Corridors Case Study
Part 1
1. Why is it more difficult for top carnivores to obtain sufficient energy resources than it is for animals lower on the food chain?
The lower the animal in the food chain, the more energy is given. The most energy comes from plants, but carnivores only eat meat so there would be less energy given.
2. What sorts of genetic changes are more common in smaller populations than large ones? Are these problematic and, if so, how?
Genetic Drift which happens when a genetic change is passed forward through the generations but is not expressed as part of the phenotype. But the impact with genetic drift is that the entire genotype is under selective pressure or not.
3. What term or concept is used to describe the population size of breeding animals (not the total population size)? What factors discussed above might reduce the number of breeding jaguars below the total number?
Effective population size is the term. Size of population and mutations that get passed on would reduce the number of breeding jaguars below total number
4. Is it important for people to try to protect endangered species?
Yes, it is important because the endangered species could be of benefit to humans.
Part 2
1. What does island biogeography theory suggest about the ideal design of a nature preserve? (Think of a preserve
as a habitat island.)
To eliminate barriers and within the geographic ranges of endangered species because it might boost their survival through both greater habitat availability and increased genetic diversity
2. What are some reasons why the number and size of nature preserves are limited? In your answer, consider what
you know about both local and international pressures (social, economic, and political).
Reasons why the number and size of nature preserves are limited is because funding/cost, legality, and industry.
3. What are some examples of corridors that already exist where you live? They may not go by this name, but still serve the same function. Think about areas where typical land use changes. For example, if you live in a farming community, are there unfarmed areas that could serve as corridors? If you live in a city, which areas are not built up and could they be corridors?
An example of a corridor that already exist where I live is the Tecelote Canyon
Part 3
1. How and why might animals move between habitat patches?
Animals might move by migration. Perhaps their current habitat patch is under environmental stress forcing them to adapt or leave area
2. How and why might plants move between habitat patches?
They may be more adaptable to other areas or animals may carry them from one patch to another
3. As Haddad et al. point out, we often think of forests as “good” habitat (ideal for corridors), when they could be a
barrier. What sorts of species might Haddad and colleagues be studying for which pine forest can serve as a barrier?
Predators that are blocked off by the barrier which separates the predators from the prey.
4. What can you predict about the species Haddad and colleagues wanted to study, based on the size and vegetation of the habitat patches and corridors they used?
If the movement of species will be affect by corridor size
5. Examining habitat patches 14, 15, and 16, can you predict the type of comparison Haddad and his colleagues would make to determine whether corridors were important to the species studied? Specifically, what type of data would you collect, and in which patches, to determine whether corridors had an influence on the species of interest?
Haddad and colleagues were trying to see if corridors would affect the movement of species. You would collect migration data from all three patches and combine them to see which patches had the most migration
Part 4
1. Briefly describe the overall pattern you see in the data.
More animals use connected corridors than unconnected corridors.
2. For which species are the results significant?
Plants have the significant results.
3. Does your answer to Question #2 suggest any patterns among species types? For example, are plants different from animals or are butterflies different from bees? Describe the patterns and try to explain them according to the characteristics of the taxa involved.
Plants spread out due to wind patterns because they had a higher population movement compared to mammal species or insects.
4. Haddad and colleagues conclude that “In our study, we lack data on population viability and genetic diversity, and our dramatic increases in movement to connected patches strongly suggest, but do not demonstrate, the value of corridors.”
(a) Do you think this statement (“suggest, but do not demonstrate”) is a fair assessment of their study? Explain your answer.
No, this is not a fair assessment of their study. Their data was inconclusive and cannot directly prove the importance of corridors
(b) What other data are the researchers suggesting they need to conclusively demonstrate the importance of corridors? Do you think they are right? For example, does knowing the level of genetic variability answer questions about long-term population survival?
The researchers were also collecting data for population size and biodiversity. They are right as if corridors can protect populations of different species, than this can be monitored to show the importance of corridors
(c) How could researchers collect these data? Give suggestions for several of the species in their study.
Researchers collect data using quadrat. Which is to check the distribution of several species over the area.
Researchers collect data using quadrat. Which is to check the distribution of several species over the area. Suggestions of species are ones that do not compete, which might affect the biodiversity in the area
5. Based on what you know from the Haddad et al. study, what would be the effects of a border fence on the population of jaguars mentioned in Part I? Explain your thinking. Specify any additional information you need in order to make sound predictions.The border fence provided negative impacts to the population of jaguars. The fence will restrict space for jaguars and increase competition which will lead to a decline and increase in the population number.
