Wednesday, October 31, 2007

Green-breasted Mangos in North America

Green-breasted Mango Anthracothorax prevostii

This species is not included in the Sibley Guide to Birds because at the time that I was planning the book there were only two records north of Mexico. By the time I had finished the book there were 7 records (enough to warrant inclusion, if only I had known sooner!). Records have continued to increase with the total as of today up to at least 16 in Texas (through 2006) and single records in NC, WI, and GA. The WI and GA records are both in fall 2007, prompting this summary. Obviously it's a species that should be watched for all over the US.

Identification
A report by John Arvin on identification of Mango Hummingbirds from the minutes of the 1995 Texas Bird Records Committee meeting:
Arvin discussed his findings regarding identification of immature/female Mango sp. hummingbirds of Central America and northern South America. Arvin has now visited 3 of the 4 major North American collections with numbers of Mango specimens (LSU, Smithsonian, and Field Museum of Chicago; American Museum of Natural History specimens have not been examined). He examined all specimens of the 3 mainland Mango species which are possibly confused:
- GBMA - Green-breasted Mango (Anthracothorax prevostii)
- GTMA - Green-throated Mango (A. viridigula)
- BTMA - Black-throated Mango (A. nigricollis)
A brief summary of distinctive aspects follows:
GTMA is a scarce hummer of n.e. S. Am. It is rare in collections. Fem/imms are easy to separate because the dark stripe on the center of the underparts is short, extending barely past the throat.
BTMA occurs in humid tropical lowlands. Fems/imms are very similar to GBMA except that the central dark stripe NEVER shows any blue or green iridescence; it is flat black.
GBMA is highly migratory at least in the northern part of its range. GBMA fem/imms have varying amounts of color in the central dark stripe but: No GBMA failed to show at least a little blue or green color (at least a few metallic feathers) in the stripe. Thus, IF a mango is a fem/imm and IF any blue/green iridescence is seen in the dark belly stripe, it is a confirmed Green-breasted Mango. If no color is seen, it may be accepted at least as a mango sp. Based on geographic probability, and the fact that the northern pops of GBMA are migratory and no other pops of any of the other spp. are, it is a virtual certainty that any mango sp. in Texas is a GBMA (barring escaped captive). TBRC members may continue to make their own decisions on how conservative they may choose to view records in which no color in the central stripe is seen.
Arvin could find no other plumage differences that would be useful at distinguishing fem/imm GBMA and BTMA. Apparently the amount of rufous/rusty on the sides of the neck does NOT help; it is quite variable within and between these two species.
North American Records:

Texas 1) - 14-23 September 1988. One female or immature was at Brownsville, Cameron Co, TX. Originally accepted only as Mango species (Anthracothorax species) this record was later accepted as a Green-breasted Mango based on geographic probability after a pattern of other documented records developed. the first record of its genus in the United States.

Texas 2) - 6-27 January 1992. One female or immature in Corpus Christi, Nueces Co, TX.
photo here and here. From TBRC 1993 report.

Texas 3) - 22-27 September 1993. One female plumaged bird, in Falfurrias, Brooks Co, TX. 1995 TBRC report

Texas 4) - 18-20 August 1993. One immature was photographed at Santa Ana NWR, Hidalgo Co, TX. 1996 TBRC report

Texas 5) - 17-20 August 1996. Up to two were at San Benito, Cameron Co, TX, 1997 TBRC report

Texas 6) - 3-8, and 21 November to 21 December 1997. One at Corpus Christi, Nueces Co, TX, 1998 TBRC report

Texas 7) - 22-23 May 1999. One at Los Fresnos, Cameron Co, TX. 2000 TBRC report

North Carolina 1) - 12 Nov - 4 Dec 2000. One immature male in Concord, Cabarrus Co, NC. Article in The Chat here (pdf) photos here and here

Texas 8) - 1-8 February 2001. A male at McAllen, Hidalgo Co, TX,

Texas 9) - 10 July-15 August 2001. A female or immature at Pharr, Hidalgo Co, TX,

Texas 10) - 28 September-18 October 2001. A male at McAllen, Hidalgo Co, TX, TBRC 2002 report

