A clear day at sea海上的晴天
Which buttons are bright? Now move the bird over Taiwan and look again.
哪幾個按鈕亮著？把鳥移到台灣上空，再看一次。
Living Things · Unit 3 · Lesson 12 · 生命與生態 單元三 第十二課
How Do Migrating Birds Find Their Way?候鳥怎麼認路？
Every year some birds fly thousands of kilometers to a place they have been before, and they arrive at the right spot. They have no map and no phone. In a 3D model, send a bird across the sea from the north, past Taiwan, to the south. Change day to night, bring in the clouds, and switch off its senses one at a time to see what it still has to steer by. Last, compare some real journeys with the length of Taiwan.
每年都有一些鳥飛幾千公里，回到牠們去過的地方，而且到得很準。牠們沒有地圖，也沒有手機。在 3D 模型裡，讓一隻鳥從北方出發、飛過海洋、經過台灣、到達南方。把白天換成夜晚、讓雲飄進來，再把牠的感覺一種一種關掉，看牠還剩什麼可以用來認方向。最後拿幾段真實的旅程，和台灣的長度比一比。
Big idea · 一句話看懂
A migrating bird does not rely on one way of finding its direction. It uses several. By day it can steer by the Sun, and by night by the stars. It can sense the magnetic field of the Earth, which is there in any weather. And it remembers landmarks such as coasts and mountains. Each clue fails sometimes, so the bird needs the others as spares. Some of this skill is inherited, and some is learned by making the journey.
候鳥認方向，不是只靠一種方法，而是同時用好幾種。白天可以看太陽，晚上可以看星星。牠感覺得到地球的磁場，而磁場不管什麼天氣都在。牠還記得海岸、山脈這些地標。每一種線索都有派不上用場的時候，所以鳥需要其他幾種當備用。這些本事有一部分是天生的，有一部分是靠實際飛過才學會的。
3D Model · 3D 模型
Four Clues 四種線索
Drag to turn the model, and scroll or pinch to zoom. The bird flies along the dotted line, there and back. Watch the four buttons. A bright one is a clue the bird can use at this moment. Change Day to Night. Switch on Clouds. Move the bird out over the sea. Then tap a button to switch that sense off, and see how few clues you can leave the bird before it loses its way.
拖曳可以旋轉模型，滾輪或雙指可以縮放。鳥沿著虛線飛過去、再飛回來。注意那四個按鈕：亮著的，就是鳥這一刻用得上的線索。把「白天」換成「夜晚」，打開「雲」，把鳥移到海上。然後點一個按鈕，把那一種感覺關掉，看看你最少可以留幾種線索給牠，牠才不會迷路。
Drag to turn · 拖曳旋轉 Scroll or pinch to zoom · 滾輪／雙指縮放
This 3D model needs WebGL, which this browser does not support. The reading and the cards below still explain everything.
這個瀏覽器不支援 WebGL，無法顯示 3D 模型；下方的課文與卡片一樣能看懂。
- Yellow ball: the Sun
黃色的球：太陽 - White points: stars
白色的小點：星星 - Purple arcs: the direction of the magnetic field of the Earth
紫色的弧線：地球磁場的方向 - Brown hills: landmarks, which glow when the bird can use them
咖啡色的山：地標；鳥用得上的時候會發亮 - Red light: the bird has lost its way
紅色的燈：鳥迷路了
A teaching model, and not a map. The three pieces of land stand for a summer home in the north, Taiwan in the middle, and a winter home in the south. Their shapes, sizes, and distances are made up. The magnetic field cannot be seen. A real bird does not switch from one clue to another as neatly as the buttons suggest, and scientists are still working out exactly how birds sense magnetism. Birds also use other clues, such as smell, that the model leaves out.
這是教學用的模型，不是地圖。三塊陸地分別代表北方夏天的家、中間的台灣、南方冬天的家；形狀、大小和距離都是虛構的。磁場其實是看不見的。真的鳥在各種線索之間並不像按鈕那樣切換得一清二楚；鳥究竟怎麼感覺到磁場，科學家也還在研究。鳥還會用氣味等其他線索，模型沒有畫出來。
Model drawn by My Culture Connect as a teaching diagram. The ideas follow the sources listed at the bottom of this page. · 模型由人師教育協會自繪示意；原理依本頁最下方列出的出處。
Reading · 英文閱讀
12
Unit 12: How Do Migrating Birds Find Their Way?
