Focus on Science: 'Poisonous' Birds -- Look, But Don't Touch

Although rare in the avian world, several species of birds smell or taste bad, and a few are even poisonous – most notably, the Blue-capped Ifrit and five species of pitohui in New Guinea. These approximately Robin-sized songbirds contain nerve-paralyzing batrachotoxins that are among the most toxic natural substances known. The compounds do not serve to kill prey, but to repel or kill external parasites (e.g., lice, mites) and predators (e.g., snakes, hawks, arboreal mammals, and humans).

The Hooded Pitohui (Pitohui dichrous; bottom bird on Science magazine 30 October 1992 cover above) is the best-studied of these unusual species. A single feather from the breast or back of this bird from a certain geographic locality, if placed on one’s tongue, “would cause a burning, tingling sensation that would last for several hours or overnight. Merely handling these birds...caused [the researchers] to sneeze, experience watery eyes and runny noses, and generally respond as if [they] were having allergic reactions.”

Toxins are most concentrated in skin and feathers, much less so in heart and liver, and least in skeletal muscle. Skin and feathers are more toxic on the back and breast than elsewhere. Since the outside of the bird is where parasites or predators are most likely to encounter toxins, these differences are consistent with their role in providing chemical defense.

Pitohuis do not manufacture the toxins from scratch, but obtain them from their food, most likely certain small beetles. The presence of toxins in internal organs shows that the birds do not merely apply them topically to skin and feathers. Furthermore, since these compounds would normally poison muscles and the liver, their presence in these organs raises the question of how the birds remain unaffected by them. The birds may have evolved biochemical means to resist the toxins internally, but these have yet to be explored.

Levels of toxins vary markedly among individuals and geographic localities, chiefly those in the skin and feathers. The causes of such variation are unknown, but may be related to the mechanisms by which the birds acquire toxins in their diet and incorporate them into their feathers.

The skin of pitohuis has the same tissue structure as that of other passerine birds and does not appear to have any obvious modifications for storing or secreting toxins. Avian skin in general secretes fatty substances and continually sheds cells from the surface. Thus, pitohui skin may be pre-adapted for confining toxins and ridding them from the body. The poisons could be taken up and stored temporarily in the lipids produced by the epidermal cells.

If you go to New Guinea to see these rare birds, look, but don’t touch!

Peter Stettenheim -– Peter is a retired ornithologist with particular interests in the functional anatomy and evolution of birds. He lives in Plainfield, NH.

JOHN P. DUMBACHER, GOPINATHAN MENON, AND JOHN W. DALY. 2009. Skin as a toxin storage organ in the endemic New Guinean genus Pitohui. Auk 126: 520-530.

Introducing 'Focus on Science'

VCE is pleased to introduce a new feature on our blog. Retired ornithologist Peter Stettenheim from Plainfield, NH will regularly present a readable and informative column, ‘Focus on Science’. Peter will condense and demystify a scientific article on birds from a peer-reviewed journal, and present it in digested form so that a reader of any background can understand and appreciate its findings. Topics will vary, but invariably be of interest to nearly anyone. We’re very pleased that Peter has offered to undertake this, and we look forward to launching his new column with a fascinating piece on ‘poisonous’ pitohuis from New Guinea. As always, we’ll appreciate any feedback from visitors to our blog. Thank you, Peter!

IUCN Red List Update

The International Union for Conservation of Nature (IUCN), the world’s oldest and largest global environmental network, has released its latest update of the IUCN Red List of Threatened Species. Of the 47,677 assessed species, the 2009 update shows that 17,291 are threatened with extinction. This includes 12% of all known birds. Of the world’s 9998 bird species, 137 are Extinct or Extinct in the Wild, with 192 Critically Endangered, 362 Endangered, and 669 Vulnerable.

BirdLife International is the Red List Authority for birds. The latest BirdLife evaluation of the world’s birds did include some good news stories. For example, effective conservation efforts have resulted in three species being downlisted from Critically Endangered to Endangered, to reflect a lower level of threat: Lear’s Macaw (Brazil), Chatham Petrel (New Zealand), and Mauritius Fody (Mauritius).
Visit the BirdLife International website for more information about the 2009 update of the IUCN Red List for birds.

Vermont eBird takes wing

BurlingtonFreePress.com - Burlington,VT,USA

It was an enduring love and life-long pursuit of “gobs and gobs” of data mixed with a hardcore birding passion that led Vermont Center for Ecostudies scientist Kent McFarland, 43, of Woodstock to coordinate the Web site Vermont eBird.

