of an article: Little-known Oriental bird, White-eyed River-Martin
Eurochelidon sirintarae by Joe Tobias, in Oriental Bird Club
Bulletin 31; June 2000.
By Nick Upton 24/03/06
Research Techniques Assignment 1
BSc (Hons) Wildlife and Countryside Conservation, Year 2
This essay is not intended to be a thourough scientific review of
the known ecology of White-eyed River-Martin nor is intended to by
an attack on the orignal article by Joe Tobias who I hope will be
flattered to know that out of millions of articles I could have chosen
to review it was his that interested me enough to do so. The remit
I was given for this assignment was to choose an article from a peer-reviewed
publication and write a balanced critique of it, with the highest
grades given to those who are able to show a high level of critical
thinking and originality. I have included my work here as I feel that
some of the points I make will be of interest and may stimulate some
thought upon the subject which in turn may contribute to rediscovering
this species if it still exists; something that was also the intention
of the original article which is reproduced here in the appendices
with kind permission of the Oriental
Bird Club (OBC) and referred to throughout the essay
by paragraph number.
Please support the OBC's conservation
work by visiting the OBC
website and becoming a member.
2. Literary Style
3. Factual Accuracy and Analysis
River-Martin (McClure, No date).
Even a cursory glance at one of the few photos in existence
of the White-eyed River-martin (See figure 1) immediately conveys
a feeling that it is a special creature, indeed, it has something
about it that makes one wonder if it is in fact a real species
and not a clever hoax. Add to this its mysterious discovery
and disappearance, and the unusually low number of these birds
that have ever been encountered, and the result is a bird of
almost mythical proportions. This article attempts to clarify
some of the facts that have become clouded since its discovery
in 1968 (Thonglongya), to summarize the speculation surrounding
its ecology and taxonomy, to rekindle hope that it may be rediscovered
by proposing areas where it may persist and ultimately to introduce
a new generation of ornithologists to a little-known and neglected
species. To achieve this, the author employs a blend of historical
narrative, extrapolation and speculation from scientific fact
with an informal style of writing.
From the beginning of the article the author attempts, rather successfully,
to create an almost fairy-tale like atmosphere, giving the reader
an early sense of how mysterious this species is and by using vocabulary
such as “spectacular”, “enigma”, “mythical”
and “cryptic” from start to finish, the reader is constantly
reminded of this theme. This element of mystery is created by placing
the reader at the scene of discovery, making one feel part of the
story from the first paragraph; setting the scene for suggesting that
the reader has a part to play in the rediscovery of the species towards
the latter stages of the discussion. By employing this style, the
author has created a connection between the reader and the River-martin
that not only results in reading the article to completion, but hopefully
continues beyond by stimulating the reader to interpret the facts
in their own way and to make further research into the subject. A
discussive style of writing also helps to keep the reader at the centre
of the article and by asking questions before answering them (Paragraph
7), it almost feels like one is having a conversation rather than
reading an article. The system of referencing by numbers adds to this
high level of readability, maintaining the flow of the argument without
confusing the eye with large amounts of names in brackets or italics,
although this is contrary to the system used by many authors.
all draw the reader further into the article once it has been commenced,
but a certain aspect of the layout does not add to its attraction;
there are no sub-headings to break the script into more digestible
chunks for the reader with lower powers of concentration. It might
be useful for the author to use headings such as “Discovery”,
Ecology” or “Where to look” to give the reader
an at-a-glance summary of the topic of each section. This is a minor
point, but as it seems that widening the awareness of the White-eyed
River-martin is an aim of the article it would seem sensible to
employ tactics designed to attract as large an audience as possible.
style of writing is largely excellent in terms of the atmosphere
it creates and in its clarity, the second paragraph is uncharacteristically
unclear in the way it attempts to explain that knowledge of the
precise site of discovery may not be as reliable as is often stated.
This is cleared up in the third paragraph, but it remains that the
information in paragraph two is rather clumsily delivered. By using
the words “Bung” and “Nong”, an assumption
that the reader has some knowledge of the Thai language is made
and this is ill-advised, further confusing the point, and when a
poor translation is also used (fen would be more appropriate (Pers.
