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Swedish Lesser Black-backed Gull with GPS/GSM transmitter

On Friday, 25 October, I was contacted by the Ringing Administration (RA) at the Natural History Museum of Denmark. They had received an exciting message about a dead Lesser Black-backed Gull (Larus fuscus) that had been found dead at the very tip of Ulvshale. The gull had been ringed in Sweden. They contacted the Swedish ringing administration, who replied that the bird should also be equipped with a GPS/GSM transmitter! An important detail that was not immediately noticed by the finder. Also, it could not be confirmed from photos of the bird. A GPS/GSM transmitter is not cheap. And if it hadn’t fallen off, the researchers behind the project were very interested in getting it back if possible.

Fortunately, I was already on Møn. We had just returned the day before from Jutland (read A late twitch after a Northern Warbler in Haurvig). After clarification of the location by Amanda and Jesper (both from RA) – I set off by bike in the hope of finding both the gull and the GPS/GSM transmitter.

The gull and the transmitter is located

I parked the bike at the Nature Agency’s red gate after the last summer cottages on (very appropriately) Mågenakken. I quickly walked out to the beach to walk along the water’s edge. I could then also test if my new rubber boots were waterproof. After just over a kilometer, I was at the expected position at the northernmost point of Ulvshales. There was also a dead Lesser Black-backed Gull – a young bird. Both the steel ring and the red coloring were still on the gull. The person who had reported the bird had not removed them from the bird. A quick inspection showed that there was indeed a GPS/GSM transmitter mounted on the back. But it could easily be missed if you didn’t look closely.

I photo-documented the find so you could see the rings and transmitter on the Lesser Black-backed Gull. I then secured the GPS/GSM transmitter. The transmitter itself was mounted on the bird using a harness around the bird’s wings – like a backpack. This keeps it attached to the body without interfering with the bird or its natural behavior. I had to cut a strap to release the transmitter. I removed the steel and the color ring. If you find a ringed dead bird you should report it. In addition, it’s a good idea to remove the rings from the bird. There are two reasons for this. One is that it’s easier to verify the information on the ring if needed. The other is to avoid multiple reports of the same dead bird. This can cause confusion and misunderstanding. But all readings/reports of live birds are important to report.

GPS/GSM senderen er på vej hjem

On 2 November, I cycled – via a detour (A NFL at the Cowboy City: Grey-necked Bunting) to the RA to hand in the transmitter. Amanda would immediately arrange for it to be sent to Sweden and the Swedish RA. The Swedes were delighted when they heard that the transmitter had been found. The technology is still not cheap. Therefore they are interested in getting the equipment back, when there is an opportunity for it. The steel and color ring was given to the Danish RA collection of recovered rings.

Preliminary epilogue

The Lesser Black-backed Gull was ringed this year (2024) as a chick north of Uppsala in Sweden. It ended its short life at Ulvshale (Møn) at the age of only about 4 months. I am now eagerly awaiting to hear more about the bird’s movements and travel history. And then I will update this “preliminary” epilogue with a little about its history.

All photos © Bente Steffensen & Uffe Damm Andersen, unless otherwise stated.