The Greatest Show on Earth
Each spring, on the plains of Manitoba, tens of thousands of red-sided garter snakes come boiling out of the depths of the earth. Before dispersing, they come together to mate in what is truly one of nature's most riveting spectacles.
By Alex Shoumatoff / Photography by Chip Simons
My eight-year-old son, Zachary, belongs to seven generations of naturalists, going back to Russia in the l830s. Most of them were lepidopterists; Zach is the first to exhibit a deep fascination for reptiles and amphibians. Part of this undoubtedly has to do with Steve Irwin, the fearless, boundlessly enthusiastic Australian "crocodile hunter" on TV, whom Zach and his two brothers and millions of other kids are devoted fans of. But Zach possesses a remarkable empathy for other forms of life, an empathy I have encountered in only a few people in 35 years of writing about the natural world and those who study it.
I've learned a lot from him about snakes, salamanders, frogs, and turtlessubtly beautiful creatures I had never paid much attention towatching him turn over rocks in Montreal's Mount Royal Park, which we live on the edge of, uncover hundreds of red-backed salamanders, or net aquatic forms of red-spotted newts in ponds around our country place in New York's Adirondack Mountains. Turning up a milk snake on a Vermont farm, or a western diamondback on an Arizona ranch, within minutes of his arrival on the scene, Zach has shown me that reptiles and amphibians are far more ubiquitous than I had suspected, even with the assault they are under from so many quarters. So I decided to take Zach to see the snakes in Manitoba, which are justly counted as the ultimate ophidian experience.
In the first weeks of May, the porous limestone country north of Winnipeg, Manitoba, becomes the scene of the greatest orgy in nature, as tens of thousands of red-sided garter snakes emerge from their winter dens and procreate in huge, writhing mating balls. This is the largest gathering of communally denning garter snakesor snakes of any kindon the planet, the only place where you can take in thousands at a glance. It is an anachronistic expression of the riotous abundance of life that once proliferated, comparable to the mile-long clouds of nymphalid butterflies that you can still be enveloped in along the Congo River. It's particularly heartening, because snakes have always been the most persecuted group of animals.
Their sexual frenzy usually peaks around Mother's Day. But this year it was taking longer for them to come up from their subterranean hibernacula, the lack of insulating snow cover during the bitterly cold winter perhaps having driven them further down. The bacchanal was only just getting under way when we arrived a week later, on Victoria Day weekend (the Canadian equivalent of Memorial Day weekend).
Flying into Winnipeg, we headed north into the interlake region, between Lake Manitoba and Lake Winnipeg, most of which is pancake flat. Only scattered copses of the original aspen parkland remain, like islands in a sea of wheat and flax. After an hour or so, the soil got noticeably thinner. Cattle were grazing in rocky pastures, and in places the limestone bedrock was exposed. We could see scratches on it from the immense glaciers that had slid over it ages ago, bringing down granite boulders from hundreds of miles to the northwest. The deeper gouges were filled with finger lakes, swamps, and marshes full of frogs.
This is great habitat for snakes, but not for humans, and like most of rural Manitoba, the interlake region is losing population. The dens are near an old Jewish colony called Bender Hamlet, which lasted only from l903 to 1927 and was abandoned after the railroad passed it by. All that is left is its graveyard, kept up by one of the descendants of the 19 families that emigrated here from the Ukraine; he owns big malls in Winnipeg. Chatfield, the next settlement to the north, is down to nine full-time residents, and Narcisse, where the snakes are, has even fewer. So it is safe to say that the greatest vertebrate biomass in the RM, or rural municipality, of Armstrong, which Narcisse and Chatfield are in, is not human, but reptilian.
Four of the dens, containing an estimated 75,000 snakes, are in the 15,000-acre Narcisse Wildlife Management Area, which was created from the Narcisse communal pasture in l982. We rendezvoused there with Bill Preston, the emeritus curator of herpetology at the Manitoba Museum and the author of The Amphibians and Reptiles of Manitoba. Bill has been visiting the dens for 30 years and was instrumental in getting them protected.
