Red Crossbills range all over North America’s western mountains and northern forests, filling the air with their brief, metallic chips and attacking pine, fir, and hemlock cones with their unique bills. But there’s a growing realization that this species consists of a whole group of distinct types—some of them possibly even full species. Plumages don’t differ much from one crossbill type to another, but the evidence lies in subtle differences among those chip notes and crossed bills.

Last week was the annual meeting of the American Ornithologists’ Union, where hundreds of scientists get together and talk about pretty much any topic of study that has ever been brushed by a feather. The University of Wyoming’s Craig Benkman summarized his career’s work studying Red Crossbills. Wesley Hochachka, assistant director of Bird Population Studies at the Cornell Lab, was on hand and sent us this account. Here’s Wes:

The world is full of amazing “radiations” of birds—that’s what evolutionary biologists call groups of closely related species that have evolved amazing diversities of plumage, size, bill shapes, and habitat requirements. The Darwin’s finches of the Galapagos Islands and the many species of Hawaiian honeycreepers are two of the most famous examples. So, why would a scientist choose to study a radiation of birds that all look very similar—all subtly hued and devoted to a single food, conifer cones?

Craig Benkman answered that question convincingly in his plenary talk on crossbills at this year’s American Ornithologists’ Union meeting. Craig has spent decades studying crossbills, and having known him for many years I think that he probably lives, thinks, and dreams crossbills (and it wouldn’t surprise me if he sprinkles pine nuts on his breakfast cereal too). Right now, we recognize two species of crossbills in North America—but Craig’s work shows ecological grounds for the possibility that there are many species of crossbills coexisting right under our noses.

Crossbills are finches whose beaks, as their name suggests, cross at the tip. This seeming malformation is actually a wonderful adaptation that allows the birds to access seeds hidden between the scales of conifer cones, seeds that are inaccessible to other species of birds. The curved bills, coupled with crossbills’ ability to shift their lower mandibles sideways, allow the birds to pry open conifer cones and extract the seeds with their tongues. If that’s hard to envision, here’s a video that explains how a related species, White-winged Crossbills, do it).

Over his career, Craig has uncovered that among Red Crossbills, this remarkable feeding adaptation is even more finely specialized. Several different types of crossbills (they may be species, or near-species) each specialize on a different species of conifer—because different kinds of trees have differently sized cones and seeds. The sizes of the crossbills’ beaks closely match the cones they feed on and can efficiently pry apart the cone scales to get at the seed inside. Even the part of the beak used to crack open the conifer seeds, once they are extracted, is sized appropriately.

In western North America, where conifers come in widely varying sizes and shapes (such as ponderosa pines, lodgepole pines, Douglas-firs, and western hemlocks), this has led to the existence of multiple “types” of Red Crossbills. Each has not only a differently sized beak but also a distinctive call note that can be used—by birds or bird watchers—to tell the types apart. These types may or may not be full species, but they use different food sources, usually live in different geographic regions, and choose members of their own type with which to mate. So they in many ways behave like isolated species. The AOU’s North American Classification Committee periodically reassesses the evidence to decide whether to grant them full species status.

Another theme to emerge from Craig’s talk was that it’s not just crossbills that adapt to cones—the cones adapt to crossbills and other seed predators, such as squirrels. Red squirrels can outcompete crossbills for conifer seeds, because the squirrels preemptively cut the cones off trees and store them underground. In places with lots of red squirrels, the types of defensive structures on cones appear aimed to dissuade squirrels and not crossbills.

Even more dramatic evidence of the competition between squirrels and crossbills comes from two “islands” in Canada: the Cypress Hills, in Alberta and Saskatchewan, and forests on Newfoundland. The latter is a true island, and the former a biological island: forested slopes surrounded by prairies. Both of these “islands” held distinct and unique types of Red Crossbills, and before human intervention neither “island” was occupied by squirrels. Now, both of these crossbill types are either extinct or approaching extinction due to the introduction of red squirrels.

While crossbills may not be the most dramatic of birds to see or hear, Craig’s story provides a fascinating look into the ways in which animals and their food supplies can be tightly, and delicately, tied to each other.

Read more about the many types of Red Crossbills in this Living Bird article from 2010.

