Transcript Issues with Animals

ISSUES WITH
ANIMALS
Invasive Species
• A non-native or exotic organism that spreads widely in a
community.
• Not all exotic species turn invasive. Some may remain small and
localized, eventually dying out. Others may simply exist without
causing problems.
• Species only become invasive
when such limiting factors as
predators, parasites or competitors are not present in their new
environment.
• The community is thrown out of balance as native species are
eliminated
Video
• https://www.youtube.com/watch?v=abImqGDzXBo
Biodiversity at Risk
• Natural Biodiversity Loss – Extinctions happen naturally
and usually occur one by one at a pace called the
background rate of extinction.
• There are times that extinction rates have been far above
normal background rates. These events are called mass
extinctions, there have been at least 5 mass extinction in
the earths history. Each time more then one fifth of all
families and half of all species have gone extinct
6th Mass Extinction
• If current trends continue, the modern geological era may
see the extinction of more than half of all species.
• Today, species loss seems to be accelerating as human
population growth puts an increasing strain on habitats
and wildlife
• These trends and predictions have caused some scientists
to claim that we are in the middle of Earth’s sixth mass
extinction
Causes of Biodiversity Loss
• Habitat Change and Loss – clearing forests for logging or road
building removes food shelter and other sourced that forest
dwelling organisms need to survive. Habitat change and loss
is by far the greatest cause of biodiversity loss today.
• Invasive Species – The introduction of non-native species to
new environments can sometimes push native species toward
extinction
• Pollution – Heavy metals, fertilizer, pesticides, and toxic
chemicals that pollute the air and water can poison people
and wildlife
• Overharvesting – for most species, hunting or harvesting by
humans does not pose a threat of extinction, but there are
exceptions. Some fish for example are facing extinction
because of over fishing. Poaching has also driven tigers and
rhinos to near extinction.
• Climate Change – Extreme weather events such as droughts
increase stress on population. Warming temperatures are
causing organisms to move towards the poles and higher
altitude where the climate is cooler
Animals as our food
• Food Inc Documentary