Each spring, hawks called gray-faced buzzards appear over Bagua Mountain in Changhua. They have flown from Southeast Asia, and they are on their way to nest in Japan, Korea, and northeastern China. In autumn they will fly back. The round trip is about 9,000 kilometers, and they make it every year.
每年春天，一種叫做灰面鵟鷹的鷹會出現在彰化八卦山的上空。牠們從東南亞飛來，正要去日本、韓國和中國東北繁殖。到了秋天，牠們再飛回去。來回一趟大約 9,000 公里，而且年年如此。
They are not the only ones. About 1,800 of the world's 10,000 kinds of birds are long-distance migrants. How do they find the way? People have studied this question for a long time, and the answer is that birds use several clues at once.
這樣做的不只有牠們。全世界一萬種鳥類裡，大約有 1,800 種是長距離遷徙的候鳥。牠們是怎麼認路的？人們研究這個問題已經很久了，答案是：鳥同時用好幾種線索。
The first clue is the Sun. But the Sun moves across the sky all day, so its direction means nothing unless you also know the time. Birds have a body clock, as we do, and they use it together with the Sun to work out direction.
第一種線索是太陽。可是太陽整天都在天空中移動，所以除非你還知道時間，不然太陽的方向沒有意義。鳥和我們一樣，身體裡有一個時鐘；牠們把時鐘和太陽合起來用，推算出方向。
At night the Sun is gone, and many birds migrate at night. They steer by the stars. In experiments, birds kept under the artificial stars of a planetarium turned to face the direction in which they would normally migrate.
到了晚上太陽不見了，而很多鳥是在夜裡遷徙的。牠們靠星星認方向。在實驗裡，把鳥放在天象儀的人造星空底下，牠們會轉向平常遷徙時要飛的那個方向。
The third clue works even under thick cloud. The Earth is a giant magnet, and birds can sense its magnetic field. Scientists showed this in 1972. They are still working out how the sense works, and there is evidence that it involves a light-sensitive protein in the bird's eye.
第三種線索，在厚厚的雲層底下也管用。地球是一塊巨大的磁鐵，而鳥感覺得到它的磁場。科學家在 1972 年證明了這一點。至於這種感覺是怎麼運作的，目前還在研究當中；有證據顯示，它和鳥眼睛裡一種對光敏感的蛋白質有關。
The last clue is memory. Birds learn coasts, rivers, and mountains, and they recognize them again. Young storks learn the route by following older ones. But in some kinds of birds the young set off alone, in the right direction, on a journey they have never made. That direction was inherited from their parents.
最後一種線索是記憶。鳥會記住海岸、河流和山脈，下次再認出來。年輕的鸛跟著年長的鸛飛，就這樣學會路線。可是也有一些種類，年輕的鳥獨自出發，朝著正確的方向，踏上一段從來沒飛過的旅程。那個方向，是從父母那裡遺傳來的。
Read aloud · 課文朗讀
Questions · 閱讀理解
Why does a bird need to know the time in order to steer by the Sun?
The Sun moves across the sky all day, so its direction only means something if you also know the time.
Which clue still works under thick cloud?
The magnetic field of the Earth.
How do young storks learn their route?
They follow older storks on their first journey.
Words & Phrases · 生字及片語
migrate(v.)遷徙Many birds migrate south for the winter.很多鳥在冬天往南遷徙。journey(n.)旅程The journey takes several weeks.這段旅程要花好幾個星期。direction(n.)方向The bird flew in the right direction.那隻鳥朝著正確的方向飛。compass(n.)指南針；羅盤A compass points north.指南針指向北方。star(n.)星星At night, some birds steer by the stars.有些鳥在夜裡靠星星認方向。magnet(n.)磁鐵The Earth is a giant magnet.地球是一塊巨大的磁鐵。landmark(n.)地標That mountain is a useful landmark.那座山是很好用的地標。inherit(v.)遺傳得到；繼承Young birds inherit a sense of direction.幼鳥遺傳到了方向感。
Quick Check · 小測驗
1. How many clues does a migrating bird use to find its way?
2. What does a bird need, besides the Sun, to steer by the Sun?
3. What do night migrants steer by?
4. Which clue works even when the sky is covered with cloud?
5. How do young storks learn the route?
How Far? · 有多遠？
Journeys measured in Taiwans 用「幾個台灣」來量旅程
Taiwan is 394 kilometers long from north to south. Choose a journey and see how many times that length it covers.