(Image: Red Crossbill photographed in British Columbia by Mike Wisnicki, via Birdshare)

What does the future of conservation look like? According to Wesley Hochachka, it looks fast and young. We last heard from Wes on the island of Helgoland, and before that in Brazil, but this week he’s at a conference at the American Museum of Natural History. Here’s Wes with his impressions:

Sure, I know that New York City has a reputation as a fast-paced place, but even here asking researchers to give a complete seminar in four minutes seems a bit much. Under these conditions, I suppose it was inevitable that someone would oblige entirely in haiku.

That’s just a glimpse of the energy and creativity in evidence at the first Student Conference on Conservation Science–New York. This conference, being attended by graduate students and postdoctoral scholars from around the world (several of them currently students in North America), is organized as a way of enabling the emerging generation of conservation researchers to make connections, exchange ideas, and help shape the direction of future research in conservation. It’s a sister to the highly successful Cambridge Student Conference on Conservation Science, which has been running since 2000 in the UK. Along with the students and postdocs are a few more-established researchers, including our contingent from the Cornell Lab of Ornithology: myself, director John Fitzpatrick, and Dr. Ben Zuckerberg, a research associate in our Citizen Science program. We are here as mentors, giving workshops, evaluating presentations, and engaging with the students. In theory we are here to impart knowledge, but in reality we are learning as well.

Even with the conference only at its halfway point, I have been impressed by the diversity of research topics presented in talks and posters, and especially by the abilities of presenters in the “speed talk” sessions. The idea is to cram as many presentations into the shortest possible amount of time, and then allow a 30-minute period for questions and discussions around the conference room.

In addition to the haiku describing research into predicted effects of climate change on life histories of cold-blooded animals (predicted to live shorter lives, work by Santiago Salinas, who is a student at the State University of New York, Stony Brook), another talk that caught several people’s attention was one examining human attitudes to threatened species, and specifically whether positive marketing of one parrot on the Caribbean Island of Dominica would rub off on the island’s other parrot (unfortunately, it doesn’t), which is work by Leo Douglas, a student at Columbia University. The general topic of human attitudes and their importance for the success of conservation projects is strongly represented on the sociological side of this conference. Those are just three examples of the diverse topics that are being discussed by the up and coming generation of conservation scientists from around the world.

A few weeks ago, Wesley Hochachka was at the International Ornithological Congress in Brazil, learning about using satellites to do fieldwork more economically. Now he’s on an island in the North Sea called Helgoland, just off Germany and Denmark. Like places such as Cape May, New Jersey, the barrier islands of the northern Gulf of Mexico, and the Farallon Islands of California, it’s a famous “migrant trap”—a patch of land surrounded by water that serves as a refuge to tired migrating birds. Here’s Wesley:

I was told to keep my travel plans flexible because bad weather could keep me from getting on or off the island. There’s not much more than half a square mile of land here, and even that has been split in two since the 1700s, when a storm washed away the connecting land. Private cars and bicycles are not permitted. The island is reputed to be the site of the world’s largest non-nuclear explosion, and now I’ve seen the crater.

I am on the island of Helgoland, where I’ve been invited to give a talk at the 143rd meeting of the Deutschen Ornithologen-Gesellschaft—the German Ornithologists’ Society. This island holds a special place in German ornithology, especially this year, which marks the centenary of the first ornithologist officially starting work here. Helgoland is a magnet for tired or lost birds migrating to and from Scandinavia and even farther afield.

This evidence, too, presented itself upon my arrival. Less than a minute after coming ashore, I found that every grassy surface held multiple Meadow Pipits and Chaffinches. After only two days, arrivals and departures are evident: yesterday was a European Siskin day; today I didn’t see a single siskin on my quick walk around the island, but Reed Buntings had appeared.