"When I first got here," he recalled, "there was a guy who collected the snakes for biological supply houses. Many of the biggest snakes were shipped to the States, where they were sold to pet stores and dissected in high school and college labs. We had a meeting at the museum, and got the province to limit collecting to only in the fall. But then Ojibway snake pickers arrived on the scene. They would set down sheets of tar paper in ditches overnight, and in the morning hundreds of snakes would be warming themselves under them. So we got the snake collecting stopped altogether and the four most productive dens annexed as provincial crown lands."
Why is Manitoba, at the northern limit of where reptiles can live, so congenial to garter snakes? I asked. Preston attributed this to the combination of the karst topography, which provides roomy chambers for them to den together in, tons of lakes with an abundance of frogs, and hot summers. The winters here can go down to minus 50 degrees Fahrenheit, but the caverns stay just above freezing. The snakes also den in shaley cliffs, and in the granitic Precambrian shield, to the east. Fifty dens are known in the province, but there are undoubtedly many more.
The red-sided garter snake, Thamnophis sirtalis parietalis, is one of at least 11 subspecies. Its lateral lines vary from white to orange to yellow; the topline is usually yellow, although not always. How the colors vary from den to den and how they relate to predation and mating success is under study.
Dana Neumann, a young interpreter with the provincial conservation department, took us to Den 3, a sinkhole (where one of the underground chambers had collapsed) on whose floor dozens of snakes were probing their way among newly leafed-out burdock and stinging nettles. Some of the snakes had formed wriggling balls. "So far it's been more of a trickle than a flood," Dana said. The den was fenced off, to keep the public from going into the pit and stomping the snakes, which used to happen. Now schoolchildren across Canada are taught that May is when the snakes emerge, and they are assigned essays about the importance of helping the snakes get safely across highways.
Some of these snakes had already climbed the walls of the sinkhole and were making their way into the woods. Zach was in seventh heaven, almost in a trance, picking up one snake after another gently and unhesitatingly and holding it for a while before placing it back in the grass. The snakes were totally docile; this is the place where someone with a snake phobia can come and get over it. "I have never caught so many snakes in my life," Zach exclaimed. "This is the most wonderful thing that has happened to me. I wish you good luck and hope you don't get eaten or stepped on or run over," he said to a snake Dana identified as a female. "The females are longer and thicker," she said. "Some are almost as big around as a loonie [a Canadian dollar coin] or even a toonie [a two-dollar coin]." Their females' tail bases taper more abruptly than the males', whose thicker tail bases house their hemipenes, or paired copulatory organs.
The vast majority of the snakes we were seeing were foot-and-a-half-long males, ranging from a year-and-a-half to 10 years old (garter snakes in captivity have lived to be 17). The males emerge first, in great number. Heating themselves up in the strong spring sunlight, they wait for the females, which emerge singly or a few at a time, nervous and exuding attractive-smelling pheromones. Most of them are quickly mobbed by males. Up to 100 males will vie for the chance to penetrate a female. Some of the females manage to run the gauntlet of the males and sneak off to safety. Some are chased up into bushes or trees. We saw several saskatoon shrubs, in white flower, englobulated with mating balls, dripping with snakes.
After inseminating the female, the successful male plugs her with a gelatinous substance secreted from his kidney, which soon hardens and emits different, unattractive pheromones. The other males leave her alonefor now. She makes her way to the summer range, along with other inseminated females, and ones that have eluded the males and will meet up with boyfriends laterin less stressful circumstancesand smaller males that have little chance of squirming and muscling their way up to the female in a mating ball.
