The Intoxicating Birds of New Guinea
by John Tidwell
It all began with an accident. In the summer of 1989, Jack
Dumbacher was a graduate student from the University of Chicago
conducting fieldwork on the ecology of Raggiana birds of paradise
(Paradisaea raggiana) in Papua New Guineas lush
Varirata National Park. Dumbacher was one of a handful of
graduate students on the National Geographic-sponsored team,
and part of his research involved catching and examining these
exotic orange-yellow birds in fine mist nets set throughout
the forest. Sometimes other birds would also get caught, and
Dumbacher spent a lot of time freeing unwanted species like
the hooded pitohui (Pitohui dichrous), a jay-sized
endemic New Guinean songbird with striking black and orange
young researchers, pitohuis (pronounced PIT-oh-wheez)
were all too familiar: They were everywhere, they fought and
scratched when being disentangled from the nets, and they
had a pungent odor that stayed on researchers hands
for daysthe local people called them rubbish birds.
One day Dumbacher was freeing yet another hooded pitohui from
his nets when its sharp beak and claws scratched his hand.
Dumbacher put his hand in his mouth and got a strange numbing
sensation that he recognized as the effect of some toxin.
At first he thought nothing of it, because he occasionally
brushed against poisonous plants in the forest. It never occurred
to him to suspect the bird. But then a few weeks later another
member of the team mentioned the same odd sensation when he
put his injured finger in his mouth. Again the culprit was
a hooded pitohui. Dumbachers interest was piqued, so
the next year he returned to New Guinea determined to examine
some of these rubbish birds more closely.
next time we caught a hooded pitohui, he remembers,
I just plucked one of the feathers and tasted it: Whammo!
Whatever it was, it was definitely in the feathers.
were only a few weeks before the arrival of the research teams
leader, Bruce Beehler, then Scientific Assistant to the former
Smithsonian Institution Secretary, S. Dillon Ripley. Dumbacher
wanted to be as sure as he could that these birds were producing
some kind of chemical in their feathers. So he and his three
assistants sampled the feathers of several other hooded pitohuis,
all with the same tongue-tingling results. As he was driving
Beehler up to Varirata from the airport, Dumbacher suggested
that the find might make an interesting field note in New
Guineas local bird journal. But Beehler, the man who
literally wrote the book on New Guinea birds, was thunderstruck.
looked at me and said Are you telling me youve
found a poisonous bird? recalls Dumbacher,
his dark eyes gleaming behind small wire-rimmed glasses. Then
he said, This should be on the cover of Science!
Turn the car around! Were going back to town to get
permission to study this bird!
In the eight years since Jack Dumbachernow a research
associate at the National Zoos Conservation and Research
Center in Front Royal, Virginiafirst published his controversial
discovery in Science,
one of the worlds most prestigious scientific journals,
his life and work have been largely overtaken by this small,
spunky bird. Dumbachers research has not only shown that
some birds may use toxins for defense, but changed the way people
think about the biology of New Guinea. It also launched a scientific
quest over several continents to find answers to the hooded
pitohuis noxious mysteries. What is staggering to Beehler
and many other scientists about this discovery is that pitohuis
have been known to science for more than 100 years and live
only a few miles from New Guineas bustling capital, Port
was right there under our noses, Beehler admits, as
he relaxes in his office at Conservation International, where
he is a senior representative for Melanesia. Pitohuis
are New Guineas most common, widespread bird. Theyve
been collected by scores of expeditions. Museums around the
world are filled with pitohuis. And yet nobody knew they were
toxic. That really says how much we dont know about
whats going on out there.
the pitohuis strange biology has been as difficult and
frustrating for Dumbacher as freeing them from his nets. When
he first returned to the U.S. in 1990 with the birds
spicy feathers in hand, Dumbacher searched for a skilled chemist
who could help him identify what kind of toxins the feathers
carried. But few took the young grad student seriously: No
one really believed that poisonous birds might exist. As months
passed, Dumbacher began losing hope of ever finding the answer
to the pitohuis riddle.
his luck finally changed. A herpetologist referred Dumbacher
to John Daly, a pioneer in pharmacology at the National Institutes
of Health (NIH) who had done groundbreaking research on South
American dart-poison frogs. It proved to be a fateful introduction.
During the 1960s and 1970s, Daly spent years in both the lab
and the tropical forests of South America studying the tiny,
brilliantly colored frogs that the Choco Indians of western
Colombia used to poison the darts of their blowguns. After
years of research Daly and his colleagues showed that these
frogs secreted a powerful collection of neurotoxins from glands
on their backs. These deadly species, including a bright yellow
frog the researchers aptly named Phyllobates terribilis,
were armed with three unique steroidal alkaloids, called
batrachotoxins (BTX), in concentrations so powerful that an
amount equivalent to a few grains of salt would be lethal
to a person who ate it.
considered one of the most deadly toxins, BTX stops all electrical
impulses in muscles and nerves, causing cardiac arrest almost
immediately. The poison had never been found before in any
organism, and for decades Daly toiled over this phenomenon,
trying to figure out how the frogs were producing it, and
why. But in the mid-1980s Colombias political climate
shifted, and foreign scientists found it nearly impossible
to get permission to work in its forests. As a result, all
further field research into the origin of the Colombian frogs
poison became impossible.