However, most of the time I’ve been in a dark room watching research presentations. In accordance with the setting, the theme of this meeting is migration, and after two days here I have heard many fascinating stories:

• The “low-tech” method of tracing bird journeys—banding, (as it is known in North America; everywhere else it’s “ringing”) still sheds new light on patterns of dispersal and migration. Wheatears from geographically distinct nesting populations have partially overlapping wintering grounds in Africa. (See yesterday’s post for more news from bird banding.)
• A “high-tech” method involves attaching devices that measure time and light levels to moderately large birds. These devices are called geolocators. From the data, scientists can determine where birds have traveled using the same kinds of calculations as early sailors used when navigating. The technique has been used with many species, including to get a better description of the complex oceanic migrations of Antarctic skuas.
• The “highest-tech” method uses GPS transmitters that relay their locations to satellites—and straight on to scientists—multiple times per day.  I heard a fascinating story about how some individual raptors make multiple attempts before they succeed in crossing the Sahara desert in spring. Some individuals in poor condition never survive the crossing, and the ones that take multiple attempts to reach their breeding grounds may fail to nest or even lose territories that they held in previous years. (More on GPS tracking: a recent story in BirdScope about Osprey migration)
• Another focus of migration-related research is navigation. Researchers are testing whether birds recalibrate their internal compasses (which are linked to their left and not their right eyes, by the way) each day based on sensing polarized light (the evidence presented was equivocal).
• Still other researchers are working to understand how songbirds decide when to start journeys across inhospitable areas. They appear to factor in what they know of directions, distance, their own physical condition, and weather conditions. Different bird species in different areas seem to use different rules: tailwinds aren’t always important, for example.

Migration is a research subject that appears to me to be more actively pursued in Europe than in North America, and I am enjoying acquiring a broader understanding of the research that is being done in Germany and nearby countries. Tomorrow, I may get to see the fabled “Helgoland trap” in action.

(Images: Wesley Hochachka)

I’ll admit it, satellites boggle my mind. Even though I’m quite happy to listen to my phone tell me where to find the best Caribbean restaurant in Albany, I still can’t quite believe that our species has built machines that fly around our planet and tell us what they see. But the truth is that satellites are so last century—so much, in fact, that scientists have begun using them to document historical changes. The above picture, from NASA’s 38-year-old Landsat program, shows the Lake Djoudj region of Senegal during a drought in 1979 and during a flood 20 years later. Even at this small scale it’s clear how much information the pictures contain about how the land has changed.

At the International Ornithological Congress last week,Wesley Hochachka, assistant director of our Bird Population Studies program, heard about similar plans to use Landsat data to find out how Important Bird Areas in Africa are faring through the years—without researchers having to get on a plane and see for themselves. Here’s Wes:

Many field ornithologists take fieldwork for granted: they routinely assess habitat conditions by going into the field and taking direct measurements. However, in many areas of the world this isn’t feasible. Trained biologists are few, travel is difficult or costly, and at times their safety cannot be guaranteed. At this IOC meeting, Paul Donald from the UK’s Royal Society for the Protection of Birds described ways to get around these challenges using freely available data from satellites in order to monitor the status of areas at relatively low cost.

Donald and his colleagues began their work-in-progress with three observations

• Data from Landsat satellites can be accessed freely, and
• Human beings are still better at analyzing images than computers are, but
• Most people lack an easy means to work with satellite data.

To this end, Donald and his colleagues created a computer program that allows someone with relatively little training to select an area of conservation concern—they started with Important Bird Areas (IBAs) in Africa. The program displays 20 years worth of satellite images, with images at five-year intervals. A person can then fairly quickly measure the amount of land within the IBA and around it that was in the habitat type of interest, as well as other types of land cover—key information that is important to bird distributions. For example, someone could assess the forested parts of an IBA and as a result identify whether it or its vicinity were stable or were being degraded. (The authors published a paper on their work in 2009.)

In practice, the authors found their computer program was very effective. With only a few hours of training, someone could accurately measure forest (or grassland) cover of an area, and changes in status. As a result conservation organizations with few resources could do basic conservation assessments that would otherwise be impossible.  Their next step is to conduct a general assessment of IBAs in Africa, and if this first test proves successful look for other areas in the world in which to make the computer program available.

The program will not provide all of the information ideally needed to assess conservation areas. Obviously, the presence of particular species of birds cannot be recorded from space, and partial degradation of forests may not be obvious from satellite images. However, in many cases the most critical information is whether or not areas of natural habitat are being encroached upon, or identifying which specific areas are facing the greatest immediate threats. With this information in hand, conservation organizations can devote their limited resources to address the most critical problems.  As a result, I thought that the work described by Paul Donald was an important and creative use of satellite image data for direct conservation application.

