Lec 13 - Sensory Ecology

Front 1

What functions does information about the environment serve

Back 1

(1) Homeostasis

(2) Phenology (timing)

(3) Spatial orientation

(4) Defense

(5) Persuasion

Front 2

What are the channels of information transfer

Back 2

(1) Electromagnetic and thermal energy
(2) Mechanical energy and force
(3) Chemicals

Front 3

advantages and disadvantages to using light as communication

Back 3

(1) Quick fadeout time and much variation so can provide detailed information quickly

(2) affected the most by the environment (obstruction, barriers)

Front 4

advantages and disadvantages to using chemical channels as communication

Back 4

Least affected by environment
Can be private limiting detection by prey or competitors

Provides least detailed picture

Front 5

What does vision involve

Back 5

The ability to detect light

uses light-detecting organs with photoreceptors

Front 6

What is vision best for

Back 6

scanning the environment, it is directional and rapid

Gives precise information on direction distance and nature of objects

Not useful in cluttered environments

Front 7

What are photoreceptor cells

Back 7

pigmented neurons with photoreceptor proteins they convert light into signals that can be interpreted by the brain

Front 8

What happens to photoreceptor cells when detecting light

Back 8

(1) Protein absorbs photons
(2) Change in shape of pigment
(3) Change in electric potential
(4) Signal sent to the brain

Front 9

What are the types of photoreceptors

Back 9

(1) Intensity detectors
(2) Direction detectors
(3) Image formers

Front 10

What do intensity detectors do
What photoreceptor proteins are involved
WHo uses them

Back 10

They are heat detectors

Proteins are bacteriorhodopsin and bacteriophytochromes

Used by bacteria and archaea too small to detect direction

Front 11

Who uses direction detectors and how do they use them

Back 11

Planaria use ocelli to move away from light
They orient so that light received by the two ocelli is equal and minimal

Daphnia use eye to avoid shore by orienting with the shadow cast by the shore and swimming until the light on all ommatidia is equal

Swum upwards in dim light and downwards in bright light for vertical migration

Front 12

How do plants use direction detectors

Back 12

They use phytochrome which detects red and far-red visible light

Front 13

What do lenses do

Back 13

increase resolution, sensistivity, aperture and number of photoreceptor cells

Front 14

Costs and benefits of compound eyes

Back 14

Cannot detect small or distant objects

Provides wider field of vision and excellent motion detection

Front 15

Camera eyes image

Back 15

Front 16

What is good about camera eyes

Back 16

They have the best sensitivity and resolution for larger animals, found in vertebrates and cephalopods

Front 17

What is the quit point

Back 17

The light intensity at which animals stop relying on vision in favour of other senses

Influenced by amount of light and mode of life

Front 18

What is an example of variation in senses using bats as an example

Back 18

(1) Tropical megabats eat fruit and nectar at dawn and dusk using big eyes instead of echolocaton

(2) Micrbats have small eyes and big ears and use echolocation for spatial orientation while flying at night

Those that feed on insects use echlocation to capture prey

Others use odor or sounds produced by their prey

Vampire bats use infrared

Front 19

What do tubular eyes do

Back 19

In Dark adapted animals they increase the amount of light that can enter the eye

Front 20

Binocular vision vs Monocular vision

Back 20

Binocular
(1) Restricts field of view

(2) Provides for focus on prey
(3) Overlapping fields = 3D

Monocular
(1) Can see behind
(2) Can see with head down
(3) Can potentially see 3D

Front 21

What are pupils

Back 21

an adjustable aperture that lets light in

Front 22

What do slit shaped pupils do

Back 22

prevent damage to the retina in bright light because it can close more

Front 23

What do rectangular pupils do

Back 23

increase the field of vision to 330 degrees

Front 24

Vision in fish (3 things)

Back 24

(1) Fish at deeper depths have just rods

(2) Fish closer to the surface can have cones

(3) Deep sea fish only see dark shapes against a lighter background

Front 25

Why dont mammals have the best colour vision

Back 25

They evolved from nocturnal animals

Front 26

What can neural processing enable

Back 26

Enhancing the detection of certain shapes or movement

Front 27

What are the uses for bioluminescence

Back 27

(1) Camouflage

(2) Mimicry

(3) Mate attraction

Front 28

How does mating in fireflies work

Back 28

(1) Males gives a species specific flash
(2) Female responds with a species specific signal

Male displays whlie flying and females display from underbrush

Males may try to interfere with competitor signals

Front 29

What do charcoal beetles do

Back 29

They chase fire using infrared sensors under their legs. They fly with raised legs to increase detection

Females lay eggs so that larvae can feed on recently burned wood

Front 30

How does thermal detection work in snakes

Back 30

Snakes use thermal detectors near their nose and the information is processed by the same part of the brain that processes visual information

Front 31

When are electrical signals most effective

Back 31

wet environments

Front 32

How are electrical discahrges detected
WHo are they found in
What purpose do they serve

Back 32

Electroreceptors which are gel filled pores

Found in
(1) Cartilaginous fish
(2) Some bony fish
(3) Monotremes

Usually for prey detection sometimes for mating

Front 33

Bees flowers and electrical discharges

Back 33

Bees tend to be + charged
Flowers tend to be - charged

When bee lands on flower pollen is transferred easily and quickly and both are neutralized

Front 34

Electrolocation is found in who and is done how

Back 34

freshwater fish
Nocturnal fish
Turbid water tropical fish

Electricity producing organs, inanimate objects have current flow away while living objects have current bend towards them