Saturday, 24 May 2014

Everything's Rosy on Rockabill

So we had our first Black Guillemot egg last Friday, our first Common Tern egg on Wednesday, and today we've found our first Roseate Tern egg! While Common Terns nest out in the open, Roseate Terns prefer to nest under cover - either at the base of some vegetation, or in one of the c.700 nestboxes we put out at the start of the season. And the first Roseate Tern egg we found was in one of our nestboxes - Box 302 - and in one of our designated study areas too!

The 1st Roseate Tern egg on Rockabill in 2014 - in Box Number 302.
(Picture taken under  NPWS license)

Roseate Tern egg - note that it's a bit more pointed than the Common Tern egg from earlier in the week, but similarly camouflaged. (Picture taken under  NPWS license)

Compared to previous years, the first Roseate Egg is perhaps slightly later than usual. Their first egg can appear anywhere from the second week of May onwards (15 May in 2011), but weather plays an important part and last year's wet summer meant the wardens had to wait until the 29th of May to find the first Roseate egg. They usually start laying 2-3 days later than the Common Terns on Rockabill, so they're fairly consistent in that respect this year.

A Roseate Tern on Rockabill, wearing a BTO ring (left leg) and 'special' ring (right leg) to enable identification of individuals. (Picture taken under  NPWS license)

Rockabill holds over 80% of the north-west European population of Roseate Terns, and almost half of the European population including the Azores, so they're our top priority in terms of conservation on Rockabill. The terns have been coming and going a lot over the last few days, so we're expecting a slow trickle of eggs over the next week, but it's great that they've gotten started!

- Brian and Donnacha

No comments:

Post a Comment