[Script Info]
Title: 
[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:08.62,0:00:13.05,Default,,0000,0000,0000,,In May of 1822, \NCount Christian Ludwig von Bothmer
Dialogue: 0,0:00:13.05,0:00:17.74,Default,,0000,0000,0000,,shot down a stork over his castle\Ngrounds in North Germany.
Dialogue: 0,0:00:17.74,0:00:23.02,Default,,0000,0000,0000,,However, he wasn’t the first person\Nto hunt that specific bird.
Dialogue: 0,0:00:23.02,0:00:25.06,Default,,0000,0000,0000,,Upon recovering the stork,
Dialogue: 0,0:00:25.06,0:00:30.21,Default,,0000,0000,0000,,von Bothmer found it impaled \Nby a yard long wooden spear.
Dialogue: 0,0:00:30.21,0:00:34.46,Default,,0000,0000,0000,,A local professor determined \Nthe weapon was African in origin,
Dialogue: 0,0:00:34.46,0:00:38.65,Default,,0000,0000,0000,,suggesting that somehow, \Nthis stork was speared in Africa
Dialogue: 0,0:00:38.65,0:00:44.01,Default,,0000,0000,0000,,and then flew over 2,500 kilometers \Nto the count’s castle.
Dialogue: 0,0:00:44.01,0:00:48.71,Default,,0000,0000,0000,,This astonishing flight wasn’t just\Nevidence of the stork’s resilience.
Dialogue: 0,0:00:48.71,0:00:54.58,Default,,0000,0000,0000,,It was an essential clue in a mystery\Nthat plagued scientists for centuries:
Dialogue: 0,0:00:54.58,0:00:57.65,Default,,0000,0000,0000,,the seasonal disappearance of birds.
Dialogue: 0,0:00:57.65,0:01:02.54,Default,,0000,0000,0000,,Ancient naturalists had various theories\Nto explain the annual vanishing act
Dialogue: 0,0:01:02.54,0:01:05.61,Default,,0000,0000,0000,,we now know as migration.
Dialogue: 0,0:01:05.61,0:01:11.04,Default,,0000,0000,0000,,Aristotle himself proposed \Nthree particularly popular ideas.
Dialogue: 0,0:01:11.04,0:01:16.75,Default,,0000,0000,0000,,One theory was that birds transformed into\Ndifferent bodies that suited the season.
Dialogue: 0,0:01:16.75,0:01:20.15,Default,,0000,0000,0000,,For example, summer time garden warblers
Dialogue: 0,0:01:20.15,0:01:24.15,Default,,0000,0000,0000,,were believed to transform \Ninto black caps every winter.
Dialogue: 0,0:01:24.15,0:01:28.92,Default,,0000,0000,0000,,In reality these are two distinct species—\Nsimilar in shape and size,
Dialogue: 0,0:01:28.92,0:01:31.91,Default,,0000,0000,0000,,but never appearing at the same time.
Dialogue: 0,0:01:31.91,0:01:36.40,Default,,0000,0000,0000,,Over the following centuries, birds \Nwere said to morph into humans,
Dialogue: 0,0:01:36.40,0:01:40.07,Default,,0000,0000,0000,,plants, and even the timbers of ships.
Dialogue: 0,0:01:40.07,0:01:45.44,Default,,0000,0000,0000,,This last transmutation was especially\Npopular with many Christian clergy.
Dialogue: 0,0:01:45.44,0:01:48.48,Default,,0000,0000,0000,,If barnacle geese were truly made of wood,
Dialogue: 0,0:01:48.48,0:01:54.41,Default,,0000,0000,0000,,they could be deemed vegetarian \Nand enjoyed during meatless fasts.
Dialogue: 0,0:01:54.41,0:02:00.08,Default,,0000,0000,0000,,Aristotle’s second and even more enduring\Nhypothesis was that birds hibernate.
Dialogue: 0,0:02:00.08,0:02:02.21,Default,,0000,0000,0000,,This isn’t so far-fetched.
Dialogue: 0,0:02:02.21,0:02:04.55,Default,,0000,0000,0000,,Some species do enter short,
Dialogue: 0,0:02:04.55,0:02:08.55,Default,,0000,0000,0000,,deep sleeps which lower their heart rates\Nand metabolisms.
Dialogue: 0,0:02:08.55,0:02:12.33,Default,,0000,0000,0000,,And there’s at least one truly \Nhibernating bird:
Dialogue: 0,0:02:12.33,0:02:16.94,Default,,0000,0000,0000,,the common poorwill sleeps out winters\Nin the deserts of North America.
Dialogue: 0,0:02:16.94,0:02:21.34,Default,,0000,0000,0000,,But researchers were proposing much more\Noutlandish forms of hibernation
Dialogue: 0,0:02:21.34,0:02:23.97,Default,,0000,0000,0000,,well into the 19th century.
Dialogue: 0,0:02:23.97,0:02:29.02,Default,,0000,0000,0000,,Barn swallows were said to remove \Ntheir feathers and hibernate in holes,
Dialogue: 0,0:02:29.02,0:02:33.59,Default,,0000,0000,0000,,or sleep through the winter at the bottom\Nof lakes and rivers.
Dialogue: 0,0:02:33.59,0:02:36.95,Default,,0000,0000,0000,,Aristotle’s final theory \Nwas much more reasonable,
Dialogue: 0,0:02:36.95,0:02:40.37,Default,,0000,0000,0000,,and resembled something\Nlike realistic migration.
Dialogue: 0,0:02:40.37,0:02:44.50,Default,,0000,0000,0000,,However, this idea was also taken \Nto extremes.
