Bird Navigation Flashcards
Griffin defined three levels of orientation ability, what were they?
1) Simple piloting based on familiar landmarks
2 Ability to fly in a particular compass direction without reference to landmarks
3) True Navigation - which is the ability to orient towards a specific goal from a variety of unfamiliar areas
Describe Schmidt-Koenig’s 1972 study into type 1 orientation ability
He fitted pigeons with translucent contact lenses, the birds could not see anything more than 3m away.
The birds were released 130km from home, (along with control pigeons), and found their way within 2-3km of their home, they could not complete the last stage of their journey.
What did Lipp discover in 2004 that supported the idea of type 1 orientation ability
He tracked pigeons and found many seem to follow railways and motoways home
Describe Perdeck’s 1958 study into type 2 orientation ability
He displaced juvenile starlings from the Hague in Switzerland just before autumn migration
When the time came to migrate, they did not detect the displacement and ended up in south-west France and Spain
Describe Kramers 1952 study into type 2 orientation ability
Invented the ‘Kramer Cage’, that allowed him to detect the migratory movements of Starlings by deflecting the position of the sun.
Describe Matthews sun-arc hypothesis
The north-south displacement is determined by the height of the suns arc
The east-west displacement is determined by comparing the the suns position with an internal clock
Describe Schmidt-Koenig’s study of the sun-arc hypothesis
He clock shifted pigeons six hours behind normal daylight time.
The sun-arc hypothesis predicts that if pigeons that have been clock shifted six hours slow are released south of their home at noon, their internal clock will tell them its 6am, and assume they have been displaced east. So they will fly WEST
The map and compass theory hypothesis predicts that the pigeons will know they have been released south of their home, using their independent map. However because they have been clock shifted 6 hours slow, when they are released at noon they will think it is 6am. At 6am the sun is normally east, to fly North they should fly 90 degrees to the sun. So they will fly EAST.
Describe Keetons 1971 study into magnetic orientation in birds
Birds that were fitted with magnets had difficulty homing on overcast days, but on sunny days it didn’t matter
What did Papi et al suggest about olfactory orientation in birds?
Pigeons form an ‘olfactory map’ based on odours borne on the wind from adjacent areas.
Describe Gagliardo’s 2011 study into olfactory orientation in birds
Blocked pigeons nostrils & tracked their movements home. Pigeons with blocked nostrils had more interruptions, especially pigeons with the right nostril blocked. Olfactory cues are processed by the left side of the brain, which is connected to the right nostril.
