May 19, 2012: Danger! High voltage (and many White Storks Ciconia ciconia)

Just west of Coimbra (Portugal) we ran into a remarkable White Stork colony. As far as we could see from our location there were about 10 of these pylons being completely overtaken by nesting storks. (Thanks to Toni!)

Lesser Black-backed Gulls (Larus fuscus) foraging on estuarine macrozoobenthic prey?

Gulls, in particular Lesser Black-backed gulls, are opportunistic omnivores, but, as visible here in Portugal, their main diet is either marine based (in particular fish) or whatever is available to them at the landfills. Throughout the winter on a daily basis I could observe that, at least around Aveiro, a few thousand gulls (primarily Lesser Black-backed -, fewer Black-headed - and some Yellow-legged Gulls) were foraging on the mudflats and inactive saltpans.

By now, most of the gulls have migrated back to their breeding grounds further to the north, but there are still a few hundred actively searching for food. I suspect that a majority of the gulls here has a strong relationship with the landfill; at least most of the rings that were read here were also seen at Taboeira.

The birds show a preference for areas that were covered with a layer of algae and it seems that the prey that they take occurs either in or directly under this layer.

I’ve seen them share the same foraging areas with Black-tailed Godwits (Limosa limosa) which at first sight appeared to be after the same type of prey that lives in or under the algae. It remains unknown to me what exactly these gulls are foraging on; maybe one of the information panels at the saltpans provides us with the answer?

Nasal saddles on ducks with David Rodrigues, Sao Jacinto, March 18 & 19, 2012

During these two days we conducted the season’s last catches and resightings in the ponds of Sao Jacinto. The weather was nice, the birds were singing and it seems that spring has been here for a while now. Most of the ducks have left the area by now and, if not shot, are on their way to their breeding grounds further to the north. When observers report these saddled ducks and the unique inscription they carry to David Rodriques, information can be retrieved on the species’ migration routes. These reports are also of help to estimate the species’ mortality.

There were still a few hundred ducks remaining, primarily Green-winged Teals, Shovelers, Mallards and Wigeons. As expected the total number of captures was low and included only 9 mallards (of which 6 were recaptures) and 2 Green-winged teals (both recaptures), meaning that after measuring and providing saddles and rings to 3 male mallards we were done and could continue to record the remaining marked birds that were present in the ponds.

Catch of the day...

The jewelry that we gave ‘m…

make it easy to record the presence of individual birds...

Unless they are sleeping.

Thankfully a goshawk made its appearance again and it caused enough disturbance to keep the ducks awake, and allow us to read pretty much all the saddled ducks that were present.

We observed this immature female making several spectacular attempts to catch a prey, but all of which were unsuccessful.

The Shovelers were ‘shoveling’…

The Little Grebes that are resident to the ponds at Sao Jacinto usually are too busy to strike a pose for the camera. This little puffball could not resist taking a little nap under the intense spring sun; only for a few seconds though, and than back to courtship and avoiding the goshawk.

More information about this project: http://www.pt-ducks.com/

Gaivotas in the mist (Taboeira landfill, March 14, 2012)

In order to read a reasonable amount of rings at the Taboeira landfill, I realized I had to get up early and be there before the kites became active and flush all the gulls. So, that’s what I did today; arriving at 6:55, even before the gulls were present at the site, and reading rings until 10:08, when the first kites flushed the birds and made further ring-reading impossible. 15 rings were read, of which 11 from Britain, 2 from Belgium, 1 from France and 1from The Netherlands. There were about 10.000 Lesser Black-backed Gulls present and the number of ring-readings could have been slightly higher if there wouldn’t have been a heavy fog present for the first two hours of observations, reducing visibility to about 50 meters.

Behind this cloud there should be a LBBG WHITE G+Y, RED inscription visible, from the hands of Peter Rock (Britain)

Taboeira landfill, March 7, 2012

Today I visited Taboeira again to see which of the known landfill gulls are still there and which new ones have appeared. By now, many of the Lesser Black-backed Gulls I resighted there this winter have made their way back to their breeding areas in NW-Europe. There are still a lot of birds present but the conditions to read off colour-rings are not getting any better; the Black Kites are getting more and more abundant and these repeatedly flush the gulls. The visit resulted in only 5 colour-ring readings; 3 Lesser Black-backed and 2 Black-headed Gulls. A record low for the location.

The birds only made a few 'touch downs' in the active dump site and refused to sit on the slopes almost completely.

The bigger dots are Black Kites; the smaller ones are gulls which are too afraid to come down. The number of kites increases during the day. As I left early today I only counted about 25 kites; employees informed me they observed about 50 kites yesterday. It seems they are still increasing...

Nasal saddles on ducks with David Rodrigues, Sao Jacinto, March 5 & 6, 2012

David Rodrigues invited me for another two days of duck catching and marking at Sao Jacinto. There were plenty of ducks in the ponds so, although the captures have been relatively low lately, I still had some expectations...

Highlights were at least one Gargany...

and a probable hybrid Green-winged Teal x American Green-winged Teal.

The catch of the day... a bit disappointing; if I remember correctly we managed to trap 11 Mallards, 3 Shovelers and 4 Green-winged Teals. All off the teals were recaptures; quite a contrast with my last visit in February, when we trapped and marked a record amount of 81 new teals and a handful of recaptures.

Female Shoveler

Beak of a male Shoveler.

Not the Blue-winged Teal, but the wing of a male Shoveler.

Yo!; a very heavy Mallard male.

The large number of waterfowl attracted the attention of two immature female Goshawks.

To make up for the disappointing captures we could enjoy quite a spectacular show...

Nasal saddles on ducks with David Rodrigues, Sao Jacinto, February 13 & 14, 2012

David Rodrigues traps ducks near the coast in Sao Jacinto and provides them with marked nasal-saddles. After I read off several of these saddles on Tufted Ducks and Mallards in several ponds near the University of Aveiro, David invited me to assist for two days in the catching and marking.

The ponds were absolutely packed with waterfowl; many of the birds were already wearing saddles, so we spent a few hours of resighting.

Catch of the day... (well, part of it)

 

We managed to catch and mark > 80 Green-winged Teals (which was a record, I believe) and fewer Mallards and Tufted Ducks. More on: http://www.pt-ducks.com/nasalsaddles.htm