U.S. Fish & Wildlife Service

A Review of the Status of Greater and Lesser Scaup In North America

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%


56 63 70 77 84 91 98

Year

0

100

200

300

400

500

600

700

800

Thousands

Population Estimate

56 63 70 77 84 91 98

Year

0123456789

10

Millions

Population Estimate


61 66 71 76 81 86 91 96

Year

0

50

100

150

Thousands

Harvest - U.S.

0

1

2

3

Immatures/Adult Ratio

61 68 75 82 89 96

Year

0

20

40

60

80

Harvest

Thousands

0

1

2

3

4

5

Immatures/Adult Ratio

Atlantic Flyway

61 68 75 82 89 96

Year

0

20

40

60

80

Harvest

Thousands

0

1

2

3

4

5

Immatures/Adult Ratio

Mississippi Flyway

61 68 75 82 89 96

Year

0

20

40

60

80

Harvest

Thousands

0

5

10

15

20

25

30

Immatures/Adult Ratio

Central Flyway

61 68 75 82 89 96

Year

0

20

40

60

80

Harvest

Thousands

0

2

4

6

8

Immatures/Adult Ratio

Pacific Flyway
61 66 71 76 81 86 91 96

Year

0

100

200

300

400

500

600

700

800

Thousands

Harvest - U.S.

0

1

2

3

Immatures/Adult Ratio

61 68 75 82 89 96

Year

0

100

200

300

400

500

Harvest

Thousands

0

1

2

3

4

5

6

Immatures/Adult Ratio

Mississippi Flyway

61 68 75 82 89 96

Year

0

100

200

300

400

500

Harvest

Thousands

0

1

2

3

4

5

6

Immatures/Adult Ratio

Atlantic Flyway

61 68 75 82 89 96

Year

0

100

200

300

400

500

Harvest

Thousands

0

1

2

3

4

5

6

Immatures/Adult Ratio

Central Flyway

61 68 75 82 89 96

Year

0

100

200

300

400

500

Thousands

Harvest

0

1

2

3

4

5

6

Immatures/Adult Ratio

Pacific Flyway

69 72 75 78 81 84 87 90 93 96

Year

0

0.5

1

1.5

2

2.5

Sex Ratio

69 72 75 78 81 84 87 90 93 96

Year

0

0.5

1

1.5

2

2.5

Sex Ratio

Atlantic Flyway

69 72 75 78 81 84 87 90 93 96

Year

0

0.5

1

1.5

2

2.5

Sex Ratio

Mississippi Flyway

69 72 75 78 81 84 87 90 93 96

Year

0

0.5

1

1.5

2

2.5

Sex Ratio

Pacific Flyway

69 72 75 78 81 84 87 90 93 96

Year

0

1

2

3

4

Sex Ratio

Atlantic Flyway

69 72 75 78 81 84 87 90 93 96

Year

0

1

2

3

4

Sex Ratio

69 72 75 78 81 84 87 90 93 96

Year

0

1

2

3

4

Sex Ratio

Mississippi Flyway

69 72 75 78 81 84 87 90 93 96

Year

0

1

2

3

4

Sex Ratio

Central Flyway

69 72 75 78 81 84 87 90 93 96

Year

0

1

2

3

4

Sex Ratio

Pacific Flyway
60 65 70 75 80 85 90 95

Year

0

1

2

3

4

5

6

7

8

9

Millions

Hunter Days

Atlantic

Mississippi

Central

Pacific

61 68 75 82 89 96

Year

0

100

200

300

400

500

600

700

800

Thousands

Scaup Harvest

4

6

8

10

12

14

16

18

Millions

Hunter Days

Greater Scaup Harvest

Lesser Scaup Harvest

Hunter Days
.

69 78 87 96

Year

0

50

100

150

Thousands

Harvest - Canada

012345

Immatures/Adult Ratio

69 78 87 96

Year

0

50

100

150

Thousands

Harvest - Canada

012345

Immatures/Adult Ratio

74 78 82 86 90 94

Year

0

50

100

150

200

250

Thousands

Greater Scaup Harvest

Canada

United States

74 78 82 86 90 94

Year

0

100

200

300

400

500

600

700

800

900

Thousands

Lesser Scaup Harvest

Canada

United States
74 78 82 86 90 94

Year

0

20

40

60

80

100

Percent

Greater Scaup Harvest

Canada

United States

74 78 82 86 90 94

Year

0

20

40

60

80

100

Percent

Lesser Scaup Harvest

Canada

United States


55 62 69 76 83 90 97

Year

0

500

1000

1500

2000

2500

3000

3500

Thousands

Pacific

Central

Mississippi

Atlantic


N

$ $ $

N

N
J
34567

0.1 0.2 0.3 0.4 0.5

Spring Population Estimate (Millions)

Variance

N

$$

(
$

$
1960 1970 1980 1990

34567

1961–1998 Multiplicative Model

Population (millions)

. . . . . . . .

.

. .

.

. . . . . .

.

. . .

. .

. . . . . . . . . . . . .

.

1960 1970 1980 1990

34567

1983–1998 Multiplicative Model

Population (millions)

. .

.

. . . . . . . . . . . .

.

o Observed Estimates

Smoothed Estimates

95 Percent CIs

1960 1970 1980 1990

34567

1983–1998 Arithmetic Model

Year

Population (millions)

.

.

.

. . . . . . . . . . . .

.
N

$

N

N

N

N

N

N

N

N

N

N

N

N