Dumbachers hooded pitohui feathers floated across Dalys
lab desk. Initially the grizzled scientist was skeptical.
He performed some routine tests, making a crude extract of
the feathers chemical and injecting it into a mouse.
Within minutes the animal was dead.
got this call from him, and he was really excited, Dumbacher
remembers. He said, Jack! Youve got to send
me more of those feathers! There is something extremely toxic
in there! Daly analyzed the pitohuis feathers,
skin, and internal organs, using chromatography to identify
extracts of the chemical. The tests detected the presence
of batrachotoxinsthe exact same compounds that Daly
had found in the frogs.
was totally unexpected, says Daly. Its just
very fortunate Jack sent the samples to us, because anybody
else might have struggled over it for years.
was a bird in New Guinea doing with lethal poisons only foundso
far as we knowin frogs from the other side of the world?
And why wasnt Jack Dumbacher dead from tasting them?
rises out of the sea about 100 miles north of Australia, with
jagged, tree-covered mountains that disappear thousands of
feet up into a nearly perpetual mist. Millions of years ago
it separated from the mainland; and native animals, like birds
of paradise [see sidebar on Birds
of Paradise] and pitohuis, followed their own evolutionary
paths. To foreigners, the island can seem ancient and magical,
like a world lost in time. But to Jack Dumbacher and his team,
its a wonderland of biological mysteries.
after Dumbachers discovery was published, he trekked
back into New Guineas interior forests to find why hooded
pitohuis were poisonous. From the start it was obvious something
complex was going on. Hooded pitohuis from some regions of
the island were found to be much less poisonous than those
from other regions. Tests on three other pitohui speciesthe
rusty (Pitohui ferrugineus), the black (P. nigrescens),
and the variable (P. kirhocephalus)showed that
they too were toxic, but not at the levels of the hooded pitohui.
In Varirata National Park alone, Dumbacher found hooded pitohuis
so full of BTX that simply holding them made him sneeze and
his eyes water. But, a few miles to the north, the same species
were almost non-toxic. To the biologists this indicated that
the birds poisons were not inherited, but rather acquired,
or sequestered, probably from something they were eating.
But proving this hypothesis has been daunting.
like looking for a needle in a haystack, Beehler explains.
New Guinea has about 700,000 species of insects and
maybe 15,000 plant species. The toxin source may only be from
one organism, at one particular time of year.
before, John Daly had brought some dart-poison frogs back
to his NIH lab in Bethesda, Maryland, for study. He fed them
a lab diet of non-toxic termites, and to his amazement, the
next generation of frogs hatched in the lab was completely
non-toxic. When the frogs matured, Daly fed them small amounts
of BTX. In no time the toxin began accumulating in their skin,
strongly indicating that the source of the frogs poison
came from an unnamed insect living deep in the Colombian rainforest.
wants to do a similar experiment with the hooded pitohuis,
and has a tentative agreement with the government of New Guinea
to bring several birds to the National Zoo this year. If the
pitohuis lose their poison it will be hard evidence that they
have a very toxic diet back home. But what? Dumbacher and
his team suspect some kind of insect is making the birds poisonous,
and they have been examining every bug pitohuis are known
to eat. But so far none has come up positive for BTX.
the idea that an insect either produces or sequesters BTX
at all is controversial. Many scientists think that insects
arent the only suspects in this biological detective
story. Some have suggested pitohuis may get their poisons
from bacteria, or that BTX is somehow assembled in their bodies
from more than one plant or insect they are eating, each providing
a vital chemical component. Todd Capson, an independent ethnobiologist
at the Smithsonian Tropical Research Institute in Panama,
is heading for New Guinea this year to mount his own search
for pitohui poison. For him the evidence points to a complex
process in which BTX is transferred from prey to predator
up the food chain to pitohuis.
I was a betting man, Id bet that a plant makes it in
the beginning, Capson says, and that plant is
then eaten by an insect, which is then eaten by pitohuis.
My personal guess is that the insect is a weevil, because
weevils are everywhere and they are known to eat every part
so, Beehler says looking for the source of pitohui BTX by
traditional scientific methods, such as by examining the droppings
and stomach contents of these birds and watching what they
eat, is not the onlyor most efficientway to find
the answer. Native Papuan tribes have been observing nature
on the island for possibly 50,000 years or more, and their
oral traditions of medicine and magic reveal a vast collection
of biological knowledge. When he returns to the New Guinea
wilds, Capson plans to seek out local village elders and wily
old men who may be able to provide clues to which local
plants or animals may be poisonous.
