Last gull rings to be read at the Eirol landfill? (February 17, 2015)

Today the landfill of Eirol got visited by Pedro Moreira and me for another day of gull ring-reading. Beforehand we got informed that certain measures were going to be taken to take care of the gull problem. These measures initiated yesterday. In about half an hour we managed to read four rings, all on Lesser Black-backed Gulls. Then a falconer made its appearance, together with two Peregrine falcons and a gas cannon.

 

Adult male Peregrine falcon.

 

Gas cannon

 

Panic
 

The first panic among the circa 4000 Lesser Black-backed Gulls and 300 Black-headed Gulls was caused by the falconer’s female Peregrine that got flown around the site for a short while. After this it was the gas cannon that made the gulls decide to abandon the site. We were later informed that the falcon had also flown away. Its gps signal indicated it already had made its way to the coast within a few minutes, probably faster than any of the gulls. In the end it was the gas cannon that made the gulls completely abandon the landfill.



Empty landfill...



Peregrine kill, but from Eirol's own falcon.


Regular blog readers will already have gotten used to the presence of a Peregrine falcon on the Eirol landfill (see previous posts). That bird already successfully reduced the number of Black-headed gulls at the site. During the past couple of weeks this now 2nd cy bird had remained faithful to the site. Today we searched for prey remains left behind by that falcon and found remains of another four Black-headed gulls. However, we did not see the bird itself. The last observation of it came from the falconer, who informed us that yesterday, after releasing his own Peregrine, our young falcon came to attack it and defend its feeding ground.

The current bird eradication program is planned to continue for two months. I suspect it will also keep out the Black kites from the landfill, which are supposed to arrive during the second half of February, and have already proven to be successful in reducing gull numbers to zero there during summer.

Gulls at the Eirol landfill, Portugal. February 26, 2014.

Due to other obligations and very poor weather conditions, the Eirol landfill had not been visited by me for a long while. Yesterday, there finally was a gap in the clouds. On this trip I got joined by Pedro Moreira. Pedro was particularly interested in the rarities that occasionally show up at the site, but as far as gulls went we did not record anything else then Lesser Black-backed -, Black-headed - and a few Yellow-legged gulls. There were plenty of gulls present; in particular the first two species were abundant. I was hoping to be able to visit the site before the first of this year’s Black Kites showed up, but we quickly found out that they were already there. We made a maximum count of 25 kites, which continuously flushed the gulls. According to personnel the first kites appeared around the 21st of this month. Between 7:15 and 16:45 Pedro and I managed to read 46 rings (44 LBBG and 2 BHG). This number could have been a lot higher if it weren’t for the dirt that covered many (about 40%!) of the rings, as well as for the time we spent talking with personnel of the site, and for the time we watched the impressive interactions between the gulls and the kites, making it a very nice day after all!

Here Fido, bring me the slipper.

 

Eirol landfill, February 19, 2013: the last of this winter's visits, and the terror birds are back!

This entry is about my most recent visit to the Eirol landfill (February 19), during which I was hoping to gain a good final number of color-ring sightings, as it would be my last visit to the site for this winter. There were still plenty of gulls present (about 16.000 Lesser Black-backed gulls Larus fuscus), but as mentioned before the ring-reading conditions there are not as good as they once were at Taboeira: rings get dirty more easily, birds are harder to observe from the right angles, and many of their roost sites are out of sight for me.
This time things were a bit different, primarily because the first Black Kites Milvus migrans have returned from their wintering quarters in Africa. These kites continuously flushed the gulls from their hidden roost sites, forcing them to perch at different locations, allowing me to see their rings more easily. A total of 58 color-rings were read and these had been applied on Lesser Black-backed Gulls in Britain (excl. Guernsey) (19), Guernsey (18), The Netherlands (10), Norway (3), Germany (2), France (2), Denmark (2) and Belgium (2).
British birds seemed to be dominating the site. I noticed a similar situation taking place a year ago at Taboeira, when during the second half of February the number of British gulls appeared to increase while those originating from other NW European countries decreased. This will undoubtedly have something to do with the gulls’ spring migration movements, as the majority of the birds will already be on their way to their breeding grounds further to the north. I will be following some of them in a few weeks from now.

 

The first of three Black Kites that showed up during the day…

…and the mass-hysteria among the gulls that always seems to follow the appearance of a kite.

These kites were more than capable of expelling the gulls from the large mound of sand that is located at the east side of the landfill. They’re more than welcome to do so, as this allowed me to observe a lot more gulls in places where their rings could actually be read...

I.e. on the roads right next to the observer.

And this time the birds roosting in the pit were too afraid to kneel down, so there were plenty of legs to scope out.

Then of course it’s important that the ring itself allows proper reading and its inscription is not either too worn or too dirty. I'm not sure where this one came from, but it's probably British.

A new one for me; Chris Perrins’ GREEN TA, with a tiny and dirty WHITE inscription (vertical inscription; top – bottom). Also very British.

Philippe Dubois’ RED 974K with a WHITE inscription, from France. Well, initially there was a white inscription visible on this ring; nowadays you'll have to get very close to this bird for a proper reading.

RED TB5.T, BLACK inscription, a bird from Paul Roper & the North Thames Gull Group, is showing an unmarked companion how to drink dewdrops in the early morning.

 David Sowter’s BLACK WC3W, YELLOW inscription; very condensed inscription, but in the end Britannia ruled the waves at the landfill.

Apart from color-ring reading I spent some time inspecting gull carcasses again. Unfortunately for Mike Marsh the only bird from him that got reported from Eirol was this LBBG RED AZ.AC, WHITE inscription (metal BTO GR20352). It was ringed as a pullus on the 4th of July 2010, on Havergate Island, Orford, Suffolk. Afterwards it got reported regularly by others in Faro (Portugal), once from Torreira, and a few times by me from the former Taboeira landfill. An additional two British ‘metal only’ LBBG’s were found. A broken wing had been the initial cause of death for all of these three gulls.

Besides the resightings, the overall birding turned out to be very good again. It all started off with an adult male Marsh Harrier Circus aeruginosus patrolling the site for a while. It caused some disturbance among the gulls, but nowhere near as much as the first kite that would show up an hour later.

A single Mediterranean Gull Ichthyaetus melanocephalus among Black-headed Gulls Chroicocephalus ridibundus and one Lesser Black-backed Gull.

A Pied Wagtail Motacilla alba yarrellii, which I consider to be part of the British invasion of the landfill as well.

I also ran into this strange looking bird, presumably a female Herring Gull Larus argentatus. Considering the number of gulls I see on a regular basis, the number of rarities that get reported by me (compared to those reported by my ‘gull friends’ from the Iberian Peninsula) seems to be rather low. I suspect that I spent too much time scoping out gull legs instead of gulls themselves, so I probably miss out on a lot of fun. Still, Herring Gulls are rare in this part of the world, but in a few weeks from now I’ll have plenty of them flying around my head and they will appear normal again.