Berrien County CBC 50-Yr Visual Trends

7/29/2019 Berrien County CBC 50-Yr Visual Trends

1/31

Christmas Bird Counts in Berrien County, Michigan:

A Visual Depiction of Trends (1962-2012)

John L. Trapp

4776 Erie Drive

Buchanan, MI 49107

17 December 2012

In the following pages, I present graphs showing trends in number of individuals of 88 species

and 2 species groups that were detected in at least 25 of the 50 years, 1962-2012.

The following conventions are used in each graph:

Parenthetical numbers following species names denote number of years detected. Numbers along the bottom of the horizontal axis denote years. To determine year, add

1962 to each number (examples: 10 + 1962 = 1972, 50 + 1962 = 2012). Numbers to the left of the vertical axis denote number of birds. Diamonds depict the actual number of birds counted, and represent the sum of all

counts conducted each year regardless of the number of counts conducted.

Solid lines depict calculated linear trends, or regressions. Regression formulas yield expected number of birds in a given year, where y= number

of birds and x= year (in this instance, a number varying from 0 to 50).

R2, a number that can vary from 0.000 to 1.000, indicates how well a regression line fitsthe data. In this instance, an R

2of 0.3000 or greater is considered to indicate statistical

significance. Species determined to have been counted in substantially greater or lesser numbers in

recent years compared to earlier years are denoted with Increase ofDecline following

the species name.

Dotted lines depict 3-year moving averages.


2/31

y = 105.07x - 1129.8

R = 0.6864

-2000

-1000

0

1000

2000

3000

4000

5000

6000

7000

8000

0 10 20 30 40 50 60

Canada Goose (n=43) - Increase

y = 0.9589x - 13.032

R = 0.4784

-20

0

20

40

60

80

100

120

0 10 20 30 40 50 60

Mute Swan (n=33) - Increase

y = -0.0185x + 6.4114

R = 0.0013

0

5

10

15

20

25

30

35

40

45

0 10 20 30 40 50 60

Wood Duck (n=42)


3/31

y = 0.3392x + 4.7314R = 0.1

0

10

20

30

40

50

60

70

0 10 20 30 40 50 60

Gadwall (n=38) - Increase

y = -0.8552x + 65.547

R = 0.1698

0

20

40

60

80

100

120

140

0 10 20 30 40 50 60

American Black Duck (n=50)

y = 36.521x + 387.02

R = 0.5125

0

500

1000

1500

2000

2500

3000

0 10 20 30 40 50 60

Mallard (n=50) - Increase


4/31

y = 0.037x + 4.5559

R = 0.0022

0

10

20

30

40

50

60

0 10 20 30 40 50 60

Canvasback (n=34)

y = 0.386x - 4.3437

R = 0.2308

-10

0

10

20

30

40

50

60

70

0 10 20 30 40 50 60

Redhead (=33)

y = 0.1449x - 0.7543

R = 0.0768

-10

0

10

20

30

40

50

0 10 20 30 40 50 60

Ring-necked Duck (n=25)


5/31

y = 2.604x - 24.303

R = 0.1826

-50

0

50

100

150

200

250

300

350

0 10 20 30 40 50 60

Greater Scaup (n=32)

y = 1.8942x - 18.722

R = 0.2802

-50

0

50

100

150

200

250

300

0 10 20 30 40 50 60

Lesser Scaup (n=41)

y = 9.3423x - 87.208

R = 0.0624

-500

0

500

1000

1500

2000

2500

3000

3500

0 10 20 30 40 50 60

scaup sp. (n=33)


6/31

y = 3.3325x + 28.082R = 0.2316

0

50

100

150

200250

300

350

400

450

500

0 10 20 30 40 50 60

Bufflehead (n=50)

y = -19.311x + 1009.3

R = 0.2771

0

500

1000

1500

2000

2500

3000

0 10 20 30 40 50 60

Common Goldeneye (n=50)

y = 0.5766x + 4.2376

R = 0.2005

0

10

20

30

40

50

60

70

80

0 10 20 30 40 50 60

Hooded Merganser (n=49) - Increase


7/31

y = -2.1464x + 153.27

R = 0.028

0

200

400

600

800

1000

1200

1400

0 10 20 30 40 50 60

Common Merganser (n=49)

y = 13.036x - 181.77

R = 0.2771

-500

0

500

1000

1500

2000

0 10 20 30 40 50 60

Red-breasted Merganser (n=50)

y = 0.4313x - 5.6171

R = 0.1505

-20

0

20

40

60

80

100

120

0 10 20 30 40 50 60

Ruddy Duck (n=27)