(Image: Landsat program, NASA)

More like this: Martjan Lammertink’s news from the International Ornithological Congress, and Wes Hochachka’s report on European bird conservation from a meeting in Spain earlier this year.

Here’s an update from Dr. Martjan Lammertink, a research associate at the Cornell Lab, an expert on the world’s large woodpeckers, and a veteran of rainforest fieldwork on at least three continents. Last night, he attended a meeting of scientists hoping to save the unique birds of the Atlantic Forest of Brazil, Paraguay, and Argentina:

In some ways, the small conference room all 40 of us packed into was appropriate: The Atlantic Forest of southeastern South America is full of species that occur nowhere else—and because of deforestation, they now have only 12 percent of the forest’s original area to live in. Many are threatened with extinction, and meeting organizers Kristina Cockle and Alberto Esquivel had convened us here to discuss how best to conserve their populations.

We quickly honed in on the one species that participants agreed is the Atlantic Forest’s most endangered species: the Purple-winged Ground-Dove (Claravis godefrida). These birds once occurred in nomadic groups of more than 100, and until a few decades ago they were a common cage bird, but in recent decades it has become extremely rare. Only two people in the room had ever seen this ground-dove, and the bird’s global population is estimated at about 250.

Like some other ground-doves, this species has been thought to follow mass flowerings of a kind of bamboo (in the genus Guadua), although one recent sighting was outside of bamboo. Fragmentation of the Atlantic Forest likely impedes these movements and this probably is the main cause of the species’ decline. Participants agreed that a priority should be the quick notification of bamboo flowerings to ornithologists and birders active in the region so that they can search for the ground-dove in these settings. A major hindrance in surveys for Purple-winged Ground-Dove is that the voice of this bird is unrecorded. Participants recommended interviewing bird trappers in Brazil that used to catch the species until about 20 years ago, to get at least an oral description of the vocalizations of the species, and other insights into its biology.

Discussions moved on to other threatened species as participants traded notes on the biology of these species among the three Atlantic Forest countries. In Brazil, including around Campos do Jordão, where we were meeting, the Black-capped Piprites (Piprites pileata) occurs in the midstory of forests, sometimes among paraná pines (Araucaria angustifolia). Here it migrates up and down slope between seasons, but in Argentina extensive searches have revealed only seven territories, and these were all in riverside forests with laurel layana (Ocotea pulchella), and on at least one of these the birds stayed year-round.

The White-bearded Antshrike (Biatas nigropectus) is closely tied to Guadua bamboo in Argentina. This bamboo is tall, with large stems. Reports from Brazil have suggested it uses a smaller bamboo (Merostachys), but Brazilian participants corrected this picture and confirmed that in Brazil Guadua bamboo was the habitat to search for this bird.

Paraguayan participants remarked on the high rate of capture of parrot chicks (Vinaceous Amazons, Amazona vinacea) by settlers around the Itaipu reserves, whereas the problem seems much less severe in Argentina because of environmental education. The species appears to be found in highest numbers in the Brazilian state of Paraná.

The flamboyantly coiffed Helmeted Woodpecker (Dryocopus galeatus) only occurs in or near mature and well-protected forests, and despite a recent increase in known occupied sites it remains a rare and vulnerable species throughout its range.

By 10 p.m., we had all agreed that Atlantic Forest birds need to be better known, not just in terms of distribution and conservation, but their ecology as well, so we can understand how to improve their situations. We will also need to study variation in how these birds live in different parts of their Atlantic Forest range—and that will require making data available between countries. The creation of an online forum is a high priority and a low cost first step. With continued cooperation, we may give these unique birds a better chance in the future. For tonight, we went our own ways, reflecting on new insights and eager to enjoy seeing more Atlantic Forest birds in the vicinity of Campos do Jordão in the coming days.

(Black-fronted Piping-Guan, Black-capped Piprites, and Helmeted Woodpecker by Martjan Lammertink. Martjan photo by Eric Liner/Cornell Lab)

The museum had two specimens of this immense, raven-sized woodpecker. As Tim checked the specimens’ foot tags he realized something even more thrilling than the birds themselves: One specimen held details relevant to one of the last known sightings of the species—an amazing first-hand story Tim had uncovered on a recent trip to Mexico.

