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Flight of the Butterflies (2012)
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NARRATOR: Fred Urquhart spent a lifetime unraveling the secrets of the Monarch butterfly. FRED (voice-over): It has been said, since Darwin's time, that evolution is written on the wings of butterflies. My destiny was written on the wings of one. NARRATOR: As a young boy in the 1920s, near Toronto, Fred wondered where all the Monarch butterflies were flying to each fall. He could never have dreamt that each year, these Monarchs join millions of others on an extraordinary journey south to a remote and distant hideaway. We begin our Monarch story today in a different time and place. Every spring, Monarch butterflies arrive here in the Texas Hill Country. It's one stage in a year-long cycle that will take at least three generations. Each generation must survive through egg, caterpillar, chrysalis and adult butterfly. Amongst the spring flowers, this female has found a plant called milkweed. Most varieties contain some level of poison. Animals avoid it. But it's the only plant Monarchs lay their eggs on. Inside this egg is a hungry caterpillar. After hatching, it snacks on its egg casing. Then milkweed is all it ever eats. Milkweed is bitter-tasting. The caterpillars can tolerate it, but it makes them an unpleasant meal for predators. Even with this milkweed protection, Monarchs are still a major food source for birds and insects. Less than one percent of eggs and caterpillars will survive to become adult butterflies. This is one of the lucky ones. We will call her Dana, from her Latin name, Danaus plexippus. Dana and her offspring must stay lucky for generations to survive the year ahead. FRED (voice-over): By the 1940s, I had become a scientist, and finding where the Monarchs went had become my quest. I had the idea that sticking tags on butterflies might work, but no one back then had ever tagged insects. So I kept on testing different glues, and made tiny tags, and tried to imitate a butterfly. NARRATOR: Back in Texas, Dana has mated. Now, she must meet new challenges. As the season advances, the dry Texas heat slows the milkweed growth. Dana and her fellow survivors must fly, following the spring bloom. The Southern Monarchs surge north, laying eggs as they go. Up to three generations over six months can swell Monarch numbers to as many as half a billion. FRED (voice-over): By the early 1950s, I had finally solved the tagging problem. WOMAN: Ready? This one's ready to go. FRED (voice-over): The newly invented sticky labels being used on groceries were the answer. They were so darn difficult to pick off, we tested them on Monarchs. They worked. WOMAN: Oh! (giggling) He gave you a little kiss good-bye. What do you think, Nora? (voice-over): While teaching, I had found another love, Nora, a fellow butterfly fan. I can't thank our friends enough. This is wonderful of them coming out here, taking the time to do this, but... (voice-over): Our challenge now was to find a way to tag them all across their breeding grounds. As Nora said, "We need a big idea to keep up with these little critters." Who will we get? NARRATOR: Dana is flying northeast from Texas. On the way, she lays eggs on milkweed bordering fields. As farms get bigger, these borders disappear and with them, the Monarch's nurseries. (engines rumbling) But Dana escapes, and lives on, until all her 300 or so eggs are laid. This is now Dana's daughter. Like the generation before, she feeds on milkweed, And then... becomes a butterfly, and feeds on nectar. FRED (voice-over): Nora and I had that big idea. We formed the Insect Migration Association. We asked for volunteers. They were known as "citizen scientists," and our tagging efforts as "the great butterfly hunt." By the 1960s, we had over 4,000 helpers. NARRATOR: Dana's daughter finds a safe haven in the fields of an abandoned farm. Amongst the flowers, she also finds a mate. Together, they will create the next generation of Monarchs. With her eggs fertilized, Dana's daughter is ready to begin laying. But this time, the threat comes from the sky. (airplane engine roars) NARRATOR: Startled by the crop duster, Dana's daughter must fly on until she finds milkweed. In a new Toronto suburb, she zeroes in on a garden. It's been planted especially to attract and feed