Conservation Biology Twu Exam 2 Chapter 8

Front 1

A species is considered rare if

Back 1

It has a narrow geographical range
It occupies one or a few specialized habitats
It is found in small populations

Front 2

Rabinowitz’s rarity is based on

Back 2

the geographic range of a species (extensive versus restricted)
habitat tolerance (broad versus narrow) and
local population size (large versus small).

Front 3

Species that have an extensive geographic range, broad habitat tolerance and large local population size

Back 3

(house sparrow, dandelions, crabgrass)

Front 4

Restricted geographic range, broad habitat tolerance and large local populations

Back 4

Galapagos medium ground finch, Monterrey pine

Front 5

Extensive geographic range, narrow habitat tolerance and large local populations

Back 5

California grey whales, Freemont cottonwood

Front 6

Primack poses the question: What makes species vulnerable to extinction?

Back 6

One aspect is certain, rare species are more vulnerable to extinction than species that are common

Front 7

By definition, common species are ________some part of their range

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abundant in

Front 8

Extensive geographic range, broad habitat tolerance and small local population sizes

Back 8

tigers and the grassfern – Asplenium septrionale

Front 9

Restricted geographic range, narrow habitat tolerance and large local populations

Back 9

fish crows, Haleakala silversword

Front 10

Restricted geographic range, broad habitat tolerance and small local population size

Back 10

Tasmanian devil and Welwitschia mirabilis

Front 11

Extensive geographic range, narrow habitat tolerance and small local populations size

Back 11

Northern Spotted Owl, Pacific yew [Taxus brevifolia])

Front 12

Restricted geographic range, narrow habitat tolerance and small local population sizes (

Back 12

Mountain Gorilla and Pritchardia monroe, Wollemi pine

Front 13

First of all, let us characterize rare by determining what all rare species share:

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Rare species occupy a specialized habitat
Rare species have a narrow geographic range
Rare species characteristically have small populations

Front 14

An ________ species is one with a special type of rarity

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endemic

Front 15

endemic species

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Species found naturally in a single geographic area and nowhere else

Front 16

____are endemic to planet earth, _____ are endemic to west Africa, ____are endemic to south eastern US

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Humans
bonobos
the Venus-flytrap and the pitcherplants

Front 17

Endemics of the United States

Back 17

Dionaea of North Carolina venus flytrap
Sarracenia from eastern US
pitcherplant

Front 18

Which are the species most vulnerable to extinction?

Back 18

Species with narrow geographic ranges – any destruction of their habitat is likely to decrease population sizes, disrupt meta-population structure, and directly impact numerous individuals. (Birds on oceanic islands, fish species restricted to one watershed, etc.)
Species with few populations – habitat destruction wreaks havoc because it could easily extirpate the few isolated populations. (Pupfish in desert Southwest, Gold-cheeked warbler that nests only in Texas Juniper ash woods)
Species that have perpetually small populations usually have low genetic variation and may be subject to repeated genetic bottlenecks that decrease genetic variation. The cheetah is notorious for this as are other top predators
Species in which population size is declining have critical demographic connections between stages in their life history which make them vulnerable. Many species of primates in Africa and South America…. This is particularly true where these primates are principal constituents of “bushmeat” which is the next category.
Species that are hunted or harvested by people.

Front 19

The IUCN categories of conservation status

Back 19