IUCN Red List Analysis: Unit V Threatened Species Worksheet

This homework assignment focuses on the study of threatened species using the IUCN Red List. The student selected the Georgia Pigtoe, a critically endangered freshwater mussel, for analysis. The assignment requires identifying the species' common and scientific names, Red List category, and habitat, which includes freshwater streams and rivers. The student details threats to the species, primarily human-caused factors such as agriculture, development, and pollution. Population trends, density-dependent and independent factors, and the impact of climate change are also addressed. Furthermore, the assignment explores conservation actions, the concept of an extinction vortex, and whether the species is a keystone species. Finally, the student discusses potential ecological changes if the species were to become extinct, considering the effects on the food web and interactions like mutualism and predation.

Unit V Homework Assignment Worksheet—Threatened Species
Introduction
This unit is about ecology, the study of the interaction between living species. As we discussed in the unit
lesson, all species are dependent on one another—even trees need birds to eat the insects that want to
devour the trees. Some trees, like oaks, need squirrels to plant their acorns. Consequently, when you
study a species in the Red List for this assignment, be aware that somewhere along the line, this species
is important.
Materials Needed:
A computer with Internet access
Directions:
1. Click on https://www.iucnredlist.org (or copy and paste the URL into your browser) to go to the IUCN
Red List of Threatened Species website. The site may load somewhat slowly, so be patient.
2. Take a moment to peruse the website. Scroll down and look at a few of the animals and the news
articles.
3. On the Redlist home page, type the state in which you reside in the search box where it says “names -
common, scientific, regions etc…” (see below). A list of species will appear in a drop-down menu. You
can select “more species” from the drop-down menu to see more. You will want to study a species that
lives near you and upon which you might be able to have an impact.
NOTE: Make sure that the species you pick actually lives near you. For example, the “South Georgia
Diving-petrel” does not live in the state of Georgia in the United States, but rather on the South Georgia
Island near Antarctica. To confirm that your chosen species lives near you, select the “Geographic range
in detail” link beneath the map that appears.
4. Do not pick a species that has a category of “least concern,” “data deficient,” or “not evaluated.”
What Information Did You Find?
Study the available information about your species and answer the following questions (in your own
words—do not copy and paste from the site). When reviewing information on the site, look for “in detail” to
get a more comprehensive picture (e.g., population in detail, conservation in detail, and so on).
Respond to each question in the blank area following it. Each area will expand as necessary.
1. What is the common name and the scientific name of your species?
Common Name - Georgia Pigtoe.
Scientific Name - Pleurobema hanleyianum.

2. What is your species’ Redlist category? (For example, endangered, critically endangered, or one
of the others.)
Redlist category – Critically Endangered.
3. What kind of habitat does the species inhabit? Briefly describe the habitat/biome.
a. Tell what other plants and animals live in this biome.
This species lives generally lives wetlands. To be specific, it lives in freshwater inland waters
such as streams, creeks and rivers. They are generally found in the medium sized river with a
good current and gravel or sand substrate. River with good current is their most suitable habitat.
Other plants and animals lives in this biome are: Altahama Skullcap, Aaron's Rod, Bog
Sneezeweed, newts, salamanders, hellbenders and frogs.
4. What are some of the threats to the species?
a. Which threats are caused by humans?
Threats of this species are:
 Agriculture and aquaculture such as livestock farming
 Commercial and residential development such as housing
 Modifications of Natural system such as construction of damn
 Pollution such as urban and domestic waste water.
All of the above mentioned threats are caused by humans.
5. Does human population growth adversely impact this species?
Yes, human population growth has adversely affected this species. Owing to the housing and
urban development caused the habitat loss of this species which led to the decline of this species
population. Growth of human population also increase the land surface runoff. Land surface
runoff also affects the quality of the water in which the species lives in.
6. Consider the population of your species.
a. What is the estimated population of the organism and how was it measured?
b. What is the population trend?
a) This species thought to be extinct in few years back. Presently, this species found in only one
or two locations only. At the moment, there are only handful of shells lives and found in the rivers
of Georgia.
U.S. Fish and Wildlife Service initiated survey was used for the measurement of the number of
the species.
b) The population trend of this species is that it is ‘Decreasing’. Since, 1950’s to 1970’s, the
species population has been decreased over 80 percent.
7. Consider the habitat for your species.
a. What might be some density dependent factors?
b. What might be some density independent factors?
c. Briefly list ways in which climate change might be affecting this creature’s habitat.
d. List two actions people can do to preserve this species and biodiversity.

a) Density dependent factors for this species’ habitat are:
 Agriculture and aquaculture such as livestock farming
 Commercial and residential development such as housing
 Pollution such as urban and domestic waste water.
b) Density independent factors for this species’ habitat are:
 Modifications of Natural system such as construction of damn
c) This species vulnerable to the natural and catastrophic events like flood scour and drought.
Climate change is primarily responsible for above mentioned catastrophic events. Hence, climate
change can effect this species habitat by the events like scour and drought.
d) Actions that can be taken to preserve this species and biodiversity are:
 Establishment of National Wildlife refuge for this species
 Watershed management as this species primary habitat is inland freshwater.
 Further studies to confirm this species taxonomy, population and genetics.
8. List some things that can be done to protect this species’ habitat.
Action that can be taken to protect this species’ habitat are:
 Land and water (site) protection of this species’ habitat
 Land and water (site) management of this species’ habitat
 Regular and periodic monitoring of Population size, trends and distribution of this
species.
9. Is your species in an extinction vortex? Explain.
Extinction vortex can be defined as a model which suggest events that a small population gets
spiraled towards extinction due to the external factors. Georgia Pigtoe had a small population and
it spiraled towards extinction due to factors like Agriculture and aquaculture, commercial and
residential development, pollution such as urban and domestic waste water. Hence, it can be
stated that this species in an extinction vortex.
Written Response Questions
10. Discuss what it means for a species to be a keystone species, and give an example.
a. Is the species you picked on the Redlist a keystone species? Why, or why not?
Keystone species can be defined as species which had significant effect on the particular
ecosystem if the species go extinct. The species that was selected for this assignment is Georgia
Pigtoe. If this species had gone extinct, no significant detrimental effect would be noticeable in
the ecosystem. Therefore, Georgia Pigtoe is not a Keystone species.
11. If your species becomes extinct, what changes might you expect to occur in its biome and the
food web?
a. Which species might benefit if your species becomes extinct, and why would that/those
species benefit?
b. Which species would be harmed if your species becomes extinct?
c. Comment on possible interaction of these on your species:
i. Mutualism (page 352 in your textbook)

ii. Predation (page 352 in your textbook)
iii. Competition (page 353 in your textbook)
a) The species that might benefit, if the species goes extinct are – phytoplankton, fungi and
bacteria.
b) The species that would be harmed, if the species goes extinct are – invertebrate and fish lives
in the same ecosystem.
c) There is a possible ‘Mutualism’ present between this species and the invertebrate and fish lives
in the same ecosystem as mussel keeps the water clean for them by eating the phytoplankton,
fungi and bacteria.