butterflies. It's an oasis of flowers, promising all sorts of nectar and milkweed. She will now lay her eggs; eggs with a truly remarkable destiny. Nora, do you have the letter with the found tag that came in this morning? FRED: Somewhere in Oklahoma, wasn't it? Altus, to be exact, Freddie. FRED (voice-over): By 1967, our unique family of citizen scientists were writing in from all over North America. This is one of the 500 we sent to Buffalo. Buffalo, Buffalo, Buffalo, Buffalo-- got it. FRED (voice-over): We sent out tags to everyone who wrote to us. When the tagged butterflies were found, their details were returned. With this information, we were able to begin to plot their flight paths. Thank you. Done. NARRATOR: Emerging from this egg is Dana's granddaughter. Hatching in the butterfly garden, she is the third generation since the Texas meadows. Each of these Monarchs is part of a "super generation destined for a spectacular journey. In two weeks, she will be 2,000 times larger. Dana's granddaughter finds a safe place for her next stage. Like all Monarch caterpillars, she has cells that can develop into an adult butterfly. In the next 15 hours, her final caterpillar skin splits, and beneath, a new skin hardens into a chrysalis. Inside, specialized cells nourish new tissue growth. Fed oxygen by hundreds of fine breathing tubes, her brain, heart and digestive tract change shape and size. New powerful flight muscles develop and compound eyes form. Long legs and sturdy wings complete the transformation. In two weeks, Dana's granddaughter has remodeled herself into a butterfly. But she will be different-- a super butterfly, destined to live eight times longer and fly much farther than her mother and grandmother. She warms her virgin wings, covered with over a million scales. These wings will take her on a flight to a secret winter home. The angle of the sun is getting lower in the sky. The days are shorter and colder. She senses these signals. It's time to fly south. After negotiating city skyscrapers, the next obstacle for Dana's granddaughter is the wide open water of the Great Lakes. (ducks quacking) There will be many more challenges on her epic journey to a place she has never known. FRED (voice-over): For years we charted the different flight paths of the Monarchs. A curious pattern began to emerge. Most of these Monarchs were flying southwest into Texas, but that would mean they were all gathering there unnoticed. How on earth could that be? Well, there was one way to find out. We moved our research to Texas for the winter of 1970, and during every spare moment, Nora and I were on the road. Traveling more than 14,000 miles, we searched high and low for large gatherings of Monarchs. But it wasn't to be. We found none. Despite spending two decades tagging with all those good people helping us, I still had no evidence of the missing Monarchs. It was like a butterfly black hole. (distant howl) NARRATOR: To make her extra long journey, Dana's granddaughter builds up fat and conserves her energy. She will not mate and she will catch free rides on the winds, sometimes flying a mile high. Monarchs are beautifully evolved navigators. Their DNA reveals clues about their exceptional ability to migrate so accurately. The multipurpose antennae constantly track time and the position of the sun. They feed a stream of signals to her brain. Tiny hairs on her head gauge the wind. Her supersensitive eyes see light waves and colors far beyond ours. As the sun moves across the sky and she keeps time, like an insect GPS, she fine-tunes her flight path. She smells with her antennae and she tastes with her feet, detecting the nectar she needs each night to refuel. These adaptations, and some we have yet to discover, make the Monarch a master of migration. FRED (voice-over): Back in Canada we received a letter that changed everything. Nora, dear, I think we may have something. MAN (voice-over): Dear Dr. Urquhart, I read with interest your article on the Monarch butterflies in my local paper in Mexico City. It occurred to me that I might be of some help. When driving through the Sierra Madre Occidental mountain range, about 120 miles due west of Mexico City, I came across wet and tattered Monarchs that had been brought down in a rainstorm. (thunder rumbles) FRED (voice-over): The letter was from Ken Brugger, an American inventor working