13/07/2006
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Focus On: seawatching

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The seawatching season is here again, with birds such as Cory's Shearwaters and Wilson's Storm-petrels already beginning to show up. I find it useful to start "revising for the exams" to ensure that I'm prepared for my forthcoming encounters with those seabirds that have been absent since last autumn. Every year it's the same scenario. We are all a tad rusty when it comes to seasonal birding and we need to re-familiarize ourselves with the birds we see on an annual, rather than daily, basis. So, I felt it a good idea to put down on 'paper' all the common, and not so common, species and the tricks to picking them up and separating them. For some, it will be a first introduction to seawatching, to others it will be a tool for revision and, for others still, a journey into the realm of nostalgia.

Shearwaters

The shearwaters are usually the most obvious, and exert the most presence, on any seawatch in July or August. By far the commonest in Irish and British waters is the Manx Shearwater. "Manxies" move in large numbers by late July and August and it is easy to train your eye on this species at most headlands in the south or west of Ireland. Depending on the lighting they can appear warm brown to a crisp black and white but on a seawatch with typical and desired weather of wind and drizzle they will appear black and white. Depending on numbers they can move in constant lines of birds moving in the same direction, or short "spurts" of birds brought in by squalls.


Manx Shearwater: A classic close "cold" light view with good contrast between the black upperparts and white underparts. Note the white spur behind the ear, black face and long sharp wings with thick black trailing edge. The level of dark marking on the underwings is variable but usually present to some degree (photo: Steve Round).


Manx Shearwater: A more distant view; often Manx Shearwaters present themselves at an angle as they arc. The wings often seem to taper into the flimsy pointed shape above (photo: Nicola Breaks).


Manx Shearwater: A "warmer" view of a Manx in stronger sunlight. The upperparts begin to appear brownish. Note the white spur behind the ear is still visible and the underparts are pure white. At times, when strongly backlit and at a distance, these features can be "burnt out", and potentially confusable with Balearic Shearwater (photo: John Molloy).

Manx Shearwaters can be quite variable depending upon the lighting conditions, and flight conditions, on any given day. In very strong sunlight, and when backlit, Manx Shearwaters can appear very brown and the underparts may not seem as white. However the undertail coverts should still seem white and the most common confusion species, Balearic Shearwater, has a distinctive "flappier" flight.

After Manx Shearwater the next commonest shearwater is the Sooty Shearwater, with often large numbers passing off the south and west coast of Ireland through August and September and into October. The Sooty Shearwater is a large, chocolate brown, shearwater with very long wings which have silvery-white undersides. This species has a determined flight pattern with deep and powerful wing beats. The body is entirely chocolate brown and torpedo-shaped allowing easy separation from Manx, even if its much larger size is not instantly apparent. They also have a tendency to approach land closer than Manx, in my experience, even in light wind conditions. This species also throws a number of distinct shapes and poses at the observer which, once learnt, aid identification.


Sooty Shearwaters: A group of Sooty Shearwaters showing some classic poses often displayed by the species. Note the long-necked appearance of this species. "Sooties" tend to favour more level flight as opposed to the arcing flight of the "large" shearwaters. Note the brown body and silvery underwings. Also notice the paler silvery area on the upperwing at the inner primaries and outer secondaries. This can often be very apparent on birds in strong lighting (photo: Arie Ouwerkerk).


Sooty Shearwaters: An underside view of a Sooty shearwater in what looks like strong wind conditions. Note how striking the underwing appears. The shape of the wings is also distinctive, with the hand appearing long, slim and sharp (photo: Martin Scott).


Sooty Shearwaters: This bird is strongly backlit and the lighter tones on the upperparts begin to become more apparent, taking on a slightly golden sheen. In such sunlight the underwings can also reflect a more yellowish colour. Again the bird appears very long necked, presenting an almost "gangly" sort of impression (photo: Russell Wynn).

