Sunday, 14 June 2015

Two sets of two chicks from two species in two days!

We've been on Rockabill a bit over a month, the weather is picking up and we're now getting into the main part of the summer. That can mean only one thing - chicks!!

The first eggs we found on Rockabill this year was a clutch of two Oystercatcher eggs. They don't usually nest on the Rock (they usually nest on the Bill and quickly get predated by Gulls...), so we weren't sure how they'd get along with the presence of both wardens and Terns.

Oystercatcher incubating two eggs. (Picture taken under NPWS license)

We were keeping an eager eye on the eggs over the last week, expecting them to hatch, and it got to a stage where we thought it might have been too late and the eggs had failed......but then on Friday evening we noticed two tiny bills, complete with small white egg-tooths, poking their way out of each egg.....

Oystercatcher eggs 'pipping' - the chicks small white 'egg-tooth' is visible, helping it to break out. (Picture taken under NPWS license)

......And on Saturday morning two Oystercatcher chicks had hatched. Unfortunately, one of the chicks died this morning after wandering away from the nest and encountering some aggressive/defensive Common Terns. We knew there was a risk of this as the Oystercatchers nested in the middle of the colony. Had they nested somewhere on the edge they would have benefited from the protection of thousands of Terns while still minimising the risk of chicks getting into trouble with the Terns. There is still one chick though - hopefully the parents can supervise and protect it and it will survive the summer.

An Oystercatcher chick - note the colours that camouflage them well until they're able to fly. (Picture taken under NPWS license)

The species we usually expect to lay eggs first out here are the Black Guillemots. As with the Oystercatchers, we knew they incubate their eggs for a bit under a month, and sure enough, right on queue we had our first Black Guillemot chicks on Friday - around half a day before the Oystercatchers! They're just small balls of black fluff at the moment, staying put in their nest-holes, but they'll grow quickly over the coming weeks!

Black Guillemot eggs in a nestbox. (Picture taken under NPWS license)
Our first Black Guillemot chicks of 2015 - sitting safely in the back of their nestbox. (Picture taken under NPWS license)

Black Guillemot chick. (Picture taken under NPWS license)

So there you have it - two sets of two chicks from two species in two days! Unfortunately one of the Oystercatcher chicks didn't make it, but hopefully its sibling will, and fledging success is usually quite high for Black Guillemot chicks here, so that's cause for optimism too. 

Roseate tern chicks take around 23 days to hatch - and it was c24 days ago when we found our first Roseate Tern keep an eye on the blog either tonight or tomorrow for news on that front.....things are about to get busy out here!!

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