APES Unit 9.9 (Endangered Species)

How species become Endangered

• Poaching 

  • Poachers hunt for exotic species for fur, tusks, horns

  • May also be for harvesting or food

  • To sell as pets

• Special food/habitat needs

  • Niche specialists are more prone to endangerment due to specific food/habitat needs

  • Less tolerant of changing climate, habitat loss, wildfires, deforestation, urbanization, etc.

• Invasives

  • Outcompete natives for resources

  • Zebra mussels have endangered 30 native mussel species in US rivers

• Climate Change

  • Shifts habitats of many species

    • Migration to new habitat is harder with fragmentation/loss

Protecting them

• Poaching Prevention

  • Hiring of armed guards to monitor populations and prevent poaching 

  • Laws that punish poaching severely, with stiff fines or jail time

• Legislation 

  • CITES: International agreement for countries to set up agencies to monitor import and export of endangered species (as specified by IUCN Red List)

  • Endangered Species Act: US law giving USFWS power to designate species as endangered or threatened, monitor trade and purchase ladn critical to these species’ habitats

• Protect wildlife habitats

  • Designating areas with important habitats as:

    • National parks

    • Wildlife preserves

    • Animal sanctuaries

    • Prevention of

      • Hunting, development, fragmentation, deforestation

    • Allow species to breed and reestablish population size

Endangerment by Taxon

• Amphibians (41%)

  • Especially vulnerable to climate change due to biphasic life and highly permeable skin

• Conifers (34%)

  • Threatened by disease and warming temperatures expanding insect pest ranges

• Warm water coral (33%)

  • Threatened by changing ocean temperature and pH

• Mammals (25%)

• Birds (13%)

Specialists vs. Generalists

• Specialists

  • Most likely to become endangered or extinct

  • Less likely to move to a new habitat

  • Less likely to adapt to new conditions

  • Disadvantaged by rapidly changing habitat conditions

  • Ex: Panda

• Generalists 

  • More likely to move to a new habitat

  • More likely to adapt to new conditions

  • Advantaged by rapidly changing habitat conditions

  • Ex: Raccoon

Competition & Endangerment

• Interspecific competition: competition for resources (food, nest sites, water) amongst members of different species 

  • Can cause species to become threatened, especially when combined with general habitat fragmentation or loss due to human land use

  • Can further threaten species already vulnerable to habitat disruption due to climate change