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Animal NavigationAnimal Navigation
There and back again—how There and back again—how we all get around!we all get around!
Duck’s Fly MoonDuck’s Fly Moon
• Birds migrate this Birds migrate this time of yeartime of year
• 50% of birds 50% of birds migrate!migrate!
• You can see them You can see them fly across the moonfly across the moon– Yes, even in NYCYes, even in NYC
• Why do they do that?
Who Migrates?Who Migrates?
Long Distances!Long Distances!
• Arctic tern: flies Arctic tern: flies 18000 km18000 km
• From pole to pole!From pole to pole!
• 3-4 days flying 3-4 days flying nonstop, no eating, nonstop, no eating, no restingno resting
• Often fly at night to Often fly at night to avoid predatorsavoid predators
How do they know when?How do they know when?
• Season---daylengthSeason---daylength
• Changes hormonesChanges hormones
• Internal clocks too!Internal clocks too!
What are costs of What are costs of migrating?migrating?
• Energy (hey, birds Energy (hey, birds eat 10% of their eat 10% of their weight a day!)weight a day!)
• WeatherWeather
• WaterWater
• PredationPredation
• Night time, and Night time, and most birds are most birds are “diurnal”.“diurnal”.
Benefits?Benefits?
• Food (we think they Food (we think they “fly south”, but they “fly south”, but they actually “fly north” actually “fly north” for the food!for the food!
• Safety: penguins Safety: penguins don’t find food in don’t find food in Antarctica, they find Antarctica, they find fewer predators.fewer predators.
How?How?
• Map:Map: says where says where you are and where you are and where you need to goyou need to go
• Compass:Compass: gives gives you direction to go you direction to go in to get there.in to get there.
Example: NYC, HumansExample: NYC, Humans
• What map do you What map do you think of? Subway, think of? Subway, real map? Your real map? Your street?street?
• Say you need to head Say you need to head east---how do you east---how do you figure that out?figure that out?– Landmarks, streets, Landmarks, streets,
real compass?real compass?
Question: Where is east Question: Where is east now?now?
• What was your first What was your first thought?thought?– Look out window, Look out window,
use your “gut”?use your “gut”?- We will do an We will do an
experiment to test experiment to test thatthat
- Things I use: sun, Things I use: sun, landmarks. I’d have landmarks. I’d have to go outside!to go outside!
- What do you use?What do you use?
Now you are a bird, a Now you are a bird, a youngsteryoungster
• Birds migrate from Birds migrate from Europe to East AfricaEurope to East Africa
• How do that their first How do that their first winter?winter?
• Scientist: moved a Scientist: moved a bunch of birds west of bunch of birds west of their normal “start”their normal “start”– Kids, ended up “west” Kids, ended up “west”
at end.at end.– Adults correctedAdults corrected– So, compass is innate So, compass is innate
(born in you) and map (born in you) and map is learned!is learned!
Adults corrected the Adults corrected the mistake!mistake!
What is the compass?What is the compass?
• Sky! Sky!
• Sun (Rises east)Sun (Rises east)
• Sunset (sets west)Sunset (sets west)
• StarsStars– Rotate around Rotate around
North Star. So you North Star. So you learn North by learn North by watching!watching!
Stars rotate in the night Stars rotate in the night sky!sky!
Want to figure out latitude?Want to figure out latitude?• Look at the big dipperLook at the big dipper
• Look at the rightmost stars Look at the rightmost stars
on the bucketon the bucket
• Those are 5 degrees apartThose are 5 degrees apart
• Measure with your thumbMeasure with your thumb
• Count down to the Count down to the
horizon from north star!horizon from north star!
Seriously…Seriously…
• ……hey, if you are ever on Survivor hey, if you are ever on Survivor this will come in handy!this will come in handy!
• As will what you learn from the As will what you learn from the experiment we’ll do later…experiment we’ll do later…
Animals learn their Animals learn their compass!compass!
• Animals learn (in Animals learn (in the nest if you are the nest if you are a bird) where the a bird) where the sun rises and setssun rises and sets
• They also watch They also watch the night sky from the night sky from their nests and their nests and learn North.learn North.
Experiment: scientist Experiment: scientist “teaches” birds in a “teaches” birds in a
planetarium!planetarium!
Magnetic Field—our friend the Magnetic Field—our friend the pigeon!pigeon! • Homing pigeons can Homing pigeons can
sense magnetic fieldssense magnetic fields
• Experiment 1 Experiment 1 (seriously): scientists (seriously): scientists put magnets on their put magnets on their heads!heads!
• Experiment 2 Experiment 2 (seriously): scientists (seriously): scientists changed the direction changed the direction of magnetic field with a of magnetic field with a hat on the pigeon’s hat on the pigeon’s heads!heads!
• Lo and behold: pigeons Lo and behold: pigeons went the wrong way!went the wrong way!
Maps? More complicated!Maps? More complicated!
• You must learn itYou must learn it
• You must store itYou must store it
• You must remember You must remember itit
• You must update itYou must update it
• Examples: magnetic, Examples: magnetic, landmarks, sound, landmarks, sound, smell, highways (!!).smell, highways (!!).
““Flyways” (sometimes over Flyways” (sometimes over water!)water!)
Our experiment: Dead Our experiment: Dead ReckoningReckoning
• Basically this is “keeping track of Basically this is “keeping track of your distance and your turns”, then your distance and your turns”, then adding them all together to figure adding them all together to figure out your “total displacement”out your “total displacement”
• Some people are good at this.Some people are good at this.• Some people---not really (like me!)Some people---not really (like me!)
