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.