Sooties, because of the numbers usually present offshore, have a tendency to "raft" along with Manx Shearwaters more so than the two other larger shearwaters (Cory's Shearwater and Great Shearwater). And the distinctive silhouette of a resting Sooty, head and shoulders above the rest, is often blatantly apparent amongst a group of the far smaller, and shorter-necked, Manx Shearwater.

The Balearic Shearwater is a confusion species for both Manx and Sooty Shearwater. The same size and similar shape as the Manx Shearwater, Balearic is more similar in plumage to the Sooty (in fact often described as a small Sooty), usually having a brown body with an off-white belly patch. However, they can be extremely variable, with some birds appearing almost completely dark-bodied and others with extensive pale bodies with just dark undertail coverts. The underwings are usually more extensively marked than Manx Shearwater. Structurally, Balearics classically show a "potbellied" shape, with the bird's centre of gravity held towards its rear, giving a slightly longer-necked appearance than Manx.


Balearic Shearwater: A middle-of-the-road Balearic Shearwater, not as dark or light as they can appear. The plumage is far browner than Manx Shearwater, but not so chocolate brown as a Sooty. This bird is showing the potbellied jizz and dark undertail coverts which also separate the species from Manx. Note also the lack of white spur behind the ear (photo: Ben Lascelles).


Balearic Shearwater: This is an excellent example of the "flappy" flight of Balearic shearwater, which can often allow the species to be picked-up on approach. Note the long-necked feel of the bird, the dark undertail coverts and the distinctive "head lift" at the end of the clip often associated with this and the rarer Yelkouan Shearwater. (Excellent ID articles on Yelkouan and Scopoli's Shearwater have been published here by Martin Garner and thus these species will not be discussed in this article). (Animated GIF: Michael O'Keefe)

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Large shearwaters

Great Shearwaters are usually annual off Irish headlands from July through August and into September, although the numbers of this species vary from year to year in Irish waters. As their name implies they are indeed "great", and are one of the two "large" shearwaters, albeit smaller than Cory's Shearwater.

On plumage Great and Cory's Shearwaters are not really confusable, with problems separating the two coming mostly from very distant birds where plumage features cannot be assessed. In such situations it is best to consign such birds to the category of "large" shearwater. Up close, however, the Great Shearwater is one of the most spectacular seabirds to be found in European waters.

Far larger than Manx or Balearic Shearwater, and larger again than Sooty, Great Shearwaters are hardy birds, usually requiring strong winds to push them to inshore waters. The Great Shearwater has a very contrasting plumage, with black primaries contrasting with a brown inner wing and mantle. The tail is dark, contrasting with white uppertail coverts, and a dark chocolate brown cap contrasting with a white collar. The underwings are white with a great deal of variation on the extent of dark markings. The underparts are white, usually with a brown belly patch, varying in extent, and sometimes not being at all obvious. Lighting is an important factor and strong sunlight can make the upperparts appear much warmer presenting potential confusion with Cory's Shearwater.

The other important confusion species is Gannet — an immature Gannet can look superficially like a Great Shearwater. However, note the head shape on Gannet, the lack of a white collar, and the different flight pattern. Gannets usually flap steadily in a direct level flight pattern interspersed with glides. Great Shearwater arcs and glides, often rising in quite high arcs in strong winds.


Great Shearwater: An underside view of a Great Shearwater. Note the neat dark chocolate cap, the smudgy brown belly patch and white collar (photo: Ben Lascelles).


Great Shearwater: A level flight view of Great Shearwater in strong sunlight. The upperparts appear much warmer than in overcast conditions, but still a tad darker than a Cory's would usually appear with a kind of "cold" feel to plumage. Note again the dark cap and white collar. Also conspicuous are the white uppertail coverts (photo: Arie Ouwerkerk).


Great Shearwater: An upperparts view of Great shearwater in overcast conditions. The upperparts appear much darker but the mantle and inner wing still appear lighter than the primaries. The dark cap contrasts strongly with the white collar and chin and the white uppertail coverts contrast strongly with the dark tail (photo: Martin Scott).


