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..?).

Reservoir ducks, cormorants and a daytime bat in Matsuyama, Japan

On December 2 a few freshwater reservoirs on a hill a few kilometers north of our place in Matsuyama were visited, in the hopes of finding some new duck species. The first bird to get my attention there was an adult Cormorant (the bird on the left of the two above) that managed to catch a big Pumpkinseed (Lepomis gibbosus), a North American freshwater fish. I’m not sure whether this is a Temminck’s or a Great Cormorant Phalacrocorax capillatus/P. carbo. Its white facial patch is not as pronounced as I’d expect from a Temminck’s. The bird on the right is an immature Temminck’s.












While scoping out the cormorants’ successful catch, there was a bat foraging above the same pond. For about half an hour it appeared to be catching prey from the water surface, possibly with its hind legs, as the third photo shows. In between foraging flights it regularly perched against the side of a concrete wall adjacent to the water.










There were plenty of ducks present at two of the four reservoirs. Besides 17 Eurasian Teals Anas crecca and a single Mallard Anas platyrhynchos, I recorded 11 Common Pochards Aythya ferina, 17 Tufted Ducks Aythya fuligula, 30 Northern Shovelers Anas clypeata and (the highlight of my visit) a single Mandarin Duck Aix galericulata male.














Red-eared slider Trachemys scripta elegans. Native to the southern United States and northern Mexico, but also present in impressive numbers in all freshwaters I’ve seen in Japan thus far.




My borrowed bike.

Rain, ducks & other matters at the São Jacinto reserve (October 1 - 4)

This four-day stay at the Sao Jacinto reserve included two days of duck captures. However, only on our second day of trapping did we manage to catch some ducks, as with our first attempt our traps remained empty. This was possibly caused by recent disturbance of an unknown kind near our catching site. With fall migration on its way, the diversity in the duck species is increasing rapidly. Besides the usual Mallards, there is now a good number of Eurasian Teals present, as well Eurasian Wigeons and about a dozen Shovelers and Gadwalls. In the end we managed to catch and mark a reasonable number of Mallards and four teals, of which two teals were actively moulting primaries in our pond. And as autumn has arrived we also received A LOT of rain, raising the water level at the pond with several centimeters during our stay. On the fourth and final day we got some attention from national media. Two reporters from SIC television visited us for a news report about the duck work in Sao Jacinto. In the morning their visit got delayed due to massive rainfall, but in the end it all worked out it seemed and we could proudly present some of our captures on national televion. The item got aired on October 12 but can still be viewed here:

http://sicnoticias.sapo.pt/pais/2013/10/12/mais-de-20-mil-aves-foram-marcadas-nos-ultimos-20-anos-em-portugal

Northern Shoveler Anas clypeata

 

One of the 14 Gadwalls Anas strepera that were present had been marked a few years earlier.

My favorite Eurasian Teal V/Y/V appeared again for the first time after being away for the entire summer. One of six marked teals that we resighted.

São Jacinto ducks: February 6 – 8

During these three days I assisted David Rodrigues (http://www.pt-ducks.com ) again in trapping and marking “patos” at the São Jacinto duck pond. Our captures were reasonable, at least in my opinion, with about 40 or so new Common Teals Anas crecca in our traps, as well as a few recaptures. Additionally, two Little Grebes Tachybaptus ruficollis and two Common Moorhens Gallinula chloropus ended up in our traps, of which only one Moorhen carried a ring. Considering the number of Little Grebes and – Moorhens that have been ringed at the pond during the last months, it was a bit surprising we only got only one recapture among these four birds. I suspect that most of our previously ringed birds were migrants and these are now elsewhere (although some Moorhens may have ended up as Common Genet Genetta genetta food it seemed)  

Most of the Mallards have dispersed by now, which considerably reduced the amount of time we needed to spend on our captures. This gave us to opportunity to clear up the trails from numerous fallen trees and other storm damage. I also trimmed some Acacia longifolia, a fast growing invasive, which after a recent forest fire has almost completely taken over the reserve (https://estudogeral.sib.uc.pt/bitstream/10316/18181/1/HeliaMarchante%20PhD%20thesis.pdf).  Its flowers are very nice, however… 

Although there was not much diversity in our captures, the number of duck species present at the pond was large; especially Eurasian Wigeons Anas penelope and Gadwalls Anas strepera are abundant at the moment, but we also observed an interesting number of Northern Shovelers Anas clypeata, as well as a few Tufted Ducks Aythya fuligula. Unfortunately, none of these ended up in our traps.

A marked Tufted Duck on the left and on the right my first observed marked Gadwall.

 

Eurasian Coots Fulica atra are common in São Jacinto’s ponds and nest there. David informed me their first clutch usually is succesful, but later layers will face low water levels and eventually the stray dogs.