Environmental and Social Research

John F. Kearney & Associates

Nocturnal Acoustic Monitoring of Migratory Birds 2017


Carleton Station, Yarmouth County, Nova Scotia (N43.9967, W65.9159)

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%

Weekly Reports for the Autumn 2017




1stWeek of October


Nocturnal migration, at just 371 calls, was down by 75% from the previous week. The most common nocturnal migrant was Palm Warbler with 63 calls. The percentage of sparrow calls increased from 20% to 27% of the total with 7 sparrow species or taxons represented.


Rare or less common birds for the week included 2 (individual) Indigo Buntings, 1 Field Sparrow on 1 October at 22:08 hours, and 1 Clay-colored Sparrow on 7 October at 21:25 hours.


A summary list is below.




Estimated

Species

Calls

Birds

Palm Warbler

63

50

Yellow-rumped Warbler

58

40

White-throated Sparrow

52

35

Common Yellowthroat

33

25

Blackpoll Warbler

26

21

Magnolia Warbler

25

22

Savannah Sparrow

21

18

Northern Parula

13

11

Unidentified Warbler

10

10

Unidentified Sparrow

9

7

Lincoln's/Swamp Sparrow

8

7

Hermit Thrush

6

3

Nashville Warbler

6

4

Chipping Sparrow

5

4

Blackburnian Warbler

4

4

Black-throated Green Warbler

4

4

Ovenbird

4

3

Song Sparrow

4

4

Black-and-White Warbler

3

2

Indigo Bunting

3

2

Black-throated Blue Warbler

2

2

Chestnut-sided Warbler

2

2

Unidentified Songbird

2

2

Rose-breasted Grosbeak

2

2

Bay-breasted Warbler

1

1

Clay-colored Sparrow

1

1

Field Sparrow

1

1

Unidentified Warbler Genus Oreothlypis

1

1

Swainson's Thrush

1

1

Tennessee Warbler

1

1

Total

371

290

 



4thWeek of September


Nocturnal migration increased marginally from an average of 141 calls per night in the 3rd week of September to 155 calls per night this week. While Common Yellowthroat remained the most abundant nocturnal migrant, the late-migrating Palm Warbler and Yellow-rumped Warbler exceeded other warbler species that, in general, were declining. The main exception was the Blackpoll Warbler that had twice as many calls recorded this week compared to the previous week.


The second most common bird this week was the White-throated Sparrow which tripled in the number of estimated birds from 32 last week to 114 this week. Other sparrows were also well represented; Lincoln’s/Swamp Sparrow (51 estimated birds), Savannah Sparrow (33), Song Sparrow (10), Chipping Sparrow (5), and Nelson’s Sparrow (4).


The first migrating American Woodcocks were detected on the morning 30 September. As to be expected, Swainson’s Thrushes declined while Hermit Thrushes increased.


Rare or less common birds for the week included Orange-crowned Warbler (3 estimated birds), Indigo Bunting (1), and Prairie Warbler (1).


A summary list of species for the week is provided below.


Species

Calls

Estimated

Birds

Common Yellowthroat

154

126

White-throated Sparrow

158

114

Yellow-rumped Warbler

126

102

Palm Warbler

130

100

Magnolia Warbler

91

75

Northern Parula

88

74

Blackpoll Warbler

82

74

Unidentified Warbler

59

56

Nashville Warbler

52

42

Ovenbird

45

38

Lincoln's/Swamp Sparrow

51

36

Savannah Sparrow

39

33

Black-and-White Warbler

35

32

Black-throated Green Warbler

36

30

Hermit Thrush

66

23

Black-throated Blue Warbler

28

21

Unidentified Songbird

20

20

American Redstart

17

15

Swainson's Thrush

20

14

Chestnut-sided Warbler

16

14

Unidentified Sparrow

17

13

Song Sparrow

11

10

Northern Waterthrush

6

5

Blackburnian Warbler

5

5

Chipping Sparrow

5

5

Unidentified Warbler Genus Oreothlypis

5

4

Nelson's Sparrow

4

4

American Woodcock

14

3

Orange-crowned Warbler

3

3

Rose-breasted Grosbeak

3

3

Tennessee Warbler

3

3

Cape May Warbler

2

2

Indigo Bunting

2

1

Bay-breasted Warbler

1

1

Prairie Warbler

1

1

Unidentified Warbler Genus Setophaga

1

1

Yellow Warbler

1

1

Total

1,397

1,104

 


