Podcast
Questions and Answers
What does a demographic study typically measure in populations?
What does a demographic study typically measure in populations?
- Growth rates, survival, and reproduction (correct)
- Migration patterns based on weather
- The impact of climate change on habitats
- Genetic variation among individuals
What is one of the key findings from satellite tracking of Magellanic penguins?
What is one of the key findings from satellite tracking of Magellanic penguins?
- Penguins can incubate eggs without foraging
- Penguins only forage within 100 km of their breeding colonies
- Penguins forage up to 600 km from their breeding colonies (correct)
- Penguins do not exhibit migratory behavior
According to the IUCN Red List criteria, what indicates that a species is critically endangered?
According to the IUCN Red List criteria, what indicates that a species is critically endangered?
- Populations have increased by over 50% in the last decade
- The species exists in only one country
- The species has a wide geographical distribution with no known threats
- The population has declined by ≥90% over the last 10 years (correct)
What does 'total geographical range' refer to in the context of conservation categories?
What does 'total geographical range' refer to in the context of conservation categories?
Which of the following threats could contribute to a species being classified under the ‘critically endangered’ category?
Which of the following threats could contribute to a species being classified under the ‘critically endangered’ category?
What is the primary purpose of conducting a census on a population?
What is the primary purpose of conducting a census on a population?
Which statement accurately describes the Lincoln-Peterson index?
Which statement accurately describes the Lincoln-Peterson index?
Why are orangutans particularly challenging to census in Borneo?
Why are orangutans particularly challenging to census in Borneo?
What is a potential limitation of using a census for certain species?
What is a potential limitation of using a census for certain species?
What is an important factor when conducting a population survey?
What is an important factor when conducting a population survey?
Flashcards
Population Census
Population Census
Counting all individuals in a population to determine population size and trends (stable, increasing or decreasing)
Population Survey
Population Survey
Repeated sampling of individuals to estimate population size. Uses statistical methods to extrapolate the total population size.
Lincoln-Peterson Index
Lincoln-Peterson Index
A method for estimating population size by marking and recapturing individuals. Calculates population estimate by using a ratio of marked to unmarked.
Population Monitoring
Population Monitoring
Signup and view all the flashcards
Population Decline
Population Decline
Signup and view all the flashcards
Demographic Study
Demographic Study
Signup and view all the flashcards
Satellite Tracking
Satellite Tracking
Signup and view all the flashcards
IUCN Red List
IUCN Red List
Signup and view all the flashcards
Red List Criteria
Red List Criteria
Signup and view all the flashcards
Critically Endangered
Critically Endangered
Signup and view all the flashcards
Study Notes
Conserving Populations and Species
-
The American burying beetle's historical range is shown on a map, along with current locations, captive populations, confirmed counties, and attempted reintroduction sites.
-
Techniques for learning a population's status to conserve it include tracking population changes (declines or increases) to enable protective strategies.
Monitoring Populations
-
Census involves counting individuals in a population and repeating the process to determine if the population is stable, increasing, or decreasing. This method works best with relatively easy-to-track organisms.
-
An example of censusing is the tracking of Hawaiian monk seal populations on Green and Tern Islands. The data shows population declines, hinting at potential extinction risk.
Survey Methods
-
Repeated sampling of individuals to get population statistics, for example, the Lincoln-Peterson index. This involves capturing and marking individuals in a first sample. Then, a second sample is taken to determine the ratio of marked vs. unmarked individuals, which helps estimate the total population.
-
The formula for estimating population size (N) based on the Lincoln-Peterson index is: N = (M * C) / R. Where M is the number marked in the first sample; C is the total caught in the second sample; and R is the number that were recaptured.
Demographic Study
-
This involves following individuals of known ages to track growth rates, survival, and reproduction patterns.
-
Satellite tracking of Magellanic penguins shows that they forage far from breeding colonies.
Conservation Categories
- The IUCN uses a system to classify species based on their conservation status. This system assesses, among other things, extinction risk and provides categories like Extinct (EX) critically endangered (CR), vulnerable (VU), Near threatened (NT), and Least concern (LC).
Red List Criteria
- Criteria for critically endangered status include a population decrease of at least 90% in 10 years or three generations, limited geographic range, predicted habitat loss, a decline of at least 25% in three years or one generation, a population count of fewer than 250 breeding individuals, and 50 or fewer mature individuals, or an estimated 50% probability of extinction within 10 years or 3 generations.
Captive Breeding Programs
- California condor chicks are raised in captivity by researchers using puppets that look like adult birds.
The Living Planet Index
- The Living Planet Index tracks the trends in populations of vertebrates. The average abundance of vertebrate species worldwide has decreased by 68% since 1970.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
