Environmental and Social Research

John F. Kearney & Associates

Beaver River, Yarmouth County, Nova Scotia


Autumn 2018



3rdWeek of September



Nocturnal migration was down by 21% (total calls) and 27% (estimated birds) from the previous week. However, the week saw two of the four peak counts of the season so far with 1625 and 1696 total calls on the nights of 19 and 20 September.


The most abundant bird was Common Yellowthroat with 893 calls representing an estimated 489 birds. Other common warblers for the week were Black-and-white Warbler (262 birds), Magnolia Warbler (150), Northern Parula (150), American Redstart (139), and Blackpoll Warbler (133).


The second most abundant bird was Swainson’s Thrush with 578 total calls representing an estimated 272 birds.


Sparrows continued to increase with 82 estimated Savannah Sparrows and 73 estimated White-throated Sparrows.


There were no rare birds but infrequent birds included an estimated 4 Gray-cheeked Thrush and 1 Prairie Warbler.


A summary table and chart are provided below.




Total

Estimated

Species

Calls

Birds

Common Yellowthroat

893

489

Swainson's Thrush

578

272

Black-and-White Warbler

407

262

warbler sp.

317

243

Magnolia Warbler

209

150

Northern Parula

235

150

American Redstart

207

139

Blackpoll Warbler

184

133

Black-throated Green Warbler

120

91

Savannah Sparrow

112

82

White-throated Sparrow

102

73

Palm Warbler

98

65

Ovenbird

68

56

Cape May Warbler

74

52

passerine sp.

51

47

Yellow-rumped Warbler

56

46

Black-throated Blue Warbler

56

44

Greater Yellowlegs

338

44

Chestnut-sided Warbler

51

38

Northern Waterthrush

41

35

Nashville Warbler

46

30

Bay-breasted Warbler

35

29

sparrow sp.

44

28

Veery

52

28

Mourning Warbler

21

17

Bobolink

20

15

Lincoln's/Swamp Sparrow

16

14

Blackburnian Warbler

16

13

Wilson's Warbler

18

13

Song Sparrow

29

12

Yellow Warbler

16

12

Rose-breasted Grosbeak

18

8

Tennessee Warbler

15

8

Chipping Sparrow

11

7

Semipalmated Plover

14

6

Gray-cheeked Thrush

6

4

Least Sandpiper

7

4

Canada Warbler

5

3

Hermit Thrush

6

3

Red-breasted Nuthatch

7

3

Solitary Sandpiper

4

2

Prairie Warbler

1

1

Spotted Sandpiper

2

1

Total

4,606

2,772





2ndWeek of September



Nocturnal migration continued to rise at Beaver River, Yarmouth County, with a 65% and 64% increase in the number of calls and estimated birds over the previous week. Total calls equalled 5,811 for an estimated total of 3,822 individual birds. Over a thousand calls were recorded on three nights beginning on 8, 9, and 12 September.


On the morning of 9 September there was large fallout of Northern Waterthrush in which 73 estimated birds were recorded in 26 minutes. This link shows the number of Northern Waterthrush calls occurring over 19 seconds, while this link is an example of 3 calls recorded within one-third of a second (the call above the middle call may be an second band of that call or a fourth call). Included in this fallout were 21 Bay-breasted Warblers.


The most common species for the week were Common Yellowthroat (an estimated 466 birds), Black-and-White Warbler (357), American Redstart (300), Northern Parula (278), Swainson’s Thrush (261), Magnolia Warbler (231), and Black-throated Green Warbler (181).


The most common sparrow was Savannah Sparrow with an estimated 119 birds.


There were a couple late Empidonax flycatchers (Yellow-bellied Flycatcher at 2300 hours on 7 September and Alder Flycatcher at 0052 hours on 9 September) while some of the later warbler migrants such as Blackpoll Warbler, Yellow-rumped Warbler, and Palm Warbler showed a stronger presence.


Rare or unusual birds for the week included 1 Dickcissel (10 September at 0219 hours), 1 Blue-winged/Golden-winged Warbler (13 September at 0402 hours), and 1 Vesper Sparrow (8 September at 0109 hours).


Further details are included in the table and graph below and nightly checklists can be found on eBird.




Total

Estimated

Species

Calls

Birds

Common Yellowthroat

756

466

Black-and-White Warbler

554

357

Warbler sp.

