The 2020 fall migration banding season at the Kiawah Island Banding Station (KIBS) concluded on Monday, 30 November. We banded at two sites on Kiawah Island again this fall: Captain Sam's and Little Bear. This was the 12th consecutive year of fall migration banding at the Captain Sam's site with banding occurring daily during the last 9 years. It was the 6th season for the Little Bear site which we initiated during the fall of 2015. The two sites are located at each end of island about 8 miles apart (Captain Sam's on the west end, Little Bear on the east end). Both sites are situated in coastal scrub/shrub and high marsh habitats, however, the Little Bear site is in an earlier stage of succession. Collectively, we banded 7,199 birds and had 1,674 recaptures of 92 different species. Captain Sam's had a small decrease in the number of birds banded compared to last year, while Little Bear showed a moderate increase. Captain Sam’s and Little Bear combined, experienced a less than 1% increase in the number of birds banded from last year. We had 12 fewer species than our record-breaking year last year but species diversity was still around the average over the last 9 years.
It was a hot and humid August and September but that didn’t seem to stop the birds from moving south as we had an above average start to the season. The first half of October was very busy, but migration slowed down substantially after mid-October and through the end of November. November experienced above average temperatures which probably contributed to the relative paucity of later migrants like sparrows, kinglets, and Yellow-rumped Warblers. Despite the 2020 Atlantic hurricane season breaking records with 30 named storms, this is the first year since 2014 when we didn't have to shut down the station for an extended period due to a tropical storm, hurricane, or 1000-year flood.
CAPTAIN SAM'S
Nets were opened for a total of 104 days from 15 August - 30
November. There were only 4 days when
banding did not occur because of inclement weather (8/23, 9/9, 11/12,
11/30). We banded 4,566 new birds of 80 different species. The most commonly
banded species were Gray Catbirds (897), Common Yellowthroats (880) and
Yellow-rumped Warbler (509). Those three
species combined made up 50% of all the birds banded this season. Gray Catbirds took over the number one spot
this year after exhibiting a 27.5% increase from last year. Catbird bird numbers were also 20% higher
this year compared to the average of the last 9 years. Alternatively, Common Yellowthroats decreased
by almost 28% from last year and 22% over the average of the last 9 years. Yellow-rumped Warbler numbers continue to decline
and were down 22.4% from last year and over 32% from the average of the last 9
years. This trend is alarming because
KIBS isn’t the only banding station in the east that is seeing this trend.
Several species exhibited record high numbers this
season: Swainson’s Thrush, Gray-cheeked
Thrush, Ovenbird, American Redstart, and Blackpoll Warbler. Alternatively, we had a few species that had
record low numbers: Ruby-crowned
Kinglet, Song Sparrow, and White-throated Sparrow.
The overall effort increased slightly from 13,103.7
net-hours in 2019 to 13,734.03 net-hours this year. We banded 20 more birds this year compared to
last year, and 5 birds more than the average for the previous 9 years. The capture rate decreased slightly by 3.3
birds/100 net-hours compared to last year but was 8.8 birds/100 net-hours lower
than the 9-year average of 50.5 birds/100 net-hours. Our capture rate has decreased every year
starting in 2012 with exception to 2017 and 2019 when we experienced small
increases from the previous year. The
capture rate of recaptures is very consistent from year to year; therefore, all
decreases in the total capture rate can be attributed to new birds.
We had 1,166 recaptures which is slightly lower compared to
last year. We recaptured many
individuals that were banded in previous years.
It will take a while to sort through all those records to determine how
many unique returns we had as some of those were undoubtedly captured more than
once during the fall. We did not
recapture any birds that were banded at a different location.
There were 9 days this fall when over 100 birds were banded
compared to 12 days last fall. The best
day of the season was on 1 October when we banded 262 birds and had 9
recaptures. The next two busiest days
occurred 2 and 3 October when 256 and 240 birds were banded, respectively. The 10-day period between 27 September and 6
October accounted for nearly a third of all the birds banded for the entire
season.
We captured one species that has never been banded at the
Captain Sam's site during the fall: Connecticut Warbler. This was also the first time a Connecticut
Warbler has been documented on Kiawah Island!
This species is one that I would have expected to have captured by now
due to their east coast migration route, but they have evaded us until this
year when we captured two of them (and another at Little Bear).
Some other rare and notable species that were banded this
fall include: Common Ground Dove (1),
Eastern Whip-poor-will (1; 3 previous), Red-breasted Nuthatch (3; 11 previous),
Brown Creeper (2; 9 previous), Clay-colored Sparrow (2; 7 previous),
Blue-winged Warbler (1; 2 previous), Mourning Warbler (1; 2 previous),
Black-throated Green Warbler (1; 5 previous).
