Friday, 13 December 2013

Wanted: First winter Oystercatcher who goes by the name “LV.”



This bird is wanted regarding a series of stabbing attacks on cockles in the Tramore area. LV (1) was ringed by members of the Dublin Bay Birds Project (DBBP) team in Kilcoole, Co. Wicklow in July and was last seen on Newcastle beach, Co. Wicklow in August, sporting the colour rings.

This photo of LV was taken during routine reconnaissance shortly after ringing. Ornithologists believe that LV, having undergone a partial post-juvenile moult, has changed considerably in appearance since then.


LV (right) pictured at the Breaches, Kilcoole,
Co. Wicklow on 8th July
Niall Keogh

It was initially thought that this serial cockle killer may have absconded on a southward migration, possibly to France, but yesterday evening, thanks to a tip off from a member of the public, ornithologists have learned that LV is still at large in Ireland.

Birdwatcher, Clare Scott, who encountered LV on Garrarus beach, near Tramore in Co. Waterford on Wednesday, told ornithologists:

“It was only when I saw the blog that I decided to report the sighting.”

Kilcoole-ringed Oystercatcher, possibly "LV" Clare Scott

An eye witness at the scene managed to snap this photograph of these three suspected mussel murderers, thought to be accomplices of LV, as they fled.

Oystercatchers on Garrarus beach, Co. Waterford Clare Scott

A BirdWatch Ireland spokesperson stated that ornithologists “are following a definite line of enquiry” regarding the ecological requirements of the birds.

A source close to the DBBP stated that a sting operation, code-named “cannon-net”, is being planned for 2014, when a number of waders will be apprehended and fitted with radio transmitters in order to keep tabs on their movements and activities:  

“This radio tracking work will allow fine-focused observations at an individual scale, which will be used to support conclusions drawn from observations of larger flocks.”

The source added:  

“Surveillance of these (radio-tagged) birds will allow their ecological requirements and any threats they face to be investigated. It will also allow us to track these birds during the hours of darkness … when it is thought that they exploit different foraging areas.”


More information on this case will be posted to the BirdWatch Ireland Facebook and Twitter pages as it comes to light. Members of the public are encouraged to remain on the lookout for colour-ringed birds and to report any sightings to ntierney@birdwatchireland.ie

Tuesday, 10 December 2013

Justin Timberlake, Hen Harrier and Health & Safety on Sandymount Strand


Apologies for the title of this post, but it is inspired by a post on the excellent Little Tern blog from way back in the breeding season.  The wardens, as a result of either sun stroke or just general eccentricity, decided to give pet names to the birds that were breeding in and around the Little Tern colony in Kilcoole.  And while reading Oystercatcher rings on Sandymount Strand the other day, I realised that I had taken a leaf out of their book - I’d started naming the Oystercatchers according to their two-letter inscriptions! My rationale is that it saves me taking out my notebook between every ring read: when the rings are coming thick and fast, it’s more efficient to remember a few in your head and then pull out the notebook (that’s my story and I’m sticking to it!).

Oystercatcer "DJ" Colin Corse

So JT, HH and HS were just three of the 29 rings I managed to read in about forty minutes at low tide on the northern part of the strand. That shows how readable these rings are, and therefore how much information we can learn from these colour-ringed birds. With so many of the Sandymount Strand Oystercatchers ringed, we have an invaluable opportunity, and perhaps even a duty, to get some science out of the re-sightings, and the more re-sightings we get, the better the science will be. We now have over 450 re-sightings logged in the database and have re-sighted 90% of the birds. Over time, we will be able to piece together the ecological story of how these Oystercatchers are faring in their winter home, and the more re-sightings we get, the more informative that story will be. I know I'm labouring the point, but I really can’t stress enough the importance of reading these rings! So please get out there with the camera or scope and make your birding count.

…What I can stress, though, is the importance of not disturbing the birds when reading the rings. Mid-winter is a tough time for these birds, as they work hard to gain sufficient reserves to stand them in good stead for the rest of the winter and into next season. Any disturbance caused by ring-readers is another straw on the camel’s back. Every time they are forced to take to the air, they are both losing valuable foraging time and wasting valuable energy. And you know what happens if the energy budgets don’t balance at the end of each day….

