Animal - Section E - Orientation

Question 1

Orientation is the ability of an animal to use…

Answer 1

sensory information to

• position itself with respect to features of its environment
• or of other organisms. (catching prey/avoiding predators)

Question 2

Give an example of exteroceptors

Answer 2

• Ears
• Eyes

Question 3

Give an example of Interceptors

Answer 3

Maculae and cristae ampullaris of the inner ear

Question 4

Sensory information is mapped within the brain to a topographic map in the _____ ______ with respect to body position

Answer 4

Optic tectum

Question 5

The optic tectum does what and what is its name in mammals

Answer 5

• maps sensory information with respect to body position
• sperior colliculus

Question 6

The brain scans sensory information in the __________ map and uses a technique called ________ to determine which information is most relevant (important) at any time.

Answer 6

• topographic
• saliency

Question 7

______-__ sensory information is scanned by ___-____ attentional scanning (called the __________ ______ _____) to determine ________ (behavioural relevance) and appropriate behaviours are __________ to address the most salient topographic information.

Answer 7

• Bottom-up sensory
• Top-down
• Attentional search light
• Saliency
• initiated

Question 8

Familiarise

Question 9

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.

Answer 9

• 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.

Question 10

Define these terms:

-kinesis

-Ortho kinesis

-Klinokinesis

Answer 10

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

Question 11

Define these terms and give an example of each:

-Phototaxis

-Chemotaxis

-Rheotaxis

-Phonotaxis

-Thermotaxis

-Electrotaxis

-Klinotaxis

Answer 11

• 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

Question 12

Define the term

-Navigation

Answer 12

The process of determining a location and moving towards it, can be achieved through:

-piloting

-compass orientation,

-true navigation.

Question 13

Define this term and give an example of an animal that uses it.

-Piloting

Answer 13

• Finding a location based on fixed land marks or reference points
• Gray whales migrate following the western coastline of North America

Question 14

Give an example of mnenotaxis

Answer 14

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)

Question 15

Define the term

-Compass orientation

Answer 15

• 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

Question 16

Describe how pilotage can be combined with compass orientation

Answer 16

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.

Question 17

Describe an ‘Emlen funnel’ and how they can be used?

Answer 17

European indigo bunting migration and an Emlen funnel

(Celestial Navigation)

1. Metal funnel with wire screen over top to stop bird escaping.
2. Ink pad on the floor which stains the birds feet.
3. When animal try’s to migrate/fly away the ink stains the funnel wall indicating the position the bird want to fly in.
4. EI Buntings fly north for spring
5. Fly south for Autumn
6. Ink marks on funnel will reflect this
7. Most of the movement done at night to avoid predators perhaps, they can use stars to navigate as seen in planetariums.

Question 18

Describe experiments undertaken with Leather back turtles and Loggerhead turtles which indicate celestial navigation

Answer 18

Leather backs

1. Conducted on juvenile Leather Back (geomagnetic orientation/navigation)
2. Put them in a tank tethered to a harness
3. 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.

Question 19

Describe how a Sahara desert ant navigates.

Answer 19

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.)

Question 20

Why do Wildebeest migrate?

Answer 20

Seasonal migration of wildebeest in the Serengeti National Park follows the seasonal availability of forage and varies with annual variation in rainfall.

Question 21

What methods of navigation and orientation do Humpback whales adopt?

Answer 21

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.

Question 22

Define path integration

(dead reckoning)

Answer 22

• 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.