Hello
Another day of sunshine and another day where most of it has been watching the birds in the garden. However I have to say it does make you appreciate how special those garden birds are and although our house is not configured appropriately to take good images unless pointing a lens though a double-glazed unit I've had a go!
The BTO have identified that the Chaffinch population in the UK and in some parts of Europe has crashed during the last decade. For those of us that feed and watch birds and even more so when you handle birds during the ringing procedures, this comes as no surprise. For every three Chaffinches that I catch I release two of them straightaway without ringing. When holding birds regularly it is possible to determine if a bird is unwell or sick - unwell birds tend to be light, lethargic and the eyes are not bright. They lack vigor and there are often other telling signs such as recent injuries, poor feather quality or parasite infestation. In fact I didn't really appreciate how many of our birds are struggling with such issues until I began ringing. Many adapt very well, particularly the wagtails with missing claws and toes (a common problem), the corvids with distorted and almost arthritic legs and feet and individual birds of many species with extended growth mandibles.
Unfortunately though Chaffinches seem to have a particularly suite of current problems which I suspect is the reason why the population is being undermined. Like many finches they regularly suffer from the disease known as Trichomonosis which is considered the most significant factor in the demise of the once common Greenfinch. This is a parasitic disease which causes legions in the throat of the birds and prevents them from drinking or eating - birds fluff up and become lethargic as they starve and dehydrate - a particularly distressing sight.
The double whammy for Chaffinches is the fact that they are also particularly susceptible to diseases affecting the legs, feet and claws. Infected birds can show a variety of sores, calcified lumps, crumbling skin and other manifestations. The birds themselves often remain healthy and although their legs and feet are almost grotesque, because it is a gradual process the birds adapt their feeding techniques and often exhibit normal weights and vigor until the disease eats away at their claws, feet and legs to the point where they are left with stumps or a congealed mass of ulcers.
When watching Chaffinches feeding on the ground the healthy birds hop about as normal. Birds with minor leg issues do much the same. As the conditions worsens though birds are unable to perch properly and when feeding on the ground balance on their sternum or breast bone. They then feed in a more ponderous manner and are often the last to fly up and as such are more likely to be predated. Some of these issues are believed to be as a result of a mite infestation.
However the main culprit is believed to be a disease called Fringilla Papillomavirus and it seems to be on the increase. Finches by nature tend to be gregarious and for much of the year different populations from around Europe move and mix freely. Bullfinches are now regularly exhibiting similar infections and occasionally it is possible to see it on Goldfinches and Yellowhammers too. Whether this is the same infestation is difficult to say but it is currently the Chaffinch which suffers most.
Certainly when I first started birding the Chaffinch was considered one of the most common birds in the UK and in the top three with Wren and Blackbird. Sadly that is no longer the case - lets hope this charismatic finch can bounce back and not suffer the same fate as our Greenfinch which now operates at a much lower population level.
Regards
Neil M
Another day of sunshine and another day where most of it has been watching the birds in the garden. However I have to say it does make you appreciate how special those garden birds are and although our house is not configured appropriately to take good images unless pointing a lens though a double-glazed unit I've had a go!
The BTO have identified that the Chaffinch population in the UK and in some parts of Europe has crashed during the last decade. For those of us that feed and watch birds and even more so when you handle birds during the ringing procedures, this comes as no surprise. For every three Chaffinches that I catch I release two of them straightaway without ringing. When holding birds regularly it is possible to determine if a bird is unwell or sick - unwell birds tend to be light, lethargic and the eyes are not bright. They lack vigor and there are often other telling signs such as recent injuries, poor feather quality or parasite infestation. In fact I didn't really appreciate how many of our birds are struggling with such issues until I began ringing. Many adapt very well, particularly the wagtails with missing claws and toes (a common problem), the corvids with distorted and almost arthritic legs and feet and individual birds of many species with extended growth mandibles.
Unfortunately though Chaffinches seem to have a particularly suite of current problems which I suspect is the reason why the population is being undermined. Like many finches they regularly suffer from the disease known as Trichomonosis which is considered the most significant factor in the demise of the once common Greenfinch. This is a parasitic disease which causes legions in the throat of the birds and prevents them from drinking or eating - birds fluff up and become lethargic as they starve and dehydrate - a particularly distressing sight.
The double whammy for Chaffinches is the fact that they are also particularly susceptible to diseases affecting the legs, feet and claws. Infected birds can show a variety of sores, calcified lumps, crumbling skin and other manifestations. The birds themselves often remain healthy and although their legs and feet are almost grotesque, because it is a gradual process the birds adapt their feeding techniques and often exhibit normal weights and vigor until the disease eats away at their claws, feet and legs to the point where they are left with stumps or a congealed mass of ulcers.
When watching Chaffinches feeding on the ground the healthy birds hop about as normal. Birds with minor leg issues do much the same. As the conditions worsens though birds are unable to perch properly and when feeding on the ground balance on their sternum or breast bone. They then feed in a more ponderous manner and are often the last to fly up and as such are more likely to be predated. Some of these issues are believed to be as a result of a mite infestation.
However the main culprit is believed to be a disease called Fringilla Papillomavirus and it seems to be on the increase. Finches by nature tend to be gregarious and for much of the year different populations from around Europe move and mix freely. Bullfinches are now regularly exhibiting similar infections and occasionally it is possible to see it on Goldfinches and Yellowhammers too. Whether this is the same infestation is difficult to say but it is currently the Chaffinch which suffers most.
Certainly when I first started birding the Chaffinch was considered one of the most common birds in the UK and in the top three with Wren and Blackbird. Sadly that is no longer the case - lets hope this charismatic finch can bounce back and not suffer the same fate as our Greenfinch which now operates at a much lower population level.
Regards
Neil M
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| Male Greenfinch. |
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| Male Yellowhammer. |
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| Pied Wagtail on our garden pond. Apart from adult males and juvenile females at either end of the spectrum, Pied Wagtails are notoriously difficult to gender and age. However despite two different ages of tertial feathers I would stick my neck out and say this bird is an adult female. Note the tick above it's right eye. |
Thank you so much for such a formative blog. It is indeed worrying for these wonderful birds.
ReplyDeleteWell said Neil and you have been kind enough to let me see these birds close up on the ringing sessions. My garden is smaller/more compact than yours - you should be able to take some pix, in the shade ans standing or sitting quietly (and with an open window sometimes) - the issue is whether you can hold the camera steady (weight wise)for any length of time. Mine scatter when I go outside but they gradually creep back! The other thing I have found is that if the sun is dazzling the birds you can get much closer! I am also grateful that you have chosen tut some of my pix up on the blog. Keep safe everyone. JHT
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