Ecology HS – Read and interpet simple data & draw on graph, Answer Questions on pdf ATTACHMENTS
Ensure your answers and data accurate and MAKE SURE YOU LABE THINGS AS DIRECTED ON THE HANDOUTS IN THE PARAGRAPHS…PLEASE READ AND COMPLETE ALL TASKS ON ATTACHED AS REQUIRED
REAS ALL PARAGRAPHS AS THERE IS REQUIREMENTS IN EACH
EMBED Excel.Sheet.8
Hares and Lynx Populations
0
10
20
30
40
50
60
70
80
90
1900
1902
1904
1906
1908
1910
1912
1914
1916
1918
1920
Year
Number of pelts in thousands
Hares (x1000)
Lynx(x1000)
_1033671615.xls
Chart1
1900 1900
1901 1901
1902 1902
1903 1903
1904 1904
1905 1905
1906 1906
1907 1907
1908 1908
1909 1909
1910 1910
1911 1911
1912 1912
1913 1913
1914 1914
1915 1915
1916 1916
1917 1917
1918 1918
1919 1919
1920 1920
Hares (x1000)
Lynx(x1000)
Year
Number of pelts in thousands
Lynx and Hare Populations
30
4
47.2
6.1
70.2
9.8
77.4
35.2
36.3
59.4
20.6
41.7
18.1
19
21.4
13
22
8.3
25.4
9.1
27.1
7.4
40.3
8
57
12.3
76.6
19.5
52.3
45.7
19.5
51.1
11.2
29.7
7.6
15.8
14.6
9.7
16.2
10.1
24.7
8.6
Sheet1
Year Hares (x1000) Lynx(x1000) H0 30
1900 30 4 L0 4
1901 47.2 6.1 a1 0.5
1902 70.2 9.8 a2 0.02
1903 77.4 35.2 b1 0.9
1904 36.3 59.4 b2 0.03
1905 20.6 41.7
1906 18.1 19
1907 21.4 13
1908 22 8.3
1909 25.4 9.1
1910 27.1 7.4
1911 40.3 8
1912 57 12.3
1913 76.6 19.5
1914 52.3 45.7
1915 19.5 51.1
1916 11.2 29.7
1917 7.6 15.8
1918 14.6 9.7
1919 16.2 10.1
1920 24.7 8.6
Year Hares Lynx
1900 30000 4000
1901 47200 6100
1902 70200 9800
1903 77400 35200
1904 36300 59400
1905 20600 41700
1906 18100 19000
1907 21400 13000
1908 22000 8300
1909 25400 9100
1910 27100 7400
1911 40300 8000
1912 57000 12300
1913 76600 19500
1914 52300 45700
1915 19500 51100
1916 11200 29700
1917 7600 15800
1918 14600 9700
1919 16200 10100
1920 24700 8600
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Hares (x1000)
Lynx(x1000)
Year
Number of pelts in thousands
Lynx and Hare Populations
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1900 1900
1901 1901
1902 1902
1903 1903
1904 1904
1905 1905
1906 1906
1907 1907
1908 1908
1909 1909
1910 1910
1911 1911
1912 1912
1913 1913
1914 1914
1915 1915
1916 1916
1917 1917
1918 1918
1919 1919
1920 1920
Hares (x1000)
Lynx(x1000)
Year
Number of pelts in thousands
Hares and Lynx Populations
30
4
47.2
6.1
70.2
9.8
77.4
35.2
36.3
59.4
20.6
41.7
18.1
19
21.4
13
22
8.3
25.4
9.1
27.1
7.4
40.3
8
57
12.3
76.6
19.5
52.3
45.7
19.5
51.1
11.2
29.7
7.6
15.8
14.6
9.7
16.2
10.1
24.7
8.6
Sheet1
Year Hares (x1000) Lynx(x1000) H0 30
1900 30 4 L0 4
1901 47.2 6.1 a1 0.5
1902 70.2 9.8 a2 0.02
1903 77.4 35.2 b1 0.9
1904 36.3 59.4 b2 0.03
1905 20.6 41.7
1906 18.1 19
1907 21.4 13
1908 22 8.3
1909 25.4 9.1
1910 27.1 7.4
1911 40.3 8
1912 57 12.3
1913 76.6 19.5
1914 52.3 45.7
1915 19.5 51.1
1916 11.2 29.7
1917 7.6 15.8
1918 14.6 9.7
1919 16.2 10.1
1920 24.7 8.6
Year Hares Lynx
1900 30000 4000
1901 47200 6100
1902 70200 9800
1903 77400 35200
1904 36300 59400
1905 20600 41700
1906 18100 19000
1907 21400 13000
1908 22000 8300
1909 25400 9100
1910 27100 7400
1911 40300 8000
1912 57000 12300
1913 76600 19500
1914 52300 45700
1915 19500 51100
1916 11200 29700
1917 7600 15800
1918 14600 9700
1919 16200 10100
1920 24700 8600
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Hares (x1000)
Lynx(x1000)
Year
Number of pelts in thousands
Hares and Lynx Populations
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Hare and Lynx Populations
Populations are always changing. Sometimes changes are the result of humans interfering with food webs or habitats. But even when humans do not interfere, populations will still naturally shift up and down or fluctuate. For example, let us study the relationship between the Canada lynx and its primary prey, the snowshoe hare.
