Friday, 1 July 2016

Rockabill Nest Census, Part Two

So last week we were delighted to announce that this year's count of Roseate Terns on Rockabill broke last year's record by around 150 pairs! We now have 1556 pairs of this fantastic seabird here, off the coast of Dublin. While counting our Roseate Terns we also carried out a full census of our Common Terns, Arctic Terns, Kittiwakes and Black Guillemots too! 

Common Tern (adult). on Rockabill, Summer 2016. (picture taken under NPWS license)
Our Common Terns have increased since last year, up by around 80 to 2029 pairs this year - good news after last year's slight decline. As well as being an impressive bird in their own right, their famous aggression (they're the ones constantly pecking us!) helps keep the more timid Roseate Terns safe - so the more of them we have the better.

Arctic Tern (adult) on Rockabill, Summer 2016. (picture taken under NPWS license)
Unfortunately our Arctic Terns continue to suffer from gull predation and so we have a maximum of around 60 pairs. The fact that they tend to nest on the peripheries of the colony, in places where Great Black-Backs can easily land and predate their eggs, make it very hard to estimate the exact numbers though in general we can surmise that they're not doing well. Hopefully they'll continue to do well in the Tern colonies in Dublin Port and on Dalkey Island!

Kittiwakes on Rockabill, Summer 2015. (picture taken under NPWS license)

Last year we had a record number of 215 Kittiwakes nesting on our cliffs and this year we have something very close to that number with what are called "apparently occupied nests". Unfortunately the Black-backed Gulls that cause our Arctic Terns such hassle have also become quite efficient at predating Kittiwake nests and as a result there are very very few active nests still left on the Bill, with some nests around Kitti-City on our main island suspected to have fallen victim to a similar fate. In the battle between the biggest gull in the world and the most beautiful gull in the world there's only one winner! 

Black Guillemot on Rockabill, Summer 2016. (picture taken under NPWS license)
Lastly, our Black Guillemots. In my first year on Rockabill our Black Guillemot population had halved from the previous year, owing to terrible winter storms in 2013/14. We had seen gradual increases in their numbers since then, though this year we have 61 nests which is two less than 2015. It seems likely that the vast majority of chicks fledged in 2013 were lost in those storms and so few if any were 'recruited' into the breeding population this year (they normally start breeding around 3 years old). If we can avoid any terrible winter storms again we're hoping the Rockabill population of this awesome Auk will come on leaps and bounds in the very near future.

So good news and bad news from the Rockabill nest census overall. After a hard few days of counting every single nest we were delighted to get a phonecall from Eoin of Skerries Seatours who soon arrived with chips and chicken wings from Ollie's Place in Skerries!! After two months out on Rockabill, needless to say we devoured the food in record timing! By this time of the summer a lot of our snacks have run out and we've been eating very similar meals on a daily basis, so this feast was a real morale booster. Our compliments to the chef! (and the boat man!)

A meal fit for a king - or two very hungry wardens!


  1. Can the Black Backs be controlled? They are not a threatened species so killing the offenders would be reasonable.

  2. Hi John, Great Black-Backed Gulls are actually an Amber-listed species so are of conservation concern, which needs to be taken into account if we were to look to control them.

  3. Fantastic news all round apart from the Gull problem. There are lots of Greater Blacks around our coasts. Could some way not be found to scare them off or make the top of the Bill less suitable for them to land on ? It is staggering to think that there are over 7,000 terns nesting on an area no bigger than a football pitch !

  4. A few more thoughts. Given the success of a small island nation in the Euros, I suspect that even a Rockabill football team could beat England at the minute ! Again some fantastic photographs of the seabirds but as a vegetarian I have to ask if that chicken gave its consent for its wings to be eaten by the hungry wardens !

    1. We're looking into a few options with regards the Gulls. I really like gulls, especially the larger species, but obviously there's potential for significant damage when you're talking about as significant a colony as Rockabill.

      I think you might be right Jim, we'd go with a 1-1-1 formation with Steve in goals! And we were assured that it was the dying wish of those chickens to get to visit Rockabill...

  5. Beautiful photos! Both series. Greetings from Montreal, Canada. :)

    1. Thanks very much Linda! Great to hear from readers from so far away! :)