The additive effect of human disturbance on wader 
over-winter survival as a result of a reduction in calorific
 intake and an increase in energetic expenditure
 during avoidance behaviour. 

Thankfully, with a telescope or a camera and decent light, you can easily read the rings without disturbing the birds, which is the whole point of colour-ringing after all.

Apart from seeing some of the regulars, it was good to catch up with CN, IN and IX, who hadn’t been re-sighted since February. It’s good to know that these three are still knocking around. 

Saturday, 9 November 2013

The wing of a Song Thrush, but the weight of three


We had an interesting capture at our wader mist netting session in Dublin Bay the other night – a Little Grebe! 


Some people call them Dabchicks (which happens to be the only bird name to have the first three letters of the alphabet occurring consecutively!), Shakespeare called them Dive-dappers, but I prefer Ducky-divers. Anyway, I flushed one while setting up the net at dusk, but I didn’t think for a second that we would be ringing one later on.

Grebes are fascinating birds: they build floating nests, which they cover with vegetation before leaving, carry their chicks on their back and pluck their own feathers and feed them to their young! And they’re quite interesting birds in the hand too.  

Little Grebe in winter plumage Clive Timmons

The short wings look like they are just about capable of dragging the rotund body from the water to splatter along the surface, but the legs and feet really are something to behold. They are disproportionately large, and placed well back on the body. While this makes them good swimmers and expert divers, it also makes them very ungainly on land. This, coupled with their small wing area, means that they are unable to take off from land. The tarsi are laterally flattened and have serrated hind edges, the front toes are separately lobed, and the claws are flat and nail-like. Another interesting feature is the tail: a bunch of wispy feathers that are no more than a token of a tail.

So you wouldn’t expect these short-winged, plump, almost tailless birds to be seasoned travellers. And you’d be right, they’re not, but check out this map of the journey of a Latvian Little Grebe. He was ringed on the nest in Latvia in June 1983 and was shot in Lancashire in January 1985 after travelling a (straight line) distance of 1,653 km! 

Recovery map for a Latvian Little Grebe
that turned up in the UK

I know I mentioned wader mist netting at the top of this post. Not much to report just yet, but watch this space...

Friday, 25 October 2013

Colour rings


I know this isn’t a Dublin Bay story, but it’ll be interesting to our colour-ring readers. 

In October, we blogged about a Galway-ringed Little Egret  that we came across on Sandymount Strand during one of our low tide surveys, and in that post mentioned the one that another of the Galway birds had ended up in the Azores. Now another of these colour-ringed birds, DH (ringed in June this year), has been seen... in ICELAND – one of a total of only 16 Little Egret records there ever! 
These birds, having colonised Ireland from the south east, must have a tendency to head north west, so maybe that’s something to do with it! The more resightings that are generated, the more chance we’ll have to piece this story together. Please report your colour-ringed Little Egret re-sightings to jlusby@birdwatchireland.ie

DH Birding Iceland

We also posted about a Greenshank colour-ringing study that aims to ascertain the wintering grounds of these waders. The latest news is that another of the Scottish-ringed birds has been recently been recorded on the Mullet Peninsula in Mayo. 


Colour-ringed Greenshank Peter Hill

This guy, “NB-LO,” was ringed in July 2010 in the Ythan Estuary in north east Scotland, was re-sighted close to the ringing location six times between then and the August 2010, and wasn’t seen again until it turned up in Mayo on the 14th October this year. Any colour-ringed Greenshanks should be sent to Brian Etheridge brian@milvus.myzen.co.uk


This lad stands out from the crowd


Have you seen this leucistic Oystercatcher around Dublin before?


The Dublin Bay I-WeBS count team say he’s a regular, and often come across him during their monthly rising tide surveys. We first noticed him this year on Sutton Strand on the 12th September, and picked him up again on the Red Arches pitches in Baldoyle yesterday.


Leucistic Oystercatcher Anna Valentín

Leucism results in white feathers, due to an absence of melanin pigment. It is an inherited trait, so we can’t know for sure if we’re looking at a single individual or perhaps one of its offspring. Aside from making affected birds more noticeable to predators, the white feathers are prone to more abrasion than normal feathers, and this can affect flight in some cases. And if that wasn’t bad enough, there is evidence that sometimes these birds aren’t recognised by their peers and potential mates!