1. Why is it more difficult for top carnivores to obtain sufficient energy resources than it is for animals lower on the food chain?
The lower the animal in the food chain, the more energy is given. The most energy comes from plants, but carnivores only eat meat so there would be less energy given.
2. What sorts of genetic changes are more common in smaller populations than large ones? Are these problematic and, if so, how?
Genetic Drift which happens when a genetic change is passed forward through the generations but is not expressed as part of the phenotype. But the impact with genetic drift is that the entire genotype is under selective pressure or not.
3. What term or concept is used to describe the population size of breeding animals (not the total population size)? What factors discussed above might reduce the number of breeding jaguars below the total number?
Effective population size is the term. Size of population and mutations that get passed on would reduce the number of breeding jaguars below total number
4. Is it important for people to try to protect endangered species?
Yes, it is important because the endangered species could be of benefit to humans.
Part 2
1. What does island biogeography theory suggest about the ideal design of a nature preserve? (Think of a preserve
as a habitat island.)
To eliminate barriers and within the geographic ranges of endangered species because it might boost their survival through both greater habitat availability and increased genetic diversity
2. What are some reasons why the number and size of nature preserves are limited? In your answer, consider what
you know about both local and international pressures (social, economic, and political).
Reasons why the number and size of nature preserves are limited is because funding/cost, legality, and industry.
3. What are some examples of corridors that already exist where you live? They may not go by this name, but still serve the same function. Think about areas where typical land use changes. For example, if you live in a farming community, are there unfarmed areas that could serve as corridors? If you live in a city, which areas are not built up and could they be corridors?
An example of a corridor that already exist where I live is the Tecelote Canyon
Part 3
1. How and why might animals move between habitat patches?
Animals might move by migration. Perhaps their current habitat patch is under environmental stress forcing them to adapt or leave area
2. How and why might plants move between habitat patches?
They may be more adaptable to other areas or animals may carry them from one patch to another
3. As Haddad et al. point out, we often think of forests as “good” habitat (ideal for corridors), when they could be a
barrier. What sorts of species might Haddad and colleagues be studying for which pine forest can serve as a barrier?
Predators that are blocked off by the barrier which separates the predators from the prey.
4. What can you predict about the species Haddad and colleagues wanted to study, based on the size and vegetation of the habitat patches and corridors they used?
If the movement of species will be affect by corridor size
5. Examining habitat patches 14, 15, and 16, can you predict the type of comparison Haddad and his colleagues would make to determine whether corridors were important to the species studied? Specifically, what type of data would you collect, and in which patches, to determine whether corridors had an influence on the species of interest?
Haddad and colleagues were trying to see if corridors would affect the movement of species. You would collect migration data from all three patches and combine them to see which patches had the most migration
Part 4
1. Briefly describe the overall pattern you see in the data.
More animals use connected corridors than unconnected corridors.
2. For which species are the results significant?
Plants have the significant results.
3. Does your answer to Question #2 suggest any patterns among species types? For example, are plants different from animals or are butterflies different from bees? Describe the patterns and try to explain them according to the characteristics of the taxa involved.
Plants spread out due to wind patterns because they had a higher population movement compared to mammal species or insects.
4. Haddad and colleagues conclude that “In our study, we lack data on population viability and genetic diversity, and our dramatic increases in movement to connected patches strongly suggest, but do not demonstrate, the value of corridors.”
(a) Do you think this statement (“suggest, but do not demonstrate”) is a fair assessment of their study? Explain your answer.
No, this is not a fair assessment of their study. Their data was inconclusive and cannot directly prove the importance of corridors
(b) What other data are the researchers suggesting they need to conclusively demonstrate the importance of corridors? Do you think they are right? For example, does knowing the level of genetic variability answer questions about long-term population survival?
The researchers were also collecting data for population size and biodiversity. They are right as if corridors can protect populations of different species, than this can be monitored to show the importance of corridors
(c) How could researchers collect these data? Give suggestions for several of the species in their study.
Researchers collect data using quadrat. Which is to check the distribution of several species over the area.
Researchers collect data using quadrat. Which is to check the distribution of several species over the area. Suggestions of species are ones that do not compete, which might affect the biodiversity in the area
5. Based on what you know from the Haddad et al. study, what would be the effects of a border fence on the population of jaguars mentioned in Part I? Explain your thinking. Specify any additional information you need in order to make sound predictions.The border fence provided negative impacts to the population of jaguars. The fence will restrict space for jaguars and increase competition which will lead to a decline and increase in the population number.