Great Shearwater: A distant level flight shot of a Great Shearwater in overcast conditions. In this shot the wings are held in a position resembling a skua species. But again note the dark cap and white collar. Even side-on, the white uppertail is clearly visible (photo: Martin Scott).


Great Shearwater: An underside view of Great Shearwater in overcast conditions. The length of the wings of shearwaters is strongly affected by lighting and often they appear longer and slimmer in overcast conditions where the strong light does not "burn out" the edges, and the effect of strong winds mean that birds arc fully, showing the true wingspan. This shot shows this exceptionally well with the wings appearing exceptionally long and almost hooked at the tips. Note also the large belly smudge and the straight winged shape of this species (photo: Martin Scott).


Gannet: An upperpart view of an immature Gannet showing the white uppertail coverts. Note the difference in head shape and the obvious bill, lack of a white collar and dark cap. The upperparts are not as contrasting between primaries and mantle, and, of course, the flight action of a Gannet is distinctly different from a shearwater even when the species is "shearing" as it appears to be doing in this shot. Note the deep rhythmic wing-beats in a Gannet's flight as opposed to the series of quick flaps and glides of a shearwater (photo: Menno van Duijn).

Cory's Shearwater is the largest of the shearwaters to be found in Irish and British waters, usually occurring through July and August. They have a very distinctive appearance at close quarters, having a large head and chest with very broad looking wings. They often seem almost "heronish" in level flight with deep broad wing beats and muscular feel to the chest.

The upperparts are light brown with a faint 'W pattern' due to slightly darker secondary coverts. They lack the dark cap and white collar of Great Shearwater, instead having an entirely grey head and neck with a dark "eyepatch" effect. Often the grey of the head extends down to the throat and chin, giving a strong contrast between throat and chest. The underparts are pure white with the underwings also the same vibrant white, with no dark markings as would be evident on a Great Shearwater. This gives the wings and chest a very broad appearance. Also Cory's has a notable bend at the carpal joint which can add to the broad appearance of the wings, whereas Great Shearwater has a straight-winged appearance (although this can be affected by wind conditions). The large yellow bill is often apparent even from a good distance. The uppertail coverts usually show a thin white band, which is often quite "neat"-looking, but usually not as thick as Great Shearwater, although there is variation.


Cory's Shearwater: An upperparts view of Cory's Shearwater in strong sunlight. Note the light greyish- brown upperparts, thin white "U" on the uppertail coverts and large yellow bill. The face and head is plain, save for the darker eye, and lacks the dark cap (photo: Menno van Duijn).


Cory's Shearwater: A more distant "cold" shot of the underside of a Cory's Shearwater. Note the large yellow bill (often appearing dark-tipped), plus the heavy white chest and broad white underwings. The wings are more rounded than Great Shearwater. The bird appears "front heavy" with its balance almost tipped forward due to the large head and chest (photo: Menno van Duijn).


Cory's Shearwater: Another "cold" underside view of Cory's Shearwater with the underparts appearing crisply white. The bird is arcing more strongly and the wings appear more pointed under these conditions, but notice the bend at the carpal joint. Note the neat dark trailing edge to the underwing. Note also the dark eye patch and yellow bill (photo: Menno van Duijn).


Cory's Shearwater: A "crisp light" upperparts shot. Up close the pale-fringed upperparts pattern can be seen. In this view the bill seems more whitish than yellow and the appearance of the bird has an almost Fulmar-like jizz (photo: Menno van Duijn).

Fulmar is the confusion species for beginners for both Cory's Shearwater and Fea's Petrel. They are large grey/white petrels with a similar arcing flight to shearwaters. However, several key structural and plumage differences are present. Fulmars have quite a "barrel-shaped" body, with the center of gravity held in the belly rather than the chest. Note also the entirely grey-white tail and large white head. The bill is short, pale, and stubby and the bird often appears to have little, or no, neck. Do beware of Northern "Blue Fulmars", which have entirely smoky-grey underparts, which can confuse birders unfamiliar with them.