台灣從北到南長 394 公里。選一段旅程，看它等於這個長度的幾倍。
Choose a journey · 選一段旅程
A bird does not fly in a straight line, so these are estimates of the distance actually covered.鳥並不是直線飛行的，所以這些是實際飛過距離的估計值。
That is as far as · 這段路相當於
×
the length of Taiwan, a distance of · 個台灣的南北長度
Try It in the Model · 在模型裡試試
Four kinds of sky 四種天空
With all four senses working, there is no combination of day, night, cloud, and sea that leaves the bird with nothing. That is the point of having spares.
四種感覺都在的時候，不管白天、夜晚、有雲、在海上怎麼組合，鳥都不會落得什麼線索都沒有。這就是有備用的意義。
A clear night晴朗的夜晚
The Sun button has gone dim, and another one has lit up to take its place.
「太陽」的按鈕暗了，另一個亮起來接替它。
A cloudy night at sea海上陰天的夜晚
No Sun, no stars, and no land in sight. What is the bird steering by now?
沒有太陽、沒有星星，也看不到陸地。鳥現在靠什麼認方向？
The last clue removed拿走最後一種線索
Watch what the bird does. Then switch its magnetic sense back on.
看看鳥的反應，然後把牠的磁場感覺打開。
Go Further · 延伸閱讀
The flying, and the sky 飛行，還有天空
Living Things · Lesson 9 · 生命與生態 第九課How Does a Bird Fly?鳥為什麼會飛？See how the same hawks ride warm air to save their strength on the way.看同一群鷹怎麼乘著熱空氣，在路上節省力氣。Go to the lesson · 前往這一課 →Astronomy · Lesson 5 · 天文教育 第五課Why Do the Stars Change with the Seasons?為什麼每個季節的星空不一樣？Learn the night sky that the birds are reading.認識候鳥在看的那片夜空。Go to the lesson · 前往這一課 →
Migration by the Numbers · 遷徙的數字
Six numbers about migration 六個和遷徙有關的數字
How many, how far, and since when we have known.
多少種、多遠，還有人類是什麼時候知道的。
1,800kinds of birds · 種鳥
About this many of the world's 10,000 kinds of birds migrate over long distances.全世界一萬種鳥類裡，大約有這麼多種會長距離遷徙。
9,000 kma year · 一年
The average round trip of the gray-faced buzzards that stop in Taiwan.在台灣停留的灰面鵟鷹，來回遷移的平均距離。
70,900 kma year · 一年
The average round trip of Arctic terns nesting in Iceland and Greenland.在冰島和格陵蘭繁殖的北極燕鷗，來回遷移的平均距離。
50million · 百萬隻
More than this many waterbirds use the flyway that runs through East Asia, past Taiwan, to Australia.有超過這麼多隻水鳥，使用穿過東亞、經過台灣、通往澳洲的這條遷徙路線。
1822the year · 年
A stork was found in Germany with an African spear through its neck, evidence that storks fly to Africa.德國發現一隻脖子上插著非洲矛的鸛，證明鸛會飛到非洲。
1972the year · 年
Roswitha and Wolfgang Wiltschko showed that migrating birds respond to the magnetic field.維爾奇科夫婦證明了候鳥會對磁場有反應。
Migration Stories · 遷徙的故事
A stork with a spear, a cage shaped like a funnel, a flight without a stop, and the hawks of two seasons 插著矛的鸛、漏斗形的籠子、不落地的飛行，還有兩個季節的鷹
How people found out where birds go, and how they get there.
