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 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