Speaking of birds standing out from the crowd, when you’re out and about this weekend, keep an eye out for some newly colour-ringed Redshanks!


Wednesday, 16 October 2013

Brent Geese arrive back as normal

Well, I say normal, but some closer scrutiny of the flocks might prove otherwise...


The Irish Brent Goose Research Group first reported geese in Ireland on the 4th September, but also remarked that, throughout September, the influx was slower than expected. This could have been down to the weather or to good feeding opportunities delaying the final leg of their journey from Iceland to Ireland. Numbers increased throughout September, and 16,000 were counted in Strangford Lough towards the end of the month. 


Brent Geese David Dillon

The first Dublin sighting was on the 20th September in Malahide Estuary, and from then on they started to be picked up at their regular haunts around the county as the birds filtered down to us along the coast. On the 4th October a flock of 25 were seen on Malahide Estuary, another flock of 11 were on Bull Island and a further 40 were at Merrion Gates on Sandymount Strand. 

The International Brent Goose Census took place on the weekend of the 5th and 6th October and 34,000 birds were counted in the most important sites at this time of the year in Iceland, Northern Ireland and the Republic of Ireland, with 150 of these in south Dublin Bay.


Brent Geese Clive Timmons

So what’s all this about closer scrutiny of the flocks? Well, this year, like last year, the folks at the IBGRG are noticing a low proportion of juvenile birds among the flocks, which of course suggests an unproductive breeding season. By mid-September, the IBGRG had reported some sightings of juveniles in Iceland, but none in Ireland. While some juveniles have been reported here since then, this is definitely something worth taking a closer look at. We have no way to know for sure what has caused this poor breeding season in Arctic Canada, but we can try to put some numbers on it by investigating the proportions of adults and juveniles in the flocks we encounter throughout the winter (see photo below). 


Brent Geese juveniles showing white barring 
on the wing coverts Billy Clarke 

As the numbers continue to build throughout the autumn, we’ll be treated to the amazing sight of these arctic breeders spending the winter right amongst us, and have the privilege of sharing our parks, pitches and beaches with these birds. The sight and sound of thousands of Brent Geese flying en masse from the city parks to roost on Bull Island is certainly something to behold, and one of Dublin’s great natural spectacles. 


Keep up to date with these developments and lots more Brent Goose stuff at: http://irishbrentgoose.blogspot.ie/ 

Thursday, 3 October 2013

Colour-ringed Little Egret

Ugly ducklings...


One of the team spotted a colour-ringed Little Egret at Merrion Gates on Sandymount Strand the other day. It turns out that “HN” was ringed on the 4th June this year at a colony in Galway Bay, and that it’s the second bird from this colony to head to the big smoke for the winter.

Little Egret nest in Galway Bay colony John Lusby

Little Egrets are a very recent coloniser – we only confirmed their breeding in Ireland in 1997, so we know very little about them here. We do know that their population and range are expanding, and thanks to a colour-ringing project, we are able to follow the movements of these pioneering birds. Chris Benson and John Lusby started to colour-ring Little Egrets in Galway in 2009, soon after they started nesting there, and they are getting some fascinating insights into the movements of these birds away from their natal colonies.


Little Egret chicks after ringing John Lusby

In January 2011, John was contacted about a resighting of one of his Galway Bay birds. You’ll all remember what a harsh winter we endured in 2011, and how we constantly mused about escaping to the sun? Well that’s just what one of John’s Galway-born Little Egrets did! This bird was seen in the Azores in Portugal in October, over 2,000 km from its natal colony! Who would have guessed that they would travel as far as the Azores?


Colour-ringed Little Egret John Lusby

Chris and John have received good numbers of resightings so far, but are of course, always keen to hear about more. As the season progresses, we’ll bring you lots of info on the colour-ringed birds that are in Dublin Bay this winter. Colour-ringing projects can tell us so much about birds – things we would have no other way of finding out.

Please report your colour-ringed Little Egret resightings to jlusby@birdwatchireland.ie  

Friday, 20 September 2013

Colour-ringed Sanderling

Keep an eye out for colour rings on these Daz-whites as they dash along the tideline. 

