ENWC201 Study Guide - Midterm Guide: East Africa, West Nile Fever, Habitat Fragmentation
18 May 2018
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Exam 2 study guide
The Pleistocene Overkill refers to the extinction of elephants, giraffes, giant bison, and many
more species of megafauna (large animals) that as caused by humans after they crossed into
North America
● Aldo Leopold
○ Father of wildlife management
○ First professor of game management, rote first wildlife textbook
● John Muir
○ Fought to conserve Yosemite and founded Sierra Club
● Teddy
○ Tripled our National Forests and created first National wildlife Refuge
○ An avid hunter and outdoorsman ho's presidency in part led to the "Golden Age
in Conservation"
● Not all wildlife in the United States has adequate regulation of their harvest (hunting) to
prevent overexploitation.
● Bushmeat trade has shifted hat used to be sustainable local consumption into an
unsustainable use of wildlife in our tropical forests. -> Defaunation (even before first is
cut down there are feer animals left
● CD is Caused by an infectious misfolded protein, or prion, that creates vacuoles in a
deer's brain and alters their behavior to the point that they slowly die from starvation
●wetlands are more productive than many other land types and provide important
habitat for many wildlife species. In the Chesapeake Bay watershed e have lost
over 60% of this land type.
● Starlings were introduced to the United States by Shakespeare enthusiasts. The
birds have since spread across the United States and are out-competing native
birds (like the blue bird).
●
Overexploitation
● Era of overexploitation in America 1850 - 1900
● Overexploitation: living off the land or seas in a manner that can not be sustained
●Exploiting is necessary for us to survive just be smart
Populations
● Southeast asia highest people to km ratio - 522 people
● Central east africa second - 99 people
● Latin america 46 people to 1 km
Medicine trade - rhino horn
● US is 2nd largest importer of wildlife products and large destination of illegal pet
trade
Habitat
● Largest threat to biodiversity and the leading cause of animal extinctions in the
world
Disease
● Disease -a disturbance to the normal function or structure of an organism
● Epizootic: a disease that appears at an unexpected rate, synonymous with Epidemic in
humans
● infectious: Viruses, Bacteria, Fungi,Parasites (Internal and external), etc.
● Pathogen-a disease-causing agent
● Non infectious : toxins (man made, plant, fungal, or bacterial) Physiological, nutritional,
congenital, degenerative,cancer
Non Infectious disease ex
● Mercury poisoning
○ Product of coal and other fossil fuel power generators
○ Heavy metal toxin –> Methylmercury
○ Also emitted hen items with mercury are incinerated (thermometers, batteries,
light switches, fluorescent bulbs)
○ Bioaccumulates, Biomagnifies
Disease Dynamics
● Reservoir: any living or nonliving substance that may perpetuate a pathogen in nature
● Reservoir Host: A host that acts as a reservoir for the pathogen, but does not suffer ill
effects from the disease
● Host- an organism on or in which another organism lives
● Vector - organism that carries pathogens from one host to another - or from a reservoir
to a host
○ Biological vector (ex mosquito) - holds the pathogen in its body
○ Mechanical vector (fly) - steps on feces and carries it on its body
● hen targeting, can target vector, host, or environment of pathogen
Disease and Agriculture
Disease and Endangered Species
Zoonosis - an animal disease that can be transmitted to humans - but we are not necessary
● Lyme disease
● west nile virus
● Ebola
● SARS - high fertility
● Avian Influenza (H5N1)
Habitat Loss, Degradation, and Fragmentation
● Habitat: the physical and biological resources required by an organism for its
survival and reproduction; these requirements are species-specific
● Largest threat to biodiversity and the leading cause of animal extinctions in the
world
● Habitat degradation: impacts, many, but not all species
○ Can have many causes, some prime examples are
■ Livestock grazing
● Rangelands ~25% of terrestrial land
■ Invasive species - creates its on culture; very fe species can live
near
● Habitat fragmentation: reduction in the area covered by habitat, change in
configuration
○ Division of large habitat area into smaller patches
■ Smaller patches = less population stability and less biodiversity
○ Island biogeography theory
■ Apply to all , originally based off islands however
■ If closer to mainland (or larger forest in terms of fragmentation)
helps lessen rate of extinction since can help repopulate
● Also has higher rate of immigration
■ Smaller patch has a higher rate of extinction
■ Best scenario is close to mainland (or large forest) and large area
■ worst scenario is the intercept between far from mainland and small
islands
■ e ant them as connected as possible to have highest biodiversity as
possible
○ Edge effects
■ these are not pros or cons, just different
● Air and soil temp, moisture, light
○ Sunlight not able to penetrate far into the brush
○ Moves into forest, cools don
● Vegetation density
● Predator intrusion
● Community composition
■ Smaller ptches = more edge , less interior per km^2
● ith fragmentation, increase in edge habitat and species
■ Not all edges are created equal
■ The matrix = surrounding landscape of fragment habitat
■ Example 1 - interior forest birds, nest parasitism
■ Example 2 - florida panther
■ Connectcity and proximity
● Stepping stones
● Landscape linkage
● Habitat loss - impacts so severe that almost all species are adversely affected
