Saturday, 30 July 2016

Come Fly With Me

After most of our Terns laid eggs in late-May and early-June, and they take around 22 days to hatch and another 28-30 days to be able to fly, we're now coming to the end of the Tern breeding season here on Rockabill. While we do still have some chicks around that have a bit more growing up to do, we have far more that are able to fly and have left the area where their nest was. Our Common Tern fledglings tend to congregate on large 'obvious' areas like the helipad or on some of the shed roofs, where they can be easily found by their parents and they can readily spot any incoming food that's either intended for them or another fledgling from whom they might be able to steal it off! Our Roseate Tern fledglings on the other hand to to stay a bit closer to their parents and hang out on the rocky parts of the edge of the island.

Some of our Rockabill Roseates have moved on already however, with sightings from elsewhere in Dublin and even as far south as Wexford already. Conversely, we've seen some fledglings from Lady's Island in Wexford here on Rockabill, with the birds from there tending to move north for a while after the breeding season before beginning their southern migration next month. So if you live on the coast keep an eye out for Terns on the move!

Productivity, that is the number of chicks that fledge per nest, hasn't been great this year on Rockabill with many chicks seemingly dying due to lack of food. But seeing the chicks that we've worked hard to protect and monitor take their first stumbling flight and even become experts in the air after a few days has provided a very welcome boost to morale as the season draws to a close!
Fledgling Common Tern on the Rockabill helipad.  (picture taken under NPWS license)

Fledgling Roseate Tern  (picture taken under NPWS license)

When it comes to ID'ing the two fledglings Roseate Tern fledglings are a little but smaller than their Common counterparts, and are generally darker in their feathering, with black legs and a black bill. Overall they bear a closer resemblance to Sandwich Tern chicks, despite not being particularly closely related to them. Common Tern fledglings have a mostly orange bill with pink-ish legs and warmer brown and light grey colours to their plumage.

Fledgling Roseate Tern calling out to its parents  (picture taken under NPWS license)

Common Tern fledgling  (picture taken under NPWS license)

Fledgling Roseate Tern and adult  (picture taken under NPWS license)

Fledgling Common Tern begging for food.  (picture taken under NPWS license)

Fledgling Roseate Tern on Rockabill  (picture taken under NPWS license)

Fledgling Common Tern having a rest in between meals. (picture taken under NPWS license)
Below are two videos of a Roseate Tern chick and parents. This chick is days away from fledging and can be seen making rough attempts at flight to get on top of the nestbox! Many of our Roseate Terns practice their flying skills in a similar way before eventually getting the skill and confidence to fly out of the nesting area. 


  1. How did the ringing go this year ?

    1. Apologies for the late reply Jim, data collation dragging out a bit this year! We ringed 971 Roseates this year, including two adults. 70 of those chicks we know failed to fledge.

      We only ringed 897 Commons this year, including 52 adults. And 358 of those chicks are known to have failed to fledge.

      We definitely missed a few Roseate chicks this year, but overall the low numbers are a reflection of the very poor productivity this year (more on that in the near future...).