Wednesday 2 March 2011

North West Black Headed Gull Study.

Over the last few years we have ringed just under 1000 Black Headed Gulls across the North West. Despite our efforts we have received only a handful of local recoveries and two overseas recoveries: one to Poland and one to Germany. Even more disparaging is the amount of recoveries we have had from chicks ringed in the last two breeding seasons at Killington Reservoir in Cumbria; with just over 800 ringed and only one recovery of 25km!

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With another trip to Killington planned for this summer and having had a successful winter hand catching adults, we decided it would be worthwhile to start using an additional mark aside from the standard BTO metal ring, both to increase recoveries and begin a colour ring study on Black Headed Gulls across the North West.

The main aims of the study are to look into:

  • Dispersal from natal colony (Killington Reservoir)
  • To study winter site fidelity (At all other sites, where adults can be caught)
  • Interchange between study sites.
  • Longevity
  • To document general movements within the UK & abroad.

In addition to a metal ring on the right leg, we will place dark blue darvics on the left leg, each with a different code which will make each bird identifiable as an individual.

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The Colour Scheme will be as follows:

One Dark Blue Darvic on the left leg with White lettering and a four digit code.

All codes start with the number 2 followed by one letter and two numbers. E.G. 2A23

There will be an additional metal ring placed on the right leg.

There is also an email address printed on the ring which is bhgulls@gmail.com

All sightings should be sent to this address, this will make it easier for either myself or Kane to respond to the sightings as they will all be in one place!

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The inspiration for the project came when we were driving around the county catching Coot to colour ring. It became obvious to us that the best sites for catching coot were also the best sites for catching or reading the rings of Black-headed gulls. So the colour ringing of Coot and gulls really are symbiotic studies!

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Photo by Zac Hinchcliffe.

Also, at almost every site we went to there was a ringed Black- headed gull, with last year being a fantastic year for controls, but unfortunately none of our Killington birds! John Wells in the Cotswolds suggested that with the numbers of birds we were catching we should start using darvics as his group has great success with them. Having considered it ourselves after getting very little information back from nearly 1000 birds, we quickly got the project up and running!

We envisage the project to last for at least 5 years and it will hopefully not only increase the amount of recoveries we receive but also enable us to build a migration map for black headed gulls in the North West of England and learn more about the movements of these charismatic birds. So next time you’re out feeding the birds, keep an eye out for any birds with blue left legs and please send us your sightings

Ciaran Hatsell.

5 comments:

  1. Sounds like a good project Kane, will follow with interest.

    Dave

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  2. Where are you getting your rings made up?

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  3. Hi Mark,

    The rings are being made by Interrex - http://interrex.nazwa.pl/colour-rings/

    Cheers Kane.

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  4. Hi Kane,

    For years we have trapped Med gulls on the nest in special traps both to control adults and to facilitate re-ringing. Naturally this works well with BH gulls too. if you are pulli ringing in colonies then you can do this at the same time; Since you disturb anyway it maximises the return. Let me know if you want details.

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  5. A great project will look out for some coming this way to the isle of man

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