Orientation and Migration

orientation:

coordinated movement (walking, swimming, flying) that occur in response to external stimulus

adaptive value of orientation:

avoid predators, find food, mate

kinesis is the …

increase in random movement

kinesis lasts until …

a favorable environment is reached

taxis is …

movement in a specific direction

taxis is either …

toward or away from a specific stimulus

taxis and kinesis are a …

one-way trip

animals can sense the …

stimuli gradient (weak —> strong)

taxis stimulus:

light, chemical, sound, humidity, wetness, magnetic field

type of stimulus is …

not important in terms of behavior

in terms of taxis, a difference in behavior is how …

an animal gets to stimulus or avoids

+ phototaxis (kinesis) goes …

towards stimulus

- phototaxis (kinesis) goes …

away from stimulus

positive and negative phototaxis are categorized by …

the type of movement (not stimulus type)

klinotaxis:

side-to-side motion of head/body with successive comparison of stimulus intensity

klinotaxis means …

to bend

klinotaxis: small organisms that tend to have …

1 sensory receptor OR 2 sensory receptors that are very close to each other

Eugleua (ex. of klinotaxis) has 1 sensory receptor to …

direct the route of stimulus

Eugleua (ex. of klinotaxis): bright light causes them to …

move away from stimulus

Eugleua (ex. of klinotaxis): dim light causes them to …

go towards the stimulus

male moth (example of klinotaxis): in order to reach a female, they will …

go towards the stimulus, which is light

tropotaxis:

stimulus is sensed by a pair of sensory receptors in a straight line towards or away from the stimulus

an example of tropotaxis is …

human ears

Snakes (example of tropotaxis):

forked tongue acts as sensory receptors

for kinesis, the change in speed of movement and change in rate of turning is directly proportional to …

the intensity of stimulation

klinokinesis:

turning movement that can change ratio of turning

klinokinesis: when an animal prefers a condition …

the turning rate increases

klinokinesis: when an animal does not prefers a condition …

the turning rate decreases

orthokinesis:

speed of movement is related to intensity of stimulus

woodloner/pill bugs (example of orthokinesis):

prefers high humidity (under rocks, logs, leaves)

woodloner/pill bugs: in low humidity,

these organisms cover a lot of distance per time

woodloner/pill bugs: in high humidity,

these organisms cover smaller distances in the same unit of time (since they actually prefer this condition and see no reason to leave)

karl von frisch dealt with …

bees & communication

karl von frisch states that communication occurs when …

sender produces signals that contain information transmitted through environment and detected by receiver who intercepts the signal and responds

honey bees use menotaxis, which involves …

directional movement and a constant angle to the source

the honey bee’s hive opening faces …

east/southeast

honey bees take part in a ‘round dance’ which …

signifies food < 50 meter away

honey bee foragers do 2 dances to …

communicate location and type of food

honey bees do …

waggle dance and round dance

migration is an example of ______ since it is a 2 way trip

long distance

during migration, you can’t …

detect stimuli

cost of migration:

lots of energy (pre-migration) —> forage (high predation and high winds) —> during migration (different predators, strong wings, alone vs. flock)

benefit of migration:

constant food, different predators may not eat you

proximate cues:

photoperiod, temperature not reliable, some places (equator) has increased quality and quantity of food resources

serengeti wildebeest migration:

biomass of grass, quality of grass, during dry season (june-oct) decreased rainfall = slower grass growth = lower nutritional value

stephen emlen and john emlen:

tried to answer “how do animals know where to go” and observed bird migration

european starling experiment:

captured 14000 starlings (adults that migrated before and fledglings who never migrated before). through communication, some went to england and france