Reservoir Ducks II

The two freshwater ponds at the University of Aveiro are currently packed with ducks, of which many are still undergoing their annual moult. Among about 360 Mallards (Anas platyrhynchos) at least 21 were carrying a nasal saddle, all of which could be read.




Also present were about nine Shovelers (Anas clypeata), one of which was marked. All of the marked ducks have previously been captured, marked and released at the Sao Jacinto dune reserve (David Rodrigues/www.pt-ducks.com).

As in the reserve, in these ponds the ducks should be relatively safe from hunting (the hunting season recently started, I believe starts September 6), but they’ll have to deal with regular disturbance by dogs and people (just as in the reserve..?).

A few photos from Austria: Graz & Vienna

I recently returned from eastern Austria, where I spent a few weeks in and around Graz, as well as a weekend in Vienna. The trip turned out to be more of the cultural type, largely due to a heat wave that coincided with my stay and resulted in record temperatures. This made it difficult to spend a lot of time outdoors.

Climbing the steps of the ‘Bärenschützklamm Gorge’ in Mixnitz (30 minutes from Graz by train). This monumental ravine has been made accessible to the public by a long series of wooden staircases. At the end cold beer is being served at the cozy ‘Almgasthof Zum Guten Hirten’. But then you'll still have to walk back.

 

With the beer came several Red Crossbills (Loxia curvirostra), here a female (I assume) (photo by Fabi).

Lurgrotte Peggau: Austria’s largest dripstone and water flowing cave. The temperature inside is a constant 10 C° and humidity 97-98%. Very nice! (photo by Fabi).

A view over Graz from the Schloßberg, a tree-clad hill in the city center and the site of a former fortress. On the right the Mur can be seen, a fast flowing river that runs through the city, providing some coolness to the scorching streets. Graz is surrounded by mountains, so there’s very little wind to provide some comfort there.

The Open Air Museum Stübing: in an idyllic setting you can find out about regionally typical ways of construction, tools and life in the old days. This saw mill runs on 100% carbon footprint neutral water power. What a great invention... (photo by Fabi).

A not so great invention...

Hooded crows (Corvus cornix) are common birds in this part of the world. They are very similar in morphology and habits to the Carrion Crow (Corvus corone). Hybridization is observed where their ranges overlap. Whether these are geographical races of one species, or whether they deserve a full species status, seems still to be subject to debate (https://whyevolutionistrue.wordpress.com/2014/07/24/a-tale-of-two-crows/).

I suspect eastern Austria makes up part of the hybridization zone, as both types of crows can be observed there, as well as hybrids between the two. In the two cities that were visited Hooded Crows however, were most abundant (like here in Vienna). Back in The Netherlands I’m used to seeing only a few of these Hooded Crows annually for the most, often during the colder winters. It was strange to observe them during a heat wave. Why they don't take their jackets off?

In Vienna, the ‘Naturhistorisches Museum’ (Museum of Natural History) is well worth a visit. Their extensive collection of rocks, stones and minerals is impressive. This is just one of several rooms entirely filled up with bizarre looking candy.

The museum’s bird collection is also interesting. However, these stuffed individuals did not make up for the rather disappointing number of species seen by me in and around the cities during my stay (only 41 species; was it really the heat?).

The São Jacinto pack

During the past years I had a few close encounters with the pack of stray dogs that roams the dunes of São Jacinto. The presence of these dogs is likely causing problems for local wildlife, but as a dog owner I’m biased and must admit I’ve gotten fascinated by them. Here are reports of some of those encounters.






September 4, 2012 - In summer, when the water level of the ponds is lowest, the pack hunts on moulting ducks (which at that time are unable to fly), as well as any nesting waterbirds. The ducks try to find a safe place at the deepest part of the pond. The second dog from the right is the suspected alpha female.




March 7, 2014 – A confrontation with the alpha female and two of her pups in the dunes.








January 23, 2015 – At the beach, where they find and eat whatever ends up on the tide line (in particular beached animals). I assume the first black individual is one of the pups seen in 2014. Whether the other two on the first photo originate from the same litter remains unknown. On the second photo the suspected alpha male and female.






July 14, 2015 – The family patrols the pond again. A life any short-living Portuguese asylum dog would dream of? In the front the alpha male and female, in the back at least one of the youngest generation.

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.

Torreira - Sao Jacinto beached bird and mammal transect (February 25, 2015)

Striped dolphin Stenella coeruleoalba # 1 No, a Common dolphin Delphinus delphis




Tail entangled?




Striped dolphin Stenella coeruleoalba #2 No, scientists are still trying to ID this one...




Tail cut off? Carcasses were reported to CRAMQ, who picked them up this morning for investigation. Unfortunate for the Greater Black-backed gulls which had found them first.




Yet another domesticated animal on the transect, a dog.

Finally!! A glass float! With original Japanese oysters attached to it!?

Two rare gulls for Portugal

Iceland gull Larus glaucoides, second winter. Still residing near Murtosa today. I was informed it’s the American subspecies L. g. kumlieni, and it’s the second winter the bird appears at the cow dung rich meadow.




Caspian gull Larus cachinnans, first winter. Seen on two dates in January in the Aveiro region. Possibly the first record of this species for that area. Found by Pedro Moreira.

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.