3rdWeek of September


Nocturnal migration decreased this week at Carleton, Yarmouth County. This may in part be due to a massive exit of birds from the province this week as evidenced by the recordings at Cape Forchu, Yarmouth County (see http://www.johnfkearney.com/Cape_Forchu_Yarmouth_County_2017.html). There was a total of 984 calls at Carleton, down 53% from the previous week. This number of calls represents an estimated 817 birds.


The most common birds were Common Yellowthroat (199 calls), Northern Parula (91), Swainson’s Thrush (77), Magnolia Warbler (71), and Black-and-White Warbler (62).


Rare or less common birds for the week included 3 Prairie Warblers, and 1 Upland Sandpiper on 18 September at 04:52 hours.


A summary table is presented below.



Estimated

Species

Calls

Birds

Common Yellowthroat

199

151

Northern Parula

91

69

Swainson's Thrush

77

59

Magnolia Warbler

71

59

Black-and-White Warbler

62

52

American Redstart

48

40

Black-throated Green Warbler

46

42

Ovenbird

44

38

Blackpoll Warbler

41

39

Unidentified Warbler

40

37

White-throated Sparrow

35

32

Chestnut-sided Warbler

28

26

Black-throated Blue Warbler

27

21

Cape May Warbler

23

20

Savannah Sparrow

18

17

Nashville Warbler

17

15

Palm Warbler

17

15

Blackburnian Warbler

15

13

Bay-breasted Warbler

11

10

Unidentified Warbler Genus Setophaga

10

10

Yellow Warbler

8

6

Yellow-rumped Warbler

8

8

Nelson's Sparrow

7

6

Prairie Warbler

6

3

Lincoln's/Swamp Sparrow

5

5

Northern Waterthrush

5

5

Song Sparrow

5

5

Unidentified Songbird

4

3

Upland Sandpiper

4

1

Veery

3

2

Canada Warbler

2

1

Unidentified Sparrow

2

2

Mourning Warbler

2

2

Hermit Thrush

1

1

Tennessee Warbler

1

1

Wilson's Warbler

1

1

Total

984

817

 



2ndWeek of September


After a very quiet 1st week of September, nocturnal migration at Carleton, Yarmouth County, picked up considerably beginning on 8 September. The highest number of calls in one night over 3 autumn seasons of monitoring at this location occurred on this night with 771 calls representing an estimated 598 birds. The two most common birds on that night were Cape May Warbler with 122 calls (about 76 birds) and Bay-breasted Warbler with 89 calls (about 63 birds). These counts illustrate the extraordinary numbers of these two species this autumn season.


Overall for the week, there was a total of 2,113 night flight calls. The most common species was Common Yellowthroat (261 calls), replacing the American Redstart for the first time this year as the most abundant species. The American Redstart (233 calls), Magnolia Warbler (207), Black-and-White Warbler (174), Cape May Warbler (149), Bay-breasted Warbler (140), and Northern Parula (129) were the most abundant warblers after Common Yellowthroat.


The Swainson’s Thrush migration also increased with 121 calls and an estimated 82 birds. The only other thrush was Veery (5 calls).


Rare or less common birds seen this week included 2 Pine Warbler (9 September at 21:44 hours and 22:34 hours) and Indigo Bunting (12 September at 20:56 hours).


A summary table is provided below.




