Wednesday, 17 June 2015

New Arrivals on Rockabill!

Our first Tern chicks have hatched!!

Last weekend we finally had our first hatchlings - Black Guillemot and Oystercatcher chicks (blog post on it here). Unfortunately the Oystercatcher chicks were attacked by nearby adult Common Terns and didn't survive, but on a brighter note we now have 10 Black Guillemot nests with chicks, and another 40 or so to come over the nest few days and weeks!

Black Guillemot chick. (Picture taken under NPWS license)

...which will grow up to look like this eventually! (Picture taken under NPWS license)

With the knowledge that Tern chicks take around 23 days to hatch, and the fact that we found our first few Tern eggs around 23 days ago, we've been on high alert to find the first Tern chicks.  Once they hatch we have to weigh and measure a subset of them every day, as well as ring them and track their survival. This morning we saw our first Roseate Tern egg 'pipping' - i.e. the chick was starting to break out, and by this evening we had four tiny Roseate Tern chicks as well as three Common Tern chicks!

A Roseate Tern chick on 'Day Zero' i.e. the day it hatched. (Picture taken under NPWS license)

Common Tern chick on 'Day Zero'. (Picture taken under NPWS license)
Two Common Tern chicks from above - well camouflaged against the ground. (Picture taken under NPWS license)

Common Tern chick. (Picture taken under NPWS license)

Chicks of both species tend to sit fairly still for their first day or two - not venturing out of their nest scrape. After that the Common Tern chicks will be running all over the place, whilst the Roseate Tern chicks will stay hidden in their nestboxes or in the nearest bit of shelter they can find. They'll grow very quickly over the next four weeks, changing shape, appearance and behaviour until they're finally able to fly. We'll do a blog post later in the season to illustrate the changes they go through.

As well as that exciting news, we've also been doing the first part of our nest census over the last two days - counting every nest on the island to establish how many breeding pairs of birds we have - and we've already broken the previous Rockabill records for two of our five species!! And we havn't even done the second part of the nest census yet!

Stay tuned later in the week for details!

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