15 April 2015

First BTO-ringed Mediterranean Gull recorded in Morocco

Sean Kingston, the British & Irish Mediterranean Gull colour ring coordinator, recently contacted us with the following story:

The breeding population of Mediterranean Gulls in the UK has gone from strength to strength in recent years with the number of breeding pairs breaching the 1,000 mark for the first time in 2010 (Holling et al 2012). 2014 was the first year that Mediterranean Gulls were recorded successfully breeding in Cambridgeshire. A pair fledged two chicks which were colour ringed by Tony Martin on 8th June 2014 as 2XL0 and 2XL1.

2XL1, the sibling of 2XL0, ringed in Cambridgeshire in 2014. Photo by Tony Martin

On Monday 30th March 2015, 2XL0 was re-sighted by Brian Small of Limosa Holidays among a flock of 15 Med Gulls at Oued Souss, about 40 minutes south of Agadir in Morocco. This is the first sighting of a BTO-ringed Mediterranean Gull in Morocco. 2XL0 had flown 1,600 miles, or 2,600 kilometres, from its birth site in Cambridgeshire to its wintering grounds in Morocco.

Photographic proof of 2XL0 in Morocco. Photo by Brian Small

Over two thirds of the Western European population of Mediterranean Gulls head south each autumn and winter primarily along the Atlantic Coast of Portugal between Lisbon and the Algarve. So while it is not unusual for Mediterranean Gulls to leave the UK in winter, it is unusual for a bird to fly as far south as Morocco, as this is close to the southern end of the wintering range for Western European Mediterranean Gulls. Renaud Flamant, international Mediterranean Gull colour ring programme coordinator, does receive occasional reports from traveling birders of European-ringed Mediterranean Gulls as far south as the Gambia and Mauritania.

Fledged Mediterranean Gulls have an annual survival rate of over 80% per annum so it is possible that 2XL0 may be around for at least the next ten years (the longevity record is held by a bird that was ringed as an adult in 1991 and caught again 15 years, 3 months and 7 days later - ed.). Hopefully 2XL0 will have sense and continue to winter in beautiful warm Morocco however this is by no means certain as many juvenile Mediterranean Gulls change their wintering location from year to year and really only become site faithful upon reaching adulthood at three years of age.

Many thanks to Tony Martin, Brian Small and Renaud Flamant.

Further reading
Holling, M., & the Rare Breeding Birds Panel. 2012. Rare breeding birds in the United Kingdom in 2010. British Birds 105: 351–430.

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