8/31

y = -5.4009x + 233.2

R = 0.3014

-100

0

100

200

300

400

500

600

700

800

900

0 10 20 30 40 50 60

Ring-necked Pheasant (n=48) - Decline

y = -0.2497x + 11.709

R = 0.3124

-5

0

5

10

15

20

25

30

0 10 20 30 40 50 60

Ruffed Grouse (n=33) - Decline

y = 0.1437x - 0.2637

R = 0.1638

-5

0

5

10

15

20

25

30

0 10 20 30 40 50 60

Common Loon (n=32)


9/31

y = -0.0062x + 7.4792

R = 0.0001

0

5

10

15

20

25

30

35

40

0 10 20 30 40 50 60

Pied-billed Grebe (n=44)

y = 0.098x + 0.4408

R = 0.1268

0

2

4

6

8

10

12

14

16

18

0 10 20 30 40 50 60

Horned Grebe (n=36)

y = 0.3103x - 1.1739R = 0.4152

-5

0

5

10

15

20

25

30

0 10 20 30 40 50 60

Great Blue Heron (n=36) - Increase


10/31

y = 0.0806x + 1.9641

R = 0.0489

0

5

10

15

20

25

30

35

0 10 20 30 40 50 60

Northern Harrier (n=38)

y = 0.1995x + 0.6335

R = 0.54360

2

4

6

8

10

12

14

0 10 20 30 40 50 60

Sharp-shinned Hawk (n=45) - Increase

y = 0.481x + 1.4343

R = 0.604

0

5

10

15

20

25

30

35

40

45

0 10 20 30 40 50 60

Cooper's Hawk (n=50) - Increase


11/31

y = 0.1503x - 1.0727

R = 0.5332

-2

0

2

4

6

8

10

12

14

0 10 20 30 40 50 60

Red-shouldered Hawk (n=36) - Increase

y = 2.8762x - 3.3633

R = 0.7743

-20

0

20

40

60

80

100

120

140

160

180

0 10 20 30 40 50 60

Red-tailed Hawk (n=50) - Increase

y = 0.3124x + 4.8335

R = 0.168

0

10

20

30

40

50

60

0 10 20 30 40 50 60

Rough-legged Hawk (n=49)


12/31

y = 0.8171x + 19.124

R = 0.2018

0

20

40

60

80

100

120

0 10 20 30 40 50 60

American Kestrel (n=50)

y = 13.217x + 80.354

R = 0.1569

0

500

1000

1500

2000

2500

0 10 20 30 40 50 60

American Coot (n=48)

y = -0.0671x + 4.6506

R = 0.0593

0

2

4

6

8

10

12

14

16

18

0 10 20 30 40 50 60

Killdeer (n=31)


13/31

y = 0.0277x + 8.4947

R = 0.0003

0

20

40

60

80

100

120

140

160

0 10 20 30 40 50 60

Bonaparte's Gull (n=27)

y = 98.047x - 765.41

R = 0.4414

-2000

0

2000

4000

6000

8000

10000

0 10 20 30 40 50 60

Ring-billed Gull (n=50) - Increase

y = 61.717x - 80.914

R = 0.3022

-1000

0

1000

2000

3000

4000

5000

6000

7000

8000

0 10 20 30 40 50 60

Herring Gull (n=50) - Increase


14/31

y = 21.235x - 284.7

R = 0.3285

-500

0

500

1000

1500

2000

2500

0 10 20 30 40 50 60

gull sp. (n=26) - Increase

y = 25.489x + 544.22R = 0.2314

0

500

1000

1500

2000

2500

3000

3500

4000

0 10 20 30 40 50 60

Mourning Dove (n=50)

y = 0.459x + 15.176

R = 0.0464

0

50

100

150

200

250

0 10 20 30 40 50 60

Eastern Screech-Owl (n=50)


15/31

y = 0.1306x + 11.731

R = 0.0288

0

10

20

30

40

50

60

0 10 20 30 40 50 60

Great Horned Owl (n=49)

y = 0.1552x - 0.1388

R = 0.4585

0

2

4

6

8

10

12

14

0 10 20 30 40 50 60

Barred Owl (n=40) - Increase

y = -0.1885x + 18.927

R = 0.1011

0

5

10

15

20

25

30

35

40

45

50

0 10 20 30 40 50 60

Belted Kingfisher (n=50)