Papuans provided vital insights for Jack Dumbacher almost
from the beginning of his adventure with the pitohuis. In
1990 when he first realized pitohui feathers might be toxic,
a co-worker mentioned that she had read about these birds
being bitter to the taste in an old book. Dumbacher looked
up the book, Birds of My Kalam Country, which was a
compilation of local Kalam tribal wisdom on highland birds,
written in 1977 by the New Zealand anthropologist Ralph Bulmer
and his Kalam colleague Ian Saem Majnep. In the book, Dumbacher
discovered a description of the wobob (the hooded pitohui)
that reported, ...some men say the skin is bitter and
puckers the mouth....
also gave a similarly tantalizing account of the blue-capped
ifrita (Ifrita kowaldi), an apparently unrelated bird
half the size of a pitohui that lives in the high mountains.
Its Kalam name, slek-yakt, literally means bitter
bird, the authors write, because if it is not
skinned before eating some men find that it burns their mouths,
making their lips sore and puckered.
Dumbacher traveled by light plane up into the highlands to
the Kaironk Valley, a remote region in the southwestern corner
of Mandang Province where Saem Majnep and his Kalam people
still live. Majnep had little formal Western education, but
among his people he was regarded as a man deeply learned in
traditional wisdom. His knowledge of the plants and animals
of the highlands had impressed Bulmer so much that he asked
Majnep to collaborate on his book on Kalam bird lore. In their
paragraph on the pitohui, Majnep also included Papuan folklore
about how the wobob bird was often evoked in Kalam
war-magic spells because it dodges around like a man avoiding
arrows, and how the word wobob itself refers to a kind
of skin disease that is uncomfortable and itchy. While such
descriptions may at first seem more like myth than science,
Dumbacher points out that if one listens carefully, one may
discover valuable information.
Bonua people of Central Province told me they knew the pitohuis
were poisonous, but that if you kill one and want to eat it,
what you have to do is mourn for it, he recalls. If
you mourn for it long enough and sincerely enough, then you
can eat it and it wont make you sick. But they said
they usually dont eat the birds because you never know
if youve mourned enough.
stories like this reveal, says Dumbacher, is that the Bonua
knew that some pitohuis are more toxic than others, but that
in general they should be avoided. Todd Capson also found
important biochemical information about pitohuis from listening
to local hunters. They told him that the only way to eat a
pitohui is to strip off its feathers and skin and then smear
charcoal all over its meat before roasting it.
most people this sounds weird, says Capson, but
to an organic chemist what they are doing is removing the
toxin, because charcoal is well known for its ability to adsorb,
or adhere to, organic compounds like homobatrachotoxin.
This process would render the bird safe to eat.
gave Dumbacher vital clues about the blue-capped ifrita as
well, and had his hunters collect some specimens. Small and
brown with a bright blue crest, the ifrita behaves like a
nuthatch, foraging for insects among the trees of the highland
cloud forests more than 12,000 feet above sea level. Everything
about it is different from a pitohui, except for one thing.
were with the local guys, Dumbacher remembers. I
was examining an ifrita and was about to taste one of its
feathers, when the locals started shouting No!!! Dont
do that!! They were absolutely convinced I would die
if I tasted it.
the results came back from NIH on the ifritas skin and
feathers, they showed nearly identical profiles of BTX alkaloids
for both birds. Dumbacher also found ifrita farther to the
east, in the Finisterre mountain range of the Huon Peninsula.
In the Kaironk Valley, ifrita were loaded with BTX, but here
they appeared uniformly non-toxic. Clearly this bird was also
getting its poisons from a food source. Now Dumbacher had
an even bigger mystery: two apparently unrelated birds, living
in two very different regions of New Guinea, yet both using
the same spectrum of toxins. This indicated that the use of
BTX among the islands birds was more than a single freak
event of evolution. Something much more complex was at work
in these forests.
British ornithologist Hugh Cott was on military leave in the
Egyptian city of Beni Suef, doing what he enjoyed most: studying
birds. He was preparing some specimens for mounting and had
left the skinned carcasses of a palm dove (Streptopelia
senegalensis aegyptica) and a pied kingfisher (Ceryle
rudis rudis) lying nearby on the grass. Then Cott noticed
something odd: Hornets, which love fresh meat, were feasting
energetically on the dove, but had left the kingfisher conspicuously
untouched. Intrigued, Cott decided to test the palatability
of kingfishers and other birds flesh, first on hornets
and then on cats and humans. Cotts research eventually
led him to conduct extensive studies that not only showed
that some bird species tasted bad, but also a possible reason
he found was that the more vulnerable a bird was, the nastier
it tasted, says Harvard anthropologist Richard Wrangham.
