Srinivasan et al., 2000 (honeybee navigation) Flashcards
What are the two main theories about how honeybees estimate the distance to food sources?
- distance flown estimated in terms of energy consumption
- estimated from visual cues, derived from the extent to which the image of the world has moved on the eye during the trip
Which theory is shown to be true?
The honeybee’s “odometer” is shown to be visually-driven
How was this found?
by observing bees dancing after flying through a short, narrow tunnel to collect a food reward
- observed in an observational hide with transparent walls
Typically, … bees were marked and used for each experiment
six
Marked bees were trained to forage at a feeders containing … …, placed in a wooden tunnel with a black insect-screen cloth above that allowed the bees to observe the sky (and be observed) as they moved through the tunnel.
sugar solution
In the first experiment, the tunnel was positioned … from the hive and lined with a … visual texture. The feeder was placed at the … to the tunnel.
Bees returning to the feeder performed predominantly … dances (85%), consistent with the theory that honeybees mainly perform … dances when visiting food sources within … of the hive.
35m, random, entrance, round, round, 50m
However, when the feeder was placed 6m inside the tunnel (experiment 2), the bees performed primarily … dances (90%). The distance flown by the bees had only increased 6m to 41m, within the 50m threshold. The feeder was at a distance at which the bees would be expected to perform …. dances (when flying outdoors).
waggle
One possible reason for this is that the … within the narrow tunnel generated an effect on the eye which … the effect of a long flight in natural outdoor conditions.
The distances to all walls of the tunnel would be much closer than nearby objects generally are during a bee’s flight, so the bee will have experienced a greater … motion of the image when flying. This may have caused the bees to infer a journey longer than ….
texture, mimicked
angle, 6m
In experiment 3, the tunnel and feeder were placed as in experiment …, but instead of a random texture the walls were lined with … … …, parallel to the direction of flight, therefore providing negligible … … cues.
Bees returning from this flight performed predominantly … dances (~87%), despite flying the exact same distance as those in experiment 2. This is evidence that the lack of image … in the striped tunnel caused the bees to infer that they had flown a very … distance
2, axially oriented stripes, image motion,
round, motion, short
In experiment 4, the walls of the tunnel were again lined with a … …, but this time the tunnel was placed a mere … from the hive exit, with the feeder 6m deep inside the tunnel.
Bees returning from this tunnel performed mainly … dances (~88%), despite the feeder being only … from the hive, well within that 50m threshold.
- can conclude that distance flown is inferred on a … basis
random texture, 6m,
waggle, 12m, visual
6m flight in the tunnel corresponded to … in a natural outdoor environment
1ms of waggle in the dance calculated to encode … of image motion in the eye (assuming bees flew directly through the centre of the tunnel) - calibrated odometer
186m
17.7°
Distance flown is not perceived directly in … …, but rather in terms of the amount of … …. perceived by the eye.
distance units, image motion
+ 1m of forward flight would depend strongly on the average distance of foliage and the ground during the bee’s journey, which could vary from one environment to the other - traditional calibration cannot be an absolute one - correct way would be as above - image motion
In nature, visual odometer of this kind is reliable because…
new recruits tend to take the same route as experienced foragers
Angular image motion with distance does not depend on…
speed of flight
