viernes, 16 de septiembre de 2016

Species status

The previous "Willow Warbler" post has given me the cue to write the following notes on species status, for the benefit of visiting birders to the island, especially those coming from European countries. If you note a touch of irritation, the reason will become clear towards the end...

As explained in the said post, the "humble" Willow Warbler (Phylloscopus trochilus) is a migrant to La Palma, not a resident if you see one on the island, it's worth sending your sighting to the regional recorder, and/or congratulating yourself for having found something exceptional. All such records are later published in Ardeola, the bi-annual Spanish Birdlife journal, and they add to knowledge of species distribution.

In other words, it's important to be aware of the status of the various species you observe on the island, in order to put your sightings into context, and decide when it's worth reporting them. You will then be able to contribute useful data to SEO/Birdlife... if you wish to do so.

Reliable details on species status have been available for many years in a number of publications, including these two popular field guides in English:

"Birds of the Atlantic Islands" Tony Clarke, Helm Field Guide

"Field Guide to the Birds of Macaronesia" Eduardo García-del-Rey, Lynx Edicions

The latter book is the more recent of the two, and is regularly cited in my blog posts, but both guides are recommendable.

To say that La Palma is "under-watched" is a gross understatement. It can be safely assumed that many vagrant birds turn up every year, only to go completely unnoticed by the island's inhabitants, let alone reported. There are also a number of resident species which are becoming increasingly scarce; some are presumed already extinct, others are on the brink of extinction. In the absence of active birdwatchers who report their sightings, it is simply impossible to assess the exact situation of the following:

Rock Sparrow (Petronia petronia), Corn Bunting (Emberiza calandra), Goldfinch (Carduelis carduelis), European Greenfinch (Carduelis chloris), European Serin (Serinus serinus).

If you observe any of the above species on the island of La Palma, please report your sighting to the Regional Recorder, or send me an email and I'll pass on the information.  Also, any updates on the Hoopoe (Upupa epops), or the Barn Owl (Tyto alba) would be greatly appreciated. Photos are always useful as evidence, but not essential.

So why the irritation? Well, take a look at the Avibase checklist for La Palma, an increasingly popular online resource for travelling birders, described on its homepage as "the world bird data base": (You'll need to enter Spain, then the Canary Islands, then La Palma).

On the Avibase checklist, there is no clear definition of status; some of the birds on the list are not residents on La Palma at all, but a European birder could well be forgiven for assuming they are; the various species labelled Rare/Accidental include infrequent, but almost annual migrants lumped together with unique, "one-off" sightings for the whole of Spain; no distinction is drawn between abundant resident species, and extremely scarce or possibly extinct ones; and some species are listed which are found on some of the other Canary Islands, but not on La Palma, etc. etc.

Similarly, is it clear from the list that there are absolutely NO resident ducks or waders on the island, or are birders supposed to draw that conclusion themselves? Furthermore, the only Chiffchaff found here is the canariensis species, the only Blue Tit is the palmensis subspecies, and the only Chaffinch on the island is the palmae subspecies.

Admittedly, the creator of the checklist does apologize for any inaccuracies in the same, and makes a plea for help in correcting any errors. But come on, that's too easy! First, you uncritically lift data from the net, paste it into a list format, and then ask for volunteers to correct it for you. Wouldn't it have been better to check with an authoratitive source beforehand (ie. copy the information contained in a field guide), or at least send the list for revision to the Regional Recorder?

Quite frankly, the whole thing comes across as rather sloppy, and needs re-working from start to finish, IMHO. After consulting the said list, people have asked me where they can see Osprey (Pandion haliaetus) on La Palma: the answer is, you can't...unless you happen to coincide with a migratory Osprey that passes through once every couple of years or so. You can similarly forget about the Lesser Kestrel (Falco naumanni) for similar reasons (although I am not aware of an accepted record for this species on La Palma in the last 10 years). On the other hand, what about the various species - waders especially -  that have been recorded on the island, but which are not included on the Avibase checklist?

So, the message to visiting birders is simply this: don't rely on the Avibase checklist, and consider getting yourselves a copy of one of the field guides mentioned above. Amongst other things, you'll save yourselves time and effort in the field trying to separate the nominate Goldcrest (Regulus regulus) from the Canary Islands Kinglet (Regulus teneriffae), which are both present on the Avibase checklist for La Palma, but unfortunately are not present on the island itself. On La Palma you only get the Goldcrest subspecies (Regulus regulus sub. ellenthalerae).

Having got all that off my chest, let me end by wishing visitors "happy birding" on the island...and keep your eyes open for migrants: the season has just started!

jueves, 15 de septiembre de 2016

Willow Warbler at Las Salinas

 Willow Warbler (Phylloscopus trochilus)

Photographed at the saltpans in Fuencaliente this morning, this juvenile Willow Warbler (Phylloscopus trochilus) came as a surprise...these are just not the sort of surroundings you expect to find this species in. The bird was foraging for small flies and other insects along the walls separating the ponds, a technique often used by the resident Berthelot's Pipit (Anthus berthelotii).

