Record-breaking Reed Warblers

Undoubtedly one of the best things about bird ringing is the learning. The discoveries. I thought I knew a lot about birds before I started to train to bird ring. And I did. But now I realise I was only scratching the surface. There are so many more fascinating facts and statistics that only come to light during the process of ringing and recording birds. From subtle morphological differences that can determine the age and sex of a bird, to details about fat, muscle, brood patches... I could go on and on. Bird ringing is a journey of discovery!

But perhaps one of the most interesting discoveries are those surrounding migration. We often get retrap reports from the BTO giving us information about birds we catch at our site near Woking, and some are very surprising.

One bird we caught recently has a truly astonishing past. On the 9th July, I processed an adult Reed Warbler, who we now know has been alive for more than 11 years. 11 years. This bird was ringed in the nest on the River Wey near Guildford in July 2006. This bird has broken the current Surrey record for oldest Reed Warber, with the national record being 12 years.

But, for me, the most astonishing part of this bird's story is its migration history. This bird has crossed the Sahara Desert 22 times! It's incredible to think that this little Reed Warbler has made such an epic journey so many times, and survived all of it. It's stats like these that are only attainable through schemes such as bird ringing.

Reed Warbler (Acrocephalus scirpaceus)

Another example of a bird with an interesting migration history is Reed Warbler '996', a bird that we ringed at our site in June 2016. After migrating to Africa over the winter, the bird returned to a different site at Thatcham Marsh, about 55km away. This bird then stayed a short while at Thatcham, where it was caught twice - once in mid-May, and a second time a couple of weeks later at the end of the month. And then, for a reason known only to the bird itself, 996 left Thatcham and returned to our site, where we caught it in late June.

Reed Warblers are known to return to the same reedbeds every year, so it was unusual for this bird to find a different site. But the interesting part of this story is that the bird discovered a new site, stayed for around a month, and then left again. A possible explanation for this is that the bird attempted to establish a territory or find a mate at Thatcham, failed, and so found its way back to Woking. How it did this I can't explain - it seems amazing that this warbler could find its way back across the countryside of England so easily to the same reedbed it had left the summer before. Another fascinating story revealed by one tiny metal ring.

A net ride stretching a small way into the reedbeds at our site

So there we have it. One record-breaker, and one traveller - with all the statistics and information revealed through the BTO's Ringing Scheme. It's stories like these, that would otherwise go unknown and unappreciated, that amaze me the most about birds, and that amaze me most about ringing. And all this from just a few months of ringing - I look forward to seeing what else we discover this summer...


  1. Great blog post and really helpful and your blog are very interesting midnightinfo


Post a Comment

Popular posts from this blog

Conservation: Costa Rica Leading By Example after Deforestation Report

Extremadura: Raptors

Bird Ringing in Surrey