On February 23 there was a 1st winter Glaucous gull (Larus hyperboreus), In Peniche. There was also another bird, 3rd winter, presumably the same bird previously discovered. It can be seen here: http://www.heldercardoso.com/english-version/category/glaucous-gull
On February 22, 2019, I found a possible Azorean Yellow-legged Gull in Peniche (west mainland Portugal). This subspecies is characterized by a well defined hood. Judging by the color of the bill and a slight brownish hue on the coverts, I would say the bird is in its third winter (4th calendar year).
The bird did not allow good photos, particularly in flight, however, here are some photos with some notes
This record will be submitted to the Portuguese Rarities Committee.
On November 20, 2005, after a bird ringing session in Paul de Tornada, Pedro Henriques and myself, decided to go to the Bay of S. Martinho do Porto (west Portugal), to take a look at the gulls. It was especially interesting because Common gulls (Larus canus) (uncomon in Portugal) and Ring-billed Gulls (Larus delawarensis) were relatively regular at this site during the winter. Sometimes 4 or 5 inds. of each species, simultaneously.
Soon as we arrived, we noticed a striking first winter Franklin´s gull (Leucophaeus pipixcan) among Black-headed gulls and a Ring-billed gull. I was still recoverying from finding a Laughphing gull, two weeks before in Peniche.
13 years ago I had a Canon analogic camera with a 70-300 lens, to update my ebird I just scanned the printed photographs, and here they are:
Some images of the Caspian Gull (Larus cachinnans) that appeared yesterday (16th February 2019) at the mouth of the São Domingos stream (Peniche). The bird was ringed yellow (P:U07) and information was already sent to the project in Poland.
At the beginning of February 2019, in one of my regular incursions to the Óbidos Lagoon, I found two Greenshanks (Tringa nebularia). The birds were relatively close, feeding on the edge of the pond. I took some photos with the purpose of practicing ageing Greenshanks, at a time of the year when it is more difficult.
I have always found, with some exceptions, relatively hard to age waders. The great variability in feather patterns and the intensity and extent of moult, makes some plumages difficult to interpret.
Summary of the moult in Greenshanks:
Post-nuptial - Complete. A part of the individuals begins primary moult still in the breeding grounds and suspends it during migration, resuming it in the wintering areas. Others begin primary moult already in the wintering areas.
Pre-nuptial - Partial. Variable, but usually includes replacing body feathers, some coverts and tertials.
Post-juvenile - Partial. Includes a variable number of coverts, body and tail feathers.
Pre-nuptial - Partial. Variable, but, as in adults, it can include multiple coverts, tail feathers and tertials. Some birds can moult outer primaries (Prater, et all, 1977).
The separation of 1st winters from adults, in autumn, is relatively easy. One of the most mentioned characters in the literature is the shape of the median coverts. Where the typical median covert has a clear pale fringe, interrupted at the tip by a brown split (Fig. 2). The bird in Fig. 1 is a 1st winter that has undergone a post-juvenile molt restricted to the scapulars, and most likely, during autumn, will replace a variable number of lesser, median and greater coverts. The tertials are juvenile, told by the brownish coloration and weak pattern, but some individuals can present gray tertials with a more defined pattern.
At the beginning of the winter, juveniles have already renovated a good part of the coverts during their partial post-juvenile moult, resembling adult plumage. Knowing that adults undergo a complete post-nuptial moult, to identify immature birds one must look for juvenile feathers that remain unmoulted. This task is increasingly complicated as winter progresses, mainly because feather wear tend to blur significant differences in plumage patterns.
One factor to take into account is the inferior quality of juvenile feathers, that lead to a slightly more pronounced wear than in adults. This wear is particularly evidenced by the coloration. For example, lesser and median coverts tend to be browner in immature birds than in adults.
Another feature that can help separating age groups at the end of winter is the wear, shape and coloring of primaries and secondaries. In my opinion, this is one of the most reliable characters, since it is less subject to variability than the coverts. Given the Greenshank moult pattern, immature should keep juvenile primaries, sometimes until the next complet moult (August-October). Some caution is needed during spring, as there seem to be some immature birds that renew the outer primaries, which would result in birds presenting the tip of the primaries "fresh", when observed in the field. In this case, a photograph with an open wing is required to see the moult limit, between the outer primaries (adult type) and the inner primaries (juvenile).
The two birds, I observed in Lagoa de Óbidos, showed a slightly different coloration of the upper parts. The bird 1 (front in the photo), presented grayer shades in most coverts, I classified this bird as adult. The bird 2 (back in the photo) had some brown coverts, as well as flight feathers, a little more worn, I classified this bird as immature (2nd calendar year).
In this photo we can see the head pattern, which is slightly different in the two birds. Bird 1 (front in the photo) features a whiter throat and bold gray stripes on the side of the neck . On bird 2 (back in the photo) the stipped pattern on the neck is thinner and less defined, creating a less "clean" appearance of the head and neck.