Dialogue: 0,0:02:44.50,0:02:50.76,Default,,0000,0000,0000,,In 1666, the leading migration advocate\Nwas convinced that each winter,
Dialogue: 0,0:02:50.76,0:02:52.89,Default,,0000,0000,0000,,birds flew to the moon.
Dialogue: 0,0:02:52.89,0:02:58.08,Default,,0000,0000,0000,,It might seem strange that prominent \Nresearchers considered such bizarre ideas.
Dialogue: 0,0:02:58.08,0:03:01.14,Default,,0000,0000,0000,,But to be fair, the true story \Nof migration
Dialogue: 0,0:03:01.14,0:03:05.18,Default,,0000,0000,0000,,may be even harder\Nto believe than their wildest theories.
Dialogue: 0,0:03:05.18,0:03:09.31,Default,,0000,0000,0000,,Roughly 20% of all bird species \Nmigrate each year,
Dialogue: 0,0:03:09.31,0:03:12.99,Default,,0000,0000,0000,,following warm weather and fresh food\Naround the planet.
Dialogue: 0,0:03:12.99,0:03:16.44,Default,,0000,0000,0000,,For birds who spend their summers\Nin the northern hemisphere,
Dialogue: 0,0:03:16.44,0:03:22.21,Default,,0000,0000,0000,,this journey can span \Nfrom 700 to over 17,000 kilometers,
Dialogue: 0,0:03:22.21,0:03:26.36,Default,,0000,0000,0000,,with some flights lasting as long\Nas four months.
Dialogue: 0,0:03:26.36,0:03:32.100,Default,,0000,0000,0000,,Birds who migrate across oceans may soar\Nwithout stopping for over 100 hours.
Dialogue: 0,0:03:32.100,0:03:37.44,Default,,0000,0000,0000,,Sleeping and eating on the fly, \Nthey navigate the endless ocean
Dialogue: 0,0:03:37.44,0:03:42.36,Default,,0000,0000,0000,,by the stars, wind currents, \Nand Earth’s magnetic field.
Dialogue: 0,0:03:42.36,0:03:47.13,Default,,0000,0000,0000,,Tracking the specifics of these epic\Nexpeditions is notoriously difficult.
Dialogue: 0,0:03:47.13,0:03:51.13,Default,,0000,0000,0000,,And while birds often take \Nthe most direct route possible,
Dialogue: 0,0:03:51.13,0:03:54.73,Default,,0000,0000,0000,,storms and human development\Ncan alter their paths,
Dialogue: 0,0:03:54.73,0:03:58.57,Default,,0000,0000,0000,,further complicating our attempts\Nto chart migration.
Dialogue: 0,0:03:58.57,0:04:02.99,Default,,0000,0000,0000,,Fortunately, Count von Bothmer’s stork\Noffered physical proof
Dialogue: 0,0:04:02.99,0:04:06.99,Default,,0000,0000,0000,,not only that European storks were\Nmigrating south for the winter,
Dialogue: 0,0:04:06.99,0:04:10.19,Default,,0000,0000,0000,,but also where they were migrating to.
Dialogue: 0,0:04:10.19,0:04:12.30,Default,,0000,0000,0000,,Ornithologists across the continent
Dialogue: 0,0:04:12.30,0:04:15.44,Default,,0000,0000,0000,,were eager to map the trajectory\Nof this flight,
Dialogue: 0,0:04:15.44,0:04:18.45,Default,,0000,0000,0000,,including Johannes Thienemann.
Dialogue: 0,0:04:18.45,0:04:22.32,Default,,0000,0000,0000,,Owner of the world’s first permanent\Nbird observatory,
Dialogue: 0,0:04:22.32,0:04:26.45,Default,,0000,0000,0000,,Thienemann was a major public advocate\Nfor the study of birds.
Dialogue: 0,0:04:26.45,0:04:28.87,Default,,0000,0000,0000,,And to solve the field’s biggest mystery,
Dialogue: 0,0:04:28.87,0:04:32.87,Default,,0000,0000,0000,,he wrangled an army of volunteers\Nfrom across Germany.
Dialogue: 0,0:04:32.87,0:04:38.82,Default,,0000,0000,0000,,His team used aluminum rings to tag\Nthe legs of two thousand storks
Dialogue: 0,0:04:38.82,0:04:42.82,Default,,0000,0000,0000,,with unique numbers and the address\Nof his offices.
Dialogue: 0,0:04:42.82,0:04:47.45,Default,,0000,0000,0000,,Then he advertised the initiative \Nas widely as possible.
Dialogue: 0,0:04:47.45,0:04:51.59,Default,,0000,0000,0000,,His hope was that word of the experiment\Nwould find its way to Africa,
Dialogue: 0,0:04:51.59,0:04:57.11,Default,,0000,0000,0000,,so people finding the tags would know\Nto mail them back with more information.
Dialogue: 0,0:04:57.11,0:05:00.96,Default,,0000,0000,0000,,Sure enough, from 1908 to 1913,
Dialogue: 0,0:05:00.96,0:05:07.100,Default,,0000,0000,0000,,Thienemann received 178 rings, \N48 of which had been found in Africa.
Dialogue: 0,0:05:07.100,0:05:13.01,Default,,0000,0000,0000,,Using this data, he plotted the first\Nmigration route ever discovered,
Dialogue: 0,0:05:13.01,0:05:18.03,Default,,0000,0000,0000,,and definitively established that storks\Nwere not, in fact, flying to the moon.