St Paul Alaska
Reindeer Population
St. Paul Facts
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200 miles from mainland Alaska
44 square miles
Good amount of vegetation
No Predators for Reindeer
No hunting of Reindeer
Book Work
 Answers the questions from your book,
on pg. 560-561.
 Question 1, A-F
 Question 2, A, C, D, H
Problem #1, A (pg. 117 in
Notebook)
1) In 1911 the population was 25 reindeer. What
was the size of the population in 1920? What
was the difference in the number of reindeer
between 1911 and 1920? What was the
average annual increase in the reindeer from
1911-1920?
Use your graph provided
To the nearest 100th
You should of got
1920= about 300 reindeer
1911-1920= increase of 250
Average annual increase was about 28
250 (# of increase) / 9 (years) = average
annual increase in reindeer
Problem B
 What was the difference in population
size between the years 1920 and 1930?
What was average annual increase in the
number of reindeer in the years between
1920 and 1930?
You should of got
1930= 500 reindeer
1920-1930= increase of 200
Average annual increase was about 20
200 (# of increase) / 10 (years) = average
annual increase in reindeer
Problem C
 What was the average annual increase in
the number of reindeer in the years
between 1930 and 1938?
You should of got
 In 1938 there were 2000 reindeer.
1930 There were 500
1930-1938 annual increase was 187
1500 (# of increase) / 8 (years) = 187 per
year
Problem D
 During which of the three time spans did
the reindeer population increase the
most?
1911-1920
1920-1930
1930-1938
You should of got
 The increase was the greatest from
1930-1938
Problem E
 What was the greatest number of
reindeer found on the island, and what
year did it occur?
You should of got
 The greatest number was 2000 in 1938.
Problem F
In 1950 only 8 reindeer were still alive.
What is the average annual decrease in
the number of reindeer in the years
between 1938 and 1950?
You should of got
 1938-1950=decrease of 1,992 deer
1992 # of difference / 12 years =
166 deer dying per year
Problem #2, A (pg. 118)
 St. Paul Island is more than 323 km (200
miles) from the mainland. Could leaving
or arriving at the island have played a
major role in determining the size of the
reindeer population? Explain your
answer.
You should have got…
 Probably not. St. Paul Island is more
than 323 km from the mainland.
Reindeer are strong swimmers, but the
distance is to great for emigration or
immigration to have a major effect.
Problem B
 Didn’t have to do
Problem C
 St. Paul Island is about 106 km2 (41
square miles). What effect might 2000
reindeer have on the island and its
vegetation?
You should have got…
 Overgrazing, death of plants, destruction
of habitats, accumulation of wastes.
Problem D
 Consider all the factors an organism
requires to live. What might have
happened on the island to cause the
change in population size between 1938
and 1950?
You should have got…
 Overgrazing resulted in the death of
plants and insufficient food. Weakened
by a lack of food, the reindeer were prey
to disease and the reproductive rate
could have declined drastically.
Problem E, F, G
 Didn’t have to do…
Problem H
 What does this study tell you about
unchecked population growth? What
difference might hunters or predators
have made?
You should have got…
 Natural controls take effect and can have
drastic results, such as the total
population dying out. Predators and
hunters might have controlled the
population, preventing exponential
growth and the destruction of the
environment, thus maintaining the carry
capacity of the environment.
Critical Thinking
(pg. 118-119)
Imagine you were the scientists in charge
of St. Paul Island and the reindeer.
1. What would you have done to sustain
the population of reindeer?