Estimated

Species

Calls

Birds

Common Yellowthroat

261

202

American Redstart

223

165

Magnolia Warbler

207

165

Black-and-White Warbler

174

140

Cape May Warbler

149

98

Bay-breasted Warbler

140

106

Northern Parula

129

101

Swainson's Thrush

121

82

Ovenbird

93

84

Unidentified Warbler

78

73

Black-throated Green Warbler

67

60

Chestnut-sided Warbler

59

51

Blackpoll Warbler

49

45

Black-throated Blue Warbler

37

32

Northern Waterthrush

34

30

Nashville Warbler

31

23

White-throated Sparrow

30

23

Savannah Sparrow

29

28

Unidentified Warbler Genus Setophaga

28

27

Yellow-rumped Warbler

26

22

Blackburnian Warbler

25

24

Yellow Warbler

22

21

Palm Warbler

21

19

Lincoln's/Swamp Sparrow

18

18

Solitary Sandpiper

15

2

Mourning Warbler

9

8

Unidentified Songbird

8

7

Tennessee Warbler

8

7

Wilson's Warbler

6

5

Veery

5

5

Bobolink

4

3

Canada Warbler

3

3

Pine Warbler

2

2

Unidentified Sparrow

1

1

Indigo Bunting

1

1

Total

2,113

1,683




1stWeek of September



Nocturnal migration came to a virtual standstill during the first week of September due to rain and unfavourable winds from southeast to southwest on four out of seven days.


Total night flight calls were one-third of the previous week with most species declining in numbers. The numbers of Bay-breasted Warblers, although down, were sufficient to place them as the second most common bird of the week.


The only rare or less common bird of the week was a White-crowned Sparrow on 5 September at 22:47 hours.


A summary of the week in table form is presented below.





Estimated

Species

Calls

Birds

American Redstart

72

52

Bay-breasted Warbler

44

38

Ovenbird

31

27

Magnolia Warbler

30

26

Common Yellowthroat

27

23

Northern Parula

32

23

Black-and-White Warbler

25

21

Unidentified Warbler

23

20

Chestnut-sided Warbler

24

19

Northern Waterthrush

11

10

Cape May Warbler

11

9

Swainson's Thrush

12

8

Yellow Warbler

7

7

Blackpoll Warbler

6

6

Unidentified Warbler Genus Setophaga

7

6

Black-throated Blue Warbler

5

5

Nashville Warbler

5

5

Blackburnian Warbler

5

4

Black-throated Green Warbler

4

4

Savannah Sparrow

4

4

Yellow-rumped Warbler

5

4

Canada Warbler

3

3

Tennessee Warbler

3

3

Lincoln's/Swamp Sparrow

2

2

Mourning Warbler

2

2

Palm Warbler

2

2

Wilson's Warbler

2

2

Unidentified Sparrow

1

1

Unidentified Warbler Genus Oreothlypis

1

1

White-crowned Sparrow

1

1

White-throated Sparrow

1

1

Total

408

339

 



4thWeek of August



The 10-day last week of August had significant nocturnal migration at Carleton, Yarmouth County. A total of 1,338 calls were recorded, representing an estimated 1,146 birds. Warblers still dominated the species composition with the most common being American Redstart (265 calls), Magnolia Warbler (125 calls), Northern Parula (99 calls), Common Yellowthroat (89 calls), Ovenbird (89 calls), and Black-and-White Warbler (82 calls). Bay-breasted Warblers, Cape May Warblers, and Wilson’s Warblers were less common warblers occurring in higher than normal numbers.


There was the beginning of the fall movement of Swainson’s Thrushes but in small numbers. There was some increase in Savannah Sparrows.


Rare or uncommon birds for the week included Pine Warbler (26 August at 23:30 hours) and Prairie Warbler (27 August at 22:53 hours).


A summary for the week is presented in the table below.



Estimated

Species

Calls

Birds

American Redstart

265

212

Magnolia Warbler

125

104

Unidentified Warbler

103

98

Common Yellowthroat

89

81

Ovenbird

89

77

Northern Parula

99

76

Black-and-White Warbler

82

66

Bay-breasted Warbler

59

50

Northern Waterthrush

49

47

Chestnut-sided Warbler

51

45

Cape May Warbler

48

43

Yellow Warbler

46

39

Unidentified Warbler Genus Setophaga

30

27

Black-throated Blue Warbler

30

26

Black-throated Green Warbler

29

25

Wilson's Warbler

25

22

Yellow-rumped Warbler

13

12

Savannah Sparrow

12

11

Swainson's Thrush

12

11

Blackburnian Warbler

14

10

Blackpoll Warbler

11

10

Canada Warbler

10

10

Nashville Warbler

9

9

Unidentified Warbler Genus Oreothlypis

9

8

Unidentified Songbird

7

7

Tennessee Warbler

8

7

Mourning Warbler

3

3

Veery

3

3

Palm Warbler

2

2

Least Sandpiper

1

1

Pine Warbler

1

1

Prairie Warbler

1

1

Spotted Sandpiper

2

1

White-throated Sparrow

1

1

Total

1,338

1,146

 