Read Tim’s story after the jump:

One of the Imperial Woodpecker specimens instantly caught my attention. Specimen number 29855 was collected by W. M. Fuelscher at Catalasia Peak, in the high country not far from the remote mountain community of Chuhuichupa in Chihuahua, Mexico. It had been added to the collection in 1949—very late for an Imperial Woodpecker specimen, most of which were collected in the late 19th and early 20th centuries.

I thought immediately about an old man I interviewed last year in the Sierra Madre who as a child had actually seen the Imperial Woodpecker. He said a “gringo” had approached his father in 1948, asking him if he could show him some Imperial Woodpeckers. His father told him that he knew where some of these birds lived in the high country above Chuhuichupa. The man and his son (who was eight years old at the time) took the American on a several-hours-long ride into the high country to reach the place where he had seen the woodpeckers. Tragically, they found a dead Imperial Woodpecker lying at the base of its nest tree—a huge pine snag with a cavity on the trunk, high above them.

Curious what might be inside the cavity, the man tied two lariats together and threw the end of the rope over a limb above the nest hole. He then fashioned a sling for his son, tied the other end to his saddle horn, and backed up the horse, hoisting his eight-year-old son 50 or 60 feet in the air. The boy pulled two partially feathered young from the nest. They were already dead though still warm to the touch, he told me. Perhaps both parents had been killed, and the young woodpeckers starved.

What the young boy (who is now 70 years old) remembered most about this experience was the American man’s response when he saw the dead nestlings. He broke down and wept, saying that the birds would become extinct and there wasn’t a thing he could do about it.

Now, what I’d like to know is whether specimen 29855 at the San Diego Natural History Museum is the same adult Imperial Woodpecker that the two men and the boy found in 1948 and whether the mystery gringo is W. M. Fuelscher. The bird was collected in the same general area at the same general time. And according to the museum’s curator of birds, Phil Unitt, this was the only specimen the collection ever obtained from Fuelscher.

I love a mystery, and perhaps someday I’ll find the answer.

(Image: Imperial Woodpecker by John Livzey Ridgway, 1898, from a scientific paper in The Auk [link to PDF including scan of original plate is here]; public domain image via Wikipedia)

On paper, last week’s AOU meetings were a solid wall of plenary talks, 15-minute research talks, and evening poster sessions. But cracks in the full schedule—coffee breaks, field trips, dinners and drinks—left plenty of room for impromptu conversations and unscheduled idea-sharing. Dr. Alan Poole, editor of the Birds of North America Online, ran across two captivating new topics this way, quite by chance.

On Monday evening we were given dinner at the San Diego Natural History Museum, with buses ferrying us over from meeting headquarters and back.  After good food, complete with a local brew or two (very decent beer here!), and a tour of the museum’s impressive collections, we were loaded onto buses for the trip back.

I plunked myself down next to a young woman with the delightful name of River Gates, an M.S. candidate at the University of Alaska, Fairbanks. We were soon engrossed in conversation about Dunlin, her main research species.  I learned how and where this shorebird nests on the arctic slopes of Alaska, about riding quad-wheeled ATVs over tundra to find the birds, and about Dunlin on winter beaches in Mexico. We marveled at the extraordinarily broad distribution of this species in winter, from beaches in southern Alaska to the semitropics of Baja California.

We discussed the feeding adaptations that might make this lifestyle possible, including unusual ones Dunlin occasionally do, like slurping “biofilm” off the top layer of wet sands. In a short 20-minute bus ride I’d learned a lot about a species that’s always intrigued me, and the Birds of North America Online had gained a potential recruit to help with the next revision of its Dunlin account. Fortuitous seating!

Tuesday evening was poster night, where researchers present findings on bulletin boards in a concise written format, rather than in a lecture and slideshow.  I like poster sessions because you can talk to the people who did the research—they stand by their posters and answer questions from those who wander by and want more detail.

There were hundreds of posters; one that caught my eye dealt with plumage details in Rusty Blackbirds—the work of Pam Sinclair and colleagues from the Canadian Wildlife Service in Whitehorse, Yukon. Truth be told, I was less interested in Rusty Blackbird plumages than I was in their population trends; this is a species that has declined drastically over the past 20-30 years, more than 90% continentwide.  I’ve heard bits and pieces of what might be driving this crash, and wondered if a consensus was emerging.  Here was my chance to find out.