On the 10th of September, three colour ringed Sanderling were spotted among a flock of 208 on Sandymount Strand, doing the usual Sanderling thing – zipping along right in front of the waves, like clock-work toys in fast-forward. All three birds were ringed in Iceland in 2011, and have wintered in Ireland every year since!

Overview of Sanderling re-sighting locations in Dublin and Iceland. 

G1RWGR was ringed on the 18th May 2011 in Sandgerði, and was last seen in Iceland on the 25th May 2011. He was picked up again in Poolbeg in Dublin Bay on the 31st July 2011, where he spent the winter, having his rings read numerous times between then and the 24th April 2012. The next sighting of G1RWGR was on the 30th July 2012, back in Poolbeg once again.

G1RWGR John Fox

Sanderlings don’t breed until they are two years old, so this guy wouldn’t have made the trip all the way the breeding grounds in Greenland or Canada in 2012. It’s likely that he did breed this year however, having last being seen in Dublin Bay on the 25th February and not being picked up again until the 10th September. 

Here's a quick summary of the re-sightings for the other two birds.

G2WWYG 
G2WWYG John Fox
22nd May 2011 - ringed in Sandgerði in Iceland
13th August 2011 – first spotted in Poolbeg, north Sandymount Strand
2011/12 winter – numerous sightings on Sandymount Strand
20th February 2012 – last seen in Booterstown Strand, Dublin
15th May 2012 – in Sandgerði harbour, Iceland
20th August 2012 – back in Poolbeg, north Sandymount Strand again
2012/13 winter - numerous sightings on Sandymount Strand
25th February 2013 – last Dublin sighting
10th September – picked up on Sandymount Strand once again


G2WGGW John fox
G2WGGW 
30th May 2011 - ringed in Sandgerði in Iceland
15th September 2011 – first spotted in Booterstown, south Dublin Bay
2011/12 winter – numerous sightings on Sandymount Strand
15th May 2012 – last seen in Poolbeg, Ireland
19th May 2012 – in Sandgerði harbour, Iceland (1,500 km in 4 days!!)
26th July 2012 – back in Poolbeg, north Sandymount Strand
2012/13 winter – numerous sightings on Sandymount Strand
12th February 2013 – last Dublin sighting in Booterstown
10th September – picked up on Sandymount Strand once again

Monday, 16 September 2013

Diamonds in the rough

Little Egrets, Grey Plovers and Black-tailed Godwits


The numbers of waterbirds in Dublin Bay are still building, but as we wait for the big numbers to arrive, we shouldn't overlook what’s already here.

Just north of the Bull Island causeway, you’ll often find an aggregation of Little Egrets – we've had up to 31 while out doing surveys recently. With their beautiful white plumage and diagnostic yellow ankle-socks, these small herons are the better looking cousin of the better known and more widespread Grey Heron.

Little Egret. John Fox.

These guys are recent arrivals from the Continent– 20 years ago such an aggregation would have resulted in hundreds of birders racing to see them – but we’re getting used to them now. That said, the Little Egret’s beautiful white plumage and their characteristic little chases after prey in our wetland pools are well worth stopping to take a look at.


Grey Plover. Richard T. Mills.
Also worth looking out for are the beautifully contrasting summer plumaged Grey Plovers – spotted black and white upperparts and black underparts with a white border. As their winter plumage takes over in the coming weeks, the drab factor will increase, and we’ll just be looking out for their black “armpits” (if you know what I mean!) to distinguish them in flight.



Black-tailed Godwits. Clive Timmons

And how can I talk about beautiful summer plumaged waders without mentioning Black-tailed Godwits! This rusty-orange plumage stands out wonderfully from the browns and greys of the mudflats. Enjoy this beauty when you can, because like the Grey Plover and the others, it will soon fade.

Don’t worry though; a host of colourful ducks have just arrived to provide another splash of colour to the mudflats.
A Black-Tailed Godwit in winter plumage, with a Wigeon.
Colum Clarke.

Friday, 6 September 2013

The boys are back in town

  

They say that one Swallow doesn't make it summer, but, for me anyway, the arrival of the Brent Geese does make it winter.


And this week, 800 of them have been reported in Strangford Lough, Co. Down, so it’s official! Birders in north county Dublin report that there are no geese present on the Rogerstown or Broadmeadow/Swords estuaries just yet, but that a single pioneering goose has been seen just inside the county border on Gormanston beach. As more and more of these birds arrive in Ireland from their breeding grounds in the Canadian Arctic, they will filter down along the east coast and into Dublin Bay.