Obs.; SE-Education, 2002; Phiromyothee, 2006)) it does not help
the reader paint a clear picture of the site of discovery.
apart, the style of the article is interesting, it is easy to understand
and very readable.
Accuracy and Analysis
Before examining the factual content of the article, or any of the
explanations it offers, it should be praised for bringing the story
of the River-martin to a wider audience. If the reader is tempted
to further his research on the subject, it immediately becomes clear
how difficult this is to achieve with most of the referenced articles
being difficult to obtain due to their age or storage in Thai libraries.
In this respect, this article does a wonderful job of bringing the
entire White-eyed River-martin story a new level of accessibility
through the traditional media of scientific bulletin and, for the
first time, through the internet.
The first nine
paragraphs of the article outline the circumstances surrounding
the discovery and disappearance of the species, and these facts
are hard to dispute. Indeed, the author does a good job of questioning
the accuracy of what has been long taken for fact, highlighting
that the original research team never actually saw the species in
the field (Paragraph 3). The author does, however, fall short of
specifically pointing out that this included Kitti Thonglongya,
who originally described the species (Birdlife International, 2001);
this point would have given weight to the theme of keeping an open
mind to the accuracy of some of the original reporting. Whilst speculating
on the location of roosting Barn Swallows Hirundo rustica,
and consequently where the River-Martin might be located, the author
does well to highlight the changing ecology of Beung (Bung) Boraphet
due to lotus harvesting (Paragraph 9), but completely omits to mention
that the fen was totally drained of water in 1959 and 1972 (Jintanugool
& Round, 1989) and again in the early 1990s (Stewart-Cox, 1995),
with further disturbances during this latter period (Round, 1990).
These facts have surely effected the stability of the ecosystem
and could prove critical to whether the site remains suitable for
White-eyed River-Martin. This section of the article also informs
the reader that a reserve ranger was killed by poachers at Beung
Boraphet; very useful in providing an insight into the problems
of conservationists in Asia, as well as rather macabrely adding
to the mystique of the narrative.
2: African River-Martin (Sinclair, 2004).
The remainder of the article discusses the possible ecology
of this species in order to speculate upon where rediscover
might occur, and in doing so draws the reader’s attention,
in paragraph 10, to another little-known species, the African
River-Martin Pseudochelidon eurystomina. As the closest
relative of White-eyed River-martin this is a natural progression
of the discussion, but despite providing excellent photos of
sirintarae there is no image of eurystomina
for comparison (See figure 2); whilst this is not a necessity
it would be of interest to the reader. Having invited comparison
with the African species, the author fails, at this point, to
explore this line of thinking further, instead a summary of
what can be inferred from the few specimens ever studied is
facts are of obvious merit, however, it would make sense to alert
the reader to these before suggesting a look at African River-Martin
and then to subsequently discuss its affinities to sirintarae
based upon African River-Martin’s behaviour is made without
properly discussing the most critical point when assessing the merits
of this theme; in which genera are the two species to be placed?
Mentioned in only fragmentary form, in paragraph four and in the
penultimate paragraph, is the fact that some authors consider sirintarae
deserving of its own genus and others consider it congeneric with
eurystomina. To so briefly deal with this issue, and in
broken fashion, would seem rather a pity, as the two species’
similarity, or difference, is vital when assessing the possible
ecology and behaviour of White-eyed River-Martin; issues that are
critical when speculating upon where it might be rediscovered due
to the scarcity of factual information. Presumably this author considers
that sirintarae should be placed in the genus Eurochelidon
as this is the taxonomy used in the article’s title, but no
explanation as to why this view has been taken is given other than
a few anecdotal observations (Paragraph 4). Perhaps this is because
this view does not really hold up to scrutiny; on re-analysis of
the data taken from the original samples there is apparently no
significant difference in the bill measurements of the two species
(Zusi, 1978), previously the only non anecdotal evidence for different
feeding ecologies and thus different genera (Turner & Rose,
1994). When it is also taken into account that the decision to place
sirintarae in its own genus was based on data from just
nine to twelve samples, certainly not enough to be conclusive, it
may explain the author’s reluctance to discuss this issue.
