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Animal Populations. What is a population of animals?. Population: _____________. What is a population of animals?. Population: group of individuals from the same species that live in the same area at the same time (that are capable of interbreeding and producing fertile offspring). - PowerPoint PPT Presentation
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Animal Populations
Population: _____________
What is a population of animals?
Population: group of individuals from the same species that live in the same area at the same time (that are capable of interbreeding and producing fertile offspring).
What is a population of animals?
Size:
Density:
Dispersion:
Age distribution
Animal Population Characteristics
Size: number of individuals
Density: the number of individuals per unit area or volume.
Dispersion: pattern of spacing among animals within geographic population boundaries.
clumped even random
Age distribution
Animal Population Characteristics
Dispersion
Dispersion
What is an example of clumping?
Dispersion
Can you think of animals who exhibit this type of population behaviors?
Dispersion
Territorial BirdsPrairie DogsNesting Seabirds
Abiotic Factors: __________
Biotic Factors: ___________
Types of factors influencing population
Abiotic Factors: Non-Living
Biotic Factors: Living
Types of factors influencing population
What Limits Population Growth?
Abiotic (Increase)Optimal light
Optimal temperature
Optimal nutrients
Abiotic (Decrease)Too much / little
light
Too low / high temperature
Too low nutrients
What Limits Population Growth?Biotic (Increase)High Reproductive
Rate
Generalized Niche
Adequate food supply
Optimal habitat
Biotic (Decrease)Low Reproductive
Rate
Specialized Niche
Inadequate food supply
Degraded habitat
Biotic Increase Continued
Ability to compete for resources
Ability to avoid predators
Ability to resist diseases
Ability to migrate
Ability to adapt to environmental change
Biotic Decrease Cont’d
Unable to compete for resources
Inability to avoid predators
Inability to resist diseases
Inability to migrate
Inability to adapt to environmental change
EXPONENTIAL GROWTH
Growth in which the rate of growth in each generation is a multiple of the previous generation
Where r is the intrinsic rate of growth& N0 is the initial population
EXPONENTIAL GROWTH
Where r is the intrinsic rate of population growth
r = (gaining)-(losing)Can be positive,
negative, or zero
r = (births + immigrations) - (deaths + emigrations)
Calculate r ?
Calculate r ?R= (gaining) – (losing)2 births + 2 Immigrates-
2 Emigrates + 1 Death
= r= 1
LOGISTIC GROWTH
Carrying capacity (K): the maximum
population size that a particular environment can support.
http://www.youtube.com/watch?v=gEwzDydciWc
What are the reasons why the bacteria won’t go on reproducing and eventually take over the world.
Limiting FactorsDensity DependentDensity Independent
Growth of bacteria
competition water-qualitypredation living spaceparasitism/ disease
Density-dependent
Effects not influenced by populations sizeTemperatureStormsFloodsDrought
Density-Independent
Refers to the number of survivors of a population after a given period of time - just like the TV show! Life tables are used to summarize patterns of life and death; follows a cohort of individuals. If we plot % survivors vs. time there are three basic patternsType I: most individuals reach physiological age,
little infant mortality, lot of maternal care (e.g., humans)
Type II: constant mortality (e.g., many animals)Type III: high infant mortality, little maternal care
(e.g., many invertebrates, fish)
Survivorship
What does this graph tell us?
Snowshoe hares are preyed upon by lynx. Both species show pronounced population cycles. The cycles are roughly synchronized, although the rise and fall of lynx populations slightly lags the rise and fall of hare populations
Population Sampling:TransectRandomTagging
How do Scientist know how many animals are in a population?
1. What are the pros and cons to using each of these types of sample counting?
2. What are types of organisms that could be used in each of these counts?
3. Can you use actual counting techniques for some of these populations?
# of Marked Recaptured = Total Marked Total Captured Total Population
Tagging Organisms
This is what field researchers are trying to find
Capture, Mark, & Recapture Lab
Randomly selected areas are counted instead of the
entire area
Make a GRIDCount the total number of squares in
the gridChoose one square of the grid at
random.Count the population in that one
square.Estimate the total population by
multiplying the number in one square time the total squares in the grid.
Random
Make a “T” on a graph
Transect
Count this box twice!!!
Population Sampling Lab packet is due tomorrow
Which method is the most accurate?
Population Sampling Lab
For tomorrow……
Find on Article on tagging animals in the wild
Deer Tagging in Wisconsin
Conservation Strategies focus in on saving an entire ecosystem rather than individual species
In 1973, the U.S. Congress passed the Endangered Species Act (ESA)
Designed to protect plant and animals species in danger of extinction against humans or government projects
The U.S. Fish and Wildlife Service (USFWS) identified 2269 species that were listed as endangered or threatened
Maybe hard for a species to be classified as “endangered”
Preserving Habitats & Ecosystems
Under the ESA, the USFWS must prepare a species recovery plan for each listed species.
Concerns from land owners, real-estate developers, and farmers
One compromise to these situations is a habitat conservation plan
A plan that attempts to protect one or more species across large areas of land through trade-offs or cooperative agreements
International Union for the Conservation of Nature and Natural Resources (IUCN)
Recovery and HabitatConservation Plans
One development of the IUCN was the Convention of International Trade in Endangered SpeciesThis was an attempt to stop the slaughter of
African elephants. CITES made the trade of ivory illegal and thus
decreased the amount of poaching and the population of the African Elephant has began to recover
IUCN
Reintroduction: placing a species into a environment that once was able to sustain
Endangered Species: a species that is likely to become extinct if protective measures are not taken immediately
Threatened Species: a species that is likely to become endangered if no measures are taken
Reintroduction of Wolves in Yellowstone
Habitat Destruction and FragmentationIn Florida, the panther is one of the most endangered
species in North America Invasive Exotic Species
Polynesian rats on Easter IslandCan you think of anymore around here?
Harvesting, Hunting, & PoachingThe African ElephantWhaling (Discovery Channel) 7 out of 13
http://www.youtube.com/watch?v=vHqIOOajgFw&feature=channel
PollutionThe Bald Eagle becoming endangered because of the
pesticide DDT
Humans causing extinctions