The site is the first state portal in the country for the national Web site eBird.org, a real-time, online checklist program that has revolutionized the way the birding community reports and accesses information about birds.

Read more...Vermont eBird takes wing

BALD EAGLE SHOT IN MILLSFIELD, N.H.: REWARD OFFERED FOR INFORMATION ABOUT SHOOTING

Officials are seeking information to aid an investigation into the shooting of a juvenile bald eagle off the Millsfield Loop Road in Wildlife Management Area B, in Millsfield, northern New Hampshire, on or about October 22, 2009.

Anyone with information should call the New Hampshire Fish and Game Department Operation Game Thief 24-hour hotline at: 1-800-344-4262, or report online anytime at http://www.HuntNH.com/OGT. Callers may remain anonymous.

New Hampshire Fish and Game Department’s conservation officers and special agents of the U.S. Fish and Wildlife Service are conducting a joint investigation into the incident. The U.S. Fish and Wildlife Service is offering a reward of up to $2,500 to the person or people who provide information leading to a conviction under the Bald and Golden Eagle Protection Act.

Local sportsmen discovered the injured bald eagle and notified the New Hampshire Fish and Game Department. A licensed wildlife rehabilitator is caring for the eagle. Examination of the eagle revealed it had been shot with a shotgun and sustained a fractured wing and other injuries. A veterinarian expects the wing will heal well enough for the eagle to fly again and for it eventually to be released into the wild. The New Hampshire moose and small game hunting seasons were open at the time the eagle was found.

In addition to the Eagle Act, state laws and the federal Migratory Bird Treaty Act protect bald eagles. Until 2007, bald eagles were also protected under the Endangered Species Act.

ROSEATE TERN: THE NOVA-SCOTIA/MASSACHUSETTS CONNECTION

Biologists from Mass Audubon’s Coastal Waterbird Program, the USGS (Patuxent Wildlife Research Center), and Bird Studies Canada were excited to find a dozen Canadian-hatched Roseate Terns at staging sites on Cape Cod, Massachusetts, over a 38-day period from 14 August to 21 September 2009.

The Canadian-banded terns were banded as chicks during the summer of 2009 on Country Island, Nova Scotia, by staff from Environment Canada’s Canadian Wildlife Service. Each juvenile tern carried color leg-bands which made them visible among thousands of Roseate and Common terns staging at eight different sites on Cape Cod. Not insignificantly, Country Island where the terns were banded is a Important Bird Area (IBA) in Nova Scotia. In addition most of the color-marked terns were also relocated at one of two highly significant Massachusetts IBAs located on Cape Cod.

The meticulous survey of color-banded terns at these IBA sites is vital to improving our understanding of the nesting, staging behavior, and migratory timing of Roseate Terns, a species classified as Threatened in Canada and Endangered in the northeastern U.S. Such observations also underscore the significance of IBAs in prioritizing habitat significance at the landscape level. Currently the northeastern population of Roseate Terns which is principally located between the south shore of Long Island, New York and Nova Scotia, Canada, contains approximately 3,000 pairs, with Massachusetts supporting the majority of the population. In 2009 the Massachusetts population was comprised of approximately 1,300 pairs.

You can find more on these particular terns from Bird Studies Canada:
www.bsc-eoc.org/organization/newsarchive/10-09-09.html

The Birding Community E-bulletin is being distributed to active and concerned birders, those dedicated to the joys of birding and the protection of birds and their habitats. You can access an archive of past E-bulletins on the website of the National Wildlife Refuge Association (NWRA):
www.refugenet.org/birding/birding5.html

Growing environmentally friendly rice in South America

The Spanish Ornithological Society (SEO/Birdlife) and the Grasslands Alliance will initiate a pilot to explore ways to grow rice in a more environmentally friendly way in the Southern Cone. The Bobolink and the Upland Sandpiper are among the migratory bird species breeding in Vermont that will likely benefit from ecologically-produced rice in South America.

In the Argentine Province of Santa Fe, NGO Aves Argentinas will be developing bird refuges in rice fields as part of a "bio-remedy" strategy for areas which have suffered from the impact of lead shot from duck hunting.

"The lead has been accumulating in the environment, and neither rice-producers nor hunters have realized what has been happening," said Rubén Favot, a rice producer and the recently posted Secretary of Production and Tourism of San Javier, Argentina. "Today measurements taken by experts in eco-toxicology show the presence of residues both in the water and in the soil."

