The Bird Listener

Mario Cohn-Haft ’83 first heard the call of the rainforest as a research intern more than 35 years ago. Today he’s the world’s foremost authority on birds of the Amazon.

Mario Cohn-Haft is 85 miles deep into the Amazon rainforest—a long way from his formative New England stomping grounds. He is a long way from everywhere. But he’s completely at home. The renowned ornithologist, armed with a tape recorder and binoculars, and his guide Pedro, a Brazilian woodsman with a machete and shotgun, are blazing a trail through dense jungle when Pedro spots an unusual bird in the distance. Cohn-Haft catches its unfamiliar song. He lets out a call that imitates the song, hoping to lure the bird closer, then lifts his binoculars.

The bird vanishes—but not before he catches a fleeting glimpse of it. “I heard it before I saw it and thought, what the heck is that?” he recalls.

Cohn-Haft later identifies the passerine in his field report as a likely immature jay. Two years and several more expeditions later, he will make the formal case that the unknown species he and Pedro encountered is a Campina jay (Cyanocorax hafferi). New to science and humanity, the bird has been considered endangered from the day they discovered it. 

Cohn-Haft calls the jay his “most spectacular discovery.” Finding it helped justify Brazil’s creation of a large national park, Parque Nacional Mapinguari, and several smaller state reserves that now protect a large expanse of the natural savannas within the jay’s range. It’s one of 15 passerines he and his colleagues added to the catalog of Amazonian birds in 2013, the largest addition since 1871. Most have been confirmed as new species previously unknown to humankind, and several of those also are threatened.

Cohn-Haft is curator of birds and the staff scientist at Brazil’s National Institute for Amazonian Research (Instituto Nacional de Pesquisas da Amazônia) in Manaus, where he has worked since January 2001. He arrived as a research intern when he was 25 and never left. His mission: “I just want to learn as much as possible about Amazonian birds.” This area of the world’s largest rainforest—in Brazil’s northwestern state of Amazonas, remote from both Indigenous and more recent populations—is a great place to look for undocumented bird species. In addition to the numerous species he has helped discover, the bird expert has documented the continued existence of the white-winged potoo, an elusive bird that had not been seen in nearly 200 years. He also helped identify the world’s loudest bird. He is dedicated to birding and ecotourism as positive contributors to the local economy, conservation efforts, and quality of life.

“There is no doubt about it, Mario Cohn-Haft is the most knowledgeable ornithologist in the Amazon—and the most knowledgeable that has ever been. He’s the best,” says Richard Prum, professor of ornithology and ecology at Yale University. “When you think of the amazing depth and breadth of the knowledge he has amassed and its importance to avifauna globally, it’s a huge contribution.”

“He definitely is within that small elite who know the ins and outs of all the Amazonian species.”

Cohn-Haft can identify birds by sight, and when they are unseen, he can identify them by sound. Not recognizing a bird’s call is a common dilemma for birdwatchers, but in his decades of snaking through the world’s largest rainforest, he has learned the songs and screeches of virtually all known Amazonian birds—nearly 1,500 species. A practiced mimic, he’s able to imitate an estimated 3,000 vocalizations. (Many birds produce a repertoire of at least two.) “Any that can be whistled readily—I’m a decent whistler,” he says, “and a few others that can be hooted or sung, but not many that need to be shouted, screeched, hissed, or squealed.”

He describes birdsong as “a powerful tool for recognizing cryptic or obscure kinds of diversity. You know, some things look the same, but they sound different—and they’re not really the same,” he says. “There are a lot more species than we thought, and they sound different. When you sequence their DNA, they are different.”

Other ornithologists attest to Cohn-Haft’s listening acumen. “Here’s the thing when you’re birding with Mario,” says Philip Stouffer, professor of natural resources at Louisiana State University, who has known Cohn-Haft since 1991. “You might think that what you’re hearing is one thing, but if Mario thinks it’s another thing, you’re wrong. He definitely is within that small elite who know the ins and outs of all the Amazonian species.”

