Distribution of Species and Ecology (up to exam 1) Flashcards
species distribution
spacial arrangement of species
home range
area a group/population moves and spend time in (typically over the course or 1 year)
- includes all areas/resources/spaces they go
core range/habitat
area w/in home range where species spend majority of their time
- most reliable food and sleep sites
methods for determining range (4)
- plot method
- quadrant method
- transect method
- GPS radio telemetry method
plot method
representative sample
- larger species/larger area = larger sample taken
Quadrat method
small square tool, count # in quadrant, repeat, (average count * area) = population size
transect method
line across entire area of species
- used for species that move quickly
methods for counting individuals
- mark/recapture
- photo collection (analyze w/ AI)
GPS radio telemetry method
trackers to track movements (home range)
- once you know home range, can estimate population size
3 types of range maps
dot maps, outline maps, contour maps
dot maps
dots at specific locations of individuals
outline maps
outline of range of individuals
- less accurate the dot maps; can over increase range
contour maps
show density of species of larger ranges
population growth
changes in # of individuals/time
exponential growth
w/ unlimited resources; populations can grow rapidly over short periods of time
- only for PERIODS bc eventually a limiting resource will run (limiting population growth)
logistic growth
a population will grow until it begins to reach it’s carrying capacity, at which growth rate begins to decrease
equation for per capita growth rate (R) / (factors that influence growth rates)
R = B + I - D - E
- B = birth rate
- I = immigration rate
- D = death rate
- E = emigration rate
density
size of population / area population occupies
density-dependent factors
density of population effects growth/mortality rates
- ex: competition, predation, disease, parasitism
density-independent factors
factors affect population same (regardless of density)
- ex: natural disasters, extreme weather, deforestation
predator-prey cycles
depends on resources and compeittion
- prey population inc. = inc. predator population = dec. prey population = dec. predator population =….
3 spatial distributions
random, uniform, clumped
when do random spatial distributions occur?
no competition
- no tendency for aggregating
- atypical
- homogenous landscape
when do uniform spatial distributions occur?
intense competition
- homogenous landscape
- territorial animals!!
when do clumped spatial distributions occur?
pack/group animals
- most common
- can create competition for resources
ecological niche
specific environment occupied by an organism including all resources/space, environmental tolerance, ecological role, biotic/abiotic factors
realized niche
actual environmental conditions in which a species survives and reproduces
- limited by competition and resources
fundamental niche
total range of environmental conditions a species could occupy/tolerate
which is larger realized or fundamental niche?
realized < fundamental
source-sink dyanmics
when landscape = heterogenous
- population moves source –> sink
(high quality –> low quality area)
- dec. reproductive success
- mortality > birth
- leads to local extinctions (w/o steady flow of source –> sink); if has enough in-flow (individuals produce in source)
splitting populations
metapopulation –> subpopulations
- when resources in 1 location are scarce
- leads to less competition
- usually seasonal
6 factors that limit species distribution
- geographic barrier
- environmental conditions
- disturbances
- behavior
- competition
- symbiotic relationships
geographic barrier
vicariance prevents further distribution
environmental conditions that limit distribution
- elevation, temp, humidity, soil, etc.
- dictates “zone of tolerance”
disturbances that limit distribution
natural and human disturbances
- small-scale = adapt
- large-scale/human = intense pressure = inability to adapt quick enough
behaviors that limit distribution
seasonal fluctuations; based on resource availability
- behavioral flexibility
behavioral flexibility
ability to shift behavior to be within range
- modify diet, range, etc. to ensure high-quality resources
fission-fusion (behavioral flexibility)
response to temporal/food shortages
- groups breaks into smaller groups to forage (reduce competition), then comes back together when more food is available
- can extend normal range
exploitative competition
individuals use up resources and make them unavailable to others
- indirect
- who’s 1st?
interference competition
individuals use aggression/dominance to deny others access to resources
- direct
competitive exclusion principle
no 2 species can occupy the exact same niche
niche separation (competitive exclusion principle)
2 species occupy (almost) exact same niche w/ 1 difference (that reduces competition enough)
3 types of symbiotic relationships
mutualism, parasitism, commensalism
mutualism
(+/+); reliant, both benefit
- one can limit others’ range
parasitism
(+/-); parasite needs host
- host limits parasites range
commensalism
(+/N); 1 benefits, other = neutral
polyspecific associations
NOT true mutualism BUT organisms develop close relationship (ex: video of wolf and badger)
competitive exclusion principle
no 2 species can occupy the exact same range (Needs at least 1 difference)