3rd Week of August



Night flight calls increased by one-third during the third week of August (evening of 15 August to morning of 22 August). The most common bird was still the American Redstart with 128 calls representing an estimated 100 birds. The other most common birds were Northern Parula (58 calls), Chestnut-sided Warbler (54 calls), Magnolia Warbler (58 calls), Black-and-white Warbler (46 calls), Yellow Warbler (50 calls), and Ovenbird (48 calls). The first Cape May Warblers, Mourning Warblers, and Tennessee Warblers were recorded this week. The most unusual warbler was a Prairie Warbler on the morning of 17 August.


All identifiable birds were warblers except for 2 Savannah Sparrows, 2 Swainson’s Thrushes, and a Bobolink.


A summary of the week is provided in the table below.




Estimated

Species

Calls

Birds

American Redstart

128

100

Northern Parula

58

48

Chestnut-sided Warbler

54

46

Magnolia Warbler

58

45

Black-and-White Warbler

46

40

Unidentified Warbler

48

40

Yellow Warbler

50

37

Ovenbird

48

35

Common Yellowthroat

33

31

Northern Waterthrush

31

26

Black-throated Green Warbler

21

18

Black-throated Blue Warbler

19

17

Canada Warbler

18

17

Yellow-rumped Warbler

15

13

Bay-breasted Warbler

12

11

Blackburnian Warbler

10

9

Unidentified Warbler Genus Setophaga

9

8

Blackpoll Warbler

7

6

Cape May Warbler

6

5

Nashville Warbler

4

4

Palm Warbler

4

4

Tennessee Warbler

3

3

Mourning Warbler

2

2

Savannah Sparrow

2

2

Swainson's Thrush

2

2

Bobolink

1

1

Unidentified Songbird

1

1

Prairie Warbler

1

1

Wilson's Warbler

1

1

Total

692

573

 


Night flight calls increased by one-third during the third week of August (evening of 15 August to morning of 22 August). The most common bird was still the American Redstart with 128 calls representing an estimated 100 birds. The other most common birds were Northern Parula (58 calls), Chestnut-sided Warbler (54 calls), Magnolia Warbler (58 calls), Black-and-white Warbler (46 calls), Yellow Warbler (50 calls), and Ovenbird (48 calls). The first Cape May Warblers, Mourning Warblers, and Tennessee Warblers were recorded this week. The most unusual warbler was a Prairie Warbler on the morning of 17 August.

All identifiable birds were warblers except for 2 Savannah Sparrows, 2 Swainson’s Thrushes, and a Bobolink.

A summary of the week is provided in the table below. The chart to the right compares total night flight calls for each autumn night at Carleton from 2015 to 2017 as well as the results from the new station at Cape Forchu.

 



Estimated

Species

Calls

Birds

American Redstart

128

100

Northern Parula

58

48

Chestnut-sided Warbler

54

46

Magnolia Warbler

58

45

Black-and-White Warbler

46

40

Unidentified Warbler

48

40

Yellow Warbler

50

37

Ovenbird

48

35

Common Yellowthroat

33

31

Northern Waterthrush

31

26

Black-throated Green Warbler

21

18

Black-throated Blue Warbler

19

17

Canada Warbler

18

17

Yellow-rumped Warbler

15

13

Bay-breasted Warbler

12

11

Blackburnian Warbler

10

9

Unidentified Warbler Genus Setophaga

9

8

Blackpoll Warbler

7

6

Cape May Warbler

6

5

Nashville Warbler

4

4

Palm Warbler

4

4

Tennessee Warbler

3

3

Mourning Warbler

2

2

Savannah Sparrow

2

2

Swainson's Thrush

2

2

Bobolink

1

1

Unidentified Songbird

1

1

Prairie Warbler

1

1

Wilson's Warbler

1

1

Total

692

573

 

 


2ndWeek of August


The volume of nocturnal migration was about 2.5 times greater this week than in the first week of August at Carleton, Yarmouth County. Total night flight calls for the week was 520 calls which represented an estimated 428 birds. The week was characterized by an influx of American Redstarts with 99 calls and an estimated 76 birds. Other common early migrating birds were Yellow Warbler, Ovenbird, Magnolia Warbler, Chestnut-sided Warbler, and Black-and-White Warbler.