Texas 11) - 23 November 2001-12 February 2002. A male at McAllen, Hidalgo Co, TX,

Texas 12) - 9 September- 23 October 2002 The same male returned to McAllen, Hidalgo Co, TX, TBRC 2003 report

Texas 13) - 22 August-5 December 2004. One adult male at McAllen, Hidalgo Co, TX, photos here

Texas 14) -
20 September 2004-25 January 2005. One (or possibly two) adult male(s) at McAllen, Hidalgo Co, TX, photo here and here and here (labeled Pharr, TX?) and here

Texas 15) -
18-20 June 2005. An imm. bird at San Benito, Cameron Co, TBRC 2005 report

Texas 16). 8-9 July 2006. An imm. bird at San Benito, Cameron Co, TX, TBRC 2006 report

Wisconsin 1) - early Sep - 5 Nov+, 2007. Immature or female at Beloit, WI; photos here and here and here. This bird was captured on 5 Nov 2007 and taken into captivity, details here.

Georgia 1) - 25 Oct - 11 Nov+, 2007. One immature or female at Dublin, Laurens Co. GA; photos here and here and here


References:
TBRC annual reports and minutes can be found here

Tuesday, October 30, 2007

Certainty in sight records

In late August 1982 I walked into the weedy fields at the South Cape May Meadows in search of rare birds. Among many species that I had in mind as possible "prizes" that day was Loggerhead Shrike and, lo and behold, a scan of the bushes ahead revealed a small, white-breasted, dark-masked bird perched conspicuously on top of a slender post - a Loggerhead Shrike!

I looked for a couple of seconds and then quickly moved closer hoping to sit down to study and sketch this rare find, only to discover that it was gone. Not only was the shrike gone, I couldn't even find the post it had been on! In place of both was a Great Egret calmly hunting the grassy edge of a pond.
Such is the power of suggestion. I thought I might be rewarded that morning with a sighting of a Loggerhead Shrike, and I managed to create the vision I desired out of the pattern of shadows on a Great Egret, complete with dark mask, long tail, and the right shape and posture.

If the situation was different and I was only able to see it from a distance for those first few seconds, it's very possible that I would have convinced myself that what I had seen was real and that I would have reported seeing a Loggerhead Shrike. And if anyone had questioned it I would have said I was absolutely certain. After all, I was an experienced observer and I saw multiple diagnostic field marks. What else could it have been?

This is the fundamental problem with all of the recent Ivory-billed Woodpecker sightings. Claims of certainty and lists of diagnostic field marks are simply not as meaningful when they are based on such brief views.

Proponents still emphasize the number of sightings and the fact that some auditory and visual encounters are clustered. They ask "What are the chances that all of those people were mistaken?" Referring to one of his own brief sightings, Geoffrey Hill asks "What are the chances that just as I was misidentifying a Pileated Woodpecker as an Ivory-billed Woodpecker, I would hear another pileated give a double-knock?"

First of all, these questions are spurious and attempt to shift the burden of proof to the skeptics. It is not up to the skeptics to show how all observers could be mistaken. The simple answer is "Yes, that is possible." There is no proof and whether these observations are more likely to be correct or incorrect is simply a debate over percentages.

I would argue that the chances are very good that one misidentification led to another, since these events are not independent. Here's a possible scenario:
An observer hoping to see an Ivory-billed has an ambiguous view of a bird flying away. In the moments after, while processing the flickering black-and-white pattern of the wings and while most susceptible to suggestion, a single double-knock-like sound is heard. The sound (even though it too was ambiguous and was clearly not produced by the bird that flew away) helps cross a decision threshold - that Ivory-billed is likely, that the white really did seem to be on the trailing edge of the wings, and that the bird that just flew away must have been an Ivory-billed.

That decision in turn influences the perception of the double-knock-like sound, which then seems less ambiguous and "must have been" a second Ivory-billed. And as the observer reconstructs memories of the event and adds other subtle impressions to support the identification ("that was no Pileated Woodpecker!"), a circular reinforcement occurs. The retrospective perception of the wing pattern and sound actually change as positive elements are replayed and negatives ignored. The more certain the wing pattern seems, the better the double-knock sounds, which reinforces the interpretation of the wing pattern, and so on.

