A Conversation With Scott Weidensaul

By Steven Brodsky
Congratulations on the release of your latest book, Peterson Reference Guide To Owls of North America and the Caribbean. You’ve authored over two dozen books on natural history, have been a Pulitzer Prize finalist, and are renowned as a field researcher. Your writing has appeared in many major publications, including Audubon and National Wildlife. You are a popular lecturer and one of the world’s most highly regarded authorities on birds. Your first visit to Hawk Mountain in Pennsylvania was a formative event in your life as a naturalist and author. Tell us about this.
I was 12, and had been campaigning pretty hard for several years for my folks to take me to Hawk Mountain, which was about an hour south of our home on the edge of the anthracite fields in northern Schuylkill County. By luck, the day they finally relented was a perfect migration day in mid-October — blustery wind, ragged clouds, hawks peppering the sky. One sharp-shinned hawk, about the size of a blue jay, dove down in screaming rage at a papier mache owl decoy the hawk watchers had placed on a high pole, and it swept just a few feet over my head. I’d never seen raptors with such intimacy, and that day I became hooked on three things: birds of prey; the Appalachian Mountains, which formed this annual flyway; and migration. Those three elements have shaped much of my life and work in the 45 years since.

When did you decide that ornithology was going to be the primary focus of your life’s work? Why birds?
I was actually much more focused on herpetology, especially snakes, when I was a kid, and right through the start of college I planned to study them. But birding was always a big part of my life, and an ornithology course I took in college really got me hooked on the science of birds. With the love of raptors I already had, that steered me into field research, starting in the 1980s when I began helping Hawk Mountain’s research team with hawk-trapping and banding to study their migrations. Within a few years I was a federally licensed bander, working first with hawks and falcons, and later with songbirds, owls and hummingbirds. Why birds? Because they perform some of the most incomprehensibly difficult journeys, across immensities of space and time, that any organism undertakes.
Does your involvement with nature entail a spiritual component?
In the traditional sense, no. In the sense of awe and humility in the face of something greater, absolutely.

Are you most at home in the field?
Without question. I am definitely not a city boy.
Your work has taken you to some of the most incredible natural settings. Tell us about some of your favorites.
Hard to narrow it down. I’ve been returning almost every year for three decades to Alaska, and have traveled all over that state, from the outer Aleutians to the North Slope and interior, but spend a lot of time there in Denali National Park. For the past several years I’ve been working with several friends and colleagues on a project to use miniaturized tracking devices to follow the migration of many of the park’s birds, which travel to Central and South America, the southeast U.S., Asia and New Zealand. It’s hard work — we’re in the field by 3 a.m. most days — but to look up and see that 20,000-foot mountain looming on the horizon with the colors of dawn makes it worthwhile. (Especially if the mosquitoes aren’t bad and you don’t piss off a grizzly bear or a momma moose.)

Other favorite spots — the coast of Maine, where I teach for Audubon every year at their Hog Island adult camp; the Peruvian Amazon, where I spent a lot of time in the early ’90s and again more recently; the pristine rain forests of Guyana; the sea islands on the coast of Georgia; the Gulf Coast in springtime, when millions of Neotropical migrant songbirds are flooding back with spring migration.
Field work has its frustrations and disappointments. Describe times they’ve been present. What kind of harsh field conditions have you encountered?
Weather’s often the most frustrating, because there’s nothing at all you can do about it. You sometimes have a relatively narrow window of time you can be in the field in a particular location, and it’s hard to be stuck in poor weather that keeps you from doing what you need to do.

Maybe the most challenging conditions weren’t in some remote location, though, but tracking northern saw-whet owls all night some years back. We were working in teams of three, using radio receivers and directional antennas to track the birds’ movements by triangulating their positions. These owls come off the roost, catch a mouse, eat — and then just sit there for three or four hours in quiet, happy digestion. Meanwhile, we humans are trying to keep warm in a December snow squall and icy winds, hopping from foot to foot trying to stay warm, taking a new directional bearing every 10 minutes only to find that, as had been the case for hours, the owl has moved not an inch. Finally, about 3 a.m. or so the owl would start hunting again, and we could finally start moving, too, working a little warmth and life back into our feet and hands..
Have you been exposed to dangerous circumstances involving animals?
Occasionally, but usually the most dangerous part of field work is getting there — the drive on the highway, or to the airport, is vastly more dangerous than anything that’s likely to happen with an animal. That said, I’ve had some close calls with grizzlies, and once with a black bear, and I’ve had some near-brushes with venomous snakes. But the single most dangerous wild animal I’m likely to encounter is a tropical mosquito or sand fly carrying a disease like malaria, dengue or leishmaniasis.