人們怎麼知道鳥去了哪裡，又是怎麼去的。
1822
The stork with a spear插著矛的鸛
For a long time, people in Europe did not know where the storks and swallows went in winter. Some thought the birds slept through the cold months, or even changed into other animals. Then, in 1822, a white stork was found in northern Germany with a spear stuck through its neck. The spear was made of wood from central Africa. The stork had been shot there and had flown all the way back. It was some of the first solid evidence that birds migrate over great distances.
很長一段時間，歐洲人不知道鸛和燕子冬天去了哪裡。有人以為鳥是睡過了冬天，甚至以為牠們變成了別的動物。後來在 1822 年，德國北部發現一隻白鸛，脖子上插著一支矛，而那支矛是用非洲中部的木頭做的。這隻鸛在那裡被射中，又一路飛了回來。這是鳥類長距離遷徙最早的確切證據之一。
Experiment · 實驗
Footprints in a funnel漏斗裡的腳印
How do you ask a bird which way it wants to go? In the migration season a caged bird becomes restless and keeps hopping in the direction of its journey. Scientists put such a bird in a cage shaped like a funnel, with an ink pad on the floor. Each hop leaves a mark on the sloping wall. By changing what the bird can see or sense, such as the stars or the magnetic field around it, they can find out which clue it is using.
要怎麼問一隻鳥牠想往哪邊去？到了遷徙的季節，關在籠子裡的鳥會變得焦躁不安，一直朝著旅程的方向跳。科學家把這樣的鳥放進一個漏斗形的籠子，底部放一塊印泥；鳥每跳一下，就在斜斜的籠壁上留下一個印子。只要改變鳥看得到或感覺得到的東西——例如星空，或是周圍的磁場——就能知道牠用的是哪一種線索。
Record · 紀錄
Alaska to New Zealand without landing從阿拉斯加到紐西蘭，不落地
The bar-tailed godwit is a shorebird about 40 centimeters long. Each autumn, some of them leave Alaska and fly across the whole Pacific Ocean to New Zealand in one go. There is nowhere to land on the way, and they do not stop to eat. It is the longest non-stop flight known for any bird. To get ready, they put on more fat than any other migrating bird that has been studied.
斑尾鷸是一種體長大約 40 公分的水鳥。每年秋天，其中有一群從阿拉斯加出發，一口氣飛越整個太平洋到紐西蘭。途中沒有地方可以降落，牠們也不停下來吃東西。這是目前已知鳥類最長的不落地飛行。為了準備這趟旅程，牠們儲存的脂肪，比任何研究過的候鳥都多。
Taiwan · 台灣
The hawks of two seasons兩個季節的鷹
Gray-faced buzzards nest in the temperate parts of eastern Asia in summer. Each September they start south, cross Taiwan, and go on to Southeast Asia for the winter. The next spring they come back along a route they know. In March and April they pass Bagua Mountain, which is their rest stop on the way north. Taiwan lies in the middle of their road.
灰面鵟鷹夏天在亞洲東部的溫帶地區繁殖。每年九月牠們開始往南，經過台灣，再飛往東南亞過冬；隔年春天，又沿著熟悉的路線回來。三、四月的時候牠們經過八卦山——那是北返途中的休息站。台灣就在牠們這條路的中間。
Myth vs. Fact · 常見迷思
Four things people get wrong 四個常見的誤會
✗ Myth · 迷思Migrating birds find their way by one special sense.候鳥靠一種特別的感覺認路。
✓ Fact · 事實They combine several: the Sun, the stars, the magnetic field, and remembered landmarks.牠們把好幾種合起來用：太陽、星星、磁場，還有記得的地標。
✗ Myth · 迷思Birds simply follow the warm weather.鳥只是跟著溫暖的天氣走。
✓ Fact · 事實They fly set routes to particular places, and many return to the same spot year after year.牠們飛固定的路線、去特定的地點，很多還年年回到同一個地方。
✗ Myth · 迷思Young birds always learn the way from their parents.幼鳥都是跟著爸媽學會路線的。
✓ Fact · 事實Some do. In other kinds, the young travel alone, in a direction they inherited.有些是這樣。另外一些種類的幼鳥是獨自上路的，方向是遺傳來的。
✗ Myth · 迷思We know exactly how birds sense the magnetic field.我們已經完全知道鳥是怎麼感覺到磁場的。
✓ Fact · 事實Not yet. There is good evidence that the eye is involved, and the research is still going on.還沒有。有不錯的證據顯示和眼睛有關，研究還在進行中。
Remember It · 記憶口訣
Finding the way in a sentence 一句話記住認路
The Sun, with a clock太陽，加上時鐘
Direction by day.