This may not be exactly what happened in this case, but all of these effects are well-documented in psychological research.

No intentional falsification or fabrication is needed, simply a subconscious selection of evidence supporting the favored conclusion, and a subconscious omission of refuting evidence. This generates false confidence. Once the perception is formed and "confirmed" it becomes nearly immune to question or revision. Claims of certainty and "multiple field marks seen" must be judged in the context of the situation. Longer and better views of a bird require less interpretation and give the observer more information and more opportunity to correct mistakes. Views as poor as all of the reported Ivory-billed sightings are far from certain.

This does not mean they should be ignored, and they have not been ignored. The reported sightings have inspired and guided massive search and conservation efforts in the last three years and before. Sightings should continue to be carefully reviewed and followed-up, but we have to be realistic about the strength of those sight records. If unprecedented search efforts fail to find what a few people glimpsed three years ago, it might indicate that those observers were mistaken.

Tuesday, October 23, 2007

Ivory-billed Woodpecker - status review

In August 2007 the US Fish and Wildlife Service published the Draft Ivory-billed Woodpecker Recovery Plan and invited public comments (the deadline was 22 Oct 2007). I'm posting a slightly edited version of my recently-submitted comments here. Although I'm critical of many aspects of the claimed rediscovery, and some may reject my views outright, I think raising these issues is in the best interests of conservation and birding, and I hope these comments can be constructive in an ongoing dialog. I think this is a very important issue with repercussions far beyond the central question of whether or not the species still exists.

I have been skeptical of the Ivory-billed Woodpecker reports since about two weeks after the announcement in April 2005. This view has only become stronger over time and is based on my thorough study of the published evidence, drawing on my 35 years of experience as a birdwatcher and student of bird identification, and on my experience reviewing countless similar rare bird reports.

I find this Draft Recovery Plan fundamentally flawed, as it presumes that there is an urgent need for action based on "convincing evidence of the species' existence" when in fact no independent review finds that evidence convincing. The 2005 claim of "irrefutable proof" was incorrect; and was based on ambiguous evidence misinterpreted through hope and desire (commonly called wishful thinking). The case for the bird's continued existence rests on a few seconds of extremely blurry video (shown to be consistent with Pileated Woodpecker), a handful of fleeting glimpses by observers steeped in expectations, faint audio recordings that more or less resemble Ivory-billed sounds (among other things), and a belief that all of these possibly suggestive bits add up to a compelling body of evidence (1). None of the evidence stands up to scrutiny; there is no proof. Most importantly, hundreds of thousands of person-hours of intensive search efforts since 2005 - which could have confirmed the sight reports - have not produced any confirmation at all.

Based on such weak and ambiguous evidence, the proposal to spend up to $27.7 million of a very limited budget on efforts to find and recover the Ivory-billed Woodpecker is unsupportable. Hundreds of other species with well-documented needs would be better-served by those resources.

Opinion vs. Science

An important point to understand is that the scientific debate does not directly address the question of presence or absence, only whether the bird's presence has been confirmed. It has not. From the lack of confirmation one can infer absence, but absence cannot be proven. The burden of proof is on those who claim to have found the bird.

Many people apparently hold a positive interpretation of the evidence because of a personal belief in one or more of the sight reports, or a feeling that the combined body of evidence is convincing and that at least one of the many reports must be correct. But the body of evidence is only as strong as the single strongest piece - ten cups of weak coffee do not make a pot of strong coffee. Without evidence that can be reviewed and verified objectively and independently (the scientific standard) the debate is just so many personal opinions.

The only potentially verifiable evidence to date is the brief video recording from Arkansas, but independent reviews have refuted the claim that this shows an Ivory-billed Woodpecker, and even the most generous impartial reviewers now consider the video inconclusive. With every day, month, and year of searching that fails to produce any other verifiable evidence, the bird's presence becomes less likely.