Whilst the author does well to encourage the reader to keep an open
mind regarding the behaviour and ecology of White-eyed River-Martin
throughout this section of the article, he might do better, considering
the lack of evidence to the contrary, to concentrate on using African
River-Martin as a model when considering the habits of the Asian
does in fact follow this theme up to a point, going on to propose
regions that would most likely harbour this elusive species if it
still exists, and this optimistic aspect is vital for the article
to inspire any ornithological expeditions. Assumptions about sirintarae’s
ecology here are indeed drawn from knowledge of African River-Martin
in that large river systems (Turner & Rose, 1995; Birdlife International,
2000) are deemed the most likely regions to examine; with rivers
in Thailand, Myanmar, China, Laos and Cambodia all suggested. The
author does well to name the last of these as since publication
there have been possible, if unconfirmed, sightings of White-eyed
River-Martin there (Silver, 2003; Judell, 2006). However, this is
simply recycling established views and although the stated aim is
just this; “to compile our knowledge” (Paragraph 1),
the author would be well advised to provide a new interpretation
to improve the chances of achieving another stated aim; “in
hope that it might lead to a dramatic rediscovery” (Paragraph
1). Indeed, it is here that the author, having made comparisons
with the African species, stops short of further extrapolation;
it is known that the African River-Martin breeds inland and migrates
down the Congo river to winter in coastal regions (Birdlife International,
2000; Birdlife International 2005), so why not consider that the
Asian species behaves the same? It has often been suggested that
sirintarae might breed somewhere in China and migrate (Dickinson
& Dekker, 2001), so the author does well to suggest the Salween,
Irrawady and Mekong, but he would be well advised to consult an
atlas to see that the Yuan in Vietnam would be equally likely (See
figure 3). Indeed, this river, and the delta of the Mekong, would
surely deserve consideration in respect of the number of scientific
discoveries, and rediscoveries, in Vietnam since the end of the
war. If beasts as large as the Vu Quang ox (Dung et al.,
1995) and Javan rhinoceros (Newsweek International, 1999) can go
unnoticed then surely there is hope for a bird as small and as mobile
as the White-eyed River-Martin?
3: River systems that could harbour White-eyed River-Martin
(Adapted from Microsoft, 2006).
short article like this does well to touch upon, if sometimes
too briefly, so many issues, and it may well be the intention
of the author to simply provide a spark to rekindle a forgotten
debate, and in this he has done well. One issue, though, does
not seem to have been dealt with at all; the possibility that
White-eyed River-Martin might only have ever occurred in Thailand
as a vagrant, something others have subsequently proposed
(Birdlife International, 2001). It is mentioned that the species
was assumed to be regular in this country because the locals
knew it by the name nok ta phong, “swollen-eyed bird”,
however, this is a name so simple that it could have been
made up on the spot by even a child, and carries no implication
that it is a long-standing name. The article does observe,
though, that rediscovery is most likely in another country,
but by refusing to outline the possibility of vagrancy, denies
the reader a vital clue to rediscovering the species. In this
theme, the article could have gone on to suggest analysing
weather patterns at the time of discovery in 1968 to see if
anything unusual occurred. In fact, this reluctance to discuss
vagrancy is perhaps similar to omitting a full discussion
of taxonomy in its Siamocentricity, a line of thought that
may have held back rediscovery of the species and may continue
to do so.
paragraph of the article sees the author back to his best,
with a splendidly optimistic and atmospheric summary of the
likelihood that rediscovery will occur, pointing out the fact
that it escaped ornithologists attention for a long period
before being discovered. The last sentence, in particular,
is well-designed to encourage the reader to further investigate
the species and possibly claim his “prize”.
This article does an excellent job in collating the current knowledge
of the species and revealing avenues of further thought that the
reader might take when considering this species. The style of writing
is interesting, upbeat and atmospheric, although at times the structure
of the discussion does not seem as logical as it might. The author
does well to draw attention to using the African River-martin as
a comparison, but stops short of exploring the full range of possibilities
this might lead to, even failing to recognise some of the basic
inferences one might draw from this. There is also a failure to
provide any conclusive evidence to explain why African and White-eyed
River-Martins should not be considered congeneric; something that
is at the centre of deciding upon their behavioural similarities
or differences and consequently where the search for sirintarae
It can be said
that the author achieves his stated aim of compiling current knowledge
in an informative and thought-provoking way. By provoking the reader
to question the facts, the author also goes some way to stimulating
the road to rediscovery, but by not taking the opportunity to follow
his train of thought to its conclusion he fails to make any ground-breaking
speculation of his own to further this aim. Indeed, since publication
a breakthrough has yet to be made (Butchart et al., 2005).
