L7 Dispersal across ecosystems Flashcards
what is the great serengeti migration
migration of wildebeest predominantly from south to north
why does the great serengeti migration occur
it is based on dry and wet season, which changes the amount of grass and therefore also impacts mating, headed south at start of wet season, norht during dry season
how does the migration of wildebeest impact the ecosystem
carry nutrients such as N and P around the habitat, plenty of them die therefore food for other organisms, connection of different ecosystems (tall grass, short grass, woodland)
how is the desert locust migration different than the great serengeti migration
locusts it “devastating” because it only happens once in a while, therefore ecosystem is not adapted
what are some characteristics of the deserts locusts
eggs may lay dormant for many years, lfe starts as a grasshoper and not all become locusts, dictated based on whether the conditions are right
how does the greater snow goose migration impact the northern ecosystem
it impacts arctic fox and lemming populations - lemmings tend to go more scarce at the end of season, foxes switch to goose eggs layed in moss
describe the migratory behaviour of erctic tern
migrates from antarcitca to arctic and back, breeding un the arctic and wintering in Antarctica
describe the migratory behaviour of european eel
from carribbean to rivers in the UK and back using drift predominantly
describe the life cycle of atlantic salmon
most of life spent in rivers, sea/ocean as an adult, groth rate rises with temperature, come to sea for higher nutrient availability but higher risk of predation
what is the difference between migration anf long distance dispersal
migration is on purpose, occurs “daily”, dispersal is more accidental, especially in larger animals, amplified due to anthropogenic forces
what does the example of long jawed orb weaver show
that the ability to disperse (via a silk balloon) can be lost (due to the fact that dispersal no longer beneficial), which leads to endemism on islands because species is genetically cut off
how does migration of mallards affect seed dispersal
able to disperse seeds across long distances due to seasonal migration, as distance increases probability of plant dispersal tapers off
