Odd shot

Larus argentatus Y.BAJ @ Schiphol Airport, March 21 2018, 12:30 (http://timvannus.blogspot.nl/2015/09/herring-gull-ybaj-schiphol-airport.html)

French Wireless gull (Larus cyborgus) @ the Eirol landfill, Portugal (November 3, 2015)

Herring Gull YBAJ @ Schiphol airport. September 29 2015, 11:50 AM

Old Cormorant

Colour-ringed Great Cormorant Phalacrocorax carbo, roosting along the Ria de Aveiro, near Bunheiro (Portugal) on February 24, 2015. Ringed as nestling at Lac de Grand-Lieu (Loire Atlantique, France) on June 16, 1998, by Loïc Marion. This is the birds’ first sighting.

Eirol landfill, Portugal (January 12, 2015)

One of two adult Herring gulls Larus argentatus present at the site.




Herring gull number two.




Ringed Mediterranean gull Ichthyaetus melanocephalus, from Véron, les Prés Pendus, Yonne, FRANCE 48,07N 3,17E. One of two birds observed.




A Pied wagtail Motacilla alba yarrellii (top) and white wagtail M. a. alba (bottom).




The only signs of the young Peregrine falcon Falco peregrinus that resided at the landfill for some time (see previous posts) were 10 older remains of Black-headed Gulls Chroicocephalus ridibundus…

...and, remarkably, the remains of a 1st winter Lesser Black-backed Gull Larus fuscus. Not a common prey for a Peregrine.

A special guest at the landfill

On October 4th 2014, Paul Veron (http://guernseygulls.blogspot.pt/) joined Pedro Moreira and me on a ring-reading trip to the landfill of Eirol. Due to the surprisingly large number of gulls present at the site (15 – 30.000) a record amount of rings were read. More about this event can be found on Paul’s blog in some time from now. Among all these birds was a single Herring Gull Larus argentatus.

Gull-rings around Aveiro, Portugal (September 11, 2014)

Gulls arriving at the Eirol landfill. We managed to read 64 rings between 07:35 - 13:15, all on Lesser Black-backed Gulls. Roughly 6000 gulls were present at the site. Many birds left the site early, presumably due to the lack of garbage being delivered to the open dump.






Xavega fishery at Praia da Vagueira. 5 rings were read between 14:00 -15:15, all on Lesser Black-backed Gulls. 150 gulls were present, primarily LBBG.




Blue 23 at Praia da Vagueira, ringed in the southwest of The Netherlands.




Red VB1.T at Praia da Vagueira. Ringed at a landfill site in Greater London, UK.




Reading rings at Porto de Pesca, Gafanha da Nazaré. 8 rings were read there, 5 on LBBG, 3 on Yellow-legged Gulls. Gulls not counted.




White HC, from the southwest of The Netherlands (photo: Pedro Moreira).




Subadult Yellow-legged Gull R:R8T; ringed in France (photo: Pedro Moreira).

Gull rings & the Yellow-legged Gull (Larus michahellis) as probable breeder in Aveiro, Portugal

Yellow-legged Gull PFFF, ringed in Spain, observed at the Porto de pesca (photo: Pedro Moreira)

 
On August 28 Pedro Moreira and I went out to search for colour-ringed gulls in the area around Aveiro, Portugal. Our day started at the Eirol landfill, where usually good numbers of gulls are present, especially now that fall migration has started. However, the number of gulls there turned out to be a bit disappointing. We made a very rough estimation of about 3500 Lesser Black-backed, 150 Yellow-legged and 20 Black-headed Gulls; similar numbers as on our visit to the site of August 21. Unfortunately, most of these birds perched on the roofs of the buildings, making it difficult to read their rings. There were moments when the whole pit remained empty from gulls. Only 35 rings were read (fewer than last time). Around noon we decided to leave the place and find out where our birds had gone to.

An empty landfill

We passed by the beaches to see if bycatch from Xavega (the traditional fishing where the catch is landed on the beach, see Paul Veron's blog entry about this event: http://guernseygulls.blogspot.pt/2014/08/the-exodus-of-lbbgs.html) was attracting them. But as the waves were too high that day (as on the previous days), there were only few gulls present, all of which were flying over the ocean. Better luck we had at ‘Porto de Pesca’, the largest fishing harbour in the area. Roughly 1500 Lesser Black-backed Gulls were present there, allowing us to read 8 rings on those. Besides these Lesser Black-backed Gulls, about 400 Yellow-legged Gulls were present in the harbour. Of these at least 5 were ringed.

Lesser Black-backed Gull 'E4', at Porto de Pesca. Ringed in the SW of the Netherlands (photo: Pedro Moreira)

 

 

 

Yellow-legged Gull N:1NC, from Spain, observed at the Porto de Pesca (photo: Pedro Moreira)

Yellow-legged Gull 1Y5 at the Porto de Pesca; note the worn and open colour-ring, about to fall off (photo: Pedro Moreira)

Some of these Yellow-legged Gulls, all adult birds, have been seen at the harbour earlier this summer. Apparently the seaport to Aveiro is attractive for this species. With many expanding breeding populations in nearby areas (i.e. Porto), it would be just a matter of time before they start nesting here (assuming that they didn’t do this already). And indeed, we found information that by now Yellow-legged Gulls nest in the harbour!