Birdlife International (2000). Threatened
birds of the world. Barcelona & Cambridge, UK.
(2001). White-eyed River-martin Eurochelidon sirintarae,
Red Data Book; Threatened Birds of Asia. Online at http://www.rdb.or.id/detailbird.php?id=257
(2005). African River-martin; Birdlife Species Factsheet, Birdlife
International website. Online at http://www.birdlife.org/datazone/species/index.html?action=SpcHTMDetails.asp&sid=70
Collar, N.J., Crosby, M.J & Tobias, J.A. (2005). Asian Enigmas:
“Lost” and poorly-known birds: top targets for birders
in Asia, Birding Asia-Bulletin of the Oriental Bird Club,
No 3, June 2005.
Dung, V.V., Giao,
P. M., Chinh, N. N., Tuoc, D. & MacKinnon, J. (1995). Discovery
and conservation of the Vu Quang ox in Vietnam, Biological Conservation,
Vol 72, No 3, pp 410-410(1).
J. & Round, P. D. (1989). Beung Boraphet, Asean Regional
Centre for Biodiversity Conservation (ARCBC) website. Online
Judell, D. (2006).
E. (No date). Photograph of White-eyed River-martin reproduced in
Tobias, J.A. (2000). Little-known Oriental bird, White-eyed River-martin
Eurochelidon sirintarae, Oriental Bird Club Bulletin
31; June 2000.
(2006). Encarta Atlas online. Online at http://encarta.mas/encnet/features/MapCenter/map.aspx
(1999). In Vietnam, a Shot in the Dark (first photograph of the
world’s most endangered animal, a Javan Rhino in Vietnam).
Newsweek International, July 26, 1999.
S. (2006). Personal communication.
Round, P. D.
(1990). Bird of the month: White-eyed River-martin. Bangkok
Bird Club Bulletin, Vol 7, No1, pp10-11. Cited
in Tobias, J. (2000). Little-known Oriental bird, White-eyed River-martin
Eurochelidon sirintarae, Oriental Bird Club Bulletin
31; June 2000.
(2002) SE- ED’s Modern English-Thai & Thai-English
Dictionary (Contemporary Edition). SE-Education, Bangkok, Thailand.
Silver, G. (2003)
Bangkok Morning/ Prek Tol, Cambodia Trip Report. Birdchat Website.
Online at http://listserv.ccit.arizona.edu/cgi-bin/wa?A2=ind0302d&L=birdchat&O=D&P=3796
(2004). Photograph of African River-martin reproduced in Trip report
from Gabon, Sao Tome & Principe, and Camaeroon, 14 February
– 11 March 2004, Tropical Birding website. Online
B. (1995). Wild
Thailand. Asia Books, Bangkok, Thailand.
K. (1968). A new martin of the genus Pseudochelidon from
Thailand. Thai National Scientific Papers, Fauna Series no 1.
Applied Scientific Research Corporation of Thailand, Bangkok, Thailand.
Cited in Tobias, J. (2000). Little-known Oriental bird, White-eyed
River-martin Eurochelidon sirintarae, Oriental Bird
Club Bulletin 31; June 2000.
Turner, A. &
Rose, C. (1994). A
Handbook to the Swallows and Martins of the World, Christopher
Zusi, R. L.
(1978). Remarks on the generic allocation of Pseudochelidon
sirintarae. Bulletin of the British Ornithology Club,
Vol 98, No 1, pp13-15.
Appendix 1: Little known Oriental Bird: White-eyed River-Martin
Eurochelidon sirintarae by Joe Tobias.
