Gull tracking on the news (2) !

José Manuel Igual speaks about the Yellow-Legged Gull study at Dragonera Natural Park to the "Mallorca Zeitung" (text in German).

Gull tracking on the news!

Photo: G. Tavecchia

GSM/GPS data are generating a growing interest in gulls' feeding strategy. A new article by E. Soto in the newspaper El Mundo (here) has just been published on the monitoring of Yellow-legged Gulls at Dragonera. Long-distance tracks and daily feeding strategies are on the spot. Thank also to the help of T. Muñoz from the GOB (Grup Balear d'Ornitologia I Defensa de la Naturalesa)

The mistery of the route to the Cantabric Sea solved!

Tracking data offered a first breakthrough to solve the mystery of the route to the Cantabric Sea.   
Yellow-legged gulls from the Balearic islands have been regularly seen in the Cantabric coast, but the route to Northern Spain was a mystery. Do they fly around the Iberian peninsula or throught the Ebro valley ? Do they use the Ebro river as a landmark? Do they reach the Cantabric sea from France? 
Last year preliminary data provided a first piece of the puzzle when a gull moved North following the Ebro river to Zaragoza. However the radio failed at the end of the summer and the route to the Cantabric sea along the Ebro river was not proved. This summer tracking data deliver the solution to the mystery, showing what is likely to be the main route to the Cantabric Sea: the Ebro valley. Interestingly, the route seems to pass north of the river and through the Basque Mountains at Estella. To be continued....

Yellow Legged Gulls: new tracks !

A Yellow Legged gull marked as a breeder in Dragonera Island (Balearic archipelago) moved North to Barcelona. It continued the journey to Narbonne. Will it move up the Canal Du Midi or move to Camargue ? Place your bet.

To be continued....

Yellow Legged Gull campaign on the starting blocks

The Yellow Legged Gull 2017 campaign at Dragonera Naural Park is on the starting blocks. We have received two nice pics from C. Loske of a newly marked gull (top) and an old one (bottom), respectively. Thank you Carl !

Gull Shopping

Photo: Björn Marten Philipps

Björn Marten Philipps from the Wadden Sea Conservation Station was visiting Palma when bumped into our GSM/GPS equipped gull shopping and scavenging at the Mercat de l'Olivar. 

Thank you very much for the picture, Björn! 

Summering in Eastern Spain

The three Yellow Legged Gulls equipped with GPS-GSM in Mallorca at the beginning of this summer decided to spend the summer in different places. As many tourists, however, they chose to spend the summer in North-Eastern Spain. One (green cyrcle) moved up to Zaragoza, a second one stayed in Mallorca (blue cyrcle) and a third spent the summer near Barcelona (red cyrcle). 

Soon will be time to decide where to spend the winter ..?! 

First long tracks from Dragonera

The GSM/GPS devices are sending interesting information on bird movements. Marked gulls seem to have moved their core area northward, between the delta of the river Llobregat and the landfill, north of Barcelona city.

The YLG 2016 campaign ended !

Photo: J. Bos

The 2016 Yellow-legged gull campaign at Dragonera Natural Park ended after a survey, egg measuring, birds' trapping and marking.
  

Photo G. Tavecchia:  A gull equipped with a GSM/GPS device

Thanks to T. Muñoz, of the G.O.B., who helped us to equip four birds with a GSM/GPS device to investigate their feeding strategy.

Photo J. Bos.

Photo J. Bos: A gull defending its nest

  

Gulls use to attack intruders, especially near the hatching period. It is a good occasion to make some pictures and read the ring. 

Can you read the ring code?

Photo J. Bos: Gulls behind a trawler

Stage at the G.E.P.

Julia Bos joined the GEP for her Erasmus+  stage.  She will be investigating the within-colony differences in egg volume, clutch size, movements and spatial structure of the Yellow Legged Gull at Dragonera Island. Welcome Julia.

YLG 2016 campaign just started !

Photo F.Pezzo

The 2016 Yellow Legged Gull campaign has just started at Dragonera island. 
Birds are building their nests while few are already incubating. A good moment to read rings.

YLG 2015 campaign ended today

 

The Yellow Legged gull campaign ended today with twenty-seven gulls marked, two surveys and eighty clutches measured along the path to the Llebeig lighthouse. Thank to everyone who helped. Eleanor Falcons have just arrived, time for us to go. 

See you next year!

Yellow-legged gull campaign on the blocks!

The 2015 campaign on Yellow-legged gull at Dragonera Natural Park is on the blocks.   First visits for some digit-scoping in search of marked  birds.

New publication on seabirds !

Steigerwald, E., Igual, J.-M., Payo-Payo, A., and Tavecchia G. Effects of decreased anthropogenic food availability on an opportunistic gull: evidence for a size-mediated response in breeding females Ibis in press

Photo: G. Tavecchia

Some opportunistic vertebrates exploit, and may largely rely upon, food generated by human activities. Better understanding the influence of this additional anthropogenic food on species’ ecology would inform sustainable waste management. In the Balearic Archipelago of Spain, closure of an open-air landfill site provided an experimental setting to measure the effect of removing anthropogenic food on the average body mass, breeding parameters and body condition of opportunistic Yellow-legged Gulls Larus michahellis. After landfill closure there was a significant decline in the average body mass of breeding females and males (-10.4% and -7.8%, respectively), in average egg volume (-4.8%), and a shift in the modal clutch size from 3 to 2 eggs. Body condition decreased after landfill closure in both sexes. In breeding females, the drop in body weight was greater for birds with a low body size index. The differential response to a reduction of anthropogenic food between small and large birds suggests that food of anthropogenic origin contributes to temper the effects of natural selection, making the long-term demographic effects of changes in food supply difficult to predict.

Caught on camera in Portugal!

Pedro Moreira and António Martins sent us this picture taken in Portugal.
The bird has been ringed by us in Mallorca in 2010 as a breeder, but apparently she prefers the Portuguese shores. Thank you very much Pedro and António. Nice pic!

If you have more of gulls ringed with an orange PVC ring and black alphanumeric code, send it to us (or if you have it, use the app seabirdstagram)