in Mexico. On his way to meet his girlfriend, he had come across something he wasn't expecting. (thunder rumbles) (indistinct conversations) KEN: Diego, look right at me. FRED (voice-over): After this encounter, Ken responded to an article Nora had placed in a Mexican newspaper, asking for help. Romance had blossomed for Ken. He married Catalina Aguado. Gracias. FRED (voice-over): As a girl, she was enchanted by small groups of Monarchs flying and resting along the cool riverside. (conversing in Spanish) FRED (voice-over): They were the ideal team. So we hired them. Catalina. Here you go, love. FRED (voice-over): Now we had two citizen scientists in Mexico. - KEN: You ready? - CATALINA: Yep. KEN: Watch your foot. (sheep bleating) (children shouting playfully) NARRATOR: Rumors spread that Ken and Catalina were looking for rare minerals or hidden treasure. CATALINA: Hola. - Buenos dias. - Buenos dias. (man speaks Spanish) It's okay, it's okay. (querying in Spanish) - No. -No. -(Catalina querying in Spanish) - No. -No. -No. Tu? (laughs) (querying in Spanish) Bueno? Tu? Gracias. (engine starts) - Adios! -(children clamoring) NARRATOR: After two years of dead ends, Catalina deciphers a clue to where the Monarchs might be gathering. Early November is the Day of the Dead festival, el Dia de los Muertos. It is the time to honor departed loved ones. In the states of Mexico and Michoacan, Monarchs drift through the cemeteries. Folklore embraces them as the returning souls of children. Ken. NARRATOR: For Catalina, her childhood memories take on a new significance. Did the flight of the butterflies point the way? (rooster crows) Early one winter morning in 1975, Ken and Catalina set out for the mountaintop of Cerro Pelon. (Ken panting with effort) (Catalina gasps) (phone line clicks) -(phone line beeping) - Freddie? Freddie? Honey, you all right? They found them. Ken and Catalina have found the Monarchs. That's wonderful. High up in the mountains. Millions of them. FRED (voice-over): It was marvelous to learn about so many butterflies. But I still had no proof that those millions had migrated from the North. (low, indistinct conversation; children squealing) NARRATOR: That September in the northern state of Minnesota, Jim Street and Dean Boen, with their teacher Mr. Gilbert, carefully log tag PS 397. All right. NARRATOR: Every autumn, the super butterflies head south in the millions. Dana's granddaughter is flying from the Great Lakes to Texas. With extraordinary aim, she will funnel across the Rio Grande into Mexico. Her target is a few forested peaks amongst thousands. When she arrives, this tiny creature will have completed one of the longest migrations on Earth. This is the mountainside that offered sanctuary to her great-grandmother exactly one year before. It is the perfect place. Far enough south for the sun's warmth, yet, at 10,000 feet, it's cool in the evergreen forest, with just the right amount of moisture. In this fragile microclimate, Dana's granddaughter will slow down, clustering for warmth and protection, and living off her fat reserves until spring. NARRATOR: Yet, even here, Dana's granddaughter will face challenges. Many of the trees have been cut down. And as the climate changes, the combination of cold and wet storms kills millions. But for the survivors, it is a winter sanctuary. NARRATOR: On January 9, 1976, the Urquharts made the trek to Mexico, despite the warnings from Fred's doctor. Heavens above. It's unbelievable. Unbelievable. What a glorious, incredible sight. I could not believe what I was seeing. One of our tags. I was holding indisputable proof of an incredible journey. One fragile, wind-tossed scrap of life, symbolized both the marvel of the Monarchs, and the priceless rewards of finally resolving an age-old scientific mystery. For one truly magic moment, time stood still. (wings rustling) NARRATOR: Those who survive the winter drink in the spring warmth. The longer days awaken the dormant urge to mate. Amongst the mating females is Dana's granddaughter. Now it's time for her to make a final flight. Catching the winds north, she will make her way to Texas, where, just like her great-grandmother, she will lay eggs on the spring milkweed. And as it has for thousands of years, the Monarchs' remarkable annual cycle will begin again. |
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