Lecture 2 Flashcards
Behaviour Controls & Information Processing
two types of neural pathways
- afferent: ascending toward the CNS; usually sensory
- efferent: descending away from the CNS; usually motor
feature detectors
specialized sensory receptors that respond to important signals in the environment
feature detection in frogs
female frogs only focus on calls from males that are the same species as them, and ignore all other frog calls
hormones
chemical substances secreted by endocrine glands that travel in the blood to target cells, triggering long-term behaviours
endocrine gland
ductless glands; secrete hormones
hormonal influence on the behaviour of female Anolis carolinensis lizards, and its importance
- in a group of all females (0 males), 80% of females are reproductively active
- in a group with 1 male courting, 100% of females are reproductively active
- in a group with 2 or more males, 40% of females are reproductively active; the males fight with each other instead of courting, and the females wait to see which males are the best
- in a group with 1 castrated male, 80% of females are reproductively active; the male doesn’t court
- in a group with 1 castrated male injected with testosterone, 100% of females are reproductively active; the male still courts
This demonstrates that testerone is one of, if not the hormone involved with female behaviour.
the role of genes in larvae
- larvae were fed on patches of yeast cells on agar plates
- rover larvae travelled between patches, whereas sitter larvae stayed where they were laid
- the behaviour of larvae (rover vs. sitter) is determined by 2 alleles on the same locus
artificial selection
- selectively breeding organisms to produce desirable traits
- can be used to demonstrate the effects of genes on behaviour, as alleles that are selected for will increase in population over time
artificial selection in dogs
- a fur farm wanted to breed foxes for silver coats, but they were too timid to be reproductively active
- geneticist Dmitry Belyaev was hired to improve breeding; he selected animals for breeding based on tameness
- within 40 years, this is what led to the creation of dogs
flight distance
the distance you can get to an animal before it runs away (i.e. the shorter the flight distance, the tamer the animal)
habitat selection
rules by which an organism makes choices about where to spend their time
two factors animals consider when selecting habitats
- resource availability
- the number of individuals within a habitat: can indicate levels of competition for resources
two types of animal (habitat) movement
- dispersal: permanent movement from one area to another (short-distance movements)
- migration: regular movements between two different locations (round-trip movements)
four dispersal hypotheses
- (resource) competition hypothesis: dispersal decreases competition for resources (e.g. northern goshawks disperse based on habitat quality)
- inbreeding avoidance hypothesis: dispersal decreases chances of breeding with close kin (e.g. male ground squirrels disperse first from mother’s burrow to avoid breeding with mother and sisters)
- mate competition hypothesis: dispersal is driven by competition for mates (e.g. young male lions are kicked out as they compete with the father for mates)
- win-stay lose-shift hypothesis: dispersal is driven by past breeding success (e.g. kittiwakes are likely to return to a breeding site if them, or the majority of the colony, are successful in mating)
kinesis vs. taxis
- kineses are random, undirected movements in response to stimuli (e.g. isopods move larger distances in low humidity)
- taxes are specific movements in response to stimuli (e.g. isopods move away from light sources)
Orientation involves, ________ not ________.
taxes, not kineses
two major issues of migration
- orientation: process of using environmental cues to determine and maintain a specific direction
- navigation: process of using environmental cues to determine where you are in relation to a particular location, and moving to said location
three examples of compass systems
- Sun compass: using the Sun (in the day)
- star compass: using the stars (in the night)
- geomagnetic compass: using the Earth’s magnetic field within latitudinal variations
biological clock
produced by interacting proteins that cycle on own to create regular rhythms
three types of biological clocks
- circadian clock: daily cycles (e.g. feeding, sleeping, hormones)
- lunar clock: cycles based on the Moon’s orbit (important for tidal species)
- annual clock: yearly/multi-year cycles
orientation in monarch butterflies
- monarch butterflies use a Sun compass for orientation
- they migrate in search of moist, moderate temperatures
navigation in homing pigeons
- when they are clock-shifted, they can navigate on cloudy days, but not sunny days
- when they have a magnet on their head, they can navigate on sunny days, but can’t navigate on cloudy days
- pigeons, hence, use a (primary) Sun compass and (secondary) geomagnetic compass to navigate