In Paraguay, the rice company Agriplús and NGO Guyra Paraguay ("Bird Paraguay") have joined forces to begin trials to produce organic rice. "It's possible that we won't be able to install this type of cultivation yet, but working with fewer costs seems to be an achievable target, which not only favors our environment, but also our economy", is the opinion of the Manager Diego Dominguez.

In addition to the pilot trials in each country, the project will fund a convention of interested rice-growers in a First Meeting of Rice Cultivation and Nature Conservation.

Key Findings on the Health of Vermont Forests

The Vermont Monitoring Cooperative has completed a comprehensive new report synthesizing over 20 years of monitoring and dozens of VMC cooperators' research, including work by the Vermont Center for Ecostudies.

The Vermont Monitoring Cooperative (VMC) was established in 1990 to track changes occurring in Vermont’s forests. Only limited information about the health and baseline conditions of forested ecosystems was available at that time. Vermont lacked the ability to perceive subtle changes in ecosystem condition over time and thus to be able to identify forces affecting forest ecosystem health and productivity. In addition, there was
no dedicated, centralized, and stable location for storing, maintaining, and
distributing important ecological data. VMC was envisioned and created to
collect, assemble, and distribute highquality, documented data and informationto better understand environmental changes and their impacts on forested ecosystems. Understanding the interactive nature of environmental changes required ecosystem-scale, integrated, multidisciplinary monitoring and research based on sound science. Those concepts lie at the heart of the Vermont Monitoring Cooperative’s existence.

This report offers a sampling of the extraordinary amount of information VMC has assembled in its first 18 years. While VMC research focuses primarily on the health of Vermont’s forests, forest ecosystems are complex
entities, affected by weather and climate, by natural and anthropogenic disturbances, and by the long reach of time. And everything in the forest relies on a web of connections, many of which are just now beginning to be understood.

Consider the tiny, reclusive Bicknell’s thrush, a major topic of VMC research efforts. Living at the top of Vermont in our most isolated areas, the bird is nevertheless buffeted by climate change, which alters its habitat both in New England and its wintering grounds in the Caribbean; by atmospheric mercury pollution, which has found its way into its blood
and feathers; and by the presence of happy skiers, who build trails ever higher on the sides of mountains. A goal of VMC is to learn how people can live side-by-side with the thrush, the salamander, and the moose, using the manifold resources provided by Vermont forests, always with an eye
toward a sustainable future.

This report represents the written contributions of 19 cooperators, but collective efforts of dozens of researchers from varying backgrounds and disciplines working collaboratively to compile and tell the stories contained
in this document. To the extent possible, the report is a multidisciplinary synthesis. The majority of datasets in the VMC data library can be broadly characterized under the following section titles of this report: The Health
of Our Forests, Weather and Climate in Vermont, and Monitoring Atmospheric Deposition. This report covers topics including the effects of land-use change on biodiversity, habitat and population levels of many animal species, as well as the effects of alpine development on the
environment. It includes current trends in meteorological parameters such as air temperature, relative humidity, and cloud cover in the Champlain Valley and Vermont.

Also discussed are current conditions and recent trends relating to atmospheric deposition, including transport, acidification of lakes and streams, ozone, and mercury in the environment. Also explored are factors influencing forest health, diversity, structure, productivity, and forests’ ability to store carbon to help mitigate the effects of greenhouse gas
accumulation in the atmosphere.

The information in this report is intended as an introduction to the body of research that has been amassed over time, and which is growing daily. Numerous scientific papers have been published using VMC data, some of which are referenced here. We have tried to highlight successes where VMC data have influenced state, regional, or national policy or where research results have helped alter the behavior of would-be polluters. As an organization, VMC believes that it has an important and timely story to tell.

Conference: Reversing the Decline of Neotropical Migratory Bird Species and Protecting Their Habitats

The Bird Conservation Alliance (BCA) is a network of nearly 200 organizations, including the Vermont Center for Ecostudies (VCE), working together to conserve native wild birds and their habitats. The BCA, which is facilitated and staffed by American Bird Conservancy, will be hosting an all-day educational conference in the Cannon Caucus Room at The Cannon House Office Building in the U.S. Capitol, Washington, D.C., on November 12th from 9:30 am to 4:30 pm. The theme is "Reversing the Decline of Neotropical Migratory Bird Species and Protecting Their Habitats."

