Environmental and Social Research

John F. Kearney & Associates

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Nocturnal Acoustic Monitoring of Migratory Birds 2016


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





Weekly Reports for the Autumn 2016





2ndWeek of November


 

This will be the last report on nocturnal migration at Carleton, Yarmouth County, for the autumn of 2016.


There was a total of 36 night flight calls this week, representing an estimated 18 individual birds. The most common birds were Dark-eyed Junco (27 calls) and Savannah Sparrow (2). A Grasshopper Sparrow recorded on 8 November was one day later than a bird of the same species on 7 November 2015. A late Common Yellowthroat was recorded on 9 November.


There was very little evidence of nocturnal migration on the weather radar at Caribou, Maine, this week.


A table showing the total calls, peak counts, and peak dates for each species recorded in 2015 and 2016 can be found in the left panel of this page. While the total number of calls was quite similar in both years, there were some major differences at the species level.


Notable increases could be seen in Black-and-White Warbler, Blackburnian Warbler, Black-throated Green Warbler, Black-throated Blue Warbler, Common Yellowthroat, Cape May Warbler, Swamp/Lincoln’s Sparrow, Northern Waterthrush, Northern Parula, Hermit Thrush, Palm Warbler, Savannah Sparrow, White-crowned Sparrow, Solitary Sandpiper, Song Sparrow, Veery, Wilson’s Warbler, Yellow Warbler, and Yellow-rumped Warbler.


Declines were seen in American Redstart, Canada Warbler, Chestnut-sided Warbler, Magnolia Warbler, Ovenbird, Swainson’s Thrush, and White-throated Sparrow.


A summary table for this week follows.




Estimated


Total

Minimum

Species

Calls

Individuals*

Dark-eyed Junco

27

9

Savannah Sparrow

2

2

American Tree Sparrow

1

1

Common Yellowthroat

1

1

Unidentified Sparrow

1

1

Fox Sparrow

1

1

Grasshopper Sparrow

1

1

Song Sparrow

1

1

Unidentified Songbird

1

1

Total

36

18

* Calls that are more than one minute apart plus calls that are less than one minute apart divided by three and rounded up to nearest whole number

 


1stWeek of November

 

Nocturnal migration was very slow this week at Carleton, Yarmouth County. The weather radar in Caribou, Maine, also showed little evidence of bird migration. At Portland, Maine, it appeared that some larger birds were heading southwest along the coast of Maine as late as the night of 7 November.

The most common birds at Carleton this week were Song Sparrow (8 calls), White-throated Sparrow (7), Dark-eyed Junco (5), and Palm Warbler (5). The last species represents 2 birds that were recorded 2:43 am on 2 November.

There remains the possibility of further nocturnal movements by juncos and sparrows in the coming week. A summary table for this week follows, and summary graphs and tables for the season can be found here.  

John



Estimated


Call

Minimum

Species

Count

Individuals*

Song Sparrow

8

5

White-throated Sparrow

7

7

Dark-eyed Junco

5

3

Palm Warbler

5

2

Golden-crowned Kinglet

4

2

Unidentified Sparrow

2

2

Fox Sparrow

2

1

Hermit Thrush

1

1

Lincoln's/Swamp Sparrow

1

1

Savannah Sparrow

1

1

Total

36

25

* Calls that are more than one minute apart plus calls that are less than one minute apart divided by three and rounded up to nearest whole number


1stWeek of November

 

Nocturnal migration was very slow this week at Carleton, Yarmouth County. The weather radar in Caribou, Maine, also showed little evidence of bird migration. At Portland, Maine, it appeared that some larger birds were heading southwest along the coast of Maine as late as the night of 7 November.


The most common birds at Carleton this week were Song Sparrow (8 calls), White-throated Sparrow (7), Dark-eyed Junco (5), and Palm Warbler (5). The last species represents 2 birds that were recorded 2:43 am on 2 November.

There remains the possibility of further nocturnal movements by juncos and sparrows in the coming week.


A summary table for this week follows, and summary graphs and tables for the season can be found in the left panel of this page.




Estimated


Call

Minimum

Species

Count

Individuals*

Song Sparrow

8

5

White-throated Sparrow

7

7

Dark-eyed Junco

5

3

Palm Warbler

5

2

Golden-crowned Kinglet

4

2

Unidentified Sparrow

2

2

Fox Sparrow

2

1

Hermit Thrush

1

1

Lincoln's/Swamp Sparrow

1

1

Savannah Sparrow

1

1

Total

36

25

* Calls that are more than one minute apart plus calls that are less than one minute apart divided by three and rounded up to nearest whole number



4thWeek of October

 

Nocturnal migration declined further this week at Carleton, Yarmouth County. Total calls fell to 49 with an estimated minimum of 29 individual birds. The most common calls were Dark-eyed Junco (28 calls), Fox Sparrow (6), and White-throated Sparrow (5). The first American Tree Sparrow was heard at 8 minutes past midnight on 28 October.