16/31

y = -0.5023x + 31.128

R = 0.0581

0

50

100

150

200

250

0 10 20 30 40 50 60

Red-headed Woodpecker (n=49)

y = 5.1898x - 8.4604

R = 0.8219

-50

0

50

100

150

200

250

300

350

0 10 20 30 40 50 60

Red-bellied Woodpecker (n=50) - Increase

y = 0.0121x + 2.7527

R = 0.0034

0

2

4

6

8

10

12

14

16

0 10 20 30 40 50 60

Yellow-bellied Sapsucker (n=41)


17/31

y = 4.216x + 123.75

R = 0.4472

0

50

100

150

200

250

300

350

400

450

0 10 20 30 40 50 60

Downy Woodpecker (n=50) - Increase

y = 0.206x + 38.667

R = 0.0374

0

10

20

30

40

50

60

70

80

90

0 10 20 30 40 50 60

Hairy Woodpecker (n=50)

y = 1.5145x + 30.481

R = 0.311

0

20

40

60

80

100

120

140

160

180

200

0 10 20 30 40 50 60

Northern Flicker (n=50) - Increase


18/31

y = 0.0045x + 1.5861

R = 0.001

0

2

4

6

8

10

12

0 10 20 30 40 50 60

Northern Shrike (n=35)

y = 11.53x + 327.98

R = 0.3442

0

200

400

600

800

1000

1200

1400

0 10 20 30 40 50 60

Blue Jay (n=50) - Increase

y = 42.684x + 54.502

R = 0.4423

0

500

1000

1500

2000

2500

3000

3500

4000

4500

5000

0 10 20 30 40 50 60

American Crow (n=50) - Increase


19/31

y = -1.9651x + 330.53

R = 0.0116

0

200

400

600800

1000

1200

1400

1600

0 10 20 30 40 50 60

Horned Lark (n=50)

y = 11.128x + 293.19

R = 0.28550

200

400

600

800

1000

1200

1400

1600

0 10 20 30 40 50 60

Black-capped Chickadee (n=50)

y = 7.5194x + 83.916

R = 0.5729

0

100

200

300

400

500

600

700

0 10 20 30 40 50 60

Tufted Titmouse (n=50) - Increase


20/31

y = 1.3635x - 2.0482

R = 0.3233

-20

0

20

40

60

80

100

120

140

160

180

0 10 20 30 40 50 60

Red-breasted Nuthatch (n=46) - Increase

y = 5.9811x + 100.2

R = 0.5457

0

100

200

300

400

500

600

0 10 20 30 40 50 60

White-breasted Nuthatch (n=50) - Increase

y = 0.0366x + 32.347

R = 0.0009

0

10

20

30

40

50

60

70

80

0 10 20 30 40 50 60

Brown Creeper (n=50)


21/31

y = 0.6858x - 5.7469

R = 0.6348

-10

0

10

20

30

40

50

0 10 20 30 40 50 60

Carolina Wren (n=42) - Increase

y = -0.1765x + 11.021

R = 0.0725

0

5

10

15

20

25

30

35

4045

50

0 10 20 30 40 50 60

Winter Wren (n=47)

y = 0.0362x + 18.378

R = 0.0011

0

10

20

30

40

50

60

70

80

90

0 10 20 30 40 50 60

Golden-crowned Kinglet (n=49)


22/31

y = 5.3239x - 61.679

R = 0.7495

-100

-50

0

50

100

150

200

250

300

350

0 10 20 30 40 50 60

Eastern Bluebird (n=45) - Increase

y = 0.0394x + 0.3747

R = 0.1287

0

1

2

3

4

5

6

7

0 10 20 30 40 50 60

Hermit Thrush (n=30)

y = 8.5x - 48.331

R = 0.0807

-500

0

500

1000

1500

2000

2500

3000

0 10 20 30 40 50 60

American Robin (n=50)


23/31

y = -0.2415x + 11.399

R = 0.1656

-5

0

5

10

15

20

25

30

35

40

45

0 10 20 30 40 50 60

Northern Mockingbird (n=37)

y = 10.44x + 7841

R = 0.0006

0

5000

10000

15000

20000

25000

30000

0 10 20 30 40 50 60

European Starling (n=50)

y = 6.5429x + 66.596

R = 0.2288

0

100

200

300

400

500

600

700

800

900

1000

0 10 20 30 40 50 60

Cedar Waxwing (n=50)