白天的方向。
The stars星星
Direction by night.
夜晚的方向。
The magnetic field磁場
It works in any weather.
什麼天氣都管用。
Landmarks and memory地標和記憶
Coasts and mountains, learned by flying.
海岸和山脈，飛過才學得會。
An Observer's Code · 觀察守則
Watching migrants without disturbing them 看候鳥，但不打擾牠們
- Migrating birds are resting and feeding to survive a long journey. Stay on the paths and watch from a distance.候鳥停下來是為了休息和進食，才撐得過漫長的旅程。請走在步道上，保持距離觀察。
- Do not chase birds into the air to get a better look or a photograph.不要為了看清楚或拍照，把鳥趕得飛起來。
- Never look at the Sun through binoculars.絕對不要用望遠鏡看太陽。
Classroom Activity 1 · 課堂活動一
Find South with a Shadow 用影子找出南方
You need · 準備材料
- A straight stick about as long as your arm, and a patch of flat ground in the sun一根大約和手臂一樣長的直棍子，還有一塊曬得到太陽的平地
- Six small stones, and a watch六顆小石頭和一支手錶
Steps · 步驟
- Push the stick into the ground so that it stands straight up.把棍子插進地裡，讓它直直地立著。
- Starting at about eleven in the morning, put a stone on the tip of the shadow every twenty minutes.大約從上午十一點開始，每隔二十分鐘，在影子的尖端放一顆石頭。
- Find the stone that is closest to the stick. The shadow was shortest at that moment.找出離棍子最近的那顆石頭。那一刻的影子最短。
- In Taiwan, for most of the year, the shortest shadow points north. Which way is south? Which way is your home?在台灣，一年裡大部分的時候，最短的影子指向北方。那麼南方是哪一邊？你家又在哪一邊？
You needed the Sun and a watch. That is what a bird's Sun compass needs too: the Sun, and a sense of time. Do not look straight at the Sun.
你需要太陽，還需要一支錶。鳥的太陽羅盤需要的也是這兩樣：太陽，還有時間感。不要直視太陽。
Classroom Activity 2 · 課堂活動二
A Migration Calendar 候鳥日曆
You need · 準備材料
- A calendar or a notebook, and a pencil一本日曆或筆記本，還有一支鉛筆
- A window, a schoolyard, or a field that you pass every day一扇窗、一座校園，或一片你每天經過的田
Steps · 步驟
- Choose two or three kinds of birds that are easy to recognize, such as swallows and egrets.選兩三種容易認的鳥，例如燕子和白鷺鷥。
- Every day for two months, write down whether you saw each one.連續兩個月，每天記下有沒有看到牠們。
- Look for a kind of bird that appears one day and was not there before, or one that stops appearing.留意有沒有哪一種鳥某一天突然出現，或是從某一天起就再也沒看到。
- Compare your dates with a classmate's, or with last year's if you can find them.把你的日期和同學的比一比；找得到的話，也和去年的比。
Spring and autumn are the best seasons for this. Scientists use records like yours, kept by thousands of people, to learn when birds are on the move.