To understand how the population of lynx and hares changes year to year, we need to collect information about the number of individuals in a population. Unfortunately, it is impossible to count the exact number of hares in Canada in any given year. Therefore, this information must be gained by capturing a small number of individuals and then estimating the actual number out in the wild. For over
30
0 years, the Hudson Bay Company has been involved in the fur trade in Canada. Detailed company records list the number of snowshoe hare pelts and the number of lynx pelts collected by hunters and trappers every year since the late 1700’s. A small sample of this data is presented in the table below.
Year
Hares (x1000)
Lynx(x1000)
19
00
30
4
1901
47.2
6.1
1902
70.2
9.
8
1903
7
7.4
35.2
1904
36.3
59.4
1905
20.6
41.7
1906
18.1
19
1907
21.4
13
1908
22
8.3
1909
25.4
9.1
1910
27.1
7.4
1911
40.3
8
1912
57
12.3
1913
76.6
19.5
1914
52.3
45.7
1915
19.5
51.1
1916
11.2
2
9.7
1917
7.6
15.8
1918
14.6
9.7
1919
16.2
10.1
1920
24.7
8.6
On the graph paper provided, use one color of pencil to graph the number of hares trapped each year between
1900
and 1920. Using another color, graph the number of lynx trapped.
Questions:
What patterns do you notice? Describe at least 3 patterns.
1.
2.
3.
First, let’s think about the hares.
Scientists observe that as the hare population gradually increases, they eat more and more grass and seeds each year until the food supply, particularly during the winter, becomes scarce. At that point, young hares have a difficult time finding enough food to survive and fewer babies are born. On your graph, label these periods of hardship with arrows and a short description of what is happening in your own words.
As the number of hares decreases, what do you think happens to the population of grass and seeds that the hares eat? Why?
After a few years, the hare population begins to increase. Why? On your graph, label these periods of prosperity with arrows and a short description of what is happening in your own words.
Now, let’s think about the lynx which eats the snowshoe hares.
In general, are there more lynx or more hares? Why?
Do the peaks in the lynx graph line up exactly with the peaks in the hares graph?
When the hare population increases, what happens to the lynx population? Why? On your graph, label these periods of prosperity with arrows and a short description of what is happening in your own words.
Look at 1903 and 1904. Think about what is happening to the hares at this time. Is the presence of more lynx helping the hares or hurting them? Why?
When the hare population declines, the lynxes compensate by switching to other prey such as squirrels, gophers, mice and other rodents. However, while there are other prey around, there is not enough to support a large lynx population. When females are in poor condition, fewer will breed and not all of those bred will produce litters. Litters will be smaller, and most, if not all, of the few kittens born will die soon after birth. On your graph, label these periods of hardship with arrows and a short description of what is happening in your own words.
Check to see that your graph has 2 lines AND 4 arrows with labels.
� EMBED Excel.Sheet.8 ���
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Year
Hares (x1000)
Lynx(x1000)
1900
30
4
1901
47.2
6.1
1902
70.2
9.8
1903
77.4
35.2
1904
36.3
59.4
1905
20.6
41.7
1906
18.1
19
1907
21.4
13
1908
22
8.3
1909
25.4
9.1
1910
27.1
7.4
1911
40.3
8
1912
57
12.3
1913
76.6
19.5
1914
52.3
45.7
1915
19.5
51.1
1916
11.2
29.7
1917
7.6
15.8
1918
14.6
9.7
1919
16.2
10.1
1920
24.7
8.6
_1033670858.xls
Sheet1
Year Hares (x1000) Lynx(x1000) H0 30
1900 30 4 L0 4
1901 47.2 6.1 a1 0.5
1902 70.2 9.8 a2 0.02
1903 77.4 35.2 b1 0.9
1904 36.3 59.4 b2 0.03
1905 20.6 41.7
1906 18.1 19
1907 21.4 13
1908 22 8.3
1909 25.4 9.1
1910 27.1 7.4
1911 40.3 8
1912 57 12.3
1913 76.6 19.5
1914 52.3 45.7
1915 19.5 51.1
1916 11.2 29.7
1917 7.6 15.8
1918 14.6 9.7
1919 16.2 10.1
1920 24.7 8.6
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Hares (x1000)
Lynx(x1000)
Year
Number of pelts in thousands
Lynx and Hare Populations
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