24/31

y = -4.3314x + 209.93

R = 0.0116

-500

0

500

1000

1500

2000

2500

3000

3500

4000

4500

0 10 20 30 40 50 60

Lapland Longspur (n=35)

y = -0.8833x + 259

R = 0.002

0

200

400

600

800

1000

1200

1400

1600

0 10 20 30 40 50 60

Snow Bunting (n=50)

y = -0.2438x + 17.498

R = 0.0678

0

10

20

30

40

50

60

70

0 10 20 30 40 50 60

Yellow-rumped Warbler (n=35)


25/31

y = -0.0483x + 2.8318

R = 0.1558

0

1

2

3

4

5

6

7

8

9

0 10 20 30 40 50 60

Eastern Towhee (n=37)

y = -9.9648x + 1536

R = 0.029

0

500

1000

1500

2000

2500

3000

3500

4000

4500

0 10 20 30 40 50 60

American Tree Sparrow (n=50)

y = -0.441x + 24.126

R = 0.134

0

10

20

30

40

50

60

70

80

0 10 20 30 40 50 60

Field Sparrow (n=39)


26/31

y = 0.0353x + 0.72R = 0.0436

0

2

4

6

8

10

12

14

0 10 20 30 40 50 60

Fox Sparrow (n=30)

y = -2.1363x + 168.66

R = 0.1632

0

50

100

150

200

250

300

350

400

450

0 10 20 30 40 50 60

Song Sparrow (n=50)

y = -0.1745x + 12.57R = 0.0604

0

10

20

30

40

50

60

70

0 10 20 30 40 50 60

Swamp Sparrow (n=49)


27/31

y = 0.2481x - 0.1469

R = 0.214

0

5

10

1520

25

30

35

40

0 10 20 30 40 50 60

White-throated Sparrow (n=40)

y = 0.8456x + 31.178

R = 0.093

0

20

40

60

80

100

120

140

160

180

0 10 20 30 40 50 60

White-crowned Sparrow (n=48)

y = 2.0925x + 2508.9

R = 0.0004

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

10000

0 10 20 30 40 50 60

Dark-eyed Junco (n=50)


28/31

y = 14.922x + 385.88

R = 0.426

0

200

400

600

800

1000

1200

1400

1600

1800

0 10 20 30 40 50 60

Northern Cardinal (n=50) - Increase

y = -0.0325x + 27.788

R = 9E-05

0

50

100

150

200

250

0 10 20 30 40 50 60

Red-winged Blackbird (n=42)

y = -0.1344x + 6.9461

R = 0.1011

0

5

10

15

20

25

30

0 10 20 30 40 50 60

Eastern Meadowlark (n=25)


29/31

y = -0.3732x + 143.68

R = 0.0001

0

500

1000

15002000

2500

3000

3500

4000

0 10 20 30 40 50 60

Common Grackle (n=42)

y = 0.2983x + 70.753

R = 0.0007

0

200

400

600

800

1000

1200

0 10 20 30 40 50 60

Brown-headed Cowbird (n=47)

y = -0.205x + 44.287

R = 0.0067

0

20

40

60

80

100

120

140

160

180

200

0 10 20 30 40 50 60

Purple Finch (n=48)


30/31

y = 37.936x - 252.42

R = 0.4379

-500

0

500

1000

1500

2000

2500

3000

3500

0 10 20 30 40 50 60

House Finch (n=31) - Increase

y = -5.5499x + 336.84

R = 0.0339

0

500

1000

1500

2000

2500

3000

0 10 20 30 40 50 60

Common Redpoll (n=37)

y = 1.208x + 34.096

R = 0.0331

0

50

100

150200

250

300

350

400

450

0 10 20 30 40 50 60

Pine Siskin (n=40)


31/31

y = 16.983x + 230.45

R = 0.4176

0

200

400

600

800

1000

1200

1400

1600

1800

0 10 20 30 40 50 60

American Goldfinch (n=50) - Increase

y = -1.1415x + 50.047

R = 0.1115

-50

0

50

100

150

200

250

300

0 10 20 30 40 50 60

Evening Grosbeak (n=27)

y = -29.341x + 4446.6

R = 0.078

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

0 10 20 30 40 50 60

House Sparrow (n=50)

Documents

Berrien County CBC 50-Yr Visual Trends