The meeting will feature keynote addresses from leaders from the Environmental Protection Agency, U.S. Department of Interior and the U.S. Fish and Wildlife Service, and a series of expert panels will review the multiple threats migratory birds currently face and discuss strategies to solve these problems. Everyone is welcome. If you would like to attend please Register Today! You can also get more involved with the Alliance's work by signing up your birding club or conservation group to become a member, or by subscribing to an email list that provides occasional updates with information about upcoming BCA meetings and webinars, votes in Congress, comment drives concerning administration decisions, and action opportunities to get involved in bird conservation campaigns. To sign up, please send an email to sholmer@abcbirds.org.

Dr. Ian Newton to Speak at Dartmouth

Dr. Ian Newton, an internationally-renowned expert on bird ecology and biogeography, will take the stage at 7pm on Wednesday, November 4th at Dartmouth College, Moore Hall, Room B03 to talk about the impact of humans on the survival of migratory birds.

Covering more than 30 years of field research in Europe and Africa, Dr. Newton will highlight the effects of land-use change, over-hunting, climate change, and other human environmental disturbances on the survival of Eurasian migratory birds and discuss ways in which these effects can be mitigated. Many migratory species are declining, and Dr. Newton’s research has targeted areas in which efforts to conserve these species might be best directed. Understanding patterns related to breeding and the wintering areas of migratory birds, including human disturbance at stopover sites, is a necessary step in conserving them effectively.

Dr. Newton began his ornithological career at the University of Oxford, where he studied the ecology and feeding behavior of finches. He then worked for the Natural Environment Research Council in Great Britain, studying waterfowl and birds-of-prey, with a particular focus on the impacts of DDT and other pesticides on avian wildlife. He has dedicated more than 25 years to the study of the European Sparrowhawk in south Scotland.

Dr. Newton has served as Chairman of the Royal Society for the Protection of Birds in the U.K. and as President of the British Ecological Society and the British Ornithologists’ Union. He is currently Chairman of the Peregrine Fund in the U.S. and of the British Trust for Ornithology. He is an elected Fellow of the American Ornithologists’ Union. He has authored nearly 300 scientific papers, made frequent TV and radio appearances and written several books on avian wildlife and their habitats, including Finches (1972), Population Ecology of Raptors (1979), The Speciation and Biogeography of Birds (2003), and The Migration Ecology of Birds (2007).

After earning a Ph.D. degree at Oxford University, Dr. Newton has gone on to receive numerous awards, including the Order of the British Empire for service to the field of ornithology, the Union Medal of the British Ornithologists’ Union, and the Elliot Coues Award of the American Ornithologists’ Union.

Dr. Newton’s talk is co-sponsored by the Vermont Institute of Natural Science (VINS) and the Dartmouth College Environmental Studies Program and open to the public.

RAIN DAMPENS BALD EAGLE BREEDING SUCCESS IN 2009

Following record breeding success in 2008, New Hampshire bald eagles experienced a far less productive breeding season in 2009. The total number of young eagles raised in nests in the state this summer was down 33% from last year. In spite of this one-year decline, 2009 was still the third best breeding year on record for bald eagles in the state.

“The number of young fledged can vary from year to year,” said Mike Marchand, a biologist with N.H. Fish and Game. “A number of factors can influence breeding success, including weather.” Marchand noted that although the number of young fledged during 2009 was lower than last year, the number of territorial pairs has been consistently increasing in New Hampshire, leading biologists to believe that the New Hampshire population will continue to grow.

The 19 territorial pairs documented in New Hampshire in 2009 represent an increase of more than 25% from the 15 eagle pairs found the state in 2008. “The growing number of breeding territories lays a foundation for more productive breeding seasons to come,” said Chris Martin, a raptor specialist with N.H. Audubon who coordinates monitoring of this state-listed threatened bird of prey. “Over time, more territories lead to more fledged young.”

Biologists and volunteer observers have documented a tripling in the number of bald eagle breeding territories in New Hampshire in the past decade, from just six pairs in 2000 to 19 pairs in 2009. “This is clear evidence of an expanding population,” Martin said.

The N.H. Fish and Game Department’s Nongame and Endangered Wildlife Program and N.H. Audubon’s Conservation Science staff work together to monitor and manage the Granite State’s recovering bald eagle population. With additional support and cooperation from land owners and from other state and federal natural resource agencies, N.H. Audubon recruits, trains, and deploys volunteer observers to document eagle distribution and productivity.

A growing number of bald eagles now call New Hampshire’s Lakes Region their home. Two new pairs were identified around Lake Winnipesaukee in 2009, raising the total number of pairs found throughout the Lakes Region to eight. Further west, on the Connecticut River in Orford, another new pair raised two young in their first try. In addition, after years of waiting, biologists believe that a pair has finally established a breeding territory on Great Bay, the state’s largest tidal estuary.