春天和秋天最適合做這個活動。科學家就是靠成千上萬人做的這種紀錄，了解鳥在什麼時候移動。
Sources · 資料出處
Facts and numbers on this page were checked against these sources (October 2026). · 本頁的事實與數字依下列資料查證（2026 年 10 月）。
- Approximately 1,800 of the world's 10,000 bird species are long-distance migrants; migrating birds navigate using the Sun and stars, the magnetic field of the Earth, and mental maps; using the Sun requires compensation for the time; landmarks and smell are also used; young white storks learn the route on their first journey from older birds, while first-year migrants of some short-lived species follow a genetically determined route; in 1822 a white stork was found in Germany with a spear of central African wood in its neck全球約一萬種鳥類中約 1,800 種是長距離候鳥；候鳥利用太陽與星星、地球磁場和心智地圖導航；使用太陽需要依時間修正；也使用地標與氣味；年輕的白鸛在第一次遷徙時跟著年長的鳥學會路線，某些短命鳥種的幼鳥則依循遺傳決定的路線；1822 年德國發現一隻脖子上插著非洲中部木矛的白鸛Wikipedia, “Bird migration” ↗
- The stork found in 1822 carried a spear from central Africa in its neck; it showed that birds migrate rather than hibernating or changing form in winter1822 年發現的那隻鸛，脖子上插著來自非洲中部的矛；牠證明了鳥是遷徙，而不是冬眠或變成別的東西Wikipedia, “Pfeilstorch” ↗
- Orientation by the Sun is combined with an indication of time from the animal's internal clock利用太陽定向，必須結合動物體內生理時鐘提供的時間資訊Wikipedia, “Sun compass in animals” ↗
- Indigo buntings often migrate at night, using the stars to navigate; placed in funnel cages under cloudless night skies or in planetariums, they chose the direction of their migration靛藍彩鵐常在夜間遷徙，利用星星導航；放在漏斗籠裡，在無雲的夜空或天象儀下，牠們會選擇遷徙的方向Wikipedia, “Indigo bunting” ↗
- An Emlen funnel is a cage shaped like an inverted cone with an ink pad on the bottom, so that the bird leaves tracks on the sloping walls埃姆倫漏斗是倒圓錐形的鳥籠，底部有印泥，鳥跳上斜壁時會留下痕跡Wikipedia, “Emlen funnel” ↗
- In 1972 Roswitha and Wolfgang Wiltschko showed that migratory birds respond to the direction and inclination of the magnetic field; there is evidence that birds use a cryptochrome protein in the eye; caged migratory birds show migratory restlessness and orient in the direction in which they would migrate1972 年維爾奇科夫婦證明候鳥會對磁場的方向與傾角有反應；有證據顯示鳥類利用眼睛裡的隱花色素蛋白；籠中的候鳥在遷徙季會焦躁不安，並朝遷徙的方向定向Wikipedia, “Magnetoreception” ↗
- Arctic terns nesting in Iceland and Greenland average an annual round trip of about 70,900 km在冰島與格陵蘭繁殖的北極燕鷗，每年來回的平均距離約 70,900 公里Wikipedia, “Arctic tern” ↗
- The flight of bar-tailed godwits across the Pacific from Alaska to New Zealand is the longest known non-stop flight of any bird; they carry the greatest fat loads of any migratory bird so far studied; body length 37–41 cm斑尾鷸從阿拉斯加橫越太平洋到紐西蘭，是已知鳥類最長的不落地飛行；牠們儲存的脂肪是研究過的候鳥中最多的Wikipedia, “Bar-tailed godwit” ↗
- The East Asian–Australasian Flyway is home to over 50 million migratory waterbirds東亞—澳大拉西亞遷徙線上有超過五千萬隻遷徙性水鳥Wikipedia, “East Asian–Australasian Flyway” ↗
- The gray-faced buzzard breeds in Manchuria, Korea, and Japan and winters in Southeast Asia灰面鵟鷹在中國東北、韓國、日本繁殖，在東南亞度冬Wikipedia, “Grey-faced buzzard” ↗
- Taiwan is 394 km long台灣本島南北長 394 公里Wikipedia, “Geography of Taiwan” ↗
- Gray-faced buzzards breed in temperate eastern Asia in summer, start south each September, pass Taiwan on the way to Southeast Asia, and return north the next spring; the round trip averages about 9,000 km; they pass Bagua Mountain from March to April, using it as a rest stop灰面鵟鷹夏季在亞洲東部溫帶繁殖，每年九月開始南遷，經臺灣飛往東南亞過冬，隔年春天北返；來回遷移距離平均約 9,000 公里；3 月到 4 月經過八卦山，在此短暫停留交通部觀光署參山國家風景區管理處〈關於八卦山賞鷹〉 Tri-Mountain National Scenic Area Administration, Taiwan ↗