L7 - Where to live Flashcards
(29 cards)
what are the two scenarios which dictate how animals may distribute themselves
IFD (when they do not defend resources)
IDD (ideal despotic distribution, when they defend resources)
what are the assumptions of IFD
all individuals free to move around, should lead to same fitness reward to all
what are the assumptions and predictions of IDD
animals will distribute themselves based on their competitive ability and the quality of available habitats, predict that strongest despots get best resources by forcing others out, resulting in unequal fitness
give an example of IDD
pied flycatcher - broad leaved forests occupied earlier for nestswhich suggests that it is preferred
dominnant indiciduals choose better habitats earlier, while also having more eggs and higher fledging success
corniferous habitat leads to lower success in offspring as it is a worse habitat
what is an example of IFD with unequal competitors
aphids and galls on differently sized leaves, although same average reproductive success across leaves, bigger leaves preferred, mothers fight for the position therefore winner mother will have a preferred position
how can the economics of resource defense and territoriality be modelled?
optimality model - territory defence economic from point A to B - maximize profit at maximum difference between cost and habitat A or B, decision will depend on cost and benefit curve shapes
what are the 3 things needed to consider when defending a territory/modelling decisions to defend a territory
is territory defense economic, are richer territories smaller, are fitness benefits greater in richer territories
what is an example showing territory defense as economic
golden-wing sunbird males need to spend less time foraging after defending their territory
what is an example showing that richer territories are smaller
side-blotched lizard and rocks - rocks needed for thermoregulation, the ones with more rocks suggested richer habitat which required less space
what is an example showing that fitness is greater in richer territories
side blothced lizards - richer territories showed higher growth rate
what is station keeping
movement within home range
what is ranging and what are its costs and benefits
movement out of home range to explore and seek new suitable home range, eg natal dispersal
costs: energy, time, higher predation, uncertainty of resources
benefits: prevention of inbreeding, decreased competition
also sex biased
what is migration
non accidental movement to a new habitat
why do animals have an initial suppression of responses when migrating
response to stimuli would otherwise stop movement, gets reactivatred eventually
what are some other ways in which migrating animals adapt
activity patterns particular to departure and arrival, preemptive response to harsh environments, specific patterns of energy and internal resource allocation, migratory restlessness, weight gain before
what is specific about the monarch butterfly migration
multigenerational circuit - one generation goes down and overwinters, 3-4 generations go back up
what are some examples of environmental triggers for migration
photoperiod change, resource depletion, temperature change (eg humpback whales sense change in water temp), also rainfall (serengeti migration)
how can animals find their way back home
path integration - idiothetic cues from own movement information combined with external allothetic cues to avoid errors
how can path integration be tested
ants - if displaced to the right, they will miss their nest by the distance they were displaced to the right
what are the 4 strategies migrants use to return home
guilding, pilotage, clock and compass, true navigation
what is guilding
following of others who have learnt the way
what is pilotage
use of familiar landmarks
what is clock and compass
innate ability to move in a set of geographic directions for a given lentgh of time (all ages, particularly useful for juveniles)
what is true navigation
udr of cognitive internal map (representantion of a landscape), need bi-coordination, restricted to adults and our knowledge of it limited
