2.1 Study Guide Flashcards
What is population?
The number of a singular species in a specified area.
What characteristics make up the individuals in a population?
-Same species
-Same area
-Same time
-Rely on the same resources
-Interact
-Interbreed
What is population density?
The actual number of individuals in a given area.
What is population distribution?
The placement and organization of the individuals in a specified area.
What is clumped distribution?
The individuals are organized in patches.
Ex: Wolf pack
Why would populations be in a clumped pattern?
-Resource location
-Social behavior/Important social networks
-large group protection against predators
What is random distribution?
The individuals are positioned independent from one another. Resources are abundant.
Ex: Wild flowers
Why would populations be in a random pattern?
-Resources are abundant
-No social interaction
-No strong social connections or networks
-Low resource requirement
What is uniform distribution?
The individuals are organized in a repeated pattern.
Ex: Penguins, corn fields, etc.
Why would individuals be in a uniform pattern?
-May result from territoriality
-Scarce resources
-Competition between or among populations
-Ensures that individuals get the proper resources
How do you calculate population density?
Number of individuals in a given area/the given area
Ex: 16 chickens/10 square feet
Calculate the population density:
There are 50 cows grazing in a portion of the pasture that has an area of 400 feet squared. What is the population density of this portion of the pasture?
Density: 0.125 cows/1 square foot
Find the population size using a quadrat:
You take 10 area samples of a sunflower field. Each of these samples has an area of 1 square meter. The sum of the sunflowers sampled is 29. There are 100 one meter grids in the field. Estimate the population size of the sunflowers.
Estimation: 290 sunflower plants in the whole field.
Find the population size using mark-and-recapture:
A biologist originally marked 80 butterflies in William Park. Over a month-long period, butterfly traps caught 200 butterflies. Of those, 40 were found to have tags. Based on this information, what is the estimated population size of the butterflies in William Park? Remember: Total population size/total number marked = total number recaptured/total number marked in recapture.
Estimation: There are approximately 400 butterflies in William Park.
Predict the population density and distribution of a herd of elephants:
There are 60 elephants in a sample area of 2 miles squared. The elephants are clumped together in small groups and are roaming the land. There are groups of lions that are prowling nearby. Estimate the population density for this group of elephants and predict what kind of distribution this is.
The elephant population has a density of 30 elephants/square mile.
The population distribution is clumped because the elephants are in patches. They are staying in these groups to protect themselves from the lions.