387

317

American Redstart

453

300

Northern Parula

430

278

Swainson's Thrush

535

261

Magnolia Warbler

325

231

Black-throated Green Warbler

254

181

Ovenbird

163

135

Northern Waterthrush

292

131

Bay-breasted Warbler

198

123

Savannah Sparrow

179

119

Blackpoll Warbler

122

93

Chestnut-sided Warbler

118

93

Black-throated Blue Warbler

110

77

Wilson's Warbler

94

76

Cape May Warbler

116

66

Palm Warbler

71

58

Yellow-rumped Warbler

60

51

White-throated Sparrow

59

45

Canada Warbler

44

37

Songbird sp.

41

34

Tennessee Warbler

46

34

Yellow Warbler

50

34

Veery

48

33

Nashville Warbler

43

31

Sparrow sp.

38

27

Blackburnian Warbler

27

22

Song Sparrow

47

20

Mourning Warbler

22

18

Lincoln's/Swamp Sparrow

16

15

Semipalmated Plover

36

15

Bobolink

24

13

Rose-breasted Grosbeak

16

11

Red-breasted Nuthatch

12

4

Solitary Sandpiper

9

4

Least Sandpiper

4

2

Prairie Warbler

4

2

Alder Flycatcher

1

1

Dark-eyed Junco

1

1

Dickcissel

1

1

Hermit Thrush

1

1

Nelson's Sparrow

1

1

Blue-winged/Golden-winged Warbler

1

1

Vesper Sparrow

1

1

Yellow-bellied Flycatcher

1

1

Total

5,811

3,822




1st Week of September



Nocturnal migration at Beaver River during the first week of September had the highest call count and estimated number of birds for the autumn migration to this point. It was up considerably (20%) from the last week of August (502 calls per night compared to 420), and up 5% from the 3rdweek of August (477 calls per night).


American Redstarts still continued to dominate in abundance with an estimated 379 birds. The most common other warblers were Black-and-White Warbler (202) and Common Yellowthroat (200). There was a very large flight of Wilson’s Warblers on the night of 31 August to 1 September with 222 calls and 122 estimated birds. They even outnumbered the American Redstarts on that night.


The Swainson’s Thrush migration continued strongly, and there was a noticeable start of the sparrow migration with an estimated 58 Savannah Sparrows. The Red-breasted Nuthatch eruption continued although it has been declining over the last three weeks.


Unusual birds for the week included 2 Vesper Sparrows (one at one at 2208 hours on 1 September and another at 2111 hours on 6 September), and 2 Indigo Buntings (one at 2253 hours on 1 September and one on 2204 hours on 6 September).


A summary for the week is presented in the table below and nightly details can be found on eBird.




Total

Estimated

Species

Calls

Birds

American Redstart

642

379

Black-and-White Warbler

294

202

Common Yellowthroat

294

200

Wilson's Warbler

304

185

Northern Parula

255

170

Swainson's Thrush

271

142

Magnolia Warbler

149

116

Chestnut-sided Warbler

111

80

Black-throated Green Warbler

80

66

Northern Waterthrush

92

64

Ovenbird

76

64

Savannah Sparrow

88

58

Red-breasted Nuthatch

135

54

Yellow Warbler

51

44

Black-throated Blue Warbler

62

43

Blackpoll Warbler

46

37

Cape May Warbler

40

31

Bay-breasted Warbler

31

26

Blackburnian Warbler

29

25

Nashville Warbler

32

24

Canada Warbler

20

19

White-throated Sparrow

17

15

Tennessee Warbler

15

13

Mourning Warbler

11

10

Song Sparrow

14

9

Palm Warbler

10

7

Yellow-rumped Warbler

7

7

Semipalmated Plover

14

6

Veery

12

6

Greater Yellowlegs

35

4

Lincoln's/Swamp Sparrow

4

3

Rose-breasted Grosbeak

7

3

Bobolink

2

2

Indigo Bunting

2

2

Solitary Sandpiper

3

2

Vesper Sparrow

2

2

Baltimore Oriole

2

1

Cedar Waxwing

2

1

Chipping Sparrow

2

1

warbler sp.

213

174

sparrow sp.

11

8

passerine sp.

28

25

Total

3,516

2,331




4thWeek of August



Nocturnal migration proceeded at an overall slower pace during the last week August except for the last night. From the evening of 30 August to the morning of 31 August, 1,845 night flight calls and an estimated 1,124 birds were recorded. It consisted of a large flight dominated by American Redstarts (estimated 151 birds) and Swainson’s Thrush (114).


Most of the rare birds for the week occurred in this large flight and included 1 Wood Thrush (0225 hours), and 1 Dickcissel (0545 hours) on 31 August. Also an Indigo Bunting was heard for the 3rd week in a row at 0226 hours on 27 August.