Paragraph 1 In January
1968, during the course of ringing activities at a wetland site
in south-central Thailand, fieldworkers discovered a strange swallow
amongst large numbers of migrant hirundines. It proved to be a new
species and was christened the White-eyed River-Martin Pseudochelidon
sirintarae by Kitti Thonglongya who dedicated this spectacular
and beautiful bird to Princess Sirindhorn Thepratanasuda. Over the
next three years several more specimens were collected at the same
site, but apart from these, and a fleeting observation in 1978,
this remarkable bird has effectively vanished. An avian enigma,
it has come to epitomise the mythical allure of rarity to the birdwatcher,
and for three decades it has symbolised the Asian mystery of the
ornithological world. As such it has appeared in logo form in the
pages of this journal as the archetypal little-known bird. The time
has come to compile our knowledge of the species and to present
it afresh in the hope that it might lead to a dramatic rediscovery.
Paragraph 2 To begin
with, we need to retrace the events of January and February 1968
and glean what we can from the available facts. The site of discovery
is first misleadingly given as a big marsh on the Chao Praya River
(1). The type-locality is then specified as Bung (= Nong = Lake)
Boraphet, Amphoe Muang, Nakhon Sawan Province, central Thailand
(1), and from its subsequent description as a shallow, marshy, reed-filled
lake of 25,000 hectares it seems clear that this is the big marsh
originally mentioned (a point confirmed by Thonglongya (2)). Rediscovery
efforts in 1980-1981 were apparently concentrated on an island where
all of Kitti's river martins had been captured (3), suggesting that,
at one time, confidence was high that a very precise origin was
Paragraph 3 This
no longer appears to be the case. The first White-eyed River-Martins
were reportedly caught while night-trapping roosting swallows (Hirundo
rustica, H. daurica, Riparia riparia), wagtails and warblers
by casting a fishing net over a reedbed (1) a method repeated by
subsequent authors (3,4,5). However, according to a local technician
who worked with the original field team, the birds were neither
seen in the field nor trapped by any of the team members, but rather
were brought in to the teams hotel in nearby Nakhon Sawan by villagers
following a broadcast appeal for live wild birds for ringing purposes
(6). It seems likely, therefore, that the precise site of collection
is impossible to determine, but that it is certainly in the region
of Bung Boraphet, and most likely at the lake itself.
Paragraph 4 Whatever
their exact origins, nine specimens were initially collected: one
each on 28 and 29 January (although the label on specimen 53-1218
actually states 27 January 1968 (6)) and seven on 10 February 1968
(1). From analysis of the resultant skins its closest ally was deemed
to be the African River-Martin Pseudochelidon eurystomina
(1). Initially described as congeneric (1), the African species
and the Asian species differ markedly in the size of their bills
and eyes, suggesting that they have very different feeding ecologies,
sirintarae probably being able to take much larger prey
and perhaps in different microhabitats (7). The gape of sirintarae
is swollen and hardened, unlike the softer, fleshier, much less
prominent gape of eurystomina(1,19). The feet and claws of sirintarae
are unusually large and robust for an aerial feeder (1) and
the two species also have different toe proportions, which might
suggest dissimilar nesting habits (19). These differences are sufficiently
pronounced in the view of some taxonomists to permit the allocation
of its own genus, Eurochelidon (7), although other authors
support the retention of both species in Pseudochelidon,
arguing that they mirror patterns in other congeneric hirundines
(8). Whether treated as one genus, or two, the syringeal structures
of the two river-martins are divergent enough from those of the
Hirundininae to confirm subfamily distinction from the true swallows,
and apparently enough to suggest that they might belong in a separate
Paragraph 5 Shortly
after these first specimens, a tenth bird was caught in November
1968 (2) and brought alive to Bangkok where it was photographed
in December 1968 (3). Furthermore, at least two birds (one pair)
reached but soon afterwards died in Dusit Zoo in Bangkok in early
1971 (3). The only widely reported field observation was of six
individuals flying low over Bung Boraphet towards dusk on 3 February
1978 (10). In addition, four probable immature White-eyed River-Martins
were reportedly observed perched in trees on Temple Island in Bung
Boraphet in January 1980 (3,5), and one was reputedly trapped by
local people in 1986 (11). Both these records remain unconfirmed.
