Weekly Reports at Beaver River for the Autumn 2018
2nd Week of November
Fall migration finally appeared to be closing this week. An abundance of rain and wind resulted in 4 nights of zero or near zero flight calls. Total numbers of birds were only a quarter of the previous week.
Nonetheless, it appeared that the last of the White-throated Sparrows were pushing through whenever the weather cleared. They were the most common species with an estimated 97 birds followed by Dark-eyed Junco with 58 birds. The first Snow Bunting of the season was recorded on the morning of 14 November. The only rare bird for the week was a Vesper Sparrow on the evening of 8 November.
Additional details are provided in the table below and the graph here. Data on individual species can be found on eBird.
|Species||Total Calls||Estimated Birds|
|American Tree Sparrow||8||6|
1st Week of November
Nocturnal migration was down by about 50% from the previous week but there was still a strong migration of sparrows and Yellow-rumped Warblers for this late in the season.
The most common species of the week was White-throated Sparrow with an estimated 410 birds. The next most common sparrows was Dark-eyed Junco with an estimated 213 birds, Song Sparrow (110), Chipping Sparrow (63), Savannah Sparrow (61), Lincoln’s/Swamp Sparrow (39), Fox Sparrow (22), American Tree Sparrow (8), and White-crowned Sparrow (2).
Seasonally appropriate warblers were Yellow-rumped Warblers (130), Palm Warbler (17), Blackpoll Warbler (4), and Common Yellowthroat (4). Seasonally late warblers were Black-and-white Warbler (2), and Northern Parula (1).
The other late species was a Gray Catbird.
Further details are available in the table below and the graph here. Data on individual species can be found on eBird.
|Species||Total Calls||Estimated Birds|
|American Tree Sparrow||13||8|
4th Week of October
The last week of October was characterized by a large movement of sparrows, with total numbers of all species almost equaling the density of migration during the first week of the month. The most common sparrow was White-throated Sparrow (estimated 751 birds) followed by Song Sparrow (194), Savannah Sparrow (162), Chipping Sparrow (122), Dark-eyed Junco (121), Lincoln’s/Swamp Sparrow (95), White-crowned Sparrow (27), Fox Sparrow (18), and Clay-colored Sparrow (1).
However, the second most common bird was Yellow-rumped Warbler with an estimated 432 birds. There were also 98 Palm Warbler, 18 Common Yellowthroat, and 13 Blackpoll Warbler. Late migrating warblers included Northern Parula (6), Magnolia Warbler (4), Black-and-White Warbler (3), and Black-throated Blue Warbler (1).
It was the first week since August without a Swainson’s Thrush but there were an estimated 51 Hermit Thrush, 1 Veery, and 1 Wood Thrush.
Another late migrating bird for the week was a Rose-breasted Grosbeak.
Further details for the week can be found in the table below and the graph here. Details on individual species can be viewed on eBird.
|Species||Total Calls||Estimated Birds|
|Black-throated Blue Warbler||1||1|
Normally the number of birds in nocturnal migration declines rapidly after October 15th. Nonetheless, total flight calls and estimated birds were down only slightly over the previous week.
Yellow-rumped Warbler was the most common nocturnal migrant with an estimated 266 birds (only one less than last week!). The next most common were Song Sparrow and White-throated Sparrow at 71 and 70 estimated birds respectively. There were still good numbers of Palm Warblers (66) and Blackpoll Warblers (24). Eleven warbler species were seen during the week. For other sparrows, Savannah Sparrow and Chipping Sparrow were close to equal in estimated numbers (47 and 42). Other sparrows included Dark-eyed Junco (24), Swamp/Lincoln’s Sparrow (23), White-crowned Sparrow (18), and Fox Sparrow (5).
While finches are primarily diurnal migrants, during their peak migration season in October, it is not unusual to detect finches that are departing before civil sunrise. This week an estimated 19 American Goldfinch, 12 Purple Finch, and 1 Pine Siskin were recorded.
The first nocturnally migrating American Woodcocks (2) were also heard along with a late Spotted Sandpiper and Greater Yellowlegs.
Migrating Golden-crowned Kinglets were also detected with an estimated 11 birds. Ruby-crowned Kinglets do not have a nocturnal flight call so are rarely heard unless one pauses long enough to give its “jeddit” call.
A late Swainson’s Thrush was recorded on the evening of 19 October.
