after the breeding season and growing others for the first time, but not acquiring full adult plumage until after the next breeding season is over. You can see this for yourself by looking carefully at male Blackbirds in the early summer. If you spot a male Blackbird who is all black apart from a few dark brown feathers in his wing, then he will be a bird born the previous year.


Getting young birds out of the nest quickly is an important strategy because it reduces the period when they may be particularly susceptible to predation. Young birds grow rapidly in the nest and need to be able to fly when they fledge. Because of this, the young tend to invest relatively little in the growth of body feathers, concentrating their efforts instead on the all-important flight feathers. As a result, newly-fledged young often look rather fluffy and ‘loose feathered’, but they will soon grow the remaining feathers, often acquiring adult body plumage over a period of several weeks. These different moult strategies are useful for me, as a ringer, since they enable me to age most birds with relative ease. There are, however, some species where the young moult through into full adult plumage soon after leaving the nest – House Sparrow and Long-tailed Tit are two examples – and these birds cannot be aged once they have gone through the autumn moult.

On the move

When you think of bird migration you tend to think of summer or winter visitors, such as Swallow, House Martin or Redwing; birds that are only with us for a small part of the year. This means that many of the birds that are on the move during autumn or spring go unnoticed, simply because they happen to belong to species that you would normally see throughout the year. For instance, birds as familiar to us as Song Thrush, Chaffinch and Goldfinch all either have a migratory component to their British breeding population or to a population elsewhere within wider European range.

While most of our breeding Song Thrushes and Chaffinches are rather sedentary in their habits, some winter abroad in France, Spain, Ireland or Portugal. At the same time, Britain also receives Song Thrushes and Chaffinches arriving here to overwinter, or passing through en route further south during the autumn months. A visit to the Norfolk coast soon after dawn may well reveal some of these visitors. On Sunday morning, for example, I saw and heard good numbers of Chaffinches and smaller numbers of Song Thrushes passing overhead at Kelling Quags, together with other autumn migrants – including Brambling, Siskin and Meadow Pipit.

Both Meadow Pipit and Chaffinch are diurnal migrants (migrating during the day), and the birds I saw may well have been continuing journeys initiated in Scandinavia over recent days. Some of these birds, notably the Brambling, will have made a direct crossing of the North Sea but others, like the Chaffinch, will have avoided the crossing altogether by taking a longer route around the North Sea coast, through the Low Countries and then making a short hop across the English Channel. Such a convoluted journey will have required some nifty navigational skills along the way, given the change in compass direction needed at different stages of the journey.

Another interesting aspect of Chaffinch migration (at least for the birds leaving the northernmost part of the breeding range) is the difference in timing between males and females, and adults and young. Females Chaffinches tend to move before males (and migrate further) and the same is true of young birds, when compared with adults. In the case of the Song Thrush, individuals from different parts of the breeding range show variation in their movements; those from the northernmost populations tend to move the furthest south, with some birds even reaching North Africa. What amazes me about all these movements is not simply that such small birds can undertake such large movements but how individuals of the same species can behave so differently depending upon where they were born, what sex they are or whether they are a young bird or not.

Add some golden glamour to your garden

At this time of the year I see increasing numbers of goldfinches visiting my garden. With their red faces, white cheeks and black and gold wings, these endearing little birds used to be popular as cagebirds, a Victorian fashion that put great strain on their population. With the passing of this particular fashion, the goldfinch population recovered only to be hit again in the late 1970s, when changes in farming practices reduced the availability of the weed seeds that were an important food during the winter months. Fortunately, goldfinches are mobile feeders and have been able to move into gardens, initially to feed on weed seeds, but more recently to take sunflower hearts and nyger seed. The increasing use of gardens has been charted through the BTO/CJ Garden BirdWatch, a year-round study of birds using gardens and involving some 17,000 people. The latest results from this project have just been published and show that goldfinches are now reported from just over 50% of gardens, increasing from 23% ten years ago. Researchers believe that the provision of food in gardens has been a major factor in helping the population to recover, highlighting the contribution that we, as individuals, can make by providing suitable food in our gardens.

If you watch goldfinches feeding you will notice that their bills are quite long and thin, something that enables them to extract seeds from plants that are usually unavailable to other species. For example, the goldfinch is the only finch able to extract seeds from teasels, although it is usually only the males that are able to do this because the female bill is slightly shorter than that of the male. The males and females are almost identical in appearance. However, the red on the face extends behind the eye in the male but remains in front of the eye in the female. Young birds are more easily distinguished for, even though they have the same wing and tail markings as the adults, they lack the red, white and black head pattern.

If you don’t have goldfinches using your garden at the moment then you should find that you can attract them by providing hanging feeders with either sunflower hearts or nyger seed. While the sunflower hearts can be provided in a standard seed feeder, you will need to buy a special nyger feeder if you wish to provide this very fine seed. Because the seed is so fine it will ‘pour’ out of a normal feeder like liquid. Although I provided nyger initially, I now just provide sunflower hearts and they seem to do the job. A free leaflet giving more advice about attracting goldfinches is available from the British Trust for Ornithology.