Tuesday, 23 July 2013

Tern chicks prepare for takeoff!

On the third monitoring visit to the Dublin Port Tern colony, most of the eggs had hatched and there was a good mix of ages, from one day old fluffies (to use the technical term!) to those almost ready to fledge.

Two fluffies and an adolescent! Niall Tierney

Most had been ringed in the previous monitoring visit and looked in great shape, and we managed to round up and ring the majority of the others. No signs of predation to report once again, which is great, especially after the devastating year they had last year when the high rainfall and unprecedented predation effectively wiped out the entire colony. Terns are long-lived and therefore have the ability to cope with terrible years like 2012, and hope to get luckier the following season. We ringed 186 Common and 19 Arctic Tern chicks, giving us a total of 450 Commons and 32 Arctics for the season. 

Arctic Tern. Dick Coombes

So what did we learn? Well, one key lesson is to always wear a hat when ringing in a tern colony (ouch!), but more importantly, ringing these chicks will allow us to learn a great deal about where these birds go, where they subsequently breed and how long they live. Who knows, we may have just ringed the future Common Tern longevity record holder!

Typical Common Tern life expectancy is about 12 years, but the maximum recorded age, according to BTO records, is 33 years and 6 days. This bird was ringed as a nestling in Northumberland on the 1st July, 1963 and it’s ring was read through a telescope in Liverpool on the 7th July 1996! 

Common Tern. Dick Coombes
Other notable bird sightings on the day included Black Guillemot, Common Sandpiper and two Sandwich Terns. The Pigeon House Kestrel nest ledge was empty and the three young were known to have fledged the previous week.

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