Fulmar: Upperparts view of a Fulmar. Note the bluish-grey upperparts, grey tail, large white head and heavy chest. The upperwings are predominantly uniform with just a few "patchy" brown feathers (photo: Sue Tranter).


Fulmar: An upperparts view of a Fulmar showing the typical "barrel" shape of the body. Note the thick Stubby bill, large head and short neck (photo: Catherine Nicol).


Fulmar: An underparts view. Not how clean white the entirety of the body and underwings are, eliminating Fea's Petrel (photo: Steven Fryer).

Fea's Petrel

Fea's Petrel, and the extremely similar Zino's Petrel, are most likely indistinguishable in the field, but for the purposes of this article will be referred to as Fea's Petrel as opposed to Fea's/Zino's. Fea's Petrel is a Manx-Shearwater-sized seabird of the genus Pterodroma. It is an incredibly distinctive species which is only remotely confusable with the other species mentioned here.

The mantle and upperwings are a light grey with darker secondary coverts and primaries giving rise to a distinct "M" pattern. The bill is dark and chunky-looking, with a dark cap extending down to the eye. The underparts are pure white contrasting strongly with dark black underwings. The uppertail is a pale grey colour contrasting against the mantle.

The wings are exceptionally long, being slim and angular-looking, always being held straight out from the body. The chest is very broad and deep, and is the widest part of the body, with the anterior section of the body tapering to the narrow tail. The classic arcing flight, with very high rounded arcs, is a feature in stronger wind conditions, at other times preferring a languid flapping flight similar to Cory's Shearwater.


Fea's Petrel: A mid-distance upperparts view in warm sunlight. The distinct "M" pattern is clearly visible, with the carpal bars meeting on the rump, contrasting with the white-grey tail. The dark eye and cap is also discernible, as is the "chunky" feel to the bill (photo: Menno Van Duijn).


Fea's Petrel: A mid-distance view of the underparts in cold crisp light. Note the wide strong chest and jet-black underwings, often showing a white armpit. At a distance this white armpit can cause the wing base to appear very slim, as if just barely stuck on. The black cap is quite visible as is the strong bill. This bird appears to be showing the typical high arcing flight pattern (photo: Menno Van Duijn).


Fea's Petrel: A closer underparts view of Fea's, again the strong chest is very obvious as is the dark grey cap and eye. Closer views of the underwings show pale bases to the primaries and outer secondaries, but nonetheless a dark underwing. Here the bird seems to be opting for a more Cory's type flight pattern, shifting from side to side over the waves in calm conditions (photo: Ashley Fisher).


Fea's Petrel: A strongly backlit view of Fea's Petrel. Note the angular wing-shape and almost "agile" impression. The pale tail is quite discernible in contrast with the dark upperparts (photo: Glen Tepke).

Storm-petrels

The Storm-petrels, due to their small size, provide yet a greater challenge on a seawatch, as a close view is necessary for a definite identification. The commonest, by far, in British and Irish waters is the European Storm-petrel, affectionately known as "stormy" to most seawatchers. It is a tiny black and white seabird and often the only view is of a small bat-like creature distantly flapping away over the waves. Stormies are very compact-looking petrels, appearing shorter-winged and -bodied than either Wilson's Storm-petrels or Leach's Storm-petrels.

The plumage is entirely black save for a white rump and rump sides/vent area which can vary in extent between individuals. The level of white extending around from the rump to the undertail coverts is not as extensive as on Wilson's Storm-petrels. The underwings often have a bold white stripe on the coverts, but this again can vary between individuals, with some almost entirely lacking white. The flight action is very distinctive, flapping furiously and continuously, interspersed only now and again with short glides. The thin white line at the base of the secondaries is not always discernable in the field.


European Storm-petrel: An upperparts view in overcast conditions. Note the compacted shape of the bird as if lacking a neck. This individual shows a thin white line along the secondaries, but nowhere near as strong as the carpal bar shown by either Wilson's or Leach's Storm-petrels (photo: Paul Bowerman).


