Roseate Tern
| Irish Name: | Geabhróg rósach |
| Scientific name: | Sterna dougallii |
| Bird Family: | Terns |
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Conservation status
Conservation status
Status
Rare summer visitor from April to October, the majority breeding at two sites in the Irish Sea, with another colony in Wexford.
Identification
Only seen over the sea. Slender seabird with narrow, pointed wings, long forked tail and long, pointed bill. Bill all dark with a red base when breeding. Grey above and white below, dark cap to head. Flight light and buoyant, can hover briefly over the sea before diving in, dives in with a distinctive angled powerful dive. A slight, elegant tern which is similar to Common and Arctic Terns. Told apart by flight action, more rapid and shallower wingbeats with shorter wings giving a more direct looking flight. Birds in adult summer plumage are very pale, much paler than other terns, with a faint rosy tinge to the upperparts. Legs are long and bright red. Tail steamers very long. Lacks dark trailing edge to primaries. Winter plumage, like all terns is different from breeding plumage. Adult winter plumage develops white forehead and dark carpal bar. Juvenile birds have bold patterns to upperparts with dark legs and bill. First winter birds similar to adults but with some retained juvenile feathers.
Voice
Calls either quick wader like "kerrick" (not unlike Sandwich Tern) or a deep, harsh "ach".
Diet
Chiefly marine fish.
Breeding
Nest colonially on the ground. Restricted to two main colonies in Ireland, one on the island of Rockabill, off Skerries, Co. Dublin and one at Lady's Island, near Rosslare, in Co. Wexford. Birds have bred at other sites recently, for example on Dalkey Island, Co. Dublin and on the Blasket Islands Co. Kerry. Rockabill holds the most important colony in Europe with up to 1,200 pairs of birds. The colony at Lady's Island is much smaller with around a hundred pairs.
Wintering
Winters in west Africa.
Monitored by
Roseate Terns are monitored annually at their breeding colonies on Rockabill Island and Lady’s Island Lake. Also all-Ireland tern survey in 1995, and through breeding seabird surveys. Breeding seabirds are monitored through breeding seabird surveys carried out every 15-20 years.
Very localised summer distribution, Winters in West Africa. Lady’s Island, near Rosslare, in County Wexford plays host to an important number of birds as does Rockabill Island off Dublin Bay. A small recently established colony exists on Maiden Rock, Dalkey, Co. Dublin.
Blog posts about this bird
Highs and Lows for Kilcoole Little Terns in 2024
There is no doubt that turning the tide against biodiversity loss is an uphill battle but despite the worrying trends for many species, there is proof out there that we can halt and reverse declines. Indeed, well-resourced, science-based and longstanding conservation projects truly work, and the Kilcoole Little Tern Project is a shining example of this. It is a National Parks and Wildlife Service (NPWS) project, run by BirdWatch Ireland to date.
Of course, every season comes with surprises and 2024 was no exception. There is usually some predictability around the dates the Little Terns arrive back from Africa, and we aim to have the colony fencing and hide in place by the time the first eggs are being laid. The Terns had other plans this year though.
“The season kicked off surprisingly early. The first egg was discovered on the 9th of May. Usually, the 14th or 15th would be considered early so we were caught off guard, in a positive way. We were still in set-up mode at that stage,” explains Brian Burke, Coordinator of the Kilcoole Little Tern Project.
“When that happens, you have to be careful when setting up the fencing to not cause disturbance. We had to tailor what we were doing to ensure that we didn’t keep them off the nests for too long. Thankfully, everything went smoothly and chicks from all of those early nests hatched successfully.”
It is difficult to pinpoint why some terns arrive early. However, it is likely influenced at least in part by the Kilcoole project itself.
“Kilcoole is a reliable and successful place for them to nest, not because there is anything particularly unique about the beach, but because of the project and the level of protection it has provided to the birds for many years,” says Brian. “The most experienced terns always start nesting first and, the more experienced terns you’ve had, the earlier the season begins.”
As the rate of new eggs being laid continued apace, it was quickly becoming clear that a very large number of Little Terns had returned to Kilcoole this year.
At its peak in early June we recorded over 270 nesting pairs of Little Terns at Kilcoole. This is the highest-ever number for the project and a long way from the 14 pairs recorded at the project’s onset many years ago. Based on these figures, Kilcoole likely had one of the largest Little Tern colonies in the Ireland and Britain this year and numbers from colonies monitored and protected by Louth Nature Trust at Baltray, BirdWatch Ireland Fingal Branch in Portrane, and NPWS in Cahore all suggest healthy nesting numbers at other key Irish sites.
The 2024 season wasn’t all plain sailing, however.
“We had one week in June where the birds’ fortunes took a hit, unfortunately. There was some predation by Hooded Crows, who caused a lot of damage in a short space of time before the wardens could put a stop to it. A few days later, stormy weather and a sea swell at high tide took a lot of medium-sized chicks on the shoreline,” says Brian.
“If these impacts happened earlier in the season when most were still on their eggs, there would have been the time and opportunity for birds to relay. Unfortunately, because of the timing in mid-June, many of the birds were too late to try again. That was the low point of the season and the hard-hitting reality of this kind of work.”
Thankfully, things have been progressing very well since. Any subsequent predation incidents were minor and successfully managed by the colony wardens and a large number of chicks have now fledged. Some of them have already been spotted at the Little Tern conservation project at Portrane in north Dublin, and Gronant in Wales, as they explore the Irish Sea prior to migration.
The colony has also managed to escape Avian Influenza (Bird Flu) for another year. While the nesting habits of Little Terns make them less vulnerable to Avian Flu than those that nest in mixed species, high-density colonies such as Common Terns and Roseate Terns, the potential threat of the deadly disease is never far from our minds during the breeding season.