If you had to choose one geographic area to confine your future field work, which one would you pick and why?
If I had to make that choice, it would be the Appalachians, since they’ve been the anchor of my life since childhood. If I had to pick beyond that, probably Alaska, for many of the reasons I mentioned earlier.

How many birds have you banded personally and how many in association with others?
I couldn’t begin to guess — many, many thousands, from hummingbirds to eagles, of hundreds of species and on multiple continents.

What kind of data does banding yield?
To paraphrase another ornithologist, almost everything concrete that we know about the lives of wild birds comes from marking them as individuals in some way, and the simplest and safest way is with a lightweight numbered leg band. This goes back to 1804 or ’05, when John James Audubon tied silver wire to the legs of eastern phoebes at his father’s estate at Mill Grove in Montgomery County, to see if the birds nesting in an old mine were the same ones each spring. (They were.)

Banding tells us where birds travel, how fast they migrate, how long they live, whether they come back to the same place to breed or to winter, whether they have the same mates from year to year. We would know precious little about the details of the lives of wild birds without banding and associated techniques like radio-tagging and color-marking.

You’ve studied bird migration extensively. What are some of the longest nonstop migratory flights that some species take?
The longest nonstop migration that we know of is made by a pigeon-sized shorebird called the bar-tailed godwit, which flies nonstop from Alaska to New Zealand and Australia every September, a journey of 7,200 miles across the widest part of the Pacific. Satellite tracking shows that the birds are in the air, beating their wings continuously, for seven to nine days. In March and April, they head northwest some 5,000 miles to the Yellow Sea in China and Korea, then make a final 2,500- to 3,000-mile flight back to Alaska. All together, they travel 18,000 miles a year, averaging 22 days of flight. And because they can live up to 30 years, they may travel most of the distance from here to the moon and back before they die.
Even tiny songbirds make incredible flights, although most are still too small to track in real time like the godwit. Blackpoll warblers and a number of other tiny songbirds make nonstop flights in autumn from the northeast coast of Canada and the U.S. across the western Atlantic to northeastern South America, a trip of some 90 or 100 hours — again, beating their wings continuously for about five days.

How is this possible? 
Birds are built for flight, and they are exceptionally aerodynamic and efficient, but it comes down to fat. Before a bar-tailed godwit takes off, it more than doubles its weight in a two-week bout of binge feeding, so that when it lifts off it is more than 50 percent fat deposits. A little warbler flying across the western Atlantic goes from 10 or 12 grams to 17 or 18 grams. By one calculation, if they were burning gasoline instead of fat, they would get 720,000 miles to the gallon.<br> There is much more, of course — their ability to orient and navigate using the night sky, the Earth’s magnetic field, ultra-low sound frequencies, polarized light and even smell; their ability to go days or weeks without sleep, often by employing nanosecond micro-naps or “hemispheric sleep,” where one half of their brain shuts down for a fraction of a second at a time.
Of now extinct bird species, which one would you most like to have had an opportunity to observe?
In terms of spectacle, it would be hard to pass up a flock of several billion passenger pigeons roaring overhead for days like a feathered river, or a flock of green-and-orange Carolina parakeets whirling in a loud, squawking mass through an East Coast forest. But the one I’d love to see the most was the great auk, a flightless, goose-sized relative of the puffin and razorbill that lived in the North Atlantic, including some of my favorite places on the Maine coast. It was the original “penguin,” since the Welsh term “pen gwyn” (“white head”) was first applied to this bird, presumably in its winter plumage, in the 1600s, and only later transferred to the unrelated birds in the Southern Hemisphere.
Who knows, I may get my wishes. There’s a project at Stanford University to resurrect the passenger pigeon, using genetic manipulation of the DNA of its closest relative, the band-tailed pigeon, and supported by the Long Now Foundation; they are also working to do the same with the heath hen, the form of prairie-chicken once found on the Northeast coast. And now a British team has announced they will similarly try to “de-extinct” (in the jargon of the day) the great auk, using DNA from old bones and eggs, and tinkering with the genome of its closest relative, the razorbill. Only time will tell.
Had you not focused on ornithology, what other career path might you have taken?
Hard to say. Probably something involving history or archaeology, which are two longstanding interests of mine.
When and why did you start to develop an interest in owls? 
The interest has always been there. I got involved in owl research in 1997, starting to band northern saw-whet owls in Pennsylvania — this is our 20th season of fall migration banding these small raptors, which only weigh as much as a plump robin and migrate through the East by the thousands each autumn. More recently, I helped start a huge, collaborative study of snowy owls known as Project SNOWstorm www.projectsnowstorm.org that uses cutting-edge tracking technology to learn more about their winter ecology.
“Wise” is the appellation that many accord to owls. How do these raptors rate on bird-brained intelligence?
Compared with birds like ravens, crows or parrots, not especially high. The “wise old owl” thing probably has more to do with the fact that they look vaguely human — round head, large forward-facing eyes — than their intelligence level. But they are exceptionally good at being owls.