Colour-ringed Brent Goose “CNRY” (right leg inscription, left leg 
inscription, right leg ring colour, left leg ring colour). Paddy Dwan. 

This population of geese is remarkably well studied, and the Irish Brent Goose Research Group have colour-ringed lots of them over the years. Ring reading, by what is now an army of dedicated amateur ring-readers, allows information on movements, site fidelity and survival to be collected. Even the social structure of this population is being studied. This will help to understand how an individual’s social standing affects its physical condition and survival.

Despite breeding in remote areas of the Arctic Canada, 
they are quite at home in the parks and pitches 
of Dublin in the winter. Matthew Silk.

Ultimately, all this work will highlight the factors that have the greatest influence on Brent Goose ecology and will feed in to future conservation actions for the species. So, when these birds turn up in Dublin Bay in the coming weeks, why not get out and see if you can see some colour-ringed ones? Any ring-reads (including the date and location) should be sent to grahammcelwaine@btinternet.com .  


Thursday, 29 August 2013

What’s in a name?

Why are our chocolate brown-headed gulls called Black-headed Gulls?


Since arriving from Spain to work on this project, I’ve been puzzled by this! At home, we call them Gaviota Reidora, or laughing gulls, due to their calls...which makes a bit more sense, doesn’t it?

Black-headed Gull, breeding plumage. Ronnie Martin

Anyway, since we started the monitoring programme in Dublin Bay, we’ve counted lots and lots of them. We had a peak count of 5,917 on the low tide count on the 19th of August. We haven’t managed to get any colour-rings just yet, but they are certainly worth looking out for. In the autumn of 2011, a colour-ringed Black-headed Gull was spotted in Booterstown. It turns out that this guy also had his colour ring read Poland in May 2010 and had flown 1,608 km to spend the winter in Dublin.

The re-sighting location and the sighting site in Poland (blue)

As it happens, the Irish Wetland Bird Survey (I-WeBS), which monitors wintering waterbirds throughout the country, is initiating a Gull Roost Survey this winter in order to get a handle on how our winter gulls are faring. If you happen to know of any places where gulls congregate at night roosts, it’d be great if you could let the I-WeBS Office at BirdWatch Ireland know. 

Black-headed Gull in winter plumage. Shay Connolly

Tuesday, 13 August 2013

Meet AJ - the record breaker


AJ holds project records for the longest distance travelled, the first Norwegian re-sighting, the second Norwegian re-sighting and is the (almost) record holder for the shortest bill at the time of ringing! What a bird!

Long distance record holder - AJ. Arnt Kvinnesland

AJ was re-sighted and photographed at Stavasanden, Karmøy, Rogaland, Norway on the 2nd of April and on the 3rd August 2013.

The re-sighting location for AJ (red) and the original ringing site (green)

AJ’s bill measured just 64 mm at the time of ringing and was beaten only by AZ (with a bill tip to feathers measurement of 63 mm). DJ, who turned up in Orkney on the 1st May, and who happens to be the previous long distance record holder, had a bill length of 90 mm at the time of ringing, which was the longest of all 119 birds ringed.

Comparison in bill length between DJ and AJ. 
Colin Corse, Arnt Kvinnesland

Oystercatcher bill length is a result of their foraging strategies. Some opt to smash open their preferred prey – cockles and muscles – by hammering at them and blunting their bills, while others take a different approach and prise them open. Their bills are constantly growing (like our finger nails), so it’s possible for them to change in length depending on the prey they are exploiting at a particular time.

Friday, 9 August 2013

Returning Waders


This project involves year-round monitoring of Dublin Bay and the waterbirds it supports. A team of ornithologists will be surveying the area at various tidal stages and times of the day (including at night!) to chart waterbird distribution, abundance and behaviour throughout the bay. This information will allow us to build up a comprehensive representation of how the birds are using the bay for roosting and foraging (click here for more info on this) and will allow us define the most important areas.