Species notably absent this year included: Eastern Screech-Owl, Acadian Flycatcher,
Marsh Wren, Swainson’s Warbler, and Nashville Warbler. Since 2012, Acadian Flycatchers have been an
annual capture with exception to 2015 and 2020.
Nashville Warblers have only been missed in 2018 and 2020.
Top 10 Species Banded at Captain Sam's
2. Common Yellowthroat (880)
3. Yellow-rumped Warbler (509)
4. American Redstart (369)
5. Red-eyed Vireo (220)
6. Northern Waterthrush (180)
7. Painted Bunting (171)
8. Palm Warbler (148)
9. Black-throated Blue Warbler (111)
10. Prairie Warbler (101)
LITTLE BEAR
Nets were opened for a total of 79 days from 24 August - 17
November. Little Bear opened a couple
days later than normal this year due to the timing of the availability of
housing for the seasonal banders.
Fortunately, we were able to extend the season by a couple of days at
the end. There were 7 days cancelled due
to bad weather (rain and/or wind).
Because the habitat at Little Bear is more open than at Captain Sam’s,
wind has a much bigger effect on the operation of the nets there. As a result, 4 or 5 days were cancelled due
to wind alone at Little Bear this year.
We banded 2,633 new birds of 71 different species. The most commonly banded species were Gray
Catbirds (568), Common Yellowthroat (531), and Yellow-rumped Warbler (172). Those three species combined made up 48% of
all the birds banded this season. Like
Captain Sam's, Gray Catbird numbers exhibited an increase (6%) compared to 2019
but showed a larger decrease of almost 8% over the last 6 years. Common Yellowthroat decreased by 15% compared
to last year and 14% compared to the average of the last 6 years. Yellow-rumped Warblers made it into the top 3
this year with an increase of 64% from last year. Unfortunately, they are still experiencing a
decline of 41% over the last 6 years. Locally,
the long-term negative trend for Yellow-rumped Warblers at Little Bear can partly be
attributed to saltwater intrusion that killed many of the mature wax myrtles in
2015 and 2016. Yellow-rumped Warblers
feed on the berries of wax myrtles and without that resource available a
decrease was evident. However,
Yellow-rumped Warbler numbers have also been decreasing at Captain Sam’s over
the same time period where the wax myrtles have not succumbed to salt water therefore there may be other factors causing this population decline. Some of the wax myrtles at Little Bear have
rebounded which might explain the increase of Yellow-rumped Warblers at Little
Bear this year.
Some of the same species that exhibited record high numbers
at Captain Sam’s did so at Little Bear too:
Swainson’s Thrush, American Redstart, and Blackpoll Warbler. Species that had record low numbers include: Song Sparrow, Yellow Warbler, and Cape May
Warbler.
We logged 7836.82 net-hours out at Little Bear this fall – a large increase from the 5,462.4 net-hours in 2019. Three additional nets were added at Little Bear this year which accounts for only 895.0 net-hours (38%). These nets were added in areas where the effects of wind might be reduced therefore allowing Little Bear to operate during windier conditions. Little Bear was also open for 4 more day this year compared to last year. In general, the nets were kept open later into the day this year than usual which helped contribute to the increased effort. Because less birds are captured later in the morning, I believe this also contributed to the substantial decrease in the capture rate we experienced this year (see below).
We banded 74 more birds this year compared to last year but 252
birds fewer than the 6-year average.
Little Bear’s capture rate decreased 27% from 55.3 birds/100 net-hours
in 2019 to 40.1 in 2020. Similarly, the
capture rate has decreased 34% compared to the 6-year average.
After 3 years in a row where we have seen a substantial
decrease in the number of recaptures, Little Bear experienced an increase in
the number of recaptures this year compared to last year (460 in 2019 and 507 in
2020). The increased effort this year
most likely was the reason as the capture rate of recaptures decreased by 2.0
birds/100 net-hours from last year.
Like in 2019, there were only 4 days when over 100 birds were banded but had 3 days in the 90’s. The best day of the season was on 1 October when we banded 140 birds and had 4 recaptures. The next two busiest days occurred 30 September and 2 October when 116 and 119 birds were banded, respectively.
We captured five species never banded at Little Bear during
the fall: Ash-throated Flycatcher,
Black-whiskered Vireo, Louisiana Waterthrush, Connecticut Warbler, and Golden-winged Warbler. This is the first time a Black-whiskered
Vireo has ever been recorded on Kiawah Island.
Additionally, it is only the 2nd record of this species in
South Carolina. Black-whiskered Vireos
are found throughout the Caribbean and only reaches the US regularly in south
Florida.