Sparrows accounted for 86% of all calls and warblers for 12%. The two warbler species recorded were Blackpoll Warbler and Yellow-rumped Warbler.


The weather radar at Caribou, Maine, displayed a corresponding paucity of migrants. The number of echoes was somewhat higher in Portland, Maine, while there still seemed to be nights of good migration in the mid-Atlantic states.


A summary table is below, and graphs and tables can be found in the left panel of this page.


Estimated

Total

Minimum

Species

Calls

Individuals*

Dark-eyed Junco

28

11

Fox Sparrow

6

5

White-throated Sparrow

5

5

Blackpoll Warbler

3

3

Killdeer

3

1

Unidentified Sparrow

2

2

American Tree Sparrow

1

1

Yellow-rumped Warbler

1

1

Total

49

29

* Calls that are more than one minute apart plus calls that are less than one minute apart divided by three and rounded up to nearest whole number



3rdWeek of October

 

Nocturnal migration was down to 88 flight calls at Carleton, Yarmouth County, this week. The estimated minimum number of individual migrants was 78. The most common species was White-throated Sparrow (23 calls) and Yellow-rumped Warbler (11). Sparrows accounted for 63% of all calls, warblers for 25%, and Kinglets for 7%. Straggling warblers included a Black-throated Green Warbler and a Black-throated Blue Warbler.


The weather radar in Caribou, Maine, indicated a similar low volume of migratory activity based on the density of echoes in clear-air mode.


A summary table is given below and tables and charts can be found on the left panel of this page.



Estimated


Call

Minimum

Species

Count

Individuals*

White-throated Sparrow

23

14

Unidentified Sparrow

11

11

Yellow-rumped Warbler

11

11

Savannah Sparrow

9

8

Song Sparrow

7

11

Golden-crowned Kinglet

6

3

Unidentified Songbird

5

5

Palm Warbler

5

5

Blackpoll Warbler

3

3

Lincoln's/Swamp Sparrow

3

3

Dark-eyed Junco

2

1

Black-throated Blue Warbler

1

1

Black-throated Green Warbler

1

1

Unidentified Warbler

1

1

Total

88

78

* Calls that are more than one minute apart plus calls that are less than one minute apart divided by three and rounded up to nearest whole number




2ndWeek of October

 

Nocturnal migration is winding down over Carleton, Yarmouth County. Total flight calls were down to 203 this week with an estimated minimum of 177 individual nocturnal migrants. The remnants of Hurricane Matthew, with heavy rain and high wind, brought migration to an apparent standstill for two days.


The most common bird of the week was Yellow-rumped Warbler (34 calls), followed by Savannah Sparrow (33 including 1 Ipswich Sparrow), Palm Warbler (29), and White-throated Sparrow (23).


The weather radar at Caribou, Maine, this week continued to show echoes travelling west and northwest over the Bay of Fundy.


A summary table for the week is below. Tables and graphs can be viewed in the left panel of this page.




Estimated


Total

Minimum

Species

Calls

Individuals*

Yellow-rumped Warbler

34

32

Savannah Sparrow

33

27

Palm Warbler

29

22

White-throated Sparrow

23

22

Song Sparrow

16

13

Lincoln's/Swamp Sparrow

11

8

Unidentified Songbird

11

10

Common Yellowthroat

9

9

Blackpoll Warbler

6

6

Black-throated Blue Warbler

5

3

Black-throated Green Warbler

4

4

Northern Parula

4

4

Black-capped Chickadee

3

2

Dark-eyed Junco

2

2

Hermit Thrush

2

2

Magnolia Warbler

2

2

Unidentified Warbler

2

2

American Robin

1

1

Chipping Sparrow

1

1

Unidentified Sparrow

1

1

Fox Sparrow

1

1

Nelson's Sparrow

1

1

Unidentified Warbler Genus Oreothlypis

1

1

Wilson's Warbler

1

1

Total

203

177

* Calls that are more than one minute apart plus calls that are less than one minute apart divided by three and rounded up to nearest whole number




1stWeek of October

 

Nocturnal migration over Carleton, Yarmouth County, this week was only one-fifth the intensity of the previous period. A total of 451 flight calls were recorded at a rate of 64 per night. The estimated minimum number of individuals was 377. The most abundant species were White-throated Sparrow with 53 calls and Yellow-rumped Warbler with 52. The other most common species this week were Common Yellowthroat (43 calls), Lincoln’s/Swamp Sparrow (39), Song Sparrow (37), Palm Warbler (34), Savannah Sparrow (27), Blackpoll Warbler (22), and Northern Parula (21). Warblers accounted for 53% of the species recorded, sparrows for 41%, and other bird families for 6%.


