Monday, September 17, 2012

ON THE TRAIL OF THE ESKIMO CURLEW

A male Eskimo Curlew collected at Cape Cod on Sept. 8, 1879
It wasn't supposed to be curlew weather- stifling hot, dead calm, sun glaring through opaque late summer humidity.  And yet, just like that, there it was- a phantom, slipping from a wet swale into surrounding dune grass- just the kind of spot where a century earlier Yankee gunners might have sought it.  It indeed seemed odd that it should slink away like some overhunted, over-persecuted game bird rather than like a typical shorebird that explodes into the air when approached.  It was a medium-sized brown thing, mottled with white, with a longish beak and a striking splash of cinnamon buff visible as it moved off- a glimpse, to be sure, but the cottony buzz filling my head told me I believed I'd actually seen it.  I had been searching for three years, not nearly long or hard enough, I had thought, but just the same there it was.  Wasn't it?

The fact is that Eskimo Curlews have been gone from the collective memories of hunters and birders for so long that it is no longer possible to be sure of what the right conditions for them might have been.  If we can believe fragmentary 19th century reports, curlew weather occurred when fall storms swept off the north Atlantic, carrying with them exhausted birds blown from pelagic routes that led from Labrador to the Argentine pampas.  These were the days that into the 1880s brought flocks of curlews to Cape Cod, Massachusetts large enough to provide sport and meat for the New England market.  A bird at the Museum of Comparative Zoology, Harvard, was purchased from the Boston game market as late as 1902.

The standard thinking is that curlews are now extinct or, even if they are not, they are for all intents and purposes functionally extinct.  And finding them?  There is so much continent to look in that the probability of locating them must approach zero.  So, why bother?  Even a flock could come through some godforsaken spot on some improbable day and who would know?  But- that's the point.  We ought to know, and no one is out looking.

Which brings up another issue: in fifty years of observing birds, I've never had to beat away the crowds to perform field studies.  Few are willing to endure the discomfort, drudgery and dogged persistence required of real field work- not a Saturday afternoon of birdwatching, but the real thing.  If someone actually went out and looked and looked hard enough and long enough in a systematic kind of way, might curlews yet be found and might we then be better positioned to do something about their endangerment?  This is certainly not a project for a new graduate student, who must gather analyzable data, or for an up and coming academic who needs to publish prolifically in order to gain tenure.  Still, shouldn't someone be looking?

Despite the negligible effort being directed toward documenting the continued existence of curlews, credible reports appear every few years- including reports from the vicinity of Cape Cod, where I have focused my efforts.  The Cape and its associated islands, jutting into the north Atlantic as they do, were the main stopover spots south of the fall staging grounds on the coast of Labrador, although conjecture has it that birds from a secondary area at James Bay, Canada, also passed directly over southern New England.

With these possible sightings as my impetus, I began my study by inviting the appropriate Federal agencies to connect their name to the project- not because I sought funding or needed help, but because I knew they should be kept abreast of what I was doing.  National Park Service was most accommodating, but Fish and Wildlife Service proved otherwise. With them, a Boston desk biologist informed me that far better than I had studied shorebirds in this region and found nothing, so there was no reason to grant me a permit to survey their lands.  I explained that those far better biologists hadn't been persistent enough or looked in the right places, but to no avail.

I'd heard all this sort of logic before.  Twenty years earlier, I was told categorically by similar all-knowing bureaucrats that another species- the Aguiguan Reed-warbler- was definitely extinct.  Repeated searches by very experienced researchers had confirmed that it had disappeared from the remote, uninhabited Pacific island of Aguiguan, its only home, and it had been gone for the better part of a decade.  Despite all that, I decided to take a small group of college students to the island for a week of floral and faunal investigations.  We found birds in two days.  It was easy- it was a little island and the species was loudly vocal.  So much for those very experienced researchers.  I don't think they understood how to look.