Overall for the week, the most abundant warblers were American Redstart (344 estimated birds), Chestnut-sided Warbler (218), Northern Parula (215), Common Yellowthroat (178), Black-and-white Warbler (163), Magnolia Warbler (147), and Ovenbird (106). With a total of 23 warbler species, Canada Warblers were down to 84 estimated birds compared to 133 in the previous week while there was a noticeable increase in Black-throated Blue Warblers from 19 to 62 birds.


Thrush migration was in full force with an estimated 130 Swainson’s Thrush and 22 Veery for the week. Sparrow numbers were still very low and there were just a few shorebirds.


A summary of the week is found in the table below and nightly data is available on eBird.




Estimated

 

Calls

Birds

American Redstart

584

344

Chestnut-sided Warbler

342

218

Northern Parula

339

215

Common Yellowthroat

285

178

Black-and-White Warbler

222

163

Magnolia Warbler

209

147

Swainson's Thrush

280

130

Ovenbird

132

106

Canada Warbler

115

84

Northern Waterthrush

113

80

Yellow Warbler

91

71

Black-throated Blue Warbler

82

62

Red-breasted Nuthatch

164

62

Black-throated Green Warbler

78

55

Blackpoll Warbler

55

50

Bay-breasted Warbler

41

35

Nashville Warbler

45

33

Savannah Sparrow

35

27

Tennessee Warbler

29

22

Veery

33

22

Wilson's Warbler

34

22

Cape May Warbler

27

21

Blackburnian Warbler

20

19

Yellow-rumped Warbler

13

10

Solitary Sandpiper

16

6

Song Sparrow

18

6

Palm Warbler

6

5

White-throated Sparrow

6

5

Prairie Warbler

5

4

Rose-breasted Grosbeak

8

4

Bobolink

5

3

Least Sandpiper

4

3

Mourning Warbler

2

2

Dickcissel

1

1

Greater Yellowlegs

8

1

House Finch

1

1

Indigo Bunting

1

1

Semipalmated Plover

1

1

Wood Thrush

1

1

warbler sp.

315

244

sparrow sp.

2

2

songbird sp.

15

14

Total

3,785

2,482




3rdWeek of August



Nocturnal migration at Beaver River, Yarmouth County, doubled in magnitude over the previous week with a total of 3,344 night flight calls and an estimated 2, 214 birds. This is 2.3 times the magnitude recorded at Cape Forchu for the same week in 2017.


American Redstarts dominated the totals this week with an estimated 385 birds, followed by Chestnut-sided Warbler (207), Magnolia Warbler (191), Northern Parula (158), Canada Warbler (133), Black-and-White Warbler (123), and Yellow Warbler (120). A total of 23 warbler species were recorded.


The number of Canada Warblers is very encouraging. The flight call of the Canada Warbler is very distinctive and is not easily confused with any other species. It is one of the few flight calls that can be quickly learned by ear without software help.


Also of note this week is the number of Red-breasted Nuthatches. Most years I record very few of these, and the estimated 62 birds this week indicates that we are in an eruptive year for this species.


By way of comparison, there was a large flight of American Redstarts at Cape May, New Jersey, about a week after the first large flights at Beaver River. On 24 August, 464 redstarts were counted there in morning flight.


Thrushes began their migration this week with an estimated 26 Swainson’s Thrush and 13 Veery. The only sparrows were an estimated 13 Savannah Sparrow and 1 Chipping Sparrow. The most common shorebird was Solitary Sandpiper (7).


Both Upland Sandpiper and Indigo Bunting gave repeat performances this week. One Upland Sandpiper at 2100 hours on 17 August and one Indigo Bunting at 2129 hours on 21 August.


Details for the week are in the table below, and nightly data can be found on eBird.




Estimated

Species

Calls

Birds

American Redstart

665

385

Chestnut-sided Warbler

345

207

Magnolia Warbler

284

191

Northern Parula

252

158

Canada Warbler

185

133

Black-and-White Warbler

164

123

Yellow Warbler

175

120

Common Yellowthroat

133

91

Ovenbird

106

85

Northern Waterthrush

90

72

Red-breasted Nuthatch

160

62

Black-throated Green Warbler

58

46

Blackpoll Warbler

45

37

Blackburnian Warbler

49

36

Bay-breasted Warbler

38

34

Swainson's Thrush

41

26

Black-throated Blue Warbler

23

19

Tennessee Warbler

21

16

Savannah Sparrow

14

13

Veery

30

13

Wilson's Warbler

14

11

Nashville Warbler

12

9

Cape May Warbler

10

7

Solitary Sandpiper

14

7

Least Sandpiper

13

6

Yellow-rumped Warbler

8

5

Mourning Warbler

3

3

Prairie Warbler

2

2

Semipalmated Plover

4

2

American Golden-Plover

1

1

Black-bellied Plover

2

1

Bobolink

1

1

Chipping Sparrow

2

1

Indigo Bunting

1

1

Palm Warbler

1

1

Pectoral Sandpiper

1

1

Upland Sandpiper

2

1

warbler sp.

