Thursday, October 27, 2016

October 27, 2016

Captain Sam's
Today at Captain Sam's we banded 42 new birds and had 23 recaptures of 9 species. Yellow-rumped Warblers led the way with 27 banded and 4 recaptures. We also recaptured 15 Gray Catbirds, some being caught many times over the last couple of weeks. Many of these may overwinter on Kiawah Island instead of continuing their migration southward. One Gray Catbird recaught today has already been caught several times this fall and was banded in the fall of 2012. It was caught again in 2013 and 2014, but we missed it in 2015. We also recaught a nice after hatch-year male Northern Parula that we've been catching the past few days. As we've been catching him, we've observed he has been putting on more fat so he should be leaving soon.


Northern Parula (after hatch-year, male)



Along with the Gray Catbird, we had a couple other interesting recaptures from previous years. These were both yellow-rumped warblers, which we tend to see many returnees that were banded on Kiawah in years prior as they come back from breeding up north. One was banded in the fall of 2014 and the other was banded in the fall of 2015. We also caught two first-of-the season birds for Captain Sam's this morning, which included a Blackpoll Warbler and a Field Sparrow. Little Bear caught a couple field sparrows last fall but Captain Sam's missed out. Also, Little Bear has already caught a couple blackpoll warblers this fall. 

Field Sparrow (hatch-year, unknown sex)


We don't catch many blackpolls during the fall because they start their migration a little north of here and fly over the ocean instead of along the coast. They jump off the coast north of Cape Hatteras, North Carolina and most fly directly over the Atlantic Ocean to their wintering range in Puerto Rico, the Lesser Antilles, or northern South America. Studies have shown, to accomplish this non-stop flight, blackpolls almost double their body mass and wait for prevailing winds to push them to their winter range. As they fly over the Atlantic, they burn 0.08 g of fat every hour. This non-stop flight is about 3,000 km and takes about 72 to 88 hours as they travel at a speed of about 27 mph. They can weigh more than 20 g before leaving and lose around 4 or more grams by the time they make it to South America. The average blackpoll flies about 2,540 km non-stop over the Atlantic, which could take 3 days. This has been proven with the use of geolocators biologists attached to blackpolls in Vermont and Nova Scotia. The Ruby-throated hummingbird may be the only other bird that travels more kilometres per gram. The chances of us catching blackpolls depends on the wind direction and the weather conditions off the coast. Storms off the coast or a change in wind direction could push blackpolls onto land. Last night, the wind shifted from the northeast to the south, which would be a struggle for a blackpoll migrating south since it would be going against the wind. These conditions most likely pushed this blackpoll onto the coast where we ended up catching it in one of our nets. It did not have any fat and was pretty emaciated, indicating the struggle it must have been facing during its journey. I wouldn't be surprised if we catch the same bird over the next couple days as it sticks around to refuel before continuing its migration southward.

Blackpoll Warbler (hatch-year, unknown sex)

-Michael Gamble

Little Bear
At Little Bear we had 54 new birds and 32 recaptures of 13 species. Today was the first time that the number of recaptured Gray Catbirds surpassed the number of new catbirds, so we may finally be nearing the end of their migration period. Some of the recaptured individuals have been hanging around the station for several weeks now and we have seen a few of them so often in the nets (sometimes multiple times a day!) that we recognize their band numbers.

The busyness of the past week has meant that we are backlogged on data entry and don't have exact up-to-date numbers in our spreadsheet at the moment, but for the season the site now has over 2,600 new birds and close to 700 recaptures, despite starting a week after Captain Sam's and losing an additional 10 days to Hurricane Matthew. Had we known we were close to our 3,000th capture of the season we would have tried to keep better track of which bird marked the milestone. If the next three weeks continue to have good movement of Yellow-rumped Warblers then maybe we'll be able to do that for a 4,000th bird of 2016.

--Blaine

  Species Captain Sam's Little Bear
New Recaps New Recaps
Common Ground-Dove
-
-
1
-
Carolina Chickadee
-
-
-
1
House Wren
-
-
-
1
Carolina Wren
-
2
-
-
Ruby-crowned Kinglet
1
-
-
-
Gray Catbird
10
15
11
17
Brown Thrasher
-
-
-
1
Northern Mockingbird
-
-
2
-
Common Yellowthroat
-
1
1
1
American Redstart
-
-
-
1
Northern Parula
-
1
-
-
Blackpoll Warbler
1
-
-
-
Black-throated Blue Warbler
-
-
1
-
Yellow-rumped Warbler (Myrtle)
27
4
35
3
Field Sparrow
1
-
-
-
Song Sparrow
1
-
-
1
Swamp Sparrow
-
-
3
3
Northern Cardinal
-
-
-
1




 Banding Stats Captain Sam's Little Bear TOTAL
# Birds Banded
42
54
96
# of Recaptures
23
30
53
# of Species
9
13
18
Effort (net-hours)
137.8
70.0
207.8
Capture Rate (birds/100 net-hours)
47.2
120.4
71.7
# of Nets
26
20
46

Banding Staff
Aaron Given (CS)
Blaine Carnes (LB)
Mattie VandenBoom (CS)
Alison Nevins (LB)
Col Lauzau (LB)
Michael Gamble (CS)
Michael Rodgers (LB)
Ryan Donnelly (CS)
Nancy Raginski (CS)