week 4 - communication general Flashcards
what is communication?
transfer of information from a signaller to a receiver
Does communication always just include a signaller and a receiver?
can be eavesdropping
What are the different modes animals can use to communicate?
visual olfactory sound electrical signals mechanosensory tactile
what are the 3 main things that animals communicate about?
foraging options
mating
danger
What is exploiting pre existing biases?
often, the evolution of a new communication signal makes use of an already existing bias on the receiver side
Case study for communication?
the honey bee dance language and its evolution
who first discovered the honey bee dance language?
karl von frisch
how does the dance encode direction?
the duration of the waggle run is the distance
the angle of the dance to the sun is the direction
What is the evolution of the dance language?
see slide
what is the forage commuication in bumblebees?
Dornhaus and chittka 1999
excited running for 13s to 10 mins
total evolution of bee dance language
see slide 13 l2 week 4
what is the adaptive significance of a behavioural trait?
testing this is to remove that trait. Drosophila people can do this by usingmutants. But we cant do that in honey bees but can use various other tricks.
jamming the information content of the waggle dance
• you can flip the hive to horizontal.
• gravity ceases to exist as a reference for direction
• they can use a light source and orient their dances relative to that
• if light source is off, they will still display waggle dances but no longer have any directional information
measuring foraging success of honeybees
one way you can measure honey bee hive foraging is by weighing the whole hive. At the end of a good foraging day the hive will be heavier at the end of the day than at the start of the day.
so did this with disoriented and oriented dances. Have this fantastically complex behaviour but when looking at foraging ability it doesn’t make a difference, they still collect the same amount of honey as before. This is strange!
thought maybe the location where we did the experiment isnt all that useful, not a natural habitat, heavily agriculture intensified. Took the same experiment to a nature reserve in spain. Again there isn’t all that much of a difference with foraging ability and oriented vs disoriented dance.
where do all the bees originally come from? epicenter of diversity is in tropical asia. Its quite reasonable to suppose that the honey bee dance language started there. So took the experiment there and a difference was found. Lower overall values of weight changes with disorientated dances vs the oriented dances. So there is a difference of taking the bee dances away from the bees but only in tropcical asia not in temperate habitats.
Why are there only differences in foraging success in tropical locations?
one of the key differences is the flora that the bees collect. In the temperate zone flowers are widley distributed and not tightly clustered in particular locations in space. In tropical habitats many of the habitat is green and no flowers are seen, it is bee desert, there are very few flowers on the ground. What you do find is blooming trees, often miles apart from each other. What that suggests is that flora food is much more spacially aggregated in fewer points in space in tropical habitats and much more widely distributed in temperate habitats. But we need to test that.
you cant sample the spatial distribution easily of all the flowers in a bees foraging range. Used bees as a radar. Did that by monitoring all the dances of bees, indicated where they found food was worth indicating. 2 examples: from temperate habitats, they are all over the place, widely distributed, every bee indicated something else. In tropical habitats, you see something entirely different, there are sectors entirely free of dances, no food there, and other clusters. In tropical habitats they are highly clumped, and in temperate habitats they are all over the place. That of course means there are differential benefits in having the dance language depending on where you forage. Ig your food is widely distributed anyway as in temperate habitats then the adaptive benefits of having code which tells someone where food is is essentially lower. On the other hand if you are in an area where food is pinpointed in certain areas then it is very useful and much more advantageous adaptively to have a dance that tells you the location of food.
where as in temperate habitats where food is more widely