367

279

passerine sp.

8

8

Total

3,344

2,214




2ndWeek of August


Nocturnal migration for the week at Beaver River, Yarmouth County, totaled 1,162 estimated birds from 1,759 night flight calls. This total was more than 2.5 times the number of birds recorded at Cape Forchu during the same week last year. At least half of this increase is likely due to the increased sensitivity of the microphone used at Beaver River.


The most common birds were American Redstart (168 estimated birds), Yellow Warbler (141), Chestnut-sided Warbler (134), and Magnolia Warbler (121). There was a very strong migration this week of Canada Warblers with 98 night flight calls for an estimated 73 birds.


Rare or unusual birds this week were 2 Upland Sandpipers at 0013 hours on 13 August, 1 Dickcissel at 0327 hours on 13 August, and 1 Indigo Bunting at 2202 hours on 11 August.


Totals for the week are presented in the table below:




Estimated

Species

Calls

Birds

warbler sp.

218

170

American Redstart

252

168

Yellow Warbler

227

141

Chestnut-sided Warbler

210

134

Magnolia Warbler

185

121

Black-and-White Warbler

117

88

Canada Warbler

98

73

Blackburnian Warbler

50

32

Northern Waterthrush

35

29

Blackpoll Warbler

35

28

Ovenbird

32

27

Northern Parula

26

22

Black-throated Green Warbler

27

20

Semipalmated Plover

45

16

Sanderling

29

10

Ruddy Turnstone

40

9

Bay-breasted Warbler

11

8

Red-breasted Nuthatch

24

8

Song Sparrow

19

8

Yellow-rumped Warbler

9

8

Common Yellowthroat

8

6

Nashville Warbler

8

5

Spotted Sandpiper

18

4

passerine sp.

4

4

Black-throated Blue Warbler

3

3

Savannah Sparrow

3

3

House Finch

5

2

Solitary Sandpiper

3

2

Upland Sandpiper

2

2

Alder Flycatcher

2

1

Cape May Warbler

1

1

Dickcissel

1

1

Hermit Thrush

1

1

Indigo Bunting

1

1

Least Sandpiper

1

1

Prairie Warbler

1

1

Short-billed Dowitcher

5

1

Swainson's Thrush

1

1

Tennessee Warbler

1

1

White-throated Sparrow

1

1

Total

1,759

1,162




1st Week of August


A new nocturnal acoustic recording station was established at Beaver River, Yarmouth County. The station deploys a 21c microphone produced by Bill Evans of Old Bird Inc. This microphone has a greater sensitivity and reach than the NFC microphone by Wildlife Acoustics that was used at Cape Forchu, Yarmouth County, last year. The 21c can detect flight calls up to 300 meters in altitude and can be expected to detect 1.5-2.0 times the number of calls than the Wildlife Acoustics microphone.


The number of estimated birds recorded on the nights beginning on 5-7 August are listed by species below.

91

American Redstart


89

Yellow Warbler


47

Magnolia Warbler


41

Black-and-White Warbler


38

Canada Warbler


15

Chestnut-sided Warbler


15

Blackburnian Warbler


15

Spotted Sandpiper


6

Ovenbird


6

Northern Waterthrush


5

Northern Parula


4

Bay-breasted Warbler


4

Blackpoll Warbler


2

Nashville Warbler


1

Savannah Sparrow


1

White-throated Sparrow


1

Black-throated Blue Warbler


1

Yellow-rumped Warbler


1

Black-throated Green Warbler


66

warbler sp.


2

passerine sp.


 























METADATA

Microphone: Old Bird 21c

<Sampling format; 16 bit

<Sampling rate: 22,050 Hz

Recording Equipment: Laptop Computer

Analysis Software: Raven Pro

High Frequency Detector Settings

>6000-11000 Hz, 23-395 ms,

>Signal/Noise 25% Minimum Occupancy

>Signal/Noise Ratio Threshold 3.5 dB

>Block Size 4992 ms, Hop Size 244 ms, 50%

Low Frequency Detector Settings

>2250-3750 Hz, 35-325 ms,

>Signal/Noise 20% Minimum Occupancy

>Signal/Noise Ratio Threshold 4.0 dB

>Block Size 998 ms, Hop Size 244 ms, 50%
NFCs_by_Night.jpg