Birds have captivated Cohn-Haft for more than half a century. The youngest of three siblings, he lit out early in life for whatever wild places and things he could find around Northampton and Williamsburg, Massachusetts. His brother Tony, 11 years older, was his first guide. “When he was really little, I was into snakes, and I got him into that,” Tony says. “And then there was a butterfly period, and pollinator plants, and frogs. He was just really interested in doing things outdoors.” Tony was a logger for a spell, and Mario would tag along.

“I remember two memorable sightings before I started considering myself a birder,” Cohn-Haft recalls of his middle school years. “One was in Northampton on the street where I grew up. It was a pileated woodpecker, and I thought, ‘Wow, now that’s pretty spectacular.’ ” Then, at summer camp, as he shot arrows at a target, a scarlet tanager—blood red with jet black wings and tail—called out, its sweet siren song beckoning from the forest edge. Archery interruptus.

When Cohn-Haft was 13 his family moved to a rural area where he lingered after meals to watch birds at a feeder outside the kitchen window. He still has the field guide to birds that he gave his mother and stepfather as a wedding present. When he arrived at Dartmouth in 1979, he embraced its leafy environs and continued his outdoor odysseys. He joined the Outing Club, majored in biology, and conducted fieldwork on the birdlife of the Hubbard Brook Experimental Forest in the White Mountains. Under the guidance of professor Richard Holmes, he compiled an illustrated field guide to the 131 birds then found in the 27,000-acre Second College Grant in northern New Hampshire. “He was a self-motivated student who went out and did his thing,” Holmes recalls.

Cohn-Haft did multiple things in College—ultimate Frisbee one year—and for a time he flirted with a career in music. He joined The Aires a cappella group and sang in a doo-wop band, The Memories. His practiced ear often comes in handy in his current endeavors. But music never really had a chance.

After a stint as a singing waiter at a dinner theater in Aspen, Colorado, he spent most of the 1980s angling for avian internships and doing entry-level research gigs in the United States and Canada. In 1987 he made his first trip to Brazil, and in 1990 he began studies to earn a master’s at Tulane University and a Ph.D. from Louisiana State University.

Cohn-Haft spent more time in Brazil as an ornithological intern than in classrooms stateside, and he met his future wife, Rita Mesquita, there. With his gifted ear, he also quickly mastered Portuguese, now his default language. When the birder wasn’t in the lab or the jungle, he and his wife and friends frequented the city’s dance clubs. “He settled into his adopted country right from the get-go,” Stouffer says. “He just took to Brazilian culture.” 

The National Institute for Amazonian Research is headquartered in the capital of Amazonas, where Cohn-Haft lives with Mesquita, a prominent plant ecologist at the institute. He is equally at home in the jungle, monitoring species and mapping their critical habitat, leading scientific forays into the rainforest, mentoring research students, and communicating his findings in journals, lectures, and videos (his YouTube channel is Cantos da Amazônia). 

Cohn-Haft speaks of birds and their mystifying behaviors with the fascination and enthusiasm of a fledgling backyard birdwatcher: “Some of them have extraordinary intelligence and incredible learning abilities. We have lots of beautiful examples of birds as artists. Birds create art. They dance, they make
music, and they do things  just for the sake of their own pleasure in doing them.”

With about 10,000 known species of birds worldwide, Cohn-Haft isn’t going to run out of subjects and behavior to study. He marvels at birds’ courtship and mating rituals: “You can find species that are classic monogamists—they mate for life—it’s romantic. But there are other species whose way of doing things is a harem, where the alpha male gets all the females, and there are a bunch of young males just hanging around waiting for the old fart to die. There is no end to things to see and learn from.”

One of the new Amazonian birds officially certified in the 2013 group submission is a small flycatcher, the Acre tody-tyrant (Hemitriccus cohnhafti). It was named in Cohn-Haft’s honor, as are two newly discovered insect species. The little tyrant is decidedly nondescript in appearance and vocalization.

Not so the white bellbird, whose brilliant white plumage in males is accented by a black bill and a mottled wattle dangling down its chest. This world-class screecher is found at high altitudes, and its ear-splitting outbursts can be heard for miles. In 2017, Cohn-Haft traveled with colleagues to Serra do Apiaú, a remote peak in northern Brazil, to determine exactly how loud the bellbird sings—if that is the right word for its grating mating entreaties. In a paper published in the peer-reviewed journal Current Biology in 2019, the team’s verdict was unanimous: When the male bellbird rang in at 125 decibels, noisier than a jackhammer, the foot-long blowhard was crowned the loudest bird on the planet. 