Finding curlews is quite another matter, however.  In this case, the species is anything but conspicuous and  birds have a whole continent to hide in.  But even this sort of Quixotic quest had a parallel in my experience that gave me some hope that the impossible was still possible.  Back at the beginning of the 1970s when I first began studying coastal birds, I was sitting one steamy summer evening at the Old Lyme, Connecticut boat launch when a silver haired gentleman pulled up in his very large car.  He walked directly over and asked, "Have you heard any?" without ever indicating exactly what he meant.  I recognized him immediately as the venerable Roger Tory Peterson, guru of all birdwatchers, although I didn't let on.  I told him I hadn't, but that I had been sitting there every night listening.  He told me he had done much the same for years but had also had no success.  Without saying so, we were talking about the mythical Black Rail, the first nest of which had been discovered nearby a century earlier.  After that time, the species had disappeared from New England as a breeder.  The rest of our conversation has faded from my memory, although I do remember telling him that I intended to keep trying.

Fourteen year later on a dreary, drizzling evening long after everyone had forgotten I was looking, I found Black Rails within yards of where they had first been discovered in the 1870s.  Trial and error, persistence and a little luck had rewarded me.  Shortly afterwards, I found several summer colonies in the wetlands of the Connecticut River.  I had learned how to find them.  So, my thinking has been that Black Rails provide a better model of what it will take to find curlews.  The rails are notoriously secretive, rare and erratically occurring throughout much of their range, so finding them is painfully hard.  Still, they breed in the temperate zone rather than in the vast and inaccessible arctic.  This alone makes them far easier to find than curlews.  I expect gaining definitive curlew evidence will be at least an order of magnitude more difficult than finding evidence for those enigmatic rails.

During my late summer trek along a path through the maddeningly unstable sands of the Cape Cod dunes, I had, however, also encountered several shreds of physical evidence that linked to my glimpsed bird.  The bird had left tracks at the swale edge that I could measure and photograph.  As I had also measured on museum specimens the middle toes of 70 curlews, I could make a comparison.  The middle toe of the track (minus its claw) was a little less than 4 cm.  The museum specimens averaged just under 3 cm.  If we take into account the expansion of track size in sand and the shrinkage and curvature of toes in specimens, then the tracks were likely at least rather similar in size to those of curlews.

Better yet, a bird had left a feather near the same spot on the swale.  Although it was impossible to know with certainty whether it came from the bird I observed, its markings were at first glance promising.  The cinnamon-buffy colors matched the prevailing colors on curlew specimens and the size and barring was quite like that of flank feathers.  A possible difference, however, appeared at the feather tip.  Here it faded to black-and-white.  In my hundreds of curlew photos, I could find nothing that matched this, although it seemed I had seen feathers like this before.  However, without museum specimens in front of me I couldn't make a positive match.  I have since carefully tucked the feather away, and during one or another upcoming museum visits I intend to find out what it is from.

The bottom line is that I may have found something quite remarkable on that hot day but, alas, the evidence remains inconclusive.  Despite that, I fully intend to continue my search.  If it proves to be anything like my rail adventures, I will be well into my 70s if not 80s, assuming I am still breathing, before I have anything resembling success.  Just the same, long after everyone has forgotten I am even looking, just maybe...


The buffy color, size and barring looked right but the black-and-white tip did not appear consistent with coloring on curlew feathers.

Tuesday, July 24, 2012

LATEST BIRD CONSERVATION NEWSLETTER NOW AVAILABLE


Dear Friends,

Welcome to the July, 2012 newsletter of Bird Conservation Research, Inc.  We invite you to make use of our freely available internet resources at www.birdconservationresearch.org, and to keep up with our latest activities via Facebook and LinkedIn.

The expanded PDF version of the newsletter may  be accessed via our web site at http://www.birdconservationresearch.org/publications/newsletters.php. The newsletter reports the latest findings of the Forest Bird Survey of Southern New England as well as news of recent field trips and recent blog posts.

