Orientation and Navigation Flashcards
What is kinesis, orthokinesis and klinokinesis?
Kinesis - The non-directional movement in response to a stimuli. Neither positive or negative but it is random to increase the chances of survival
Orthokinesis - Stimuli’s intensity determines the organism’s speed of movement
Klinokiesis - stimuli’s intensity determines the organisms rate of turning
Examples of kinesis?
Woodlice move faster in bright light and slower in dim light - photo-orthokinesis
woodlice move faster and turn more in low humidity - hygro-orthokinesis, hygro-klinokinesis
What is taxes?
simplest form of directional orientation and generally moves the animal towards or away from an external stimulus i.e move towards light = positive photo-taxis
What are the 3 types of taxes?
Klinotaxis
Tropotaxis
Menotaxis
What is klinotaxis?
Occurs in organisms with receptor cells but no paired receptor organs
Receptor cells located all over the body
Detects stimuli by turning head sideways and compares the intensity
when intensity is balanced - moves in a straight line
What is tropotaxis?
Occurs in organisms with paired receptor cells
It can compare and steer a course towards or away from the stimulus
What is menotaxis?
Orientation at an angle to the direction of the stimulus
Commonly seen in insects that use the sun for homing behaviours
What are the main ways in which animals navigate?
Landscape
Odor
magnetoreception
Celestial cues
Give an example of an animal using landscape to navigate
Timbergen’s wasps
Bee-killing digger wasps - females dig burrows, nursery for offspring, forages for bees to bring back, continues until larva have ~2 bees each, comes back and forth multiple times
Timbergen marked nests with pinecones, sticks, stones etc and moved them when wasp left nest. Found that wasp would always return to the middle of the landmarks
How is odor used in navigation and give an example?
May act as beacons, track concentration gradients
Provide map info for true navigation
Migratory salmon - use olfactory cues to return to breeding streams
- amazingly precise navigation, use magnetic, celestial and polarised light to navigate at sea
- when they return to the river they switch to olfactory
May use imprinting in the sense that they remember chemical cues from the river they were born in at birth
What is magnetoreception and give an example of an animal that uses it?
Sense which allows an organism to detect a magnetic field to perceive direction, altitude or location
Orientation to the Earth’s magnetic field lines
European eels
Experiment into the sun as a celestial cue?
Kramer 1957 - mirrors to manipulate sunlight entering cage of starlings
Birds consistently orientated with the sun no matter how it entered the cage
Name some animals that use the stars as a compass
Mallard ducks
Seals
Moths
Humpback whales
Describe a study done on an animal using celestial cues
Dacke et al 2014
Dung beetles form balls of dunk and rolls with head down
orientates by dancing on top of the ball of dung (turning around)
Observed more in rough ground than on flat surfaces - uses the dung as a vantage point to fix navigational mistakes
Experiments were done by placing obstacles in the beetles path, changing the beetles direction and forcing the beetle of course
In diurnal species it was found that the sun was being used and that when the sun was highest in the sky there was mmore errors
In nocturnal species it was found that the stars were being used, beetles with no obscuration of the stars crossed a board in ~40 secs as opposed to ~130 seconds in those with stars obscured
What is orientation and goal orientation?
Orientation - taking up particular bearing with respect to current position, regardless of destination
Goal orientation - Taking a particular bearing with respect to current position and heading towards a particular location