European Storm-petrel: An individual showing the distinctive white underwing. Note also the black area on the undertail coverts both features eliminating Wilson's or Leach's Storm-petrel (photo: Paul Bowerman).

Leach's Storm-petrel is quite regularly encountered on seawatches off the west coast of Ireland in late August, and through September into October, with over 1,000 birds occurring at a given watchpoint on some days. It is also a speciality from the Irish Sea watchpoints in the west of Britain during favourable conditions.

Leach's is a much bigger bird than European Storm-petrel with proportionately longer wings and a forked tail. A strong pale carpal bar is present on the upperwing and the mantle area is slightly paler, tinged grey, compared to the primaries and tail. The white rump does not extend onto the undertail coverts and the rump itself often, but not always, shows a dark line connecting the tail and mantle, although this can be hard to see at a distance. The flight is very distinctive, the long wings being held arched and high, with deep strong wingbeats. The wings are quite angular, as compared with either Stormy or Wilson's, and the flight action is a mix of deep wing-beats and sweeping glides.


Leach's Storm-petrel: A close upperparts view of Leach's Storm-petrel. Note the strong carpal bar and paler saddle. The forked tail is also visible (photo: John Malloy) .


Leach's Storm-petrel: A more distant upperparts view. Here the full upperwing pattern can be seen. Note the forked tail, divided rump, and in particular, the distinctively held long wings (photo: Roy Harvey) .


Leach's Storm-petrel: A "strong light" upperparts view. Note the contrast of the upperparts pattern, forked tail and long angular wings (photo: Menno Van Duijn).

Wilson's Storm-petrel is the rarest of the three Storm-petrels discussed here, with most records occurring on pelagics, off the Scillies and south of Ireland, and on seawatches off the west of Ireland. Wilson's are slightly larger than European Storm-petrels, with longer wings, but not as large and gangly looking as Leach's Storm-petrel.

The upperparts show a similar contrasting pattern to Leach's but with a more "golden" tinge to the carpal bar. The underwings at a distance appear wholly dark, showing a bronze sheen with close views, and the broad white rump extends right around to the undertail coverts, often with just a thin black strip and the legs preventing complete encirclement. The feet project just beyond the tail with close views and the wings are more rounded than Stormy being especially paddle-shaped when feeding on the water. The flight action is particularly distinctive, with active flight having a distinct "rowing" quality, interspersed with very long glides on flat wings. Indeed, the length of the glides are sometimes exceptionally long, at times lasting for a minute or more.


Wilson's Storm-petrel: Note the distinctively shaped wings, more rounded than Stormy and held straighter. The feet project beyond the tail. Here the upperpart pattern has been "burnt out" by strong sunlight (photo: Ben Lascelles).


Wilson's Storm-petrel: A close "crisp" view of the upperparts. Note the strong carpal bars, though not as obvious as Leach's, the broad white rump, and feet projecting beyond the tail. The overall body shape is not as compact as Stormy, appearing longer, with a distinctly long-necked feel (photo: Ben Lascelles).


Wilson's Storm-petrel: Note the extent of white on the undertail of this bird, the dark underwings, strong upperparts pattern and feet projecting beyond the tail. The length of the bird is very obviously greater than that of European Storm-petrel (photo: Michael O'Keefe).


Wilson's Storm-petrel: This short piece shows the distinctive rowing flight quite well, with the bird sweeping its wings back strongly, followed by a long glide on flat wings. Note the extensive white rump and longer shape than European Storm-petrel. (Animated GIF: Michael O'Keefe)

Of course, one could go on for hours on the topic of seabirds, and the possibility of far rarer species should always be considered. Hopefully, however, this article has served to whet the appetite of the many seawatchers out there and interested some new souls willing to brave the wind and rain. Good birding and see you on the cliffs.

Many thanks to numerous contributors involved in this article. In particular, Menno Van Duijn, Arie Ouwerkerk, and Michael O'Keefe.

Written by: Owen Foley