Best wishes,
Robert J. Craig, Executive Director

Friday, June 15, 2012

STATE OF CONNECTICUT FOREST BIRDS

The State of the Forest Birds, a paper prepared by Bird Conservation Research, Inc. for the 2011 Connecticut State of the Birds, is now available through the Bird Conservation Contributions web site.  The paper is newly abstracted and updated from its original version, and includes absolute population estimates for a number of species.  The estimates are based on data gathered during the eight year Forest Bird Survey of Southern New England, which employed the variable circular plot technique to survey 148 transects in both summer and winter.  Most notably,  the data showed that several species thought to be rare in Connecticut, such as the Cerulean Warbler, had populations larger and more widespread than previously believed.

Wednesday, May 30, 2012

BIRD CONSERVATION CONTRIBUTIONS DEBUTS


This graph illustrates the seasonal change in habitat occupancy by southern New England's Red-bellied Woodpeckers.  Populations shift subtly but significantly from closed canopy forest (cover values approaching 3) in summer to open canopy forests in winter (see Contribution 17 of the Contributions series for details).


Bird Conservation Contributions is now available for use by the scientific community.  It is a new web site  created by publicly supported, non-profit Bird Conservation Research, Inc. that is devoted solely to showcasing scientific publications.   It features a page that links to each work published exclusively by BCR, and it also has a separate page linking to BCR papers published by other outlets. 

Original scientific contributions to the Contributions series are invited.  Instructions to authors are available on the Submissions page.  The Contributions series offers a low cost and unbiased publishing alternative to traditional print outlets.

Thursday, May 17, 2012

POWERPOINT HIGHLIGHTS FOREST BIRD SURVEY OF SOUTHERN NEW ENGLAND




A newly updated, expanded and re-written PowerPoint presentation available from Bird Conservation Research, Inc. highlights accomplishments of the eight-year long Forest Bird Survey of Southern New England- the largest field study on birds in the history of New England wildlife conservation.  It details  initial findings and charts future plans for the data. Earlier versions of this PowerPoint have been used by regional conservation groups as a tool in persuading conservation agencies to protect extensive parcels of forest habitat.  It can also be used as a teaching tool to demonstrate how science theory and science application (in this case, bird conservation) are interconnected and how scientists proceed from asking questions to gathering relevant data to drawing conclusions.

Thursday, May 10, 2012

VARIABLE CIRCULAR PLOT LAB DEMONSTRATES RESEARCH COMPLEXITY

 
The detectability curve for the Brown Creeper provides a mechanism for computing population densities.
Upgrades of the AP Environmental Science lab, Variable Circular Plot, have yielded a college-level investigation into bird community relationships.  It is based on an actual study of forest bird communities and is designed to introduce students to the complexities of real scientific research.  In particular, it illustrates the following:


1. Modern environmental science research is dependent upon tools made available through advanced mathematics.
2. Large samples are essential for uncovering patterns in nature that are distinguishable from random variation.
3. Statistical considerations like sampling independence must be considered if data gathered are to be validly interpreted.
4. Data may be categorized as continuous or categorical, and doing so affects the type of analyses that can be performed.
5. Real scientific investigations often require teams of individuals to work together in order to gather sufficient data to evaluate hypotheses.
6. A first step in understanding data gathered is exploratory data analysis, which includes graphing raw data to preview them for the occurrence of patterns.
7. Developing greater insights into findings often involves using synthetic data- data derived from raw numbers; e.g.converting numbers to percents, converting counts of birds into population density estimates.
8. Completely understanding what an investigation shows is a complex task that involves examining data from multiple points of view.
9. Because hypotheses to be tested are not explicitly spelled out, students must consider what hypotheses are testable with available data and which of these hypotheses are worthy of consideration.

Friday, May 4, 2012

SCIENTIFIC WRITING PRIMER AND LAB REPORT RUBRIC

The lab activities tab of the Bird Conservation Research, Inc. web site has been updated, notably by the inclusion of a step-by-step primer on how to write lab reports in scientific paper format.  Attached to this is an updated lab report rubric.