Tuesday, December 17, 2019

2019 Fall Migration Summary


The 2019 fall migration banding season at the Kiawah Island Banding Station (KIBS) ended on Saturday, 30 November. We banded at two sites on Kiawah Island again this fall:  Captain Sam's and Little Bear.  This was the 11th consecutive year of fall migration banding at the Captain Sam's site with banding occurring daily during the last 8 years.  It was the 5th 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 7,146 birds and had 1,670 recaptures of 104 different species.  Captain Sam's had an increase in the number of birds banded compared to last year while, Little Bear showed a significant decrease.  Captain Sam’s and Little Bear combined, experienced a 6% increase in the number of birds banded from last year, and a 2.7% decrease on average of the last 5 years.  Cold fronts were more numerous this year compared to last fall.  We even experienced a couple of rare August cold fronts which brought us a good number of early migrants.  Late migrants like sparrows, kinglets, and Yellow-rumped Warblers that we would normally start catching at the end of October didn’t show up until mid-November.  We had a few very busy late November days which is unusual.  Unfortunately, Little Bear missed out on this late season push because we closed it down on 14 November.

CAPTAIN SAM'S
Nets were opened for a total of 97 days from 15 August - 30 November.  There were only 11 days in which banding did not occur.  Hurricane Dorian shut us down for 7 consecutive days from 2- 8 September.  Hurricane Dorian was a strong Category 5 storm that made landfall on 1 September in the Bahamas.  The storm weakened while moving north just off shore along Florida, Georgia, and South Carolina before making landfall again in Cape Hatteras, NC as a Category 1 on 6 September.  Even though this storm did not affect the Charleston area to the degree that was predicted, the intensity and unpredictable track of the storm caused mandatory evacuations for the all coastal areas of South Carolina.   Kiawah saw substantial wind damage and some minor flooding.  The banding stations fared well except for some trees, limbs, and debris that fell in the net lanes.  This is the fourth year in a row that a hurricane/tropical storm has affected our banding.

We banded 4,586 new birds of 86 different species.  The most commonly banded species were Common Yellowthroat (1219), Gray Catbird (703) and Yellow-rumped Warbler (656).  Those three species combined made up 56% of all the birds banded this season.  After dropping to #2 last year, Common Yellowthroats were back at the top as the most commonly banded species.  Common Yellowthroats were up almost 48% from last year and exhibited a 4.7% increase from the 8-year average.  Gray Catbird numbers were down 24% from last year but only 3.6% from 8-year average.  Yellow-rumped Warbler numbers continue to show decreases and were down 16% over the last 8 years but showed a 6.7% increase from last year.  

The overall effort increased slightly this year from 12,559.9 net-hours in 2018 to 13,103.7 net-hours.  We banded 553 more birds this year compared to last year, and 37 birds more than the average for the previous 8 years.  The capture rate increased slightly by 1.6 birds/100 net-hours compared to last year but was 7.5 birds/100 net-hours lower than the 8-year average of 51.7 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 1,207 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 12 days this fall when over 100 birds were banded compared to only 4 days last fall.  The best day of the season was on 6 October when we banded 286 birds and had 6 recaptures.  The next two busiest days occurred 10 and 17 October when 214 and 257 birds were banded respectively. 

We captured three species that have never been banded at the Captain Sam's site during the fall:  Sora, Seaside Sparrow, and Fox Sparrow.  This was also the first time a Fox Sparrow has been documented on Kiawah Island!

Some other rare and notable species that were banded this fall include:  Ash-throated Flycatcher (1 previous banding record), Philadelphia Vireo (4 previous), Winter Wren (3 previous), Sedge Wren (1 previous), Saltmarsh Sparrow (1 previous), Orchard Oriole (2 previous), Black-throated Green Warbler (5 previous), and Rose-breasted Grosbeak (3 previous).  Ash-throated Flycatchers are “western” species – a rare find in the eastern U.S.  They breed from western Texas to California and Nevada and north into central Oregon and spend the winter in coastal Mexico.  Some years this species strays far from its normal range and finds its way across the eastern US.  This was one of those year as Ash-throated Flycatchers have been seen up and down the east coast.  In fact, at least three 3 individuals were present in South Carolina in November.     

Species notably absent this year included:  Common Ground-Dove, Eastern Screech-Owl, Sharp-shinned Hawk.  Sharp-shinned Hawks have shown a steady decline (albeit a small sample size) since 2012. 