Ornithology, it turns out, isn’t all nerds and birds. Noting that male bellbirds broadcast their jarring pickup line at close range to potential mates, the authors wrote, tongue in beak: “We propose that bellbird females balance an interest in sampling males at close range with a need to protect themselves from hearing damage.”

Cohn-Haft is one of those rare people who has managed to transform a lifelong passion into a career, one that is equal parts work and wonder. “I have no interest in retiring at this point,” he says. “I do Pilates so that I’ll always be ready for our next field trip.” In 13 years, when he is 75, the Brazilian government will insist he step down. By then he will have observed changes to the Amazon for half a century.

For now, as he continues to search for new species, he also encounters new and worrisome scars in the rainforest. In an ambitious, multistage 2016 expedition that he organized and led into the Serra da Mocidade, an unexplored mountainous area in the middle of the jungle, Brazilian military helicopters ferried scores of researchers in but could not always maintain contact because of the smoke wafting overhead from fires set to clear the jungle for development. When military officials cut the trip short, the researchers already had documented more than 80 previously unknown species of Amazonian dwellers, including insects, mammals, amphibians, and plants. They have published descriptions of 12 creatures new to humanity in the scientific literature, and more are in the certification pipeline. Their discoveries included a new bird species, the brush finch, and three other South American birds never documented in Brazil.

“I think I’m most proud of the expeditions I’ve organized and conducted through the years,” Cohn-Haft says. “Getting competent scientists into carefully chosen remote places where everybody can work their magic and figure stuff out feels like what I was put here on Earth to do. Unraveling mysteries, breaking paradigms, and discovering novelties is to me what natural science is all about. And turning young people on to this, bringing everyone back in one piece, and then telling the world about it in ways that excite people feels like a job well done.”

Grifa Films produced a documentary on his Serra da Mocidade expedition and footed much of its costs. Scientific forays into the rainforest often come from funding sources outside the National Institute’s modest $5-million annual budget. Cohn-Haft and his colleagues conduct their research in the shadow of such hazy handicaps. These days in Brazil, more money goes for commercial development than science. “Fifteen years ago, we had a research staff of more than 800 scientists, and now we have fewer than 200,” he says. “I haven’t had any new hires, or even a raise to accompany inflation, in more than 10 years. There have been massive retirements without replacement, and considerable death of staff due to Covid.” He speaks without rancor. He is simply sharing data. 

Not all is gloom and doom: The administration that took office last year, led by President Luiz Inácio Lula da Silva, is decidedly more ecologically minded than the previous one. Mesquita recently was tapped by the Brazilian Ministry of Environment and Climate Change to be its secretary of biodiversity. “She is on loan from the institute,” Cohn-Haft says. “It is exciting, and it makes me even a little bit more optimistic than I would have been, just because I know what she’s capable of.”

As to why birds matter, and the significance of the possible extinction of species that few human beings, if any, will ever see, Cohn-Haft reflects on the sacredness of all life forms. “What we are losing when species go extinct are links in a very complex system that we barely understand,” he says. “It is pure hubris to think that we could do anything better than nature, which is an incredibly synchronized system of millions of interacting species creating an environment that fosters our own survival.”

In the face of looming extinctions, he maintains that Brazil’s birdlife, at least in aggregate, will survive, even as government data estimates that 18 to 20 percent of the Amazon rainforest has been deforested and another 20 percent substantially degraded. 

Cohn-Haft doesn’t dwell on it. He has work to do. The jungle holds more surprises, such as the white-winged potoo, a Muppet-like, moth-eating forest dweller. To document and describe it, Cohn-Haft used alpine climbing gear to reach a treetop observation platform, then spent the night above the canopy. He and the bird briefly sang to one another. The potoo had not been seen in nearly two centuries. 

“I do have clear priorities of where to go and what to do,” he says, “and one of them is the Amazonian mountains, which are very poorly explored. People don’t think of the Amazon as having mountains. I suspect that I will run out my years getting to as many mountains as I can.”                   


David Holahan is a freelance writer in Connecticut.


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