Most of the Kilcoole Little Terns have now left the site and the few remain will soon depart, leaving Brian and the wardens behind with reports to write and reflections on another busy season!
“The lesson this year is that every year is different. We are constantly trying to control what we can control but of course, some things are uncontrollable. Overall, it's about us giving the birds more good years than bad years,” says Brian.
[Nesting Little Tern Photos by Brian Burke, taken under NPWS licence]
The Kilcoole Little Tern Project is an NPWS project run by BirdWatch Ireland under a competitive tender agreement in 2024.
It is difficult to pinpoint why some terns arrive early. However, it is likely influenced at least in part by the Kilcoole project itself.
“Kilcoole is a reliable and successful place for them to nest, not because there is anything particularly unique about the beach, but because of the project and the level of protection it has provided to the birds for many years,” says Brian. “The most experienced terns always start nesting first and, the more experienced terns you’ve had, the earlier the season begins.”
As the rate of new eggs being laid continued apace, it was quickly becoming clear that a very large number of Little Terns had returned to Kilcoole this year.
At its peak in early June we recorded over 270 nesting pairs of Little Terns at Kilcoole. This is the highest-ever number for the project and a long way from the 14 pairs recorded at the project’s onset many years ago. Based on these figures, Kilcoole likely had one of the largest Little Tern colonies in the Ireland and Britain this year and numbers from colonies monitored and protected by Louth Nature Trust at Baltray, BirdWatch Ireland Fingal Branch in Portrane, and NPWS in Cahore all suggest healthy nesting numbers at other key Irish sites.
The 2024 season wasn’t all plain sailing, however.
“We had one week in June where the birds’ fortunes took a hit, unfortunately. There was some predation by Hooded Crows, who caused a lot of damage in a short space of time before the wardens could put a stop to it. A few days later, stormy weather and a sea swell at high tide took a lot of medium-sized chicks on the shoreline,” says Brian.
“If these impacts happened earlier in the season when most were still on their eggs, there would have been the time and opportunity for birds to relay. Unfortunately, because of the timing in mid-June, many of the birds were too late to try again. That was the low point of the season and the hard-hitting reality of this kind of work.”
Thankfully, things have been progressing very well since. Any subsequent predation incidents were minor and successfully managed by the colony wardens and a large number of chicks have now fledged. Some of them have already been spotted at the Little Tern conservation project at Portrane in north Dublin, and Gronant in Wales, as they explore the Irish Sea prior to migration.
The colony has also managed to escape Avian Influenza (Bird Flu) for another year. While the nesting habits of Little Terns make them less vulnerable to Avian Flu than those that nest in mixed species, high-density colonies such as Common Terns and Roseate Terns, the potential threat of the deadly disease is never far from our minds during the breeding season.
Most of the Kilcoole Little Terns have now left the site and the few remain will soon depart, leaving Brian and the wardens behind with reports to write and reflections on another busy season!
“The lesson this year is that every year is different. We are constantly trying to control what we can control but of course, some things are uncontrollable. Overall, it's about us giving the birds more good years than bad years,” says Brian.
[Nesting Little Tern Photos by Brian Burke, taken under NPWS licence]
The Kilcoole Little Tern Project is an NPWS project run by BirdWatch Ireland under a competitive tender agreement in 2024.
Rockablog: Eggs, eggs, and more eggs!
At the end of our last update, we mentioned that the terns had just begun landing on the island. Now, it's hard to imagine a time when they weren't here! While we've been very busy monitoring the island's changes, the terns have been even busier. Over the past two weeks, they have transitioned from cautiously inspecting potential nest sites to enthusiastically and vigilantly protecting their nests and eggs.
We can confirm that all three species—common, Arctic, and Roseate Terns—are nesting on the island, with different pairs at various stages of nesting. Some terns have already begun incubating their full clutches of three-egg nests, while others are still selecting suitable areas to settle down.
First, let's check in with each species of tern.
- Common Tern
A full clutch of Common Tern eggs on Rockabill – May 2024 (photo taken under NPWS license).
Defensive Common Terns.
- Roseate Tern
Roseate Tern pair sitting on a nest box (photo taken under NPWS license).
Roseate Tern sitting on eggs in an open nest (photo taken under NPWS license).
- Arctic tern
Arctic tern among the scurvygrass.
When we are not checking on the tern nests in our study sites, we are busy in ring reading. We are getting great use out of the 5 hides that we set up around the island. In the hides we can use the scopes and binoculars to read rings on as many birds as possible. By reading these rings we can gather information on the birds' origins, ages, nesting locations, mating patterns, changes in nesting success over time, and sometimes, their migration patterns when the same rings are spotted away from Rockabill.
We haven't forgotten about the other nesting seabirds spending the summer with us! Every day, we make sure to check on the Black Guillemot and Kittiwake breeding pairs, who have been just as busy as the terns, building nests and incubating eggs.
- Black Guillemot
Most Black Guillemot pairs have already started incubating their eggs. Black Guillemot eggs are much larger than tern eggs and have a purple- blueish hue to them. We have been finding Black Guillemot eggs in the nest boxes that we deployed under the helideck and to the south of the island but we have also been finding plenty of eggs in dark cavities all over the island. Black Guillemot parents incubate their eggs for longer periods than terns, with both parents typically sharing incubation duties for 28 to 32 days.
Black Guillemot on top of one of the 5 hides.
Black Guillemot egg in a wall cavity (photo taken under NPWS license).
- Kittiwake
Kittiwakes on their nests (photo taken under NPWS license).
- What's Next?