Unusual or new birds for the week included: Orange-crowned Warbler, Field Sparrow, Vesper Sparrow, and White-crowned Sparrow. Late Chestnut-sided Warblers were recorded on the evening of 6 October.


The Caribou, Maine, radar showed a corresponding decrease in bird echoes during this week. There was also an interesting shift of flight direction on some nights to the west and northwest. This is very consistent with results obtained by smaller-scale marine radars used by ornithologists who have noted these more westerly movements over the Bay of Fundy in later part of fall migration. It is believed that these birds cross the Bay of Fundy to avoid a more perilous route over the Gulf of Maine.


A summary of the week can be found below and supplementary tables and graphs on the left panel of this page.




Estimated


Total

Minimum

Species

Calls

Individuals*

White-throated Sparrow

53

43

Yellow-rumped Warbler

52

43

Common Yellowthroat

43

34

Lincoln's/Swamp Sparrow

39

32

Song Sparrow

37

28

Palm Warbler

34

29

Savannah Sparrow

27

22

Blackpoll Warbler

22

22

Unidentified Sparrow

21

19

Northern Parula

20

16

Magnolia Warbler

16

13

Unidentified Warbler Genus Setophaga

12

12

Black-capped Chickadee

10

10

Unidentified Songbird

10

10

Black-throated Blue Warbler

9

6

Unidentified Warbler

9

9

Black-throated Green Warbler

8

7

Golden-crowned Kinglet

5

2

Chestnut-sided Warbler

4

2

Hermit Thrush

4

3

Orange-crowned Warbler

3

2

Dark-eyed Junco

2

2

Ovenbird

2

2

Black-and-White Warbler

1

1

Blackburnian Warbler

1

1

Chipping Sparrow

1

1

Field Sparrow

1

1

Nashville Warbler

1

1

Unidentified Warbler Genus Oreothlypis

1

1

Vesper Sparrow

1

1

White-crowned Sparrow

1

1

Wilson's Warbler

1

1

Total

451

377

* Calls that are more than one minute apart plus calls that are less than one minute apart divided by three and rounded up to nearest whole number




4thWeek of September

 

It was a week of spectacular nocturnal migration at Carleton, Yarmouth County. With a total of 2,215 night flight calls, and a estimated minimum of 1,859 birds, this nine-day period accounted for 29% of all the flight calls that have been detected since the last week of July. The average nightly rate was 246 calls, about 50 calls per night higher than during the first week of September.


There were two major flights during this period; the night of 22-23 September when 742 calls were detected and the night of 29-30 September when 648 calls were recorded. The first of these nights, the 22nd-23rd, appeared to be a fallout of birds resulting from rain coming across the Bay of Fundy during the night. You can find more details about these conditions here: http://www.johnfkearney.com/Fallout_2016.html. The flight on the second night, the 29-30th, seems to be the result of moderately strong northeast winds through the entire night. Just after dusk the winds were from the northeast at 35 km/hr and had diminished to 24 km/hr at dawn. This provided a tail wind for southwest movement. The steady flow of calls through the night indicated that birds were both departing and arriving.


Among species groups, 65% of the calls this week were warblers, 28% sparrows, and 2% thrushes. The most common warblers were Common Yellowthroat (380 calls), Yellow-rumped Warbler (147), Palm Warbler (130), Magnolia Warbler (121), and Northern Parula (108). The most common sparrows were Savannah Sparrow (163), White-throated Sparrow (159), and Lincoln’s/Swamp Sparrow (155). Given the time of the season, the last group would be largely or entirely Swamp Sparrows. The most common thrush was Swainson’s Thrush (39).


Among the unusual birds of the week were 11 White-crowned Sparrows during the flight of the 29-30th. There were probably even several more as I noted some weaker calls that were likely this species. Also recorded during the week were 6 Indigo Buntings, 1 Prairie Warbler, 1 late Canada Warbler on 24 September, and a possible Prothonotary Warbler on 23 September (weak call). Among the 77 Savannah Sparrow calls on the 29-30th were two Ipswich Sparrows. A summary table can be found below and more analysis in the graphics and tables in the left panel of this page.




