• Home
  • Textbooks
  • Ecology : The Experimental Analysis of Distribution and Abundance
  • Applied Problems III: Conservation Biology

Ecology : The Experimental Analysis of Distribution and Abundance

Charles J. Krebs

Chapter 17

Applied Problems III: Conservation Biology - all with Video Answers

Educators


Chapter Questions

02:00

Problem 1

Barro Colorado Island was formed 85 years ago in central Panama when Gatun Lake was created as part of the Panama Canal. since that time 65 of 394 species of birds have disappeared from the island, 21 of them in the past 25 years. Discuss what mechanisms might cause extinctions of birds that can fly in an undisturbed area of tropical forest. Robinson (1999) discusses these changes.

Nick Johnson
Nick Johnson
Numerade Educator
01:50

Problem 2

Review the claim of Sagoff (2005) that introduced species are not a serious problem for conservation, and the rebuttal of this by Simberloff (2005) and by Clavero and Garcia-Berthou (2005).

Hast Aggarwal
Hast Aggarwal
Numerade Educator
01:27

Problem 3

When organisms of the same species are brought together to breed from divergent geographic areas, outbreeding depression may occur in which the fertility or viability of the offspring is impaired (Templeton 1986)$.$ This is one reason why some biologists were opposed to the addition of panthers from Texas to the Florida panther population in $1995 .$ Discuss the reasons outbreeding depression occurs and its implications for the conservation of the Florida panther. Pimm et al. (2006) give an overview of the controversy.

Simon Sauvageau
Simon Sauvageau
Numerade Educator
01:50

Problem 4

One of the most extensive ecological experiments is being carried out by the Biological Dynamics of Forest Fragments Project in the Brazilian Amazon. One experiment has involved creating small isolated patches of rain forest and following the extinction and colonization of these patches over time. Ferraz et al. (2007) have reported on the impacts of fragmentation on Amazon birds. Discuss what predictions you would make for this experiment from island biogeography theory, and review the results to date.

Courtney Burson
Courtney Burson
Numerade Educator
04:34

Problem 5

Kirtland's warbler is an endangered species that breeds in northern Michigan jack pine forests. From the 1950 s to the 1970 s the population of this species declined, and it numbered about 200 individuals in $1971 .$ It was stable in numbers from 1971 to 1986 The most important factor in the population decline seemed to be increasing parasitism of nests by brown-headed cowbirds. Cowbirds were removed from the breeding area of Kirtland's warbler starting in 1971 , but no change occurred in warbler numbers by $1986,$ and speculation began that it was being limited on its wintering grounds in the Bahamas. The alternative hypothesis was that habitat was becoming unsuitable for these birds. Extensive habitat management was begun in 1987 and two large wildfires rejuvenated the jack pine stands in which it breeds. The warbler increased in numbers fourfold in the 1990 s. What management plans would you now recommend for this endangered species? Probst et al. (2003) provide recent evidence on this endangered bird.

Lindsay Mayer
Lindsay Mayer
Numerade Educator
02:23

Problem 6

One of the possible reasons for the continuing decline of the northern spotted owl is interference competition with the larger barred owl (Anthony et al. 2006 ). Discuss how you would test this competition hypothesis, and what measurements you would require to do so.

Courtney Burson
Courtney Burson
Numerade Educator
10:11

Problem 7

Review the history of the successful rehabilitation of the endangered Lord Howe Island woodhen (Tricholimnas sylvestris) on Lord Howe Island in the Pacific (Caughley and Gunn $1996,$ pp. $75-81$ ). Discuss the reasons for the success of this project and the general principles it illustrates for conservation problems

Leah Lampen
Leah Lampen
Numerade Educator
02:50

Problem 8

One possible impact of invasive species is called "invasional meltdown" to describe situations in which invasive species facilitate more invasive species, thus accelerating the impact of invasives (Simberloff 2006 ). The best case so far described is the invasion of yellow crazy ants on Christmas Island (O'Dowd et al. 2003). Review this case and the message it provides for conservation biology.

Victoria Karaluz
Victoria Karaluz
Numerade Educator
01:12

Problem 9

Discuss the assumptions underlying the nested subset model of patch occupancy (see Figure 14 ). Explain what ecological processes could produce "holes" in the data matrix (see Table 5 ), and what processes could produce "outliers."

Carson Merrill
Carson Merrill
Numerade Educator
02:23

Problem 10

Amphibian populations have been declining in many parts of the world during the past 20 years (Stuart et al 2003 . Discuss the hypotheses proposed to explain these declines and suggest a research plan to rescue these populations. Davidson and Knapp (2007) discuss multiple causes for these declines, and Whitfield et al. (2007) provide a global overview of the problem.

Victoria Karaluz
Victoria Karaluz
Numerade Educator