Rare or uncommon birds for the week included 1 Pine Warbler and 1 Indigo Bunting. At 0132 hours on the morning of 14 August, a possible Cerulean Warbler night flight call was recorded (see this photo). While the flight call of the Cerulean Warbler is difficult to distinguish from that of the Blackpoll Warbler, the measurements for this spectrogram met all the requirements for both species, except the time between modulations. The average time was less than expected for Blackpoll but within range for Cerulean. However, given the limited data on flight call characteristics, it is not possible to be even near 100% certain of the identification.


The table below summarizes the nocturnal migration activity this week.




Estimated

Species

Calls

Birds

American Redstart

99

76

Ovenbird

55

49

Yellow Warbler

47

37

Magnolia Warbler

43

37

Black-and-White Warbler

42

37

Chestnut-sided Warbler

44

34

Unidentified Warbler

36

33

Unidentified Warbler Genus Setophaga

17

17

Black-throated Blue Warbler

20

16

Northern Parula

18

15

Canada Warbler

15

13

Black-throated Green Warbler

16

11

Blackburnian Warbler

13

11

Bay-breasted Warbler

14

10

Northern Waterthrush

9

9

Yellow-rumped Warbler

5

5

Common Yellowthroat

5

4

Blackpoll Warbler

4

4

Nashville Warbler

3

3

Palm Warbler

2

2

Solitary Sandpiper

6

1

Lincoln's/Swamp Sparrow

3

1

Cerulean Warbler (see text above)

1

1

Pine Warbler

1

1

White-throated Sparrow

1

1

Indigo Bunting

1

1

Total

520

428



1stWeek of August

 

Nocturnal migration at Carleton, Yarmouth County, picked up some steam during the first week of August with a total of 204 calls, representing an estimated 158 birds, and 18 species. This averages out to 29 calls and 23 birds per night. As indicated in the table below, the nocturnal migrants were dominated by early migrating warblers, such as the American Redstart, Black-and-White Warbler, and Yellow Warbler. Less common warblers such as the Bay-breasted Warbler and Canada Warbler tend to be well represented in the August migration. There have been no rare species thus far during this early autumn migration.

 



Estimated

Species

Calls

Birds

American Redstart

49

39

Black-and-White Warbler

48

33

Yellow Warbler

22

19

Ovenbird

12

10

Chestnut-sided Warbler

12

9

Magnolia Warbler

7

7

Northern Parula

9

7

Yellow-rumped Warbler

10

7

Bay-breasted Warbler

8

6

Canada Warbler

6

6

Black-throated Blue Warbler

3

3

Unidentified Warbler

3

3

Common Nighthawk

4

2

Wilson's Warbler

2

2

Black-capped Chickadee

2

1

Black-throated Green Warbler

3

1

Northern Waterthrush

1

1

Savannah Sparrow

2

1

Veery

1

1

Total

204

158

 

 

Last Week of July

 

I started recording nocturnal migration on July 28 at the Carleton station in Yarmouth County. A total of 123 calls representing about 58 birds was recorded. While this is a time of post-fledgling movements within the province, most of the warblers recorded are those species noted for their early migration. These are American Redstart, Yellow Warbler, Black-and-White Warbler, Northern Waterthrush, and Canada Warbler. Some of these actually peak in mid-to-late August. The migrating Solitary Sandpipers are not unusual at this inland location. The total for these four days are listed below.

 



Estimated

Species

Calls

Birds

American Redstart

19

15

Black-and-White Warbler

13

9

Yellow Warbler

9

8

Solitary Sandpiper

57

6

Chestnut-sided Warbler

5

5

Northern Waterthrush

3

3

Canada Warbler

2

2

Unidentified Warbler

2

2

Yellow-rumped Warbler

3

2

Bay-breasted Warbler

3

1

Common Nighthawk

1

1

Unidentified Sparrow

1

1

Hermit Thrush

2

1

Magnolia Warbler

1

1

Spotted Sandpiper

2

1

Total

123

58

 

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