How are owls equipped for their nocturnal activities? 
The most obvious adaptation are their extremely large eyes, which are even bigger than they appear to us. If we had eyes proportionately as large as an owl’s, we’d have eyeballs the size of grapefruits. The large eyes, with an abundance of light-sensitive rod cells, give them good night vision — though not as well-developed as some nocturnal mammals, which have a reflective layer at the back of the eye called the tapetum lucidum (that’s why many mammals’ eyes shine in headlights). They also have excellent hearing, which in some owls may be more important for hunting than their vision.
Many people are surprised to learn that owls’ ear tufts don’t assist the birds with hearing. Why do they possess them?
The tufts are primarily for camouflage, and may also convey mood and emotion. The ears themselves are simply holes in the skull, usually at the lower edge of the round facial disk of feathers that gives owls their characteristic appearance. The facial disk, including muscular flaps below the feathers, act like parabolic reflectors to direct sound waves into the hidden ear openings. A few owls, like northern saw-whet owls, boreal owls and great gray owls, have highly asymmetrical ear openings, one high on the head and facing up, and one low on the head and facing down. This creates slight time-lags between when sound waves reach each opening, allowing them to very precisely pinpoint the source of faint noises, like those of small mammals.
What else surprises the general public the most with regard to owls?
That most of them sound nothing like our stereotyped assumptions. A few owls hoot, but there are owls that scream, whinny, toot, bark, meow, hiss, roar, click, snap and growl.

Which owls are Pennsylvanians most likely to see?
See? Probably none, unless you go looking for them at night. You’re better off listening, which brings me to your next question..
Readers of the book can download a companion album of 86 representative vocalizations for the 39 owl species you’ve described and range mapped. What vocalizations are Pennsylvanians most likely to hear in the outdoors?
The two most common are the great horned owl, which gives a string of five to nine deep, resonant hoots; and the eastern screech-owl, which gives either a high, descending whinny or a monotone trill. Juveniles of either species, in late summer and early fall, make a grating, harsh begging call demanding that their parents feed them. In some places, the most common owl is the barred owl, whose whooping call is usually rendered as “Who cooks for you, who cooks for you aaaaallll?”

The one “owl” call that isn’t is the somber, four-noted call of the mourning dove: “Whoo-OOO ho, hoo-hoo.” If you hear what you think is an owl in the daytime, it’s probably the dove.

Is it difficult for photographers and other observers to get close to owls without eliciting fright and flight reactions? 
Depends on the owl. Many species can be approached carefully if they’re found in the daytime, largely because the owl would rather trust to its camouflage and remain hidden than risk a daytime flight when crows, hawks and other potential hazards might spot it. But some of the boreal and Arctic species, like great grays, snowy owls and northern hawk owls, seem to have little natural fear of humans, and will allow a close approach (though it’s always a good idea to give the owl plenty of space).
Why is the population of barn owls declining in many areas of their range?
Probably several factors. They need barns, old structures of some sort or hollow trees, and such places are harder and harder to come by. Because they feed on rodents, they are especially susceptible to rodenticide poisoning. Although barn owls nest in barns and the like, they hunt in meadows and open grasslands, fewer and fewer of which remain in many areas — and the landscape is more fragmented now with woodlots and backyards, creating good habitat for great horned owls, which prey on them. And finally, barn owls hunt by coursing back and forth low above the ground — meaning that they’re at great risk of vehicle collisions along roadways.

Which species do you take the most satisfaction in finding in Pennsylvania?
After 20 years, and more than 10,000 banded, I’m still not tired of saw-whet owls — and we’re still learning a lot about this small, beautiful owl.

Of all the species described in your book, which one do you find to be the most beautiful?
Tough question. Owls in general, because of their complex, cryptic coloration, are beautiful. Some, like the pygmy-owls and saw-whets, are simply cute to a human eye. Some of the tropical species, like black-and-white owl and crested owl, are strikingly attractive. But snowy owls have both the size and regal presence to go along with their stunning plumage — plus they’re fast, powerful and agile.

Are you working on another book?

I am — a book on global bird migration and conservation, which will have me occupied the next three years. I’ll be all over the map — India, China, Korea, sub-Saharan Africa, South America, the Arctic and the high seas. And also in the lab with scientists, writing about the latest advances in our understanding of migration science.

Posted Oct. 27, 2016

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