All the skepticism of Ivory-billed Woodpecker reports could be reversed by a clear photograph tomorrow, in the same way that scientific skepticism over ESP could be reversed by one reproducible experiment. The steady decline in confidence about the Ivory-billed Woodpecker is largely because an intensive research effort over the last three years has failed to produce any proof. In fact what discoveries have emerged from those three years of research (on sounds, flap rates, etc.) have only weakened the original case.

Thomas Gilovich (1991, writing about ESP research) suggests that we can gain perspective by reframing the question we ask. There is a tendency to ask simply: "What evidence supports the claimed rediscovery?" This naturally causes us to emphasize only the supportive elements of the evidence. Instead we can ask: "If Ivory-billeds survived, and an intensive research effort was designed to document their presence, what would we expect to discover in three years of field work?" This question directs us to consider the negative data - the absence of confirmation - along with the positive points. As of October 2007 there are a few reported brief sightings but no photograph (not even a prolonged view). There are tantalizing faint snippets of audio recordings but not a single recording of a clear series of Ivory-billed sounds. There are suspicious excavations and bill-markings on trees, but automated cameras have repeatedly revealed only common woodpecker species at these sites. I'm sure everyone expected more, and is disappointed by the few fragmentary bits of ambiguous data that have actually emerged from all of this effort.

And the formal search efforts of the last three years are dwarfed by the combined observations of millions of naturalists and birders across the southeast over many decades. For over sixty years birders have been fascinated by the Ivory-billed Woodpecker. They have searched promising habitat and followed up any plausible report with genuine excitement and hope, and with a total absence of definitive results. The modern style of birding (chasing rare birds) relies on the fact that a bird - once found - can be found again. Birders avidly check out all kinds of rumors, share directions to the locations of rare birds, and develop bird-finding skills to the point where even the most elusive species can be found and refound (a single Yellow Rail in a marsh in Massachusetts, for example). If the Ivory-billed Woodpecker still existed, the odds that it could consistently elude this army of skilled searchers is vanishingly small. There are still plenty of discoveries waiting to be made, but the implication that birders have been unmotivated and unobservant, and that a population of giant woodpeckers could remain undetected across several states, is simply not plausible (2).

Sightings as evidence

About 30 sightings have been reported since 2004. Many people now point to these as the most convincing evidence, and misrepresent the skepticism over sight records. All sightings to date have been extremely brief glimpses of birds, most were flying away, and most were viewed by a lone observer without the aid of binoculars. All sightings emphasize a single field mark - the white trailing edge of the wing. Some mention vague and subjective (and inconsistent) impressions of size and shape. Other distinctive field marks (such as the large pale bill) have not been seen. Several of the observers actually admit that they are not certain what they saw.

The psychology of perception is very well-studied (1) and shows that all kinds of observer effects can operate subconsciously to alter perception and cause misinterpretation. This is particularly true when the thing being observed is ambiguous (such as a very brief and incomplete view of a bird flying away). What we perceive under those circumstances is easily influenced by expectations, peer pressure, hope, and many other factors.

As most birders know from personal experience, the excitement and anticipation of searching for any reported rare bird often generates spontaneous "false positive" sightings of the sought-after species. Our perception can be very different from reality, and the expression "I know what I saw" is never strictly true. The heightened excitement of the search could easily cause some observers to misinterpret the white wing pattern on a bird glimpsed flying away.

This is why experienced birders repeatedly emphasize the importance of seeing more than one field mark to double-check an identification, and of seeing a bird long enough to confirm and reconfirm all of the observed features. That is still no guarantee of accurate perception, but even that minimum threshold is not met by any of the reported Ivory-billed Woodpecker sightings.

The skeptical position is not in any way a rejection of the value of sight records in birding. Skeptics include the vast majority of North America's most experienced birders, who all rely on sight records but understand how easy it is to make a mistake. Questioning these sight records does not question the honesty or integrity of the observers, it simply acknowledges the fact that perception can be flawed, and that brief views are easily misinterpreted. All observers are fallible, and errors in bird identification are common. The bottom line is that there is simply no way of knowing what was seen.

