navigation and migration Flashcards
what’s the definition of navigation
piloting a course from one location to another
waggle dance
-bees dancing
-occurs in 2 forms
-one is round dance when food is close to the hive (<50m), dance performed in nest on vertical cores in darkness
-figure of 8 dance when food isn’t close to the hive (>50m), involves dance followers where the dancers touch with their interiors
what does the duration of waggle run mean
by dancing, the worker bees are telling the follower bees how far it is it thinks its flown
ant navigation: foraging in desert ants
-worker desert ants forage for dead insects
-an ant locates itself by integrating distance and direction moved
-it measures distance by amount of walking its done and direction by the suns position or polarised light pattern
how is sun used as a landmark in navigation
-animals which use the sun for navigation have to compensate for the movement of the sun
-bees have a clock to measure time and a stopwatch to measure short periods (waggle dance)
long distance navigation in homing pigeons
-can find their way home from large distances
-experiment where a GPS was attached to the pigeon and then they were tracked on how they found their way be home
-GPS technology had excellent spatial and temporal resolution
-they found that the pigeon didn’t always go directly home but they followed linear features such as roads and rivers to find their way home- found after 20 flights or so
what’s the hippocampus
-found in inner region of temporal lobe
-like a stored mental map
-right hippocampus lit up during MRI of someone whilst navigating themselves therefore this is where the navigational processing happens
where does the navigational processing happen
right hippocampus in brain
is there a correlation between the hippocampal ability and the navigational ability
yes
what is the hippocampus like in taxi drivers brains
-taxi drivers need a lot of spacial awareness
-posterior hippocampus of London cabbies is larger than that on non-taxi drivers- the more years of driving, the bigger it gets
definition of migration
seasonal movement of animals between the location where they breed and the location where they live during the non-breeding period
monarch butterfly migration
-the butterflies move down south to near Mexico which is thousands of miles, then they migrate back up north in 2 generational stages
-one species goes up and east
-the other goes up to northern states
blackcap migration
-pre 1950’s no migration of blackcap of blackcaps to Britain
-post 1950’s, blackcaps would migrate to Britain during the winter because Britain was warmer and after the war, people started to feed the birds due to less starvation
quantifying migratory behaviour
-using an Ellen funnel, Berthold measured the direction the blackcaps tried to migrate, and the timing at which they tried to leave
-did this by using an ink pad at the bottom of the funnel, where the birds feet would touch
-they then measure the number and intensity of marks showing the intensity the birds made- this is called nocturnal migratory restlessness (intensity of black ink feet marks)
heritability of migratory activity
-a significant relationship between the phenotype of the offspring and the mean of their two parents