Greenshank (right) with Redshank  John Fox 


Our first counts took place last month, and we notched up 24 different waterbird species. As expected, numbers were still low, as the majority of the northern breeders have yet to arrive. We had good numbers of Greenshank, most presumably on passage, but we didn’t manage to see any colour rings (click here for more info on colour-ringed Greenshank). Curlew, Redshank and Oystercatcher were present in decent numbers, and we had a few Whimbrel too.

Curlew Dick Coombes

It was great to be watching Bar-tailed Godwits in their “tomato soup” coloured summer plumage and Black-headed Gulls with their chocolate brown hoods while listening to House Martins and Swallows chattering overhead on their aerial pursuits. But it won’t be too long now before the summer plumage and the hirundine backing track fades, and we’re left with drab winter plumage and cold hands…


Monday, 29 July 2013

New Tern raft


You may be wondering about the new structure in the Tolka Estuary? 

In May this year, a raft was moored in the Tolka Estuary by the Dublin Port Company, with welcome assistance from members of the Clontarf Yacht and Boat Club.

Dublin Port Company’s tern raft near Clontarf. Richard Nairn

This large steel pontoon, last used for the Tall Ships’ visit to Dublin Port, has been specially adapted for breeding terns, by adding timber walls and a gravel layer, to mimic a single beach. 

Common Terns carrying fish to chicks on the tern raft. John Fox


Up to 12 Common Terns have been recorded on the raft over the summer, with one pair successfully raising young. 





Tuesday, 23 July 2013

Tern chicks prepare for takeoff!



On the third monitoring visit to the Dublin Port Tern colony, most of the eggs had hatched and there was a good mix of ages, from one day old fluffies (to use the technical term!) to those almost ready to fledge.

Two fluffies and an adolescent! Niall Tierney

Most had been ringed in the previous monitoring visit and looked in great shape, and we managed to round up and ring the majority of the others. No signs of predation to report once again, which is great, especially after the devastating year they had last year when the high rainfall and unprecedented predation effectively wiped out the entire colony. Terns are long-lived and therefore have the ability to cope with terrible years like 2012, and hope to get luckier the following season. We ringed 186 Common and 19 Arctic Tern chicks, giving us a total of 450 Commons and 32 Arctics for the season. 

Arctic Tern. Dick Coombes

So what did we learn? Well, one key lesson is to always wear a hat when ringing in a tern colony (ouch!), but more importantly, ringing these chicks will allow us to learn a great deal about where these birds go, where they subsequently breed and how long they live. Who knows, we may have just ringed the future Common Tern longevity record holder!






Typical Common Tern life expectancy is about 12 years, but the maximum recorded age, according to BTO records, is 33 years and 6 days. This bird was ringed as a nestling in Northumberland on the 1st July, 1963 and it’s ring was read through a telescope in Liverpool on the 7th July 1996! 


Common Tern. Dick Coombes
Other notable bird sightings on the day included Black Guillemot, Common Sandpiper and two Sandwich Terns. The Pigeon House Kestrel nest ledge was empty and the three young were known to have fledged the previous week.


Tuesday, 16 July 2013

Celtic links


Ninety one of the 119 Oystercatchers that we ringed on Sandymount Strand last February have now been re-sighted at least once. The majority of these re-sightings have been from locations on Sandymount Strand itself, but there have also been several reports from some playing pitches in south Dublin and individual sightings at Bull Island, Dalkey Island and Baltray, Co. Louth.

And we’ve just heard about two birds that have been re-sighted in Scotland, providing an international context to the study. JL was re-sighted in Argyll on the 10th April, and DJ was photographed in Orkney on the 1st May.

Re-sighting locations for JL (green) and DJ (red).


We’re not surprised that these birds have been seen in Scotland, but these records are notable as they are our first international re-sightings. Who knows where our next international records will come from? 

DJ at St Peter's Pool, Deerness, Orkney on 1st May, 2013. Colin Corse.

Friday, 12 July 2013

Meet LV


We ringed this guy and his two siblings last week in Kilcoole, Co. Wicklow. It will be interesting to see if he turns up in Dublin Bay this winter. 

Oystercatcher "LV" foraging with parent. Niall T. Keogh

Looks like he’s getting a foraging lesson from one of his parents. Who knows, today’s lesson could be on whether he’s going to be a smasher or a splitter! It has long been thought that juvenile Oycs learn their foraging strategy from their parents, i.e. whether they gain access to mussel shells by hammering at them or by prising them open. However, it now seems that things are more flexible, and that the birds can switch between foraging approaches. 