Heading for the swamps and marshes at the top speed of a person walking, the snakes feast on wood frogs, boreal chorus frogs, gray tree frogs, and leopard frogs. The imperative now is to eat. Each snake has lost 10 percent of its body weight over the winter, Dana explained, and has been losing an additional 1 percent a day since it emerged. Many don't make it. Some are caught by crows, hawks, foxes, coyotes, or great horned owls. We saw several dead females whose livers had been picked out by crows. Others are run over by cars or trucks.
We were joined by Dave Roberts, Manitoba Conservation's "wildlife technician" for the interlake region. In the fall of 2003, 2,000 snakes were killed on Highway 17. He told us that the annual slaughter occurs despite the fact that 12 new culverts were put under the road and a long fence beside it, thanks to the generosity of Manitoba Hydro, the province's power company.
Despite this attrition, enough females make it to the swamps, where they bear 30 to 50 live young (the record is 70), which they have nothing further to do with. One brood can have several fathers, but the female bears young only once every two years. The gelatinous plug falls out within 36 hours of mating, so a female can mate again. She can store sperm, sequestering it over many ovulation cycles yet still keeping it viable, until she finally gets pregnant. Dana said one female in a lab had young seven years after her last contact with a male! The young snakes spend their first winter at the summer range; in their second fall, they return to the dens with the others.
Zach and I spent the night in Inwood, 20 minutes south. The garter snakes around here den not only in sinkholes and quarries but in old foundations and wells. They have colonized the abandoned Inwood creamery, and even the crawl space of Inwood Manor, the local old folks' home, where they have appeared in hallways and rooms, scaring the daylights out of the residents.
"They seem to like the manor, and just in the last few years they've gotten bad," the manor's cook told me when we dropped in that afternoon. "We saw probably a dozen over the winter, but now they have probably left to wherever they go. They do their snake business in the summer months. This summer we'll be doing major excavation around the whole building so they won't be able to get in anywhere, so that should take care of it."
We spoke with a white-haired woman in the home named Ethel Dadswell, who was knitting in the television room. Ethel was the resident snake catcher. "I hate themenough to pick them up and throw them out the door," she told us.
"Why are people so afraid of snakes?" I asked.
"You've got to admit, they're a nasty-looking thing," Ethel said. "Okay, you can see them outside, and that's fine. But when you're sitting here reading, completely relaxed, and there's one in the corner, with its head reared up and looking aroundthat's not a pleasant thing. I'm one of the people that nothing much bothers. If something needs to be done, I'll do it. But others have a very real fear. They scream and scream and get frantic and can hardly breathe. That's not a nice thing, when it can be controlled. I'd like someone to tell me why they're so precious. What good do snakes do?"
"They eat bugs and help keep things in balance," Zach said.
"They keep down the frog population," I suggested, rather lamely in view of the dire straits the world's batrachians are in almost everywhere. (But a frog population that is out of control because not enough of them are being eaten by snakes and other predators can become a horrendous problem, like the introduced bullfrogs in British Columbia.)
"They torture the frogs," Ethel countered. "A frog is a nice thing. Frogs don't do us any harm. Where I grew up, in Norris Lake, 11 miles south of here, when spring came the frogs used to sing me to sleep. But here you don't hear anything, because there are so many snakes. If all they do is kill the frogs, then I'd rather not have them. This thing that they're absolutely harmlessthat doesn't apply to anything. Not even people."I don't see how anyone can not like snakes," Zach got up the gumption to say.
In the morning it was raining. Zach and I went to say goodbye to the snakes and to see whether the wetness had slowed their emergence and dampened their ardor. Some were out and about, but not as many as the day before. Zach picked one up from a large, writhing pile. He turned over a rusty metal plate, exposing hundreds more. "Come on, Zach, we have to go," I said.
"Just one more snake," Zach pleaded. He picked up another one, and, laying it back down softly on the scree, said, "Bye, snakey. I love you."
A former staff writer at The New Yorker and contributing
editor of Vanity Fair, Alex Shoumatoff is the author of 10
books and the publisher/scribe of DispatchesFromTheVanishingWorld.com.
© 2004 National Audubon Society