Pam did a great job bringing me up to date. In a nutshell, we still don’t know for sure, but clearly loss of breeding habitat—as the boreal forest gets chipped away by forestry, farms, and development—is front and center. I’d always thought of the boreal forest as vast and untouched. Time to wake up! (You can find more about boreal conservation issues from the Boreal Songbird Initiative)

So there’s lots to be learned at an AOU meeting, but it’s not always in ways one expects.  I like the serendipity of encounters here, and all that goes along with those surprises. It’s tempting to just hang out with old friends and colleagues, pleasant as that is, but stepping outside the circle has its rewards.

(Image: Dunlin over mudflats by longspur via Birdshare)

It’s time for another annual meeting of the American Ornithologists’ Union. Just like last year in Philadelphia and 2009 in  Portland, we’ll be bringing you stories from the floor of the meeting, where hundreds of ornithologists have gathered for four days of intense science.

First up is Living Bird editor Tim Gallagher to report on Monday’s plenary talk, given by University of Montana’s Ken Dial. Over the past decade, Dial and his collaborators have proposed a surprising new theory about how birds first began to fly. And with a wicked snowstorm shutting down air travel back East, the evolution of flight seemed perhaps the perfect topic. Read Tim’s account after the jump.

The 128th annual meeting of the American Ornithologists’ Union (which this year is a joint meeting with the Cooper Ornithological Society and the Society of Canadian Ornithologists) got off to a slightly bumpy start Monday morning at 8:00 a.m. It seems the first plenary speaker, Scott Derrickson of the Smithsonian’s National Zoological Park, got stuck in the snowstorm blanketing Washington, D.C., and couldn’t make it to San Diego last night.

Not to be stymied by a little thing like inclement weather, the AOU leadership pivoted instantly and asked Kenneth P. Dial of the University of Montana to present his scheduled Tuesday morning plenary 24 hours early.

Now, for many people, having to deliver a talk a day early can be horrendous. There you are, expecting to have all this extra time to prepare and practice, but instead you just have to get up and go at a moment’s notice. Fortunately, Dial was more than up to the challenge. With his exuberant personality, a sense of humor and comic timing as well honed as most stand-up comedians, and a boundless passion for his topic of study, he presented his hypotheses on the evolution of flight in birds. In the process, he took on 150 years of entrenched dogma.

Dial began his talk by apologizing for not having time to dress up and get his hair done for the talk. (He was clad in blue jeans and a sweater and has a shaved head.) Then he launched into his talk, exploring whether bird flight had an arboreal (trees-down) or a terrestrial (ground-up) origin. The long-accepted belief has been that birds originated in the trees, but Dial takes on this idea, presenting a compelling array of data to support his view that flight originated from the ground up

.

Others have pointed out that some feathered dinosaurs had tiny wings, much too small to be used in flight. Why is that? Were they just useless appendages? Or did they help vulnerable young dinosaurs to scramble up inclines to escape predators.

Dial has looked at numerous species of fledgling birds—tinamous, megapodes, brush-turkeys, chukars, swifts, pigeons, owls, and more—and has documented this kind of “wing-assisted incline running” in all of them. The young birds use their stubby wings to help them gain traction as they run up the side of a tree or other incline and also to flutter back down to the ground safely. Could this have been how flight originated—at first as a way for a fledgling to escape predators?

At the University of Montana’s Flight Laboratory, Dial uses high-speed x-rays to explore flight in adult birds as well as the mechanisms by which fledglings scramble up inclines—some at a 90-degree angle. (You can watch slow-motion videos of birds flying in wind tunnels.) One could easily imagine an Archaeopteryx making a similar ascent before diving off the end of a branch and gliding downward again.

Ken Dial ended his talk with a plea to ornithologists to always be open to new ideas in their research and especially in their teaching of young scientists. Whether or not you agree with his hypotheses (and he perhaps left the audience with more questions than answers), this felt like the perfect kind of rousing, fascinating discussion to get a meeting going. You could see it in the eyes of the students as they left the ballroom and walked downstairs for the coffee break.

(Image: AOU 2010 logo by David Stamp)