Daily Response

1) What is the difference between immigration and emigration?2) What is a limiting factor?3) Name 3 limiting factors.4) What happens to a population when the birth rate is bigger

than the death rate?5) What happens to a population when the death rate is bigger

than the birth rate?

Determining Population Size

4 different techniques scientists use to estimate the size of populations

Direct Observation

What is the population of penguins?Count them.

Direct Observation

What is the population of seagulls?Count them.

Indirect Observation

What is the population of rabbits?Since you can not see the rabbits you have to count the number of rabbit holes. Next, estimate how many rabbits you think live in each hole. Multiply the numbers to get the population size.

Indirect Observation

What is the population of birds?Since you can not see the birds you have to count the number of nests. Next, estimate how many birds you think live in each nest. Multiply the numbers to get the population size.

Sampling

What is the population of ants?Take a small section of the ant hill and count the ants. Find the total area of the ant hill. Follow the equation below to find the total population of ants. There are 20 ants in one square cm.The ant hill is 100 square cm.

20 ants = ? 1 cm 100 cm

Sampling

A biologist collected 1 gallon of pond water and counted 50 paramecium. The pond holds 2,000 gallons of water. What is the population of paramecium?

50 paramecium = ?1 gal 2,000 gal

Mark and Recapture

This method is most useful when dealing with an animal population that moves around

1)individual organisms are captured (unharmed)2) They are counted and marked or tagged and

then released back into the environment3) After some time some are recaptured and we

count how many have the mark and how many do not

Mark and Recapture

http://www.youtube.com/watch?v=AuIRdK5IfNo&feature=player_detailpage

http://wwf.panda.org/what_we_do/where_we_work/arctic/wildlife/polar_bear/tracker

/

http://www.youtube.com/watch?v=lKyj7gEAAS8

http://www.youtube.com/watch?v=VRTNQpXEZE4

Journal Entry

Explain the four ways we determine population size. Then write your own example for each one.

(It may not be the examples from the book , outline or power point.)

Direct Observation

Indirect Observation

Sampling Mark and Recapture

Explanation - Explanation - Explanation - Explanation -

Example - Example - Example - Example -