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, Karm√ły, 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…