Several subsequent searches have tried to locate the species around
the site. For example, eleven amateur birding groups surveyed the
lake unsuccessfully during 1979 (3). Investigations were carried
out between December 1980 to March 1981 by a team from the Association
for the Conservation of Wildlife but, despite netting many roosting
Barn Swallows in reedbeds, they failed to reveal any river-martins
(12). In 1988 another concerted effort to relocate the species was
undertaken at Bung Boraphet, ending with failure as the swallow
roosts were highly disturbed and mobile (13).
Paragraph 6 The
real number of White-eyed River-Martins trapped in the 1960s and
1970s may have been much higher than these figures suggest. In the
wave of public and media interest following the sensational discovery
of the species, trappers are rumoured to have caught around 120
individuals and sold them to the director of the Nakhon Sawan Fisheries
Station (3,5). Moreover, local markets were reported to have had
several other specimens in January-February of succeeding years
(10). Having been found on Thai soil and decorated with the name
of Thai royalty, there was a significant local demand for specimens
or caged examples of the species, for zoos, presentation to dignitaries
or as curios for the affluent.
Paragraph 7 What
has become of the White-eyed River-Martin? Did this harvest of hirundines
extinguish it entirely? Were these last known individuals merely
the doomed remnants of a population displaced by disturbance from
a specialised breeding habitat? (5) Perhaps. It is quite conceivably
extinct, and if it still survives its population seems likely to
be tiny. The original series of specimens taken in early 1968 were
outnumbered by hordes of trapped Barn Swallows by a ratio of 9:6,000
(1). In spite of this exceptional rarity, it was thought that the
species might be regular at Bung Boraphet since the local bird-catchers
had a name for it, nok ta phong, the swollen-eyed bird (1). Unfortunately,
there has been a drastic decline in the Bung Boraphet swallow population
from hundreds of thousands reported around 1970 to maximum counts
of 8,000 made in the winter of 1980-1981, although it is not certain
if this represents a real decline or a shift in site in response
to persecution (3). However, an estimated 100,000 swallows were
present at a roost near Chotiravi, near Bung Boraphet, in August
1986 (11) and there were 30,000 at Bung Boraphet in May 1988 (11).
Nevertheless, a dealer working the large Chotiravi roost claimed
never to have encountered the species (11). The general feeling
is that an absence of sightings since early 1980, despite numerous
observational efforts, cast ominous doubts over the survival of
the White-eyed River-Martin (3).
Paragraph 8 Unfortunately,
the habits of swallows around the lake appear to have altered recently,
with very few birds roosting in the reedbeds until late winter (13).
Much of the population now roosts in sugar cane plantations, moving
back to the reedbeds after the cane has been harvested (13). The
roosts also form well after dark, whereas they once gathered before
dusk (13). These changes are probably the result of prolonged disturbance
by trappers (11). In any case, the swallow roosts are more mobile
and difficult to locate, factors that have further obstructed the
rediscovery of the White-eyed River-Martin.
Paragraph 9 The
reduction in Barn Swallow populations in the Bung Boraphet area
is difficult to explain but intensive trapping activities for the
purpose of selling birds as food in local markets must have played
a major role, as must the annual destruction of roosting sites to
make way for lotus cultivation (3). Huge areas of reedbed in areas
frequented by roosting swallows were being burnt in February 1986
(11). The hunting of hirundines without a licence has been illegal
since 1972, although this legislation is rarely enforced (3). Relations
between conservationists and bird trappers at Bung Boraphet are
occasionally fraught, to the extent that a reserve ranger was killed
when trying to apprehend poachers at roosts in 1987 (13).
