Exam 23: Conservation Biology

Refer to the figure. The figure shows the current level of threat faced by each biome from a variety of sources. The arrows show the direction whether the threat is decreasing, continuing, increasing, or rapidly increasing. -In which biome does habitat loss pose a very high and rapidly increasing risk?

Researchers have helped increase the abundance of the red-cockaded woodpecker by

Suppose the background extinction rate of birds is 5 per 1,000 years. During the twentieth century, 17 birds went extinct. The extinction rate of birds is now about how many times the background rate?

There are many threats to Earth's biodiversity, and these threats are constantly changing in type and severity. Based on currently evolving threats, what trends are likely in the future of conservation biology? That is, what fields of research and/or methods of maintaining biodiversity might become more important in the near future?

For any given species or larger taxonomic group, such as mammals, extinction is most likely caused by

Suppose the background extinction rate of amphibians is 8 per 1,000 years and that during the twentieth century, 20 amphibians went extinct. The extinction rate of amphibians is now about how many times the background rate?

List several reasons that it might be important to preserve biodiversity. Which of these reasons do you think is most important and why?

Describe some ways in which overexploitation affects biodiversity loss, with examples.

In the late nineteenth and twentieth centuries, several massive losses of organisms occurred. Bison, passenger pigeons, and many other birds declined rapidly or went extinct. Most deciduous forests and prairies were replaced by agricultural fields. These changes led to

Genetic rescue of endangered species would be most useful in a species that

Refer to the figure. The figure shows changes in biodiversity of different groups on continents versus oceanic islands. Based on this information, it can be said that, as compared to continents, oceanic islands

Which study would best fit into the science of conservation biology?

Currently, about one percent of all known species of organisms are threatened with extinction. This percentage is likely to be an underestimate because many species

Which of these is an example of taxonomic homogenization?

The vaquita, a tiny marine porpoise, is found only in the northern Gulf of California, and is the most endangered marine mammal in the world. There are only 10-15 individuals left. They are caught and killed in gillnets used to capture the totoaba, a fish that is caught illegally and sold in China. Give reasons for and against using ex situ conservation to prevent extinction of the vaquita.

Biologists brought California condors back from the threat of extinction by

Refer to the figure. The figure shows the current level of threat faced by each biome from a variety of sources. According to the figure, what is the most serious threat now facing marine ecosystems?

Off-road mountain vehicles and mountain bikes trample various plant species in the Santa Cruz Mountains and hills of California. Although plants still persist in the area and many species are unaffected, habitat quality for many species has declined. This is an example of habitat

Scientists have great difficulty determining how rapidly Earth's eukaryotic species are going extinct. This is primarily because

The introduction of invasive plant species all over the world and the resulting extinction of native, endemic species has led to