Proponents often argue that when skeptics discount the eyewitness reports they are setting unreasonably high standards for the evidence. This is not true, and ignores the fundamental weakness of the evidence to date. The opinions of many skeptics would change based on a single sighting of a bird watched for a substantial period of time (even one minute would do), seen through binoculars, with multiple field marks studied and reconfirmed. Experience with other rare birds, especially resident species, suggests that any valid sighting should very quickly lead to more sightings. A pattern of sightings by independent observers, of birds well-seen and studied (not just flying away), would be convincing to most birders even without photos, at least for a while. But even that confidence would fade if the sightings did not eventually lead to verifiable evidence such as clear photos or video.

This level of evidence - redundant sightings and photos - is not difficult to reach with any other North American bird. Yet the Ivory-billed Woodpecker, supposedly resident in a defined area of wooded habitat and reportedly seen by a few observers, still cannot be found and confirmed by thousands of searchers. The continuing absence of any confirmation has caused many birders to reexamine the reported sightings of Ivory-billeds in that context. Should we put more faith in the few reported glimpses, or the countless thousands of hours of unsuccessful follow-up search efforts?

Proponents argue that the sightings are unquestionable and that the species must have become very silent and secretive since the 1940s, and thus very difficult to find. Skeptics argue that all sightings are inherently questionable, and do not confirm the bird's presence, let alone a change in behavior. Accepting the sightings requires one to ignore mounting negative evidence and to invoke a radical and speculative (and unlikely) hypothesis of behavioral change (3). It now seems far more likely that the few reported sightings involve simple, everyday mistakes in perception, and the reason the bird cannot be confirmed is because it is not there.

The Draft Recovery Plan

The authors of the plan admit that confirmation is lacking, but still insist that the evidence is "convincing" and strong enough to warrant a potential $27.7 million of spending in five years (2006! to 2010) which is nearly 5% of the Endangered Species Program's total budget for those years. Some of the money (about half) would be spent on habitat management, the rest on search efforts and research, but regardless of how it's being spent $27 million of public money is too much for an unconfirmed species and could be more beneficial to other species.

The Draft Plan (p. 3) defends this high level of attention by stating that "the U. S. Fish and Wildlife Service is charged to promote conservation and recovery of this species" [emphasis added]. But the U. S. Fish and Wildlife Service is charged to promote the conservation and recovery of all threatened and endangered species, not just this one. Making the Ivory-billed such a high priority inevitably diverts resources from other species.

If every endangered and threatened species had a multi-million dollar budget the Ivory-billed funding would not raise serious concerns. But proposing $27 million for the Ivory-billed Woodpecker, when nearly 1400 other threatened and endangered species receive an average of only a few thousand dollars each, is shockingly unfair.

The Endangered Species Act specifies that:

"The Secretary, in developing and implementing recovery plans, shall, to the maximum extent practicable - (A) give priority to those endangered species or threatened species, without regard to taxonomic classification, that are most likely to benefit from such plans..."

It doesn't say "most charismatic" or "most popular", or even "rarest", it says "most likely to benefit". The Ivory-billed Woodpecker appears likely to be extinct, and therefore not likely to benefit from a recovery plan. Unless it can be found and studied, there is no evidence that it needs any management, and no way of knowing what actions might be harmful. Based on what is known today, almost any of those 1400 other species are more likely to benefit from the resources allocated to the Ivory-billed.

We need to do more for endangered species and I support major increases in funding for the Endangered Species Program. But spending such a large proportion of the current limited budget on one questionable species is wrong and appears to violate the Endangered Species Act. It diverts resources from many species with real, well-documented needs to a single unconfirmed species in an unknown location. In a finite budget there is no conceivable rationale for giving an unconfirmed species hundreds of times more funding than the average threatened or endangered species.

Disturbingly, the recovery plan dismisses the scientific debate in a few sentences. In fact, the debate has been largely one-sided. Not a single independent review has supported the claimed rediscovery of Ivory-billed Woodpecker. All independent reviews to date have reached the same conclusion: that the video from Arkansas matches a Pileated Woodpecker, and that all other evidence is, at best, inconclusive. My colleagues and I published a careful analysis of the Arkansas video (Sibley et al. 2006) showing that a Pileated Woodpecker could account for all of the observed features. The Draft Plan dismisses our work and doesn't even mention independent published research (e.g. Collinson 2007) that fully supports our conclusions. This selective and biased presentation, and the cursory dismissal of objective science by the draft plan, is extremely troubling.