Paragraph 10 It
seems that any rediscovery efforts should now be targeted away from
Bung Boraphet, and indeed perhaps away from Thailand. How might
we judge where best to look? What secrets have hitherto been disclosed
that might help direct our search? Unhelpfully, the ecology of this
bird remains almost totally unknown, and thus ornithologists have
looked to its presumed relative, the African River-Martin, to provide
clues. Since P. eurystomina feeds largely over both forest
and open grassy country, nesting colonially in tunnels dug in sandbars
of large rivers (14) it has been inferred that E. sirintarae possibly
does or once did the same (4). However, the differently shaped toes
might suggest otherwise (19). At least one of the initial specimens
had mud or sand adhering to its claws, and while this perhaps suggests
a terrestrial perching habit (6), most swallows occasionally do
the same, especially when collecting nest material. Another clue:
in holding cages used during the swallow ringing programme, the
birds stood quietly in the corner of the cage in strong contrast
to other swallows which move rapidly from perch to perch calling
Paragraph 11 In
the unconfirmed report of 1980, individuals were flying after insects
with some Barn Swallows and sometimes perching on the tops of trees
(20). During the 1978 sighting they were apparently skimming the
water surface, possibly to drink (10). While these accounts describe
behaviour characteristic of most swallows, the only direct dietary
evidence is the fragment of a large beetle found in the stomach
of a specimen (1). This fact, along with the mandibular morphology
of the species, implies that it consumes sizeable prey.
Paragraph 12 What
about breeding season, distribution and migratory behaviour? Five
of the nine specimens collected in late January and early February
1968 were immature (1); they were later termed juvenile, and some
of the other material as subadult (2) (although this is not mentioned
in the original description). A breeding site within Thailand was
initially considered plausible on the grounds that so many of the
type series were young (2). It has also been speculated that if
nesting occurs in Thailand it is most likely to do so between March
and April, as this coincides with the local nesting season for the
majority of insectivorous birds, while the monsoon rains from May
onwards presumably raise water levels above the riverine sandflats
postulated to be the favoured nesting habitat of the species (5,6,10).
It is unlikely, however, that juvenile plumage would be retained
for eight months, and thus these two facts are difficult to reconcile.
The White-eyed River-Martin has otherwise been thought a non-breeding
visitor to south-central Thailand (20) and clearly migratory (4),
but these assumptions should also be treated with care. Although
it has only been found between December and February, and despite
the above disparity, there is insufficient information to rule out
breeding in the Nakhon Sawan area (6,11). In conclusion, it is unclear
whether the species is, or was, a migrant at all.
Paragraph 13 As
recent searches around Bung Boraphet have been unsuccessful, let
us assume it is a migrant. If it travelled across Thailand, where
did it come from? The riverine nesting grounds might possibly lie
along one of the four major watercourses (the Ping, Wang, Yom and
Nan) which drain northern Thailand, either in the immediate vicinity
of Nakhon Sawan or to the north (5,6). If it came from further afield,
perhaps these putative breeding grounds lie on one of the other
major river systems of South-East Asia, such as the Mekong in China,
Laos or Cambodia, or the Salween and Irrawaddy in Myanmar (5,6).
Evidence that the species breeds, or has ever occurred, in China
is scant, although a painting by a Chinese artist held in the Sun
Fung Art House of Hong Kong appears to depict the species (15).
This tentative clue has failed to lead to any further information,
and in any case the subject of the painting is more likely to be
an Oriental Pratincole Glareola maldivarum (16).
Paragraph 14 A survey
of the Nan, Yom and Wang rivers in northern Thailand was carried
out in May 1969, but was not comprehensive and relied chiefly on
interviewing villagers, none of whom seemed to know the bird (2).
Rivers near the Chinese border of Laos were searched in April 1996,
local people being shown illustrations of the species, but without
success (W. Robichaud verbally 1997). Very few other surveys have
looked for it outside Thailand and there is still scope for research
in remote regions where a population might survive.
Paragraph 15 Throughout
its possible range there is a catalogue of pressures potentially
imposed on the species (5,6). Man has drastically altered the lowlands
of central and northern Thailand: huge areas are now deforested,
agriculture has intensified, pesticide use is ubiquitous and urban
environments have spread extensively (5,6). In addition, all major
lowland rivers and their banks suffer a high level of disturbance
by fishermen, hunters, vegetable growers and sand-dredgers (5,6).
Whole communities of nesting riverine birds have vanished from large
segments of their ranges in South-East Asia owing to habitat destruction,
human persecution and intense disturbance of most navigable waterways
(5,17,18). Local people routinely trap or shoot birds for food and
for sale in local markets (5,6). Even at Bung Boraphet Non-Hunting
Area (established in 19793) the trapping of birds has continued,
at some level, up to the present (5,6). If the species preferentially
forages over forest, its numbers could already have declined to
a perilously low level at the time of its discovery because of deforestation
and the intensification of agriculture in river valleys (5,6).