While searching for rings we noticed two immature Yellow-legged Gulls begging at two adults, which were involved in some kind of social conflict with a third adult bird. With the appearance of our car, the adults started to alarm. Both chicks were able to fly properly and could be considered fledged.

Two begging Yellow-legged Gull chicks and their presumed parents (photo: Pedro Moreira)

Of course, observations of begging but fledged gull chicks are by no means good evidence that the chicks were born in the area, as they are capable of following their parents over long distances. However, our suspicion that these were in fact local birds gets supported by the following information I received from Pedro.

The same begging Yellow-legged Gull chicks and their presumed parents (involved in social interactions with a third bird)

On August 8 Pedro visited the harbour to read rings and talked there with a fisherman, very close to the particular location. He was told “You are late! You should have come earlier to see the nest!”. Apparently there had been a nest on the dock on a rolled up rope, containing three eggs. Out of these two chicks hatched. It was the first time the fishermen had seen it there. When Pedro approached the location of the nest he got dive-bombed by an adult Yellow-legged Gull. A bit further away he saw a young juvenile (about the same in size as the ones on the photos above). Then Pedro realized he had been dive-bombed at the same location earlier in the summer, on July 17. He never saw the nest but never looked for it either. At inspection of the location on August 28 we did not find any remains of any nest, but by that time it would have been washed away by the elements. It seems probable that the two chicks we observed belonged to this nest.

It would be interesting to see how in the future the migrant and wintering population of Lesser Black-backed Gulls in this part of the world is going to deal with an increasing Yellow-legged Gull population, since competition for food between the two species can be expected. If you happen to know more about nesting gulls in or near Aveiro (and this would not be the first nesting of the Yellow-legged in the area) I would be very interested in this information.

After this encounter, we headed to the Porto de Commercial, where during the high tide a large parking place gets used by the gulls as a roost. 2000 Lesser Black-backed, 500 Yellow-legged and one Greater Black-backed Gull were present. 8 rings were read.

Part of the large gull-roost at the Porto de Commercial, Aveiro

This number of gulls however did not explain where many of the gulls had gone to (we still had the impression we were missing many). It may be possible that some of the recently arrived Lesser Black-backed Gulls found a better place at the larger fishing harbours in i.e. Leixoeis or Figueira da Foz, where the larger fishing boats arrive, which are better at dealing with the waves.

Subadult Greater Black-backed Gull Larus marinus (photo: Pedro Moreira)

Year of the Sturnus vulgaris

One of the first two colour-ringed Common Starling Sturnus vulgaris today at the bird ringing station Hessenpoort, in Zwolle, The Netherlands. Ringed by Jan van Dijk.

In The Netherlands, Commong Starlings are rapidly declining. The reason for their decline is poorly understood. Sovon (Dutch Centre for Field Ornithology) and the Dutch branch of Bird Life, announced 2014 to be the “Year of the Starling”. These rings can be donated to ringers/starlings by the public: https://www.vogelbeschermingshop.nl/uitgelicht-natuurcadeau?product_id=827 They’re 8 Euro’s each, but should last a starling’s life time.

Gulls at the Eirol landfill, Aveiro (Portugal): March 11, 2014

On March 11 Pedro Moreira and I visited the Eirol landfill again. We searched for rings between 7:00 and around 14:30. The weather was great, no or hardly any clouds and a lot of sun, probably a bit too much for the time of the year. There were fewer gulls present; about 9.000 Lesser Black-backed Gulls, 1500 Black-headed Gulls, 40 Yellow-legged Gulls and two Mediterranean Gulls. Highlight of the day was a first observation of a Common Gull for the site. We managed to read the rings of 35 Lesser black-backed Gulls and 2 Black-headed Gulls.

 Common Gull Larus canus

Procambarus clarkii is a freshwater crayfish species, native to the Southeastern United States, but found also on other continents, where it is often an invasive species. In this area these tasty snacks are taken by White Storks and Lesser Black-backed Gulls in marshy areas. They can currently be found around the landfill in large numbers in the shape of regurgitations that were dropped there primarily by the gulls, I suspect. The number of storks is currently very low; we counted only one during this stay, though it might be possible that more storks visit the site at later times of the day. On the other hand, the recent floodings in the area might be very beneficial for the storks (as well as for Procambarus clarkii?) so there maybe is no need for them to come to the landfill. I hope that the people involved in this study: http://www.bto.org/science/migration/tracking-studies/stork-tracking/about are aware of relatively recent and increasing occurrence of Procambarus clarkii in the White Stork’s wintering areas.

Lost racing pigeon Columba livia forma domestica, with a ring we did not manage to read.

 Two photos of the first recorded Water pipit Anthus spinoletta for the Eirol landfill (thanks to Pedro).