Bird 1 (front in the photo), also has two tertials, in the left wing, very "fresh" and gray. I am not sure if they were renewed in a late post-nuptial moult or in the pre-nuptial moult. Therefore, it is quite possible that the bird is in active moult of coverts and / or body feathers.
Bird 1 - Flight feathers with little wear, presenting a well defined white edge in secondaries and inner primaries. The upper parts have a greater uniformity of coloration, with the lesser and median coverts dark gray.
Bird 2 - Primaries and secondaries with some wear, showing a weak white trailing edge. The upper parts have areas with light brown coverts, particularly in lesser and median coverts. Note the innermost great covert of the right wing, showing a good amount of wear.
Comparison of the shape and level of wear on the primaries and secondaries. (Bird 2 - left, Bird 1 - right). Note the broader upper edge of the flight feathers on bird 2, creating a more "blunt" tip, characteristic of juvenile feathers.
The wear and pattern of the tail feathers, in particular of R1 and R5, has been mention out as a way to separate juveniles and adults. I believe it may work in some inds., although In the case of these two birds, from what I could perceive in the field and in the photos, it seems to me that both replaced the tail feathers, making it useless as an ageing criteria.
Ageing Greenshanks in late winter, or early spring, can be a tricky task. The extent of post-juvenile moult can lead to some individuals getting plumages very much like adults. So when we come across a Greenshank we should take into account the following:
- Check if there are any median coverts with the typical juvenile pattern;
- See if different generations of feathers occur in the coverts, in particular, if there are brownish feathers and with enough wear on the upper parts. There must be some caution because adults, at the end of winter, can also exhibit different generations of feathers, as a result of partial pre-breeding moult. Immatures will show old brownish feathers, not gray;
- Observe the wear on the primaries, if it has wear, the bird should be an immature;
- In the literature it is mentioned that some immature birds can moult the outer primaries in the pre-nuptial moult. I do not know exactly how much this happens in the populations that winter or migrate through Portugal. So, if a bird in late winter, or early spring, displaying "fresh" primaries tip may be an immature one. In this case, it is necessary to check for juvenile coverts or, if an open wing photo is obtained, if there are moult limits on the inner primaries.
- If you get an open wing photo, we can also observe the shape of the primaries and secondaries, which apparently seems to be different in adults and immature birds (I need to test this theory better);
- To verify the wear of the tail feathers, some juveniles seem to retain some tail feathers in the post-juvenile molt.
To Peter Potts, Pedro Lourenço and Leila Durte.
Demongin, L. 2016. Identification guide to birds in the hand. Laurent Demongin (privatly publish)
Message, S. and Taylor, D. 2005. Field Guide to the Waders of Europe, Asia and North America. Christopher Helm, London.
Meissner, W. 2008. Ageing and sexing series. Part 3: Ageing and sexing the Common Greenshank Tringa nebularia. Wader Study Group Bull. 115(3): 182–184.
Prater, A.J., Marchant, J.H. & Vuorinen, J. 1977. Guide to the Identification and Ageing of Holarctic Waders. BTO Tring.
On the morning of February 1st 2019 mainland Portugal was beginning to feel the effects of the depression "Helena". The day broke with showers and moderate SW wind. I decided to go to Peniche, one of my local patches, to take a look at seabird movement and check the gulls. To my pleasant surprise there was a Glaucous gull (Larus hyperboreus) resting among a group of Lesser black-backed gulls (Larus fuscus) and Yellow-legged Gulls (Larus michahellis), at the mouth of the Saint Domingos river.
Although I have observed this species several times in the past, particularly during the winter influx of 2013/2014, I had never observed this plumage. The bird, at first sight (and light conditions), had an adult appearance with a gray mantle and light iris, but with an immature bill. The bird was kind and allowed me to spend some time studying and photographing the plumage details.
The bird had a pale pink yellow bill, with a dark, relatively well-marked, subterminal stripe. The tip was ivory. The legs were pink, more intense than the beak. The iris was pale olive and had a dark pre-ocular mark. Note the pale brown infusions on the side of the chest, extending to the nape.
The third left tail feather (R3) presented a slight brown infusion along the shaft.
The coloration of the primaries begins to approach the adult pattern, however, it presents with a less obvious division between the white of the feather tip and the interior.
A good portion of the innermost greater and median coverts, as well as the tertials, were white.
In flight we can observe the marbled pattern formed by the contrast between the white and buffish coverts and the gray.
The underwing coverts presented creamy tones in the median and lesser coverts, forming a slight brownish bar, which contrasted with the white axillaries.
He began birding at the age of 11 and has never stopped since. His involvement in bird ringing has developed over the years and he has a special interest in moult in passerines. He currently works as a bird guide in Portugal and Spain and is an environmental consultant.
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