Goldcrest: A Small Bird With Big Journeys

My report analyses for the work my team does in the Braydon Forest runs from the 1st April of the current year to 31st March of the following year.  By doing so, we have consistency of reporting and cover not just the seasons but also the key movement times of our birds.  For example, we can effectively compare winter figures in a way that you cannot if you use the calendar year as your guide.  Whilst we are in this state of lockdown I will use some of those analyses as the basis of some blog posts.

As anyone who has been birding for any length of time knows, the Goldcrest is our smallest resident species.  Over the course of the year we will catch birds with weights between 4.5g and 6.0g.  To put this into perspective, a two-pence piece weighs 7.05g.

20130921 Webbs Wood

We had a particularly good year for Goldcrest in the Braydon Forest this year, 2019/20.  Our previous best catch was a total of 95 birds ringed in 2016/17.  Generally we catch and ring between 50 and 70 of them each year.  Recovery rates are quite low compared to other species within the Forest, but we regularly recapture around 15 individuals each year.  This year we caught and ringed 146 birds and recaptured 42.  Naturally, some of those recaptured birds were birds that had been ringed in the period, and some birds were caught more than once. In reality, we processed 157 individual Goldcrest this year: a 50% increase on our previous largest catch.  The vast majority were processed in the last 6 months of the year, and were mainly juvenile birds.

Whilst it is always encouraging to see ringing catches improve over time, what set this year apart for Goldcrest is what was recaptured.  Goldcrest are renowned for flying long distances for such a small bird.  Many of the northern European population either fly across the North Sea or down the west coast of mainland Europe, to cross to the UK much further down to over-winter.  The longest ringing recovery of Goldcrest was back in 2010, when a bird ringed in the Orkney Islands was recovered 29 days later, 830km away in Suffolk.

Having access to all of our ringing group’s records, through the BTO’s DemOn on-line recording and retrieval system, I had a look at the recovery records for Goldcrest, going back 20 years, to see if we had any unusual recoveries before this year.  All previous recoveries were of birds ringed on our allocated ring series.

On the 19th October 2019 we carried out a ringing session in the Firs nature reserve and had a modest catch of 8 Goldcrest ringed and one recovery. However, the recovery did not have one of our rings on it.  When the information came through from the BTO a couple of days later, it showed that this bird was ringed as an adult male on the Calf-of-Man, at the Bird Observatory, on the 7th April 2019.   That in itself is interesting: the Calf of Man is not renowned for its conifer forests and at that time of year that bird would be heading northern latitudes for breeding.  Ending up in the Firs in October is quite something.  It means that the minimum distance it flew to get there was 338km in 169 days. I suspect it had flown a lot further than that, bred and ended up in the Firs on its subsequent autumn migration, for the reasons given previously.

On the 3rd November 2019 we caught and ringed 7 Goldcrest in Ravensroost Woods and recaptured one more. Astonishingly, this bird, a juvenile male, had a very similar ring number to the one caught in the Firs, and had also been ringed on the Calf-of-Man, this time on the 5th September 2019, and had flown 335km to get to our site.  This was its first trip south.

I don’t know what it was about this period last year but to go from never having recaptured a Goldcrest from “out of town” to recapturing two that had clearly migrated along the west coast of the UK was very exciting.

As I was putting the finishing touches to my annual report, I received notification from the BTO that an adult female Goldcrest that we had ringed in the Firs, in that session on the 19th October, had been recovered at the Bardsey Island bird observatory on the 26th March. Clearly there is possibly a western flyway for Goldcrest along the west coast of the UK.  Why we have started to get evidence of that in Wiltshire this year I have no idea, but I am hoping that we can get a lot more evidence to support the hypothesis over the next few years.

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