He defined vulnerability as being brightly
colored or slow moving or the like. He also found that across
Europe, Africa, and North America black birds generally taste
bad as well. So the old refrain about eating crow
studies have suggested that many birds may be using some kind
of chemical weaponry as defense, much like insects and amphibians.
Ocean-going fulmars spit noxious stomach oils to drive away
predators, some species of grackle give off a terrible odor
when threatened, and many passerine birds, of which pitohuis
and ifrita are members, have been known to smear their feathers
with ants, apparently to repel parasites. Some birds, like
the Eurasian quail (Coturnix coturnix cortunix), the
spur-winged goose (Plectropterus gambensis) and the
African olive-pigeon (Columba arquatrix), are suspected
of being toxic as a result of eating poisonous insects and
plants [see Quailing from Quail].
Two species of Australian bronzewing (Phaps sp.)
may even be sequestering the lethal toxin fluroacetate, more
commonly known as 1080, a poison that occurs naturally
in their diet of heartleaf (Gastrolobium bilobum).
But no one knew exactly which chemicals were being used.
pitohuis and the ifrita are the first examples of birds that
use an identified toxin as part of their defense strategy,
says Cornell chemical ecologist Thomas Eisner. That
discovery changed everything about how we think about birds.
Papuan birds and Colombian frogs diverge, Eisner says, is
in the way they use their poisons. The tiny frogs store highly
concentrated BTX alkaloids in glands on their backs, so that
when they are threatened they secrete almost pure toxin. The
pitohui and the ifrita, on the other hand, seem to have BTX
in their dander, which diffuses all over their bodies, making
the birds poisonous but not necessarily lethal. In fact, Dumbacher
noticed that the greatest levels of BTX were found on the
birds breasts and underside, suggesting that their eggs
and nests may also be infused with BTX. This would be a particularly
effective defense against snakes, which Dumbacher sees as
a likely pitohui predator. Snakes hunt birds in their nests
at night, and tend to taste with their tongues before striking.
One quick flick of a serpents tongue might instantly
tell it that pitohuis and ifrita were too risky to eat. Dumbacher
thinks BTX might even act as a natural bug repellant, driving
off hungry lice and mosquitoes.
of Dumbachers ideas say that his team is placing too
much emphasis on the fact that these birds are toxic, not
noticing the possible cocktail of other repellant chemicals
at play in both species. Todd Capson disagrees.
is a real advantage to being able to use and sequester homobatrachotoxin,
he explains. Not only is it very effective at protecting
these birds against predators, but it also guarantees them
an exclusive food source because they can eat bugs with this
toxin that nothing else can.
cases predators wouldnt have to get close enough to
taste these birds, or get a whiff of their distinctive smell.
Like monarch butterflies and gila monsters, pitohuis are bright
orange and black, a color-coded warning that tells predators
they are poisonous. Pitohuis of both sexes are equally toxic
and colorful, a signal that may play a larger role in the
New Guinea ecosystem. According to University of California
at Los Angeles writer, physiologist, and naturalist Jared
Diamond, large flocks of several brown and black bird species
are known to forage together in the islands swampy lowlands.
Usually these flocks are led by members of at least three
of the toxic pitohui species, suggesting a highly complex
social defense system among New Guineas birds. Writing
in the British journal Nature shortly after Dumbachers
initial discovery, Diamond even proposed that birds of paradise
might also be distasteful.
least 15 species of birds of paradise join the pitohui flocks,
he says, and the taste of birds of paradise has been
reported as: the most shocking flesh I have ever eaten
truly abominable. So interactions with
poisonous brown and black birds may have a long-standing selective
force on birds of paradise.
now, however, the only thing that has been shown about pitohuis
and ifrita is that they use BTX, and that it appears to repel
some of their parasites. Whether the birds use BTX for defense,
where it comes from, and how they are able to withstand its
effects are questions that remain tantalizingly unanswered.
Jack Dumbacher and his team plan to return to New Guineas
Varirata National Park to continue the search, looking for
pitohui nests, fitting birds with radio collars to track their
feeding habits, and sending new batches of suspicious bugs
back to Daly at NIH for analysis. Coupled with information
from Capson and Majnep, Dumbacher hopes that his project will
answer some of the questions his research has raised. But
the process could take years. For scientists like Jack Dumbacher,
thats all part of the allure of New Guineas biological
Almost nothing has been studied there, says Dumbacher,
so you can stumble across tree kangaroos and poisonous
birdsall kinds of weird things. Ive always tried
to let the animals tell me where to look and what to study.
In a place like New Guinea, nature is way ahead of our imagination.
Tidwell, a freelance writer and independent television producer,
last wrote about parrot
smuggling in the November/December 2000 ZooGoer.
30(2) 2001. Copyright 2001 Friends of the National Zoo. All