Monday, July 11, 2016

Kelp Gull in the Algarve today

Kelp Gull (Larus domincanus) is a southern hemisphere gull and breeds during the north winter, coastal mostly, in Southern Africa, South America, Antarctica, South Australia and New Zealand. It is a very rare vagrant to the Western Palearctic (Morocco mainly).
This bird here was found by Thijs Falkenburg on July, 5th in Olhão ("Quinta do Marim"). It belongs to the subspecies L.d. vetula ("Cape Gull") which breeds in Southern Africa. Cape Gulls are the largest among this species and they are particularly long-legged like this bird. Also the olive-green tinge to the leggs is typical, the crown is flat and the bill is heavy with a deep gonys angle, all together being jizz-wise much closer to a Greater black-backed Gull (Larus marinus) than to the also very dark-backed nominate form of Lesser-black-backed Gull (Larus fuscus fuscus), especially when dealing with an adult male, like in this case. An (older) article on Kelp Gull ID is here.
A curiosity is, that Thijs also found the first Kelp Gull for the Algarve (on 14-Aug-2013) only a few kms further west, at sewage works (ETAR) between Faro and Olhão (possibly the same bird?). Now this time this Kelp Gull showed up right at his work place, the recovery centre for injured birds and other wildlife (RIAS) in "Quinta do Marim", Olhão, sitting upon the cages containing chicks of Yellow-legged Gulls (Larus michahellis) and showing up there daily since about one week now. This is where I took these photos this morning (11-July-2016). So far this bird is the 5th record for Portugal.

Wednesday, July 6, 2016

Pelagic off Olhão

(all photos are clickable to enhance)
Yesterday morning, 5th of July, we went out on a boat with Passeios Ria Formosa (Fuzeta), this time departing from next to the Real Marina Hotel in Olhão and headed for the waters off Culatra Island. There was an overcast in the beginning, therefore not a hot morning, calm sea and hardly any noticeable wind. The light improved along the trip. Despite not getting any fishing vessel within reachable distance, it turned out to be a very successful trip.

Great Shearwater (Ardenna gravis) with Cory's Shearwaters (Calonectris borealis) off Culatra Island, 05-Jul-2016.

For more than one hour we were basically surrounded by a huge pod of over 100 Short-beaked Common Dolphins (Delphinus delphis) and also well over 100 Cory's Shearwaters (Calonectris borealis) among which we coud also identify and photograph at least three Scopoli's Shearwaters (Calonectris diomedea) a species (or still a subspecies, depending on systematic - but have a look here). There are only a hand full of records of this taxon in the Algarve so far anyhow and as far as I know none of them documented by photos. On the other hand, Scopoli's mainly breeds in the Mediterranean and winters in the South Atlantic, so occurance in Algarvian waters during non-breeding season at least makes sense. Identification in the field is often not straight forward (good views or better, photos of the underwing neccessary) and therefore the few Scopoli's among the majority of Cory's go easily unidentified.

Scopoli's Shearwater (Calonectris diomedea) off Culatra Island (Olhão) 05-Jul-2016. Note 
the white extending into the wing tip (web of primaries).

After searching for quite a while, we also spotted two Sooty Shearwaters (Ardenna griseus) and finally a single Great Shearwater (Ardenna gravis) - both giving great and close views and this is only the very beginning of the season for both species.

Great Shearwater (Ardenna gravis) with Cory's Shearwater (Calonectris borealis) in the background.
Off Culatra Island, 05-Jul-2016.

Cory's Shearwater (Calonectris borealis). Off Culatra Island, 05-Jul-2016.

We also encountered Storm Petrels, among them Wilson's SP and European SP - perhaps three or four Ind. of each species, but did not get the best views, because without the birds foraging (next to a fishing boat pulling in the net, for instance) but only travelling, even photographing them is not an easy task. However, we managed at least record shots and thought to have found also one "Band-rumped Storm Petrel". The now potentially 4 species in this species-complex (compare Robb et al., 2008) were previously all lumped as Madeiran Storm Petrel (Oceanodroma castro or Hydrobates castro). Systematic here is not uniform and field-ID within the "Band-rumped SP -complex" is very difficult if not impossible, but have a look  here). Interesting is that also the recently published "Atlas of Marine birds in Portugal" (in Portuguese) shows the occurence of this species in Algarvian waters.
However, after reviewing the ID and getting expert opinions, it turned out to be "just" a Wilson's SP flying with feet retracted and therefore completely lacking feet projection over the tail, one of the most usefull fetaures to ID Wilson's in the field. The Storm Petrel in question also shows a too short arm and too weak bill to be a possible "Band-rumped". We will keep looking....

Wilson's Storm Petrel (Oceanites oceanicus) off Culatra Island (Olhão) 05-Jul-2016.

The following five photos show a potential "Band-rumped Storm Petrel" we saw during the trip. But for the reasons explained above, it turned out to be another Wilson's Storm Petrel in the end.

Expert opinion on the above Storm Petrel by Bob Flood is here:

In my opinion, this is a Wilson's Storm-petrel. It has a small squarish head and slim bill (Band-rumped has bulkier head and deeper bill, even the smaller forms). The arms are short and broad, hands medium length, and wing tips pointed (Band-rumps have medium-length arms, long hands, while some forms do have fairly pointed wing tips). The leading edge of the wing is moderately angular, but the trailing edge is fairly straight in most shots (typically angular in Band-rumps). I don't think the tail is really forked; this may be an impression given by a toe projection. It has a long caudal projection (rear carriage behind wing, longer than Band-rumps). The head, body and tail are fairly sleek (unlike Band-rumps). The white 'rump patch' folds over to the underside and joins the thigh patches (depth greater than N Atlantic Band-rumps). The upperwing ulnar bars are variable in intensity in Wilson's and we see quite a few with dullish bars, as this bird (affected by wear and bleaching). Second-year and older Wilson's start moult by early June, but juveniles do not start the complete preformative moult until at least mid July, most later, so presumably this is a juvenile (plumage looks pretty fresh). By the way, it always helps if you describe flight behaviour, because this can be very important in storm-petrel ID.
Hope this is of use.

Robert L. Flood DSc, PhD, BSc (1st Hons)
Twitter: @Scillypelagics

Naturally we saw many Northern Gannets and also had one immature Pomarine Skua (Stercorarius pomarinus) flying over.

New dates for Pelagics have been scheduled on my website here. Available dates are: July, 22nd; August, 2nd; August 12th; August 25th; September 6th; September 30th; October, 13th. We can organize a pelagic at any time between June and October/November when the participation of min. 4 people is assured.

 Pomarine Skua (Stercorarius pomarinus) pale morph juvenile flying over. C. 3 miles off Culatra Island, 5th of July 2016.

Fresh juvenile Audouin's Gull (Ichthyaetus audouinii) in Ria Formosa, next to Olhão on the way back in. In the background: Caspian Tern, Sandwich Terns and an adult Yellow-legged Gull. July, 5th, 2016.

Fresh juvenile Audouin's Gull (Ichthyaetus audouinii) in Ria Formosa, next to Olhão on the way back in. In the background: Caspian Tern, Sandwich Terns and an adult Yellow-legged Gull. July, 5th, 2016.

And the Caspian Tern (Hydroprogne caspia) turned out to be color-ringed. Red: FY2. Still looking for the program...