After three years of fruitless search efforts, with several studies refuting the original claim and not a single independent study supporting it, it is grossly misleading to suggest that the evidence is "convincing" and it is irresponsible to place the hypothetical needs of this species ahead of the known needs of so many others. Relentlessly pushing an expensive, single-species policy without scientific support reflects badly on the entire endangered species program. It invites criticism, fosters dissent, and erodes trust.

Ultimately, there is the simple truth that beliefs and possibilities are not a valid basis for conservation policy. Chasing hopeful stories rather than following sound science sets a very bad precedent and leads down a slippery slope where political manipulation thrives.

This recovery plan should be shelved until a real living Ivory-billed Woodpecker is found and confirmed. After three years of unsuccessful government-funded search efforts, the continuing search can safely be left to the army of highly trained and motivated volunteer birdwatchers and naturalists, and the $27 million should be distributed to those confirmed endangered species that are most likely to benefit.

The big picture

The use of the Ivory-billed Woodpecker's questionable rediscovery as a beacon to guide and promote conservation is fraught with pitfalls. Since 2005 a tremendous amount of work has been done exclusively for this species. Some of that work will benefit other species incidentally, but we will never know what could have been accomplished if those same resources had been put to use in a more inclusive plan. Intangible gains from this episode (such as increased public awareness and engagement) are offset by long-term losses (such as disillusionment and distrust) as it becomes clear that the dream we gambled on is actually not becoming a reality.

The rediscovery of the Ivory-billed Woodpecker was hailed as a bright spot in the often-discouraging environmental news. It is a very alluring and positive story of hope, but its central claim is apparently false and it is promoting a fantasy - that living things are ever so resilient and that we have an opportunity for a sort of environmental salvation, a chance to redeem our past transgressions.

The story that we have a second chance with the Ivory-billed carries the dangerous implication that clear-cutting the southern hardwood forests a century ago was not as devastating as we all thought. It promotes the false hope that in spite of our unsustainable use of resources the Ivory-billed Woodpecker was able to adapt and to survive the total destruction of its habitat. And some will take the next logical step and assume that if we have a second chance to save the Ivory-billed, maybe we can continue to clear-cut and develop land and still expect a second chance to save Spotted Owl, California Gnatcatcher, and others.

Efforts to preserve and restore bottomland hardwood forests in Arkansas are laudable, and we all decry the short-sightedness that allowed the cutting of those forests seventy years ago. But even as we focus on those Arkansas forests and the plight of the Ivory-billed, we continue to demand the cutting of old-growth forests elsewhere. Our unrestrained and unrepentant consumption is still dismantling other ecosystems across the continent today. We have failed to apply the most basic lesson that the Ivory-billed Woodpecker's history should teach us.

We all wish that Ivory-billed Woodpeckers still lived, but unrealistic hopes of the species' survival are not helpful. We need to accept the tragic loss of the Ivory-billed Woodpecker, and move beyond it, in order to understand the consequences of our actions then and now. Only that will give us the clarity and the commitment needed to take on the biggest environmental challenges of the present.

Notes

1 - for a detailed review of the psychological aspects and how even scientists can succumb to wishful thinking see Risinger et al., 2002 and Gilovich, 1991.

2 - Skepticism of the Ivory-billed's ability to hide from birders was expressed more eloquently in Rick Blom's commentary in Bird Watcher's Digest which was published in 2003, well before the Arkansas reports.

3 - Among many logical flaws in the supporters' arguments is the logical fallacy known as affirming the consequent. The example from Logical Fallacies:

(1) If Zeus was a real, historical figure, but the Catholic Church covered up his existence, then we wouldn't have any evidence of a historical Zeus today.
(2) We don't have any evidence of a historical Zeus today.
Therefore:
(3) Zeus was a real, historical figure, but the Catholic Church covered up his existence.
This is obviously flawed, but corresponds to what Geoff Hill and others are saying:
(1) If the Ivory-billed Woodpecker survived past the 1940s, but became extremely wary and silent, we wouldn't be able to find solid evidence of it today.
(2) We can't find solid evidence of it today.
Therefore:
(3) The Ivory-billed Woodpecker survives but is extremely wary and silent.