Estimated


Total

Minimum

Species

Calls

Individuals*

Common Yellowthroat

380

282

Savannah Sparrow

163

130

White-throated Sparrow

159

120

Lincoln's/Swamp Sparrow

155

114

Yellow-rumped Warbler

147

119

Palm Warbler

130

105

Magnolia Warbler

121

96

Northern Parula

108

88

Unidentified Sparrow

100

88

Black-and-White Warbler

95

77

Unidentified Warbler

87

83

Black-throated Green Warbler

83

71

Blackpoll Warbler

80

73

Unidentified Songbird

60

145

Unidentified Warbler Genus Setophaga

42

41

Swainson's Thrush

39

24

Black-throated Blue Warbler

34

29

Solitary Sandpiper

28

4

Ovenbird

27

23

Song Sparrow

26

19

American Redstart

21

16

Blackburnian Warbler

17

15

Cape May Warbler

17

11

Chestnut-sided Warbler

14

14

Golden-crowned Kinglet

13

6

White-crowned Sparrow

11

11

Chipping Sparrow

7

7

Bay-breasted Warbler

6

6

Hermit Thrush

6

4

Indigo Bunting

6

6

Wilson's Warbler

6

6

Nashville Warbler

5

4

Mourning Warbler

4

4

Nelson's Sparrow

4

4

Dark-eyed Junco

3

3

Unidentified Warbler Genus Oreothlypis

3

3

Yellow Warbler

2

2

American Pipit

1

1

Canada Warbler

1

1

Gray-cheeked Thrush

1

1

Northern Waterthrush

1

1

Prothonotary Warbler (possible)

1

1

Prairie Warbler

1

1

Total

2,215

1,859

* Calls that are more than one minute apart plus calls that are less than one minute apart divided by three and rounded up to nearest whole number




3rdWeek of September

 

Total night flight calls at Carleton, Yarmouth County, were down from the previous week due to rainy and unsettled weather during the period of 17-20 September. There was a total of 828 calls, at a nightly rate of 118. Species consisted 79% of warblers, 11% of thrushes, 9% of sparrows, and 1% of other family types. The most common species of the week were Common Yellowthroat with 181 calls, Magnolia Warbler (71), Northern Parula (54), Blackpoll Warbler (47), Black-and-white Warbler (44), American Redstart (40), Black-throated Green Warbler (39), and Swainson’s Thrush (36). There was a marked increase in Palm Warblers (22), and the first movement of Hermit Thrushes was on 15 September. Cape May Warblers (2) were scarce while Black-throated Blue Warblers continued at the same pace (21) as previously. A further expected increase in Yellow-rumped Warblers did not yet materialize. Rare birds for the week were Indigo Bunting and Gray-cheeked Thrush. The Gray-cheeked Thrush has quite a distinct flight call which you can hear by clicking on this link: Gray-cheeked Thrush Flight Call. The best time to listen is in the hour or two before dawn. A summary for the week follows in the table below. Tabular and graphic data can be found in the left panel of this page.

 

Estimated

Total

Minimum

Species

Calls

Individuals*

Common Yellowthroat

181

136

Magnolia Warbler

71

57

Northern Parula

54

46

Blackpoll Warbler

47

41

Black-and-White Warbler

44

35

American Redstart

40

28

Black-throated Green Warbler

39

34

Unidentified Warbler

39

35

Swainson's Thrush

36

28

Savannah Sparrow

29

22

Yellow-rumped Warbler

27

20

Unidentified Warbler Genus Setophaga

23

22

Chestnut-sided Warbler

22

19

Palm Warbler

22

17

White-throated Sparrow

22

18

Black-throated Blue Warbler

21

20

Hermit Thrush

19

7

Unidentified Sparrow

15

14

Ovenbird

13

12

Nashville Warbler

11

6

Unidentified Songbird

9

8

Bay-breasted Warbler

8

7

Lincoln's/Swamp Sparrow

6

6

Blackburnian Warbler

5

5

Song Sparrow

5

2

Wilson's Warbler

5

4

Cape May Warbler

2

2

Northern Waterthrush

2

2

Solitary Sandpiper

2

1

Tennessee Warbler

2

1

Veery

2

2

Unidentified Thrush

1

1

Canada Warbler

1

1

Gray-cheeked Thrush

1

1

Indigo Bunting

1

1

Mourning Warbler

1

1

Total

828

661

* Calls that are more than one minute apart plus calls that are less than one minute apart divided by three and rounded up to nearest whole number