Our second monitoring visit to the Dublin Port Tern colony showed that things are progressing well. On a warm sunny day in the first week of July, we ringed the majority of the ringable Common and Arctic Tern chicks.
So why ring these chicks? Well, it allows us to find out how many young birds leave the nest each year and survive to become adults, how long these adults live and where they breed in subsequent years. To learn more about ringing click here.
As we approached platform, we estimated the flock size to be 285 adult Common Terns (but bear in mind that a good deal of the colony will have been off foraging). On climbing up onto the platform, we could immediately see that things were going really well - there were good numbers of chicks and quite a few already on the run - it only takes a couple of days before these guys are mobile. We ringed 262 Common and 13 Acrtic Tern chicks.
|Arctic Tern nestling. Niall Tierney|
Thankfully, there was no evidence of the egg predation that we reported in the last post. Now that the colony is in full swing, let’s hope that the terns can drive off any intruders. A passing Great Black-backed Gull got the “tern treatment” while we were ringing, and it made as fast an escape as possible!
Tern eggs show remarkable variability, but these erythristic Arctic Tern eggs were interesting.
|Erythristic Arctic Tern eggs. Niall Tierney|