Details by date can be found in the “Species Map” section of eBird. Totals for the week are summarized in the table below. A graph of total calls by date can be seen here.
|Black-throated Blue Warbler||7||3|
|Black-throated Green Warbler||3||2|
2nd Week of October
Flight calls and estimated nocturnal migrants were down by half from the previous week. Yellow-rumped Warbler remained the most common migrant with an estimated 267 birds, followed by Blackpoll Warbler (167), and White-throated Sparrow (113).
Unusual or rare birds for the week included 4 Indigo Buntings, 1 Clay-colored Sparrow, 1 Field Sparrow, 1 Orange-crowned Sparrow, 1 Pine Warbler, and 1 Prairie Warbler.
Details by date can be found in the “Species Map” section of eBird. Totals for the week are summarized in the table below.
|Black-throated Blue Warbler||18||11|
|Cape May Warbler||4||3|
|Black-throated Green Warbler||1||1|
1st Week of October
Night flight calls increased by 34% over the last week of September. The 1st week of October often has high nightly counts but this year, the highest count for the autumn migration occurred on the night of 5-6 October with 2,252 flight calls representing an estimated 1,270 birds.
The most common species for the week was Yellow-rumped Warbler with an estimated 412 birds followed by Palm Warbler (305), Blackpoll Warbler (229), and Common Yellowthroat (217). There were another 14 warbler species recorded during the week; a good diversity for so late in the warbler migration.
The most common sparrow was White-throated (177 estimated birds) and Savannah Sparrow (155). Other sparrows included Song Sparrow (85), Lincoln’s/Swamp Sparrow (58), Chipping Sparrow (56), Dark-eyed Junco (10), White-crowned Sparrow (5), Fox Sparrow (3), and Vesper Sparrow (1).
There were still good numbers of Swainson’s Thrushes (89 estimated birds), a few Hermit Thrushes (7), and a single Veery.
Unusual or less common birds for the week included: Indigo Bunting (estimated 5 birds), House Finch (2), Black-crowned Night-Heron (1), and Northern Mockingbird (1)
Further information is presented in the table below.
|Black-throated Green Warbler||35||26|
|Cape May Warbler||27||18|
|Black-throated Blue Warbler||21||17|
4th Week of September
Nocturnal migration was down considering in the fourth week of September (the morning of 21 September to the morning of 30 September). Nonetheless one of the five peak nights of the season occurred on the night of 27-28 September. It was the first big night of the autumn for Blackpoll Warblers with 344 calls representing an estimated 163 birds.
Blackpoll Warblers were the dominant species during the whole period with an estimated 262 birds. Common Yellowthroats and Yellow-rumped Warblers were the second and third most abundant nocturnal species with an estimated 212 and 148 estimated birds respectively.
Swainson’s Thrush rapidly declined in numbers to only 52 estimated birds for the period while Hermit Thrushes were remarkably sparse.
The sparrow push took on greater strength with an estimated 104 Savannah Sparrows, 96 White-throated Sparrows, 37 Song Sparrows, 12 Chipping Sparrows, 11 Swamp/Lincoln’s Sparrows, and 5 Dark-eyed Juncos.
Rare or unusual birds for the week included 2 Pine Warblers, 2 Indigo Buntings, 1 Prairie Warbler, and 1 late Canada Warbler.
The table below presents a summary for the week and detailed information for each night can be found on eBird.
|Species||Total Calls||Estimated Birds|
|Black-throated Green Warbler||94||66|
|Black-throated Blue Warbler||38||29|
|Cape May Warbler||29||17|
3rd Week 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.
|Black-throated Green Warbler||120||91|
|Cape May Warbler||74||52|
|Black-throated Blue Warbler||56||44|
2nd Week 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 below, and nightly checklists can be found on eBird.
|Black-throated Green Warbler||254||181|
|Black-throated Blue Warbler||110||77|
|Cape May Warbler||116||66|
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 3rd week 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.
|Black-throated Green Warbler||80||66|
|Black-throated Blue Warbler||62||43|
|Cape May Warbler||40||31|
4th Week 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 was just a few shorebirds.
A summary of the week is found in the table below and nightly data is available on eBird.
|Black-throated Blue Warbler||82||62|
|Black-throated Green Warbler||78||55|
|Cape May Warbler||27||21|
3rd Week 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.
|Black-throated Green Warbler||58||46|
|Black-throated Blue Warbler||23||19|
|Cape May Warbler||10||7|
2nd Week 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.
|Black-throated Green Warbler||27||20|
|Black-throated Blue Warbler||3||3|
|Cape May Warbler||1||1|
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.
|1||Black-throated Blue Warbler|
|1||Black-throated Green Warbler|