Although more bald eagle pairs were found in the state this year, rainy weather and other factors limited their reproductive success. A total of 16 bald eagle chicks reached fledging age in the state this summer, down one-third from the 24 young produced in 2008. Incubation behavior was confirmed at 11 nests in 2009, also down slightly from 2008 levels. Nine of the 11 incubating pairs fledged young. Juvenile bald eagles are considered fledged at about 11 weeks old, when they first begin to fly to and from the nest.

“Several eagle pairs built nests but did not incubate eggs, and two more pairs abandoned nests at about the time of hatch,” said Martin. Productivity was also limited by fact that none of the New Hampshire nests produced three fledglings in 2009, compared with three nests with trios in 2008.

Since 1988, when bald eagles first began nesting again in New Hampshire, a total of 123 young eagles have fledged from nests in the state. Nearly 60% of those (73 eaglets) have been raised in the last four years alone.

Martin estimates that over 50% of New Hampshire’s breeding adult eagles wear coded aluminum leg bands placed on them when they were nestlings. These bands provide biologists with opportunities to identify and track movements and longevity of individuals. Included among these banded eagles is New Hampshire’s oldest known eagle, a 17-year-old female hatched in captivity in Massachusetts, placed in a Quabbin Reservoir nest and raised by foster eagle parents. She has been breeding at Nubanusit Lake in Hancock for the past 11 consecutive years.

MORE PIPING PLOVER PAIRS NEST ON N.H. SEACOAST, BUT FEW YOUNG SURVIVE

The spring breeding season got off to a promising start for New Hampshire’s state and federally endangered piping plovers, but as the 2009 summer came to a close, just two chicks had fledged.

This year, a total of five pairs of the shorebirds returned to coastal beaches in Seabrook and Hampton, an increase from the three pairs that have nested in New Hampshire in recent years. Spring weather was mild, and each pair of plovers quickly established a territory and a nest. “We started off with three nests in Seabrook and two nests in Hampton,” said Brendan Clifford, a biological technician with the New Hampshire Fish and Game Department’s Nongame and Endangered Wildlife Program. Each nest had a full clutch of four eggs, so had all of them survived, they would have produced 20 chicks. Sadly, only two plover chicks survived to the end of summer.

Even sadder, human disturbance was the most likely cause of the season’s low productivity. At Hampton Beach State Park, the first nest established had protective fencing, called an “exclosure,” set up around it to keep predators at bay. Early in the year, a person broke into the fence and stole one of the plover eggs, an incident investigated by U.S. Fish & Wildlife Law Enforcement officers. Although the adult plovers continued to incubate the remaining three eggs after the incident, only one of them hatched.

At Seabrook Beach, beachgoers were frequently observed disregarding signs and walking directly through a roped-off plover breeding area. These intrusions repeatedly scared one pair of piping plovers off of their nest, preventing them from being able to incubate their eggs. Eventually, the pair abandoned the nest altogether.

In all, two of five of New Hampshire’s plover nests were abandoned prior to hatching. Of the three nests that successfully hatched eggs, two produced a single fledgling each, while no chicks survived from the final nest.

Nongame and Endangered Wildlife Program biologists and volunteers monitored the plovers on a daily basis during the summer to determine the number of birds present, nest locations, nest success or failure, incubation periods and chick survival.

Since protection efforts began in 1997, a total of 83 piping plover chicks have fledged from New Hampshire's seacoast. New Hampshire's efforts are part of a region-wide protection program; overall, the Atlantic coast population of piping plovers continues to hold steady.

Protection of this endangered species is a cooperative effort of the N.H. Fish and Game Department, the U.S. Fish & Wildlife Service, N.H. Division of Parks and Recreation, the towns of Seabrook and Hampton, volunteers, local residents and beach visitors.

See photos of the New Hampshire plovers and learn more about this endangered species at http://www.wildnh.com/Wildlife/Wildlife_profiles/piping_plover.html.

Researchers discover a second breeding season for five migratory songbirds

Biologists studying songbirds that breed in North America and then migrate to Mexico have discovered something totally unheard of in the New World — a second breeding season.

Five species — Yellow-billed Cuckoo, Orchard Oriole, Hooded Oriole, Yellow-breasted Chat, and Cassin's Vireo — breed primarily in the United States and Canada. Then they squeeze in a second breeding season during a stopover in western Mexico on their southward migration.

Read more on the Birder's World magazine blog...

Read the abstract from the scientific publication.