Thursday, 11 July 2013

Don't mind Evelyn Cusack…


It’s officially autumn…the breeding season, and therefore the summer, is over.


OK, this may not be strictly true, but it may make you think twice about the way that we define the seasons. The reason I say this is because for some waders, the breeding season is already at an end, and northern breeders are starting to trickle in to our wetlands once again. Failed breeders start to arrive on our shores from as early as late June, and as July progresses this passage of waders will increase.




With that in mind, I want to mention a colour-ringing project that is hoping to get to grips with the migration ecology and wintering areas of the Scottish breeding population of Greenshank. The researchers are very keen to get any records they can of their Greenshanks passing through or wintering in Ireland, and these movements are already likely to have begun. So, please keep an eye out for colour-ringed Greenshanks if you are out and about. Please send details (date, location, etc.) and any photographs to Brian Etheridge (brian@milvus.myzen.co.uk).

And if you happen to come across some of our colour-ringed Oystercatchers on your travels, all the better! The latest reports we have suggest that as many as 18 colour-ringed Oycs have summered in Dublin Bay. So get out there - there really is no better weather for ring-reading!


Friday, 5 July 2013

First Tern chicks hatch at Dublin Port


Our second monitoring visit to the Dublin Port Tern colony showed that things are progressing well. On a warm sunny day in the first week of July, we ringed the majority of the ringable Common and Arctic Tern chicks.

So why ring these chicks? Well, it allows us to find out how many young birds leave the nest each year and survive to become adults, how long these adults live and where they breed in subsequent years. To learn more about ringing click here.

As we approached platform, we estimated the flock size to be 285 adult Common Terns (but bear in mind that a good deal of the colony will have been off foraging). On climbing up onto the platform, we could immediately see that things were going really well - there were good numbers of chicks and quite a few already on the run - it only takes a couple of days before these guys are mobile. We ringed 262 Common  and 13 Acrtic Tern chicks.


Arctic Tern nestling. Niall Tierney

Thankfully, there was no evidence of the egg predation that we reported in the last post. Now that the colony is in full swing, let’s hope that the terns can drive off any intruders. A passing Great Black-backed Gull got the “tern treatment” while we were ringing, and it made as fast an escape as possible!

Tern eggs show remarkable variability, but these erythristic Arctic Tern eggs were interesting.


Erythristic Arctic Tern eggs. Niall Tierney


Other bird sightings included Cormorants, Black Guillemots, Common Sandpipers and three well grown Kestrel nestlings in ‘window-nest’ at old Pigeon House power station. A Peregrine was heard calling briefly as well.

Friday, 21 June 2013

Breeding terns update


The main tern nest census was carried out on a fine day last week, and showed good increases in the number of nests and clutch sizes since our last visit.

As we rowed out to the platform, we could see that something was distressing the terns – they were repeatedly diving at an unseen intruder towards the eastern end of the platform – and we immediately suspected a pillaging corvid. We climbed the ladder to the platform and carefully picked our way (tern eggs are almost invisible on the shingle substrate) to the eastern end to find a Kittiwake spread-eagled across one of the nests. A quick examination revealed that the bird was very freshly dead, but showed no signs of external injury. Whatever the cause of death, this bird picked a less than peaceful refuge for its final moments... 

Common Tern nest in Dublin Port. Niall Tierney. 

Anyway, we promptly got back to the job in hand – the nest census. This is simply a count of the number of nests and the number of eggs per nest. This, along with the estimation of the number of adult birds present, allows us to see how the colony is faring from year to year. On the main platform, 418 Common Tern nests were recorded, with clutch sizes ranging between 1 and 4. There were 25 Arctic Tern nests, with clutch sizes of 1-2. There was an increase in the number of cached depredated egg shells, indicating that the (still unidentified) avian predator had been on the platform since the earlier visit (see previous post).

Two Arctic Tern nests in Dublin Port. Niall Tierney.

Once the census was complete, we quickly vacated the platform to allow the adults to resume incubation. Peak hatching is expected to be around the turn of the month. We’ll check back in on the colony again in the coming weeks to monitor breeding success and will post another update then.