Some other rare and notable species banded include: Least Flycatcher (1; 4 previous), Warbling
Vireo (1; 2 previous), Lincoln’s Sparrow (2; 3 previous), Blackburnian Warbler
(1; 2 previous), Bay-breasted Warbler (1; 2 previous).
Species notably absent: Acadian Flycatcher, Great-crested
Flycatcher, House Finch, Field Sparrow, and Nashville Warbler.
Top 10 Species Banded at Little Bear
2. Common Yellowthroat (531)
3. Yellow-rumped Warbler (172)
4. Painted Bunting (152)
5. Palm Warbler (146)
5. American Redstart (146)
7. Red-eyed Vireo (122)
8. Northern Waterthrush (110)
9. House Wren (61)
10. Black-throated Blue Warbler (53)
ACKNOWLEDGEMENTS
Without the cooperation of many people and entities, this
work would not be possible. The success
of this project relies on their commitment, and I am in a debt of gratitude to
everyone involved.
First, I'd like to thank my awesome team of banding
assistants (Kristin Attinger, Josh Lefever, Dan Errichetti, Vince Weber, Sarah
Stewart, and Sarah Mueller). Their hard
work over the course of this long season was outstanding. It was a fun season and I would like to wish
them all the very best of luck in the future.
 |
| The 2020 KIBS Banding Crew From left to right: Sarah Stewart, Dan Errichetti, Josh Lefever, Vince Weber, Kristin Attinger, Aaron Given. Not pictured: Sarah Mueller |
Next, I'd like to acknowledge the Town of Kiawah Island for providing funding for equipment and banding assistant stipends, the Kiawah Island Conservancy for providing funding for the housing of the banding assistants, and the Kiawah Partners and the Bear Island Holding Trust for allowing access to their property for banding.
This is usually the part where I thank our awesome volunteers but I because of restrictions due to COVID-19 we did not allow any volunteers or visitors at the banding station. We sure did miss having their help this year and hope to have them back again next year.
-Aaron
|
SPECIES |
CAPTAIN
SAM’S |
LITTLE
BEAR |
||
|
New |
Recapture |
New |
Recapture |
|
|
Common Ground Dove |
1 |
- |
- |
- |
|
Mouning Dove |
4 |
- |
- |
- |
|
Yellow-billed Cuckoo |
12 |
- |
5 |
- |
|
Chuck-will's-widow |
- |
- |
2 |
1 |
|
Eastern Whip-poor-will |
1 |
|
2 |
|
|
Sharp-shinned Hawk |
2 |
- |
- |
- |
|
Eastern Screech-Owl |
- |
- |
4 |
1 |
|
Yellow-bellied Sapsucker |
6 |
1 |
4 |
1 |
|
Downy Woodpecker |
5 |
15 |
4 |
1 |
|
Ash-throated Flycatcher |
- |
- |
1 |
- |
|
Great Crested Flycatcher |
4 |
2 |
- |
- |
|
Eastern Kingbird |
3 |
- |
3 |
- |
|
Eastern Wood-Pewee |
7 |
- |
5 |
- |
|
"Traill's" Flycatcher |
23 |
3 |
16 |
- |
|
Least Flycatcher |
1 |
- |
1 |
- |
|
Eastern Phoebe |
29 |
9 |
29 |
- |
|
White-eyed Vireo |
75 |
37 |
48 |
16 |
|
Blue-headed vireo |
4 |
- |
3 |
- |
|
Warbling Vireo |
- |
- |
1 |
- |
|
Red-eyed Vireo |
220 |
17 |
122 |
3 |
|
Black-whiskered Vireo |
- |
- |
1 |
1 |
|
Carolina Chickadee |
4 |
23 |
4 |
8 |
|
Tree Swallow |
28 |
- |
- |
- |
|
House Wren |
45 |
14 |
61 |
6 |
|
Marsh Wren |
- |
- |
2 |
- |
|
Carolina Wren |
14 |
65 |
16 |
52 |
|
Brown Creeper |
