Populations

1
Populations

• Chapter 9 Abundance

2
Rarity and Vulnerability to Extinction

• What makes a species rare and/or vulnerable to
  extinction?
• Habitat restrictions
• Low reproduction
• Geographic range

3
What makes a species rare and/or vulnerable?

• Geographic rangesmall vs. large
• Habitat tolerancebroad vs. narrow
• Local populationsmall vs. large

4
Geographic range large vs. small

• Large geographic range
• Bracken ferns
• Dandelions
• House sparrows

5
Small geographic range

• Texas Blind Cave salamander
• One cave in Texas
• Monterey Pine
• A few locations on the California coast

6
Rarity and vulnerability Habitat tolerance

• California grey whale

7
Rarity and vulnerability to extinction small
population

• 3 (4?) of 9 subspecies are extinct

8

• 400 individuals of Amur Tiger
• 400 of Sumatran Tiger

9
Restricted range and narrow habitat tolerance

• Silver sword Narrow range (Haleakala crater,
  Hawaii)
• Habitat high and dry volcanic areas

10
Habitat tolerance and small population

• Northern spotted owl
• Must live in forests gt125 years old
• Vulnerable therefore to logging

11
Everythings wrong

• Restricted range (a few montane cloud forests in
  C. Africa)
• Narrow habitat tolerance
• Small populations