In mid October I went on a ringing trip to Gibraltar for 18 days, based at the Straits of Gibraltar Bird Observatory, situated on the steep slopes of ‘the rock’. This was my fourth autumn visit, and with the coast of North Africa being visible from the obs, there is a constant reminder of why this is such a good location to monitor bird migration.
Looking across to Africa
We used up to 18 nets on a daily basis, the majority being located on the slope immediately above and below the obs building. The terrain in places is very steep with loose rock underfoot, so care is needed on the net-rounds. I wore my Garmin watch for one morning session of net rounds, which recorded a distance completed of almost five miles!
There were never more than three of us staying at the obs at anytime, but on some mornings we were joined by one or two local ringers.
In the time that I was there over 3000 birds were caught and processed, with our busiest single day being 340 birds.
Blackcap was by far the most numerous bird encountered, accounting for almost 70% of the total. We had 3 ‘controls’ of Blackcaps that had been ringed in Belgium, and 2 of Serins ringed in Spain. The amount of fat on the Blackcaps varied significantly, with the lightest Blackcap I ringed weighing just over 13 gms, and the heaviest over 27gms.
There were also good numbers of familiar birds such as Robin, Greenfinch, Goldfinch, Chiffchaff and Song thrush, and less familiar species such as Sardinian warbler, Serin and Black Redstart.
Other species ringed in my time there included Red-rumped swallow, Scops owl, Dartford warbler, Yellow-browed warbler, Bluethroat, Blue rock thrush and Red-breasted flycatcher.
I was very fortunate to have the opportunity to help catch and ring Crag martins at a cave roost, and the experience of sitting near the cave entrance with Crag martins flying above and all around on their way into the roost will stay in my memory for a long time.
In total, I ringed over a thousand birds of 26 species, and it was a busy but very enjoyable trip.
My thanks to Ian Lees ( ringer in charge) and fellow ringers Matt, Peter, Charlie and Jill.
Further information about birds and ringing in Gibraltar can be found on the website of the Gibraltar Ornithological and Natural History Society - www.gonhs.org
Bird bag laundry day