2 |
1 |
- |
- |
|
Red-breasted Nuthatch |
3 |
- |
- |
- |
|
Blue-gray Gnatcatcher |
8 |
1 |
4 |
2 |
|
Golden-crowned Kinglet |
8 |
1 |
- |
- |
|
Ruby-crowned Kinget |
63 |
13 |
31 |
2 |
|
Veery |
17 |
- |
3 |
- |
|
Gray-cheeked Thrush |
10 |
- |
6 |
- |
|
Swainson's Thrush |
95 |
2 |
30 |
- |
|
Hermit Thrush |
21 |
24 |
4 |
2 |
|
Wood Thrush |
1 |
1 |
- |
- |
|
American Robin |
6 |
- |
1 |
- |
|
Gray Catbird |
897 |
374 |
568 |
185 |
|
Brown Thrasher |
15 |
14 |
2 |
2 |
|
Northern Mockingbird |
16 |
4 |
13 |
2 |
|
House Finch |
2 |
- |
- |
- |
|
American Goldfinch |
1 |
- |
- |
- |
|
Eastern Towhee |
5 |
15 |
6 |
6 |
|
Clay-colored Sparrow |
2 |
- |
- |
- |
|
Field Sparrow |
- |
1 |
- |
- |
|
Savannah Sparrow |
6 |
- |
2 |
- |
|
Saltmarsh Sparrow |
2 |
- |
- |
- |
|
Song Sparrow |
24 |
9 |
20 |
4 |
|
Lincoln's Sparrow |
- |
- |
2 |
- |
|
Swamp Sparrow |
47 |
17 |
39 |
5 |
|
White-throated Sparrow |
5 |
3 |
3 |
2 |
|
White-crowned Sparrow |
1 |
- |
- |
- |
|
Yellow-breasted Chat |
13 |
1 |
8 |
- |
|
Baltimore Oriole |
2 |
- |
2 |
2 |
|
Ovenbird |
51 |
13 |
26 |
2 |
|
Worm-eating Warbler |
9 |
4 |
5 |
- |
|
Louisiana Waterthrush |
- |
- |
1 |
- |
|
Northern Waterthrush |
180 |
49 |
110 |
13 |
|
Golden-winged Warbler |
- |
- |
1 |
- |
|
Blue-winged Warbler |
1 |
- |
- |
- |
|
Black-and-white Warbler |
43 |
2 |
17 |
- |
|
Prothonotary Warbler |
11 |
1 |
2 |
- |
|
Swainson's Warbler |
- |
- |
2 |
- |
|
Tennessee Warbler |
1 |
- |
3 |
1 |
|
Orange-crowned Warbler |
20 |
6 |
13 |
1 |
|
Connecticut Warbler |
2 |
- |
1 |
- |
|
Mourning Warbler |
1 |
- |
- |
- |
|
Common Yellowthroat |
880 |
69 |
531 |
62 |
|
Hooded Warbler |
7 |
- |
3 |
- |
|
American Redstart |
369 |
23 |
146 |
6 |
|
Cape May Warbler |
13 |
- |
14 |
1 |
|
Northern Parula |
35 |
1 |
23 |
2 |
|
Magnolia Warbler |
10 |
- |
1 |
- |
|
Bay-breasted Warbler |
- |
- |
1 |
- |
|
Blackburnian Warbler |
- |
- |
1 |
- |
|
Yellow Warbler |
33 |
- |
21 |
2 |
|
Chestnut-sided Warbler |
1 |
- |
- |
- |
|
Blackpoll Warbler |
19 |
2 |
14 |
1 |
|
Black-throated Blue Warbler |
111 |
3 |
53 |
2 |
|
Palm Warbler |
148 |
3 |
146 |
3 |
|
Pine Warbler |
2 |
1 |
- |
- |
|
Yellow-rumped Warbler (Myrtle) |
509 |
82 |
172 |
7 |
|
Yellow-throated Warbler |
1 |
- |
2 |
- |
|
Prairie Warbler |
101 |
8 |
52 |
9 |
|
Black-throated Green Warbler |
1 |
- |
- |
- |
|
Summer Tanager |
4 |
- |
2 |
- |
|
Scarlet Tanager |
3 |
- |
2 |
- |
|
Northern Cardinal |
30 |
111 |
28 |
36 |
|
Rose-breasted Grosbeak |
2 |
- |
- |
- |
|
Blue Grosbeak |
2 |
- |
1 |
- |
|
Indigo Bunting |
35 |
1 |
9 |
1 |
|
Painted Bunting |
171 |
120 |
152 |
54 |
|
BANDING
STATISTICS |
CAPTAIN
SAM'S |
LITTLE
BEAR |
TOTAL |
|
# of Birds Banded |
4,566 |
2,633 |
7,199 |
|
# of Recaptures |
1,166 |
507 |
1,673 |
|
# of Species |
80 |
71 |
92 |
|
Effort (net-hours) |
13,734.6 |
7,839.8 |
21,571.5 |
|
Capture Rate (birds/100 net-hours) |
41.7 |
40.1 |
41.1 |
|
# of Nets |
30 |
23 |
53 |
|
# of Days Operated |
104 |
79 |
- |
|
Dates of Operation |
8/15-11/30 |
8/24-11/17 |
- |
No comments:
Post a Comment