Top 10 Species Banded at Captain Sam's

1.  Common Yellowthroat (1,219)
2.  Gray Catbird (703)
3.  Yellow-rumped Warbler (656)
4.  American Redstart (230)
5.  Palm Warbler (217)
6. Red-eyed Vireo (166)
7.  Painted Bunting (133)
8.  Northern Waterthrush (106)
9.  Black-throated Blue Warbler (95)
10.  Ruby-crowned Kinglet (91)


LITTLE BEAR
Nets were opened for a total of 75 days from 22 August - 14 November.  We had 12 days cancelled due to weather including an 8 day stretch from 2-9 September for Hurricane Dorian.  Wind also caused Little Bear to shut down for a few days scattered throughout the season.  After three years in a row of tropical storms and hurricanes, the Little Bear site has suffered from saltwater intrusion which has killed many of the wax myrtles, marsh elders, and Baccharis around the site.  Wax myrtles are the dominant plant at Little Bear and the reduced cover around the nets have caused the nets to become much more exposed to the elements - wind and heat being the biggest threats.  Because of this, Little Bear had to close early many days when the temperature got too warm to safely (for the birds) capture birds.  Additionally, winds with a northerly component to them affected the nets considerably.  The predominant winds in the fall are usually from the north (especially following a cold front) therefore the wind is a constant factor at Little Bear.

We banded 2,560 new birds of 78 different species.  The total number of species captured at Little Bear is actually 79 because of a Sharp-shinned Hawk that was recaptured (originally banded in 2017 at Little Bear).  The most commonly banded species were Common Yellowthroat (627), Gray Catbird (539), and Palm Warbler (210).    Those three species combined made up 54% of all the birds banded this season.  Like Captain Sam's, Common Yellowthroat numbers exhibited a significant increase (17%) compared to 2018 but showed a minuscule decrease of 0.6% over the 5-year average.  Gray Catbird decreased by 14% compared to the 5-year average and decreased 31% from last year.  Palm Warblers were up this year with a 13% increase from the 5-year average and a 15% increase from last fall.  In 2015 and 2016, Yellow-rumped Warblers were in the top three species banded.  In fact, they were the most commonly banded bird in 2016 with 659.  This year only 105 Yellow-rumped Warblers were banded and 113 in 2018.  Their numbers have decreased by 67% over the last 5 years.  This decrease can largely 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 intrusion therefore there may be something else causing this population change.  

We logged 5,462.4 net-hours out at Little Bear this fall – up a little bit from the 5,148.6 net-hours in 2017.  We banded 151 fewer birds this year compared to last year and 379 birds fewer than the 5-year average.  Little Bear’s capture rate decreased 7.6% from 63.0 birds/100 net-hours in 2018 to 55.4 in 2019.  Similarly, the capture rate has decreased 10.8% compared to the 5-year average. 

Like last year, Little Bear experienced a large decrease in the number of recaptures this year compared to last year (529 in 2018 and 463 in 2019).  This is the 3rd year in a row where we have seen a substantial decrease in the number of recaptures.  Because of the more frequent and long-lasting flooding of saltwater, the wax myrtles and other shrubs cannot recover. This is probably reducing the quality of habitat to negatively affect the bird’s stopover time. 

There were only 4 days when over 100 birds were banded compared to 5 days last fall.  The best day of the season was on 17 October when we banded 205 birds and had 7 recaptures.  The next two busiest days occurred 30 September and 12 October when 128 and 106 birds were banded respectively. 

We captured four species never banded at Little Bear during the fall:  Solitary Sandpiper, Loggerhead Shrike, Winter Wren, and Nelson’s Sparrow.  This is the first time a Solitary Sandpiper has ever been banded on Kiawah Island.   

Some other rare and notable species banded include:  Black-billed Cuckoo (1 previous banding record), Green Heron (1 previous), Yellow-crowned Night-Heron (2 previous), Yellow-bellied Flycatcher (1 previous), Clay-colored Sparrow (3 previous), Lincoln’s Sparrow (2 previous), Dark-eyed Junco (1 previous), Bobolink (2 previous), Mourning Warbler (2 previous), and Northern Flicker (2 previous).

Species notably absent: Acadian Flycatcher, Blue Grosbeak.

Top 10 Species Banded at Little Bear
1.  Common Yellowthroat (627)
2.  Gray Catbird (539)
3.  Palm Warbler (210)
4.  Painted Bunting (158)
5.  Yellow-rumped Warbler (105)
6.  Northern Waterthrush (97)
7.  American Redstart (77)
8.  House Wren (61)
9.  Red-eyed Vireo (55)
10. Yellow 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, Beth Darby, Dan Errichetti, Arcata Leavitt, and Dave Sandahl).  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.  

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. 

And last but not least, I'd like to thank the many volunteers that donated their time to come out and help with this project.  Bill Kee, Vince Spagnuolo, David McLean, Katie Doherty, Lydia Moore, Sarah Stewart, and Michael Gamble put in many hours volunteering during times when they were needed the most.  I could always count on them to show up and help make those busy days go much more smoothly and efficiently.

