Greenfinches used to be common at our birdfeeders. Then, two years ago, suddenly, their numbers started to decline. We saw a few, often looking sick, and we found one dead in the garden, and then they all disappeared. The cause was a disease, trichomonosis, which was first found in the British greenfinch population in 2005 but took some time to reach this part of the country. Trichomonosis is a parasite which is passed from one bird to the next when they feed each other with regurgitated food, but contamination at bird tables was also a cause of infection. What was so unusual about the disease is that it didn't seem to affect other small birds.
We missed them. Not only are they a very pretty bird, they are interestingly aggressive, one of the few who are quite prepared to see off any unruly chaffinches that come near them. This one is looking annoyed at having to share his feeder with a goldfinch.
Over the last winter we began to notice them again, just one or two at first, then more. By the end of the winter we were seeing them regularly, and recently we've watched parents feeding young. So, despite the recent weather, it looks as if the population is re-establishing itself.
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