Errol knows a thing or two about Goldfinch. He lives in the south of England and he sees and catches plenty of them because it’s warmer down there than in the north west of England where I live. He probably also sees a lots more on migration than I do here in Lancashire because many Goldfinches migrate south in the autumn.
After my recent October 2009 retrapping of a Goldfinch that had been ringed down in sunny Surrey in January 2009 Errol told me about some of his own experiences with ringing Goldfinches in the last six or seven years where he lives in Bedfordshire.
Surrey to Lancashire 341 kms
Below I quote Errol’s work on the subject.
“During the last six or seven years, the number of Goldfinches using garden feeders has increased. This is partly due to the presence of Nyjer feeders but, more lately, the addition of sunflower hearts to the garden bird-table menu. As a consequence, numbers have also increased “in the field” throughout the year, allowing the species to be caught away from garden sites".
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Goldfinch x Month 2007
"There is a distinct pattern to the numbers of birds caught in any month. The above graph shows quite clearly the better numbers caught from August to December, with a distinct peak in September and October. This coincides with the main passage movement southwards of the species, together with the presence of many young of the year. Garden feeders are an easy source of protein shortly after first-light, especially after a ‘cold’ night, and again in the afternoon if foraging for natural foods has not been very successful for the birds. A second noticeable feature of trapping Goldfinches is the variance between the sexes at different times of the year. An analysis of our data (for 2007) shows that males in the population seemingly outnumber the females by ~5:4. More importantly, the percentage of females caught during the year varies quite a lot. This may be an artefact of catching at feeding stations or differential feeding strategies between the sexes. However, it is more likely defined by the differential abmigration between the sexes (females moving further south in winter – possibly to Europe). Female numbers are at their lowest in January at less than 20%, as in the graph below".
% of Female Goldfinch
It is reasonably easy to distinguish male and female Goldfinch in the hand, less so in the field, but of course it is only by ringing them that individual males and females may be recognised. The page reproduced from “Svensonn” shows the differences.
Page 295, Identification Guide to European Passerines
Thanks for the gen Errol.
Read more from Errol and the local ringing group exploits at http://ivelringinggroup.blogspot.com/
After my recent October 2009 retrapping of a Goldfinch that had been ringed down in sunny Surrey in January 2009 Errol told me about some of his own experiences with ringing Goldfinches in the last six or seven years where he lives in Bedfordshire.
Below I quote Errol’s work on the subject.
“During the last six or seven years, the number of Goldfinches using garden feeders has increased. This is partly due to the presence of Nyjer feeders but, more lately, the addition of sunflower hearts to the garden bird-table menu. As a consequence, numbers have also increased “in the field” throughout the year, allowing the species to be caught away from garden sites".
.bmp)
"There is a distinct pattern to the numbers of birds caught in any month. The above graph shows quite clearly the better numbers caught from August to December, with a distinct peak in September and October. This coincides with the main passage movement southwards of the species, together with the presence of many young of the year. Garden feeders are an easy source of protein shortly after first-light, especially after a ‘cold’ night, and again in the afternoon if foraging for natural foods has not been very successful for the birds. A second noticeable feature of trapping Goldfinches is the variance between the sexes at different times of the year. An analysis of our data (for 2007) shows that males in the population seemingly outnumber the females by ~5:4. More importantly, the percentage of females caught during the year varies quite a lot. This may be an artefact of catching at feeding stations or differential feeding strategies between the sexes. However, it is more likely defined by the differential abmigration between the sexes (females moving further south in winter – possibly to Europe). Female numbers are at their lowest in January at less than 20%, as in the graph below".
It is reasonably easy to distinguish male and female Goldfinch in the hand, less so in the field, but of course it is only by ringing them that individual males and females may be recognised. The page reproduced from “Svensonn” shows the differences.
Thanks for the gen Errol.
Read more from Errol and the local ringing group exploits at http://ivelringinggroup.blogspot.com/
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