Willow Warbler (Phylloscopus trochilus) foraging along the walls at Las Salinas

The Willow Warbler is a passage migrant to the Canaries (all islands and islets), and I recorded one on La Palma in April 2015 (see corresponding blog entry).  On that occasion, however, the bird was spotted in bushes at an irrigation pond in Las Martelas (Los Llanos de Aridane), in what was seemingly more appropriate habitat.

Few migrant passerines turn up at the saltpans: exceptions in recent years have been Citirine Wagtail (Motacilla citreola), and a nominate/Iberian Chiffchaff (Phylloscopus collybita). But the location attracts waders, and the following common species have all been seen there in recent weeks: Green Sandpiper (Tringa ochropus), Redshank (Tringa totanus),  Dunlin (Calidris alpina), Sanderling (Calidris alba), Little Stint (Calidris minuta), Ruff (Philomachus pugnax), Common Sandpiper (Actitis hypoleucos), Ringed Plover (Charadrius hiaticula), and Turnstone (Arenaria interpres).

Separation of this bird from the Chiffchaff is based on the following field marks: pale as opposed to dark legs, conspicuous supercillium and dark eye stripe, and a relatively long primary projection in comparison with P. collybita.

Willow Warbler (Phylloscopus trochilus), showing relatively long primary projection.

lunes, 13 de junio de 2016

American Golden Plover, update 3

The American Golden Plover (Pluvialis dominica), first discovered on May 25, was still at the same location this morning, June 13.

The irrigation pond is rapidly drying up, there being little more than a shallow puddle of water left in the bottom at the moment. Two things can happen:

1. The owners will allow the pond to dry out completely, in order to carry out cleaning or repairs.

2. The pond will be refilled, and the habitat will be transformed, making it unsuitable for the plover, and for waders in general.

It looks like the American Golden Plover will soon be forced to move on...

lunes, 6 de junio de 2016

American Golden Plover, update 2

The American Golden Plover (Pluvialis dominica) was still present at the same location in Las Martelas this morning, June 6.

martes, 31 de mayo de 2016

American Golden Plover update 1

 American Golden Plover (Pluvialis dominica)

The American Golden Plover (Pluvialis dominica), first discovered on the evening of May 25 was still present at the same location this morning (May 31).

The bird is foraging in the bottom of a partially-empty irrigation pond in Las Martelas (Los Llanos de Aridane), and is not unduly disturbed by the presence of a few vehicles and people in the vicinity.

However, it deliberately bypasses the resident Coots (Fulica atra), now incubating their second clutch of the year, and behaving territorially towards this Transatlantic migrant. The Muscovy Ducks (Cairina moschata) which also live in the pond, just ignore the visitor.

jueves, 26 de mayo de 2016

American Golden Plover

 American Golden Plover (Pluvialis dominica)

I don't usually expect waders on La Palma at this time of year, let alone rare ones, so imagine my surprise yesterday evening when I discovered this American Golden Plover (Pluvialis dominica) at an irrigation pond in Las Martelas (Los Llanos de Aridane). The last time I observed this species on the island was Sept-Nov 2010, when no less than three individuals turned up at various locations.

The first photo above was taken in less than ideal light conditions on May 25. The bird's  long primary projection can be appreciated, with at least 4 of the primary tips beyond the tertials. Also its slim, elongated build, and prominent supercillium are diagnostic.

The remaining images were all captured this morning, May 26, at the same pond:

To further support the case for dominica, note the buff-grey axillaries above.

 American Golden Plover (Pluvialis dominica) with another denizen of the pond.

 American Golden Plover (Pluvialis dominica)

Clearly visible above, the wing tips extending well beyond the tail.

The American Golden Plover is a Nearctic shorebird which breeds in W. Alaska and N. Canada, and winters in S. America. There have been at least 23 records on the Canaries in recent years (La Palma, n=4, Tenerife n=13, Fuerteventura, n=3, Lanzarote, n=3), mostly in Sept-Nov. ["Rare Birds of the Canary Islands", E. García-del-Rey and F. J. García Vargas, Lynx Edicions, 2013].

The present sighting will be submitted to the Spanish Rarities Committee in due course.

sábado, 6 de febrero de 2016

Black-tailed Godwit

 Black-tailed Godwit (Limosa limosa)

On Feb 8 2013, and then one year later almost to the day, on Jan 29 2014, I photographed two migratory Black-tailed Godwits (Limosa limosa) at irrigation ponds in Las Martelas (see relevant blog posts). In 2015, I drew a blank for this species on the island. However, on Feb 5 2016, a solitary bird was discovered at a pond in Tazacorte. The dates are all very close, and the half-empty irrigation ponds are all located on the west side of the island, within a short distance of each other.

In the above image, the black tail is clearly visible, plus the white square on the bird's rump. Two races of Black-tailed Godwit are currently recognized, the nominate limosa, and islandica. With its deep bill base, the present bird looks like an adult limosa in non-breeding plumage. The winter distribution  of islandica does not extend as far south as the Canary Islands.

Black-tailed Godwit (Limosa limosa)

The white underwing coverts enable the Hudsonian Godwit (Limosa haemastica) to be discounted.