The 2019 KIBS Banding Crew
From left to right:  Dave Sandahl, Arcata Leavitt, Josh Lefever, Beth Darby, Dan Errichetti, Kristin Attinger, Aaron Given

Species
Captain Sam's
Little Bear
New
Recapture
New
 Recapture
Solitary Sandpiper
-
-
1
-
Common Ground Dove
-
-
1
-
Mouning Dove
2
-
-
-
Yellow-billed Cuckoo
32
8
14
2
Black-billed Cuckoo
-
-
1
-
Chuck-will's-widow
2
-
-
-
Sora
1
-
-
-
Green Heron
-
-
1
-
Yellow-crowned Night-Heron
-
-
1
-
Sharp-shinned Hawk
-
-
-
1
Cooper's Hawk
2
-
1
-
Eastern Screech-Owl
-
-
4
-
Yellow-bellied Sapsucker
8
2
2
-
Downy Woodpecker
8
15
4
2
Northern Flicker
1
-
1
-
Ash-throated Flycatcher
1
1
-
-
Great Crested Flycatcher
5
3
-
-
Eastern Kingbird
1
-
1
-
Eastern Wood-Pewee
4
-
5
-
Yellow-bellied Flycatcher
1
-
2
-
Acadian Flycatcher
2
-
-
-
"Traill's" Flycatcher
11
-
12
2
Least Flycatcher
1
-
-
-
Eastern Phoebe
60
7
42
-
Loggerhead Shrike
-
-
1
-
White-eyed Vireo
50
26
29
9
Blue-headed vireo
7
-
4
-
Philadelphia Vireo
1
-
-
-
Red-eyed Vireo
166
3
55
1
Carolina Chickadee
9
54
6
19
Tufted Titmouse
2
5
2
-
House Wren
63
22
61
8
Winter Wren
1
-
4
-
Sedge Wren
2
-
-
-
Marsh Wren
1
-
2
-
Carolina Wren
13
26
8
28
Blue-gray Gnatcatcher
7
2
-
-
Golden-crowned Kinglet
3
-
1
-
Ruby-crowned Kinget
91
34
29
6
Eastern Bluebird
1
-
-
-
Veery
15
1
3
-
Gray-cheeked Thrush
2
-
3
-
Swainson's Thrush
34
-
17
-
Hermit Thrush
48
36
20
2
Wood Thrush
9
-
1
-
American Robin
11
-
-
-
Gray Catbird
703
349
539
112
Brown Thrasher
13
17
4
1
Northern Mockingbird
13
18
6
3
House Finch
3
-
-
-
Eastern Towhee
11
22
8
9
Chipping Sparrow
2
-
3
-
Clay-colored Sparrow
-
-
1
-
Field Sparrow
7
1
-
-
Savannah Sparrow
1
-
3
-
Seaside Sparrow
1
-
-
-
Nelson's Sparrow
-
-
1
-
Saltmarsh Sparrow
1
-
-
-
Song Sparrow
51
15
26
6
Lincoln's Sparrow
-
-
1
-
Swamp Sparrow
48
21
26
5
White-throated Sparrow
12
5
1
-
White-crowned Sparrow
3
-
3
-
Fox Sparrow
1
-
-
-
Dark-eyed Junco
-
-
1
-
Yellow-breasted Chat
14
5
7
2
Bobolink
-
-
1
-
Orchard Oriole
1
-
-
-
Baltimore Oriole
1
-
2
-
Ovenbird
24
3
8
-
Worm-eating Warbler
-
-
1
-
Northern Waterthrush
106
32
97
36
Black-and-white Warbler
25
3
10
-
Prothonotary Warbler
7
1
4
-
Swainson's Warbler
1
-
-
-
Tennessee Warbler
10
-
7
-
Orange-crowned Warbler
24
9
12
2
Nashville Warbler
3
-
1
-
Mourning Warbler
-
-
1
-
Common Yellowthroat
1,219
133
627
48
Hooded Warbler
2
1
1
-
American Redstart
230
21
77
2
Cape May Warbler
17
-
26
6
Northern Parula
41
-
13
-
Magnolia Warbler
11
-
10
3
Bay-breasted Warbler
2
-
-
-
Yellow Warbler
27
-
53
-
Chestnut-sided Warbler
-
-
2
-
Blackpoll Warbler
3
1
6
2
Black-throated Blue Warbler
95
7
45
1
Palm Warbler
217
19
210
10
Pine Warbler
-
-
1
-
Yellow-rumped Warbler (Myrtle)
656
128
105
4
Yellow-throated Warbler
-
-
1
-
Prairie Warbler
86
15
52
5
Black-throated Green Warbler
2
-
-
-
Wilson's Warbler
1
-
-
-
Summer Tanager
6
-
1
-
Scarlet Tanager
4
-
-
-
Northern Cardinal
28
63
30
55
Rose-breasted Grosbeak
1
-
-
-
Blue Grosbeak
2
-
-
-
Indigo Bunting
39
1
29
1
Painted Bunting
133
72
158
70


BANDING STATISTICS
CAPTAIN SAM'S
LITTLE BEAR
TOTAL
# of Birds Banded
4,586
2,560
7,146
# of Recaptures
1,207
463
1,670
# of Species
86
79
104
Effort (net-hours)
13,103.7
5,462.4
18,566.1
Capture Rate (birds/100 net-hours)
44.2
55.4
47.5
# of Nets
28
20
48
# of Days Operated
97
75
-
Dates of Operation
8/15-11/30
8/22-11/14
-

Please note that these numbers are still preliminary and may change after the data is thoroughly proofed.