Paragraph 16 These
threats are based on the ecological traits inferred by its suspected
taxonomic affinities. It should be borne in mind that riverine nesting
habits and preferences for forest are only an assumption, and that
it might conceivably utilise some entirely different habitat. Even
the name river-martin is perhaps a complete misnomer, as the species
has never been seen on a river and is no longer considered congeneric
with the African River-Martin (7). Interestingly, the most recent
scrutiny of specimens suggested that it was perhaps nocturnal, or
at least highly crepuscular, based principally on its unusually
large eyes (19). This raises the possibility that it is normally
a cave dweller or a hole-rooster in trees or rock, emerging to feed
in twilight or darkness, and this opens up new avenues of exploration.
There are, for example, limestone caves not far from Bung Boraphet,
and many more in Laos and southern China.
Paragraph 17 While
there is only a faint chance that this, one of the most elusive
species in the world (15) still survives, it bears the extraordinary
distinction of being highly unusual in appearance yet overlooked
by naturalists in a well-worked country until the late 1960s. As
it is thus either extremely rare or inexplicably cryptic, it is
not yet time to give up hope for the swollen-eyed bird. Its possible
range should be revisited with a broader outlook. The prize, to
any successful searcher, is considerable: solving one of the most
puzzling mysteries of Asian ornithology.
1. Thonglongya, Kitti (1968) A new martin of the
genus Pseudochelidon from Thailand. Thai
National Scientific Papers, Fauna Series no. 1. Bangkok: Applied
Scientific Research Corporation of Thailand.
Kitti (1969) Report on an expedition in northern Thailand to
look for breeding
sites of Pseudochelidon sirintarae (21 May to 27 June). Bangkok:
Applied Scientific Research
Corporation of Thailand
and Dobias (1984) The fate of the Princess Bird, or White-eyed River
(Pseudochelidon sirintarae). Nat. Hist. Bull. Siam
Soc. 32(1): 1-10.
4. Turner and
Rose (1989) Swallows and martins of the world. Bromley,
UK: Christopher Helm.
5. Round, P.
D. (1990) Bird of the month: White-eyed River-Martin. Bangkok
Bird Club Bulletin 7(1): 10-11.
International (in press) Threatened birds of Asia.
7. Brooke, R.
K. (1972) Generic limits in old world Apodidae and Hirundinidae.
Bull. Brit. Orn. Cl. 93: 53-57.
8. Zusi, R.
L. (1978) Remarks on the generic allocation of Pseudochelidon
sirintarae. Bull. Brit.
Orn. Cl. 98(1): 13-15.
9. Mayr, E.
and Amadon, D. (1951) A classification of recent birds.
Amer. Mus. Novit. 1496: 1-42.
10. King and
Kanwanich (1978) First wild sighting of the White-eyed River-Martin,
Pseudochelidon sirintarae. Biol. Cons. 13:
11. D. Ogle
in litt. (1986).
12. Anon. (1981)
A search for the White-eyed River Martin, Pseudochelidon sirintarae,
Boraphet, central Thailand. Bangkok: Association for the conservation
of Wildlife of Thailand.
13. D. Ogle
in litt. (1987-1988).
14. Keith. S.,
Urban, E. K. and Fry, C. H. (1992) The Birds of Africa,
volume 4. London: Academic
E. (1986) Does the White-eyed River-Martin Pseudochelidon sirintarae
China? Forktail 2: 95-96.
K. C. (1987) Letter: was the Chinese White-eyed River-Martin an
Forktail 3: 68-69.
17. Scott, D.
A. (ed.) (1989) A Directory of Asian Wetlands. IUCN, Gland,
J. W., Salter, R. E. and Khounboline, K. (compilers) (1999) Wildlife
in Lao PDR:
1999 Status Report. Vientiane: IUCN-The World Conservation
Society/Centre for Protected Areas and Watershed Management.
19. P. M. Rasmussen
in litt. (2000).
20. Ogle, D.
(1986) The status and seasonality of birds in Nakhon Sawan Province,
Hist. Bull. Siam Soc. 34: 115-143.