Animal - Section E - Orientation Flashcards
Orientation is the ability of an animal to use…
sensory information to
- position itself with respect to features of its environment
- or of other organisms. (catching prey/avoiding predators)
Give an example of exteroceptors
- Ears
- Eyes
Give an example of Interceptors
Maculae and cristae ampullaris of the inner ear
Sensory information is mapped within the brain to a topographic map in the _____ ______ with respect to body position
Optic tectum
The optic tectum does what and what is its name in mammals
- maps sensory information with respect to body position
- sperior colliculus
The brain scans sensory information in the __________ map and uses a technique called ________ to determine which information is most relevant (important) at any time.
- topographic
- saliency
______-__ sensory information is scanned by ___-____ attentional scanning (called the __________ ______ _____) to determine ________ (behavioural relevance) and appropriate behaviours are __________ to address the most salient topographic information.
- Bottom-up sensory
- Top-down
- Attentional search light
- Saliency
- initiated
Familiarise
Tentacle snake study
- Only snake with _______ _________ on its head.
- Tentacles detect aquatic movements.
- Study: Probed around on surface of skin and they recorded what was happening on the optic tectum of the brain.
- Sensory nerves from head and tentacles project into the optic tectum.
- When they probe the snakes head, neurons start firing which can be measured.
- Fish have an incredibly fast escape response stimulated by the Mauthner? cell in the brain. The fish uses the lateral line to detect an increase of water movement on one side of its body, certain velocity’s are associated with predator strikes which initiates a reflex turn of the fish which turns the fish 180 away from the movement. The tentacle snakes receptors measure water movements around it, so when a fish moves close to the snake, the snake feels the movements and identifies a fish, the snake then makes a tiny disturbance in the water so the fish reflex turns 180 towards the snake and the snake catches it and eats it.
Define these terms:
-kinesis
-Ortho kinesis
-Klinokinesis
Kinesis
Random change in an animals’s speed or direction of movement in response to environmental cues - not directed.
Ortho kinesis
The speed of movement is dependant on the strength of the environmental stimulus e.g. slaters will reduce their movement as humidity increases as they like humid environments.
Klinokinesis
The rate of turning is dependant on the strength of the environment stimlulus e.g. planaria will increase the frequency of turns in stronger light to help them find a darker microenvironment
Define these terms and give an example of each:
-Phototaxis
-Chemotaxis
-Rheotaxis
-Phonotaxis
-Thermotaxis
-Electrotaxis
-Klinotaxis
- Taxis in response to light (positive or negative)
- Taxis in respose to chemicals (pheromones)
- Taxis in response to water flow (upstream salmon migration)
- Taxis in response to sound (Noctuid moth)
- Taxis in response to temperature (negative feedback homeostasis)
- Taxis in response to an electric field
Klinotaxis
Taxis demonstrated by organism without paired receptors
e.g. animals with receptors all over the body surface may turn from side to side to test the strength of an environmental stimulus
Tropotaxis
Demonstrated by animals with paired receptors
Simultaneous measures of the strength of a stimulus on both sides allows the animal to move straight towards or away from a stimulus on both sides allows the animal to move straight towards or away from a stimulus without turning
Menotaxis
Taxis at an angle to the source of a stimulus e.g. maintaining a fixed angle of orientation with respect to the sun
Define the term
-Navigation
The process of determining a location and moving towards it, can be achieved through:
-piloting
-compass orientation,
-true navigation.
Define this term and give an example of an animal that uses it.
-Piloting
- Finding a location based on fixed land marks or reference points
- Gray whales migrate following the western coastline of North America
Give an example of mnenotaxis
Digger wasps & mnemotaxis (piloting)
(orientation based on the memory of landmarks)
- Digger wasps demonstrate mnemotaxis and this is an excellent example of pilotage.
- Pilotage is a form of navigation that can only work in finding a precise location within a limited area.
- The wasp circles over the nest before she departs to memorize the visual landmarks that characterise the nest site.
- Changing the landmarks confuse the wasp.
- (Niko Tinbergen pinecone experiment)
Define the term
-Compass orientation
- Maintaining a heading without using fixed landmarks
i. e. moving in a geographical direction rather than to a specific location. Taking a particular compass bearing in order to get to the
Describe how pilotage can be combined with compass orientation
Pilotage could be combined with compass orientation using celestial (sun, stars) or geomagnetic (magnetic compass) clues to navigate over longer distances. The problem with using the sun is that it moves constantly throughout the day so sun compass orientation must be combined with an internal clock to calculate the relative position of the sun at different times of the day.
Describe an ‘Emlen funnel’ and how they can be used?
European indigo bunting migration and an Emlen funnel
(Celestial Navigation)
- Metal funnel with wire screen over top to stop bird escaping.
- Ink pad on the floor which stains the birds feet.
- When animal try’s to migrate/fly away the ink stains the funnel wall indicating the position the bird want to fly in.
- EI Buntings fly north for spring
- Fly south for Autumn
- Ink marks on funnel will reflect this
- Most of the movement done at night to avoid predators perhaps, they can use stars to navigate as seen in planetariums.
Describe experiments undertaken with Leather back turtles and Loggerhead turtles which indicate celestial navigation
Leather backs
- Conducted on juvenile Leather Back (geomagnetic orientation/navigation)
- Put them in a tank tethered to a harness
- They can measure the direction that the turtle swims by measuring the orientation of the dial that the harness is attached too.
Loggerhead turtles
Geomagnetic compass orientation was demonstrated in loggerhead turtle hatchlings by manipulating the magnetic field of the tank using copper coils to replicate the geomagnetic fields of different locations around the Atlantic Ocean. The ability to orientate by knowing their geomagnetic location allows them to remain within the gyre current which affords them better feeding opportunities.
Describe how a Sahara desert ant navigates.
Sahara desert ants use more than distance and direction to navigate by employing path integration. They determine their direction using sun compass and count their steps (pedometer) to measure distance.
(Manipulating the length of the ants’ legs by cutting them shorter or gluing stilts on them to lengthen them resulted in the ants either undershooting or overshooting, respectively, the position of their nest.)
Why do Wildebeest migrate?
Seasonal migration of wildebeest in the Serengeti National Park follows the seasonal availability of forage and varies with annual variation in rainfall.
What methods of navigation and orientation do Humpback whales adopt?
Example: Humpback whale
True navigation over long distances employs multiple orientation senses including:
- Piloting using land marks
- Compass orientation using celestial geomagnetic cues
- Path integration
Recent tracking of humpback whales show they make long distance movements through open ocean with very little course deviation. Horton et al 2011 - Straight as an arrow: Humpbacks swim constant course tracks during long-distance migration.
Define path integration
(dead reckoning)
- Path integration is the name given to the method thought to be used by animals for dead reckoning.
- In navigation, dead reckoning is the process of calculating one’s current position by using a previously determined position, or fix, and advancing that position based upon known or estimated speeds over elapsed time and course. The corresponding term in biology, used to describe the processes by which animals update their estimates of position or heading, is path integration.