Literature cited:

Blom, E. A. T. 2003. Seeking the Ivory-billed Woodpecker. Bird Watcher's Digest. Sep/Oct

Collinson, J. M. 2007. Video analysis of the escape flight of Pileated Woodpecker Dryocopus pileatus: does the Ivory-billed Woodpecker Campephilus principalis persist in continental North America? BMC Biology 5:8

Gilovich, T. 1991. How We Know What Isn't So: The fallibility of human reason in everyday life. The Free Press: New York. 218pp.

Risinger, D. M. et al. 2002. The Daubert/Kumho Implications of Observer Effects in Forensic Science: Hidden Problems of Expectation and Suggestion. California Law Review. 90:1-56

Sibley, D. A. et al. 2006. Comment on "Ivory-billed Woodpecker (Campephilus principalis) Persists in Continental North America". Science 311:1555

Saturday, October 13, 2007

Troubled times for Spoon-billed Sandpiper

The enigmatic and charismatic Spoon-billed Sandpiper may be headed for extinction according to a Bird Life International report. The population estimate, never more than a few thousand pairs, has recently plummeted to only 200 to 300 breeding pairs.
The reasons for these losses are complex, involving changes to habitat during migration and loss of breeding areas. What is clear is that nest predation by foxes and disturbance by people and dogs could prove to be the final nail in the coffin for the few birds left.
This is just one of many species in decline, of course, and we shouldn't play favorites, but this would be a particularly tragic loss. Check out the Bird Life report for more details and to help.

Wandering Flamingos

A fascinating story of two flamingos, one from the Yucatan that provides a very rare undisputed US record of a wild bird, and another from the Old World (via a Kansas zoo) that shows how widely an escaped bird can wander.

Details and a great comparison photo are on the Louisiana Ornithological Society website

Thursday, October 4, 2007

More Siberian vagrants

In my previous post about Siberian birds I made a tenuous connection between an above-average season for vagrants in the Bering Sea and a few vagrants farther south and east. Updates from Gambell by Paul Lehman show a continued surge of Siberian birds, highlighted by North America's first Sedge Warbler, and even more of the species recorded earlier in the fall (e.g. a final season's total of ten Little Buntings). Saint Paul Island in the Pribilofs has been just as exciting (updates here and some photos here - but you'll have to search all the way back to Aug 2007), with North America's 2nd or 3rd Grey Heron, another Yellow-browed Warbler (second this fall and fifth for North America), and a remarkable fallout of multiple Eye-browed Thrushes and Grey-streaked Flycatchers, along with Siberian Rubythroats and other species. This fallout also reached Adak 450 miles southwest in the Aleutians and a few birds reached Gambell 450 miles north of St Paul. The total number of Eye-browed thrushes and other species falling out across such a wide area must have been huge.

Back in the lower 48, along with the 3 Arctic Warblers and the Common Rosefinch previously reported, there was an undocumented report of a possible Old World Flycatcher in Monterey, CA on 30 Sep, with one listserv post suggesting that Mugimaki Flycatcher was the leading ID contender. That bird was not relocated and remains unconfirmed, the same as a report of a Brown Shrike near Anchorage AK at about the same time.

I still think it's wise for birders all over North America to familiarize themselves with Eye-browed Thrush, Siberian Rubythroat, Little Bunting, Siberian Accentor, Brown Shrike, and other species so that you will be prepared for the remote possibility that one lands in front of you. But also bear in mind that increasing expectations like this will lead to "false alarms" as Mark Brown describes here, turning an apparent Savannah Sparrow into a possible Lanceolated Warbler- it happens to all of us. But if you're pretty certain you've found something rare, get the word out so other birders can see it, and try to take photos to document it.

The first challenge is finding or noticing the bird: overcoming the natural tendency to pigeon-hole it into an expected species. After that you can worry about confirming your identification.