Monday, 20 September 2021

End of year bits...

Four stormies we caught on Nan Ron in August have now come back as new ringings all performed in July - so not really that interesting other than that they are still around after a month. We managed to add to data by sexing and aging two as 6Fs.

The Great Skua we resighted by colour-ring was a juvenile bird of this year too, and the one found dead, alongside the dead Greater Black-backed chick were also of this year.

Friday, 3 September 2021

A flood of recoveries

 Many recoveries we get of birds caught and/or recaptured on Nan Ron come about by the contribution of others. To date 46 other permit numbers have contributed to retraps or controls, from individuals to partnerships, ringing groups or observatories.

This flurry of recoveries is a combination of our work on Nan Ron and the work of the Bache, Shearwood and McShane Ringing Partnership (now Belvide RG) and Stefan Bodnar. Fifteen other permit numbers have been responsible for other ringing or recaptures of birds reported here.

This post reports seventy-seven birds caught and recaptured on Nan Ron. The four oldest were greater than 14 years old (5837, 5458, 5111, 5103 days between ringing and recapture) while another four were greater than 11 years old. The graph shows the time elapsed between ringing and recapture of these 77 birds. Twenty-two birds were within year retraps while 28 were recaught approx two years after ringing.



Two birds ringed this year in July were recaptured elsewhere: one at Fair Isle BO (19days and 189km later) and one at Score, Highland Region (10days and 154km later).

Thirty-one birds ringed elsewhere were recaptured (controlled) on the island. These ranged from seven birds all recaptured within a year from St Johns Point, Highland Region to one originally ringed on Priest Island 5867 days previous (c15 years). An interesting movement is abird from Collieston, Aberdeenshire to nan Ron, 196km in two days (although this is well within reported foraging distances for Storm Petrels). Any birds caught with an elapsed time of >1000days between ringing and recapture could be considered to be local breeders.

Note also the one bird from Cork, we don't get that many movements from Ireland, and one bird originally ringed on Skokholm in 2019.