Tuesday, September 22, 2020

Happy Autumnal Equinox!

Captain Sam's:

Fall was in the air today at Captain Sam's as we rang in the official start of autumn with a productive day of banding. The temperature at the banding station was in the low 60's most of the morning, which was very welcome after the 90+ temperatures we were experiencing not too long ago! We had a diverse array of birds today, with 71 total captures of 16 species representing several different bird families: warblers, wrens, catbirds, woodpeckers, and buntings. We also had another first-of-season today: House Wrens, who don't breed on Kiawah Island but spend winters here.

My favorite bird of the day was a feisty adult White-eyed Vireo. Most of the White-eyes that we catch are hatch-years, which have brownish eyes that lighten to become white in adults. This bird truly lived up to the name! White-eyes inhabit scrubby areas across the southeastern US, and can easily be found by listening for their rapid song. Like other vireos, both male and female White-eyes build the nest, incubate eggs, and feed nestlings. This makes the vireos unusual among songbird species, where females typically build the nest and incubate eggs while the male defends the territory. It also makes vireos more challenging for banders to sex during the breeding season, since both males and females can develop a brood patch to help them incubate eggs more efficiently.

After hatch-year White-eyed Vireo - note the bright white eye! (Photo: SM)

-Sarah M.

Little Bear:

The wind was more favorable today than yesterday, allowing us to open the station and most of our nets. Overall it was a slower day with 36 new captures and 5 recaptures across 12 species. As has been our daily expectation, Common Yellowthroats(Geothlypis trichas) accounted for most of these birds with 25 total. Little Bear also caught its first-of-season Gray Catbird (Dumetella carolinensis). There have been a few captured at Captain Sam’s already. We will be seeing a lot more of them soon enough. Other notable captures were two Baltimore Orioles (Icterus galbula), one of which was a recapture that was banded last week. Typically this site only gets one or two of this species per season.

We also caught one of the most enigmatic species in North America — a Yellow-breasted Chat (Interia virens). This species is quite strange, and it’s place in taxonomy has been debated for years. Formerly it was lumped with warblers in the family Parulidae. However, this bird is roughly three times the size of a Common Yellowthroat and just about every other species of warbler. In 2017, the American Ornithologists’ Union finally decided to place this odd species into a family of its own—Icteriidae. There is much yet to learn about this species. Genetic sampling is needed to illuminate its phylogenentic origins. Behavioral observations are lacking, especially on breeding grounds. Their habitat is difficult for humans to move through, which is typically dense and shrubby. The molt cycle is also poorly understood.

Hatch-year Yellow-breasted Chat (Photo: Vincent Weber)
Eccentric molt pattern in the left wing (Photo: Vincent Weber) 

We are collecting data on molt for each bird we catch. The Yellow-breasted Chat from this morning was a hatch-year with an eccentric molt. This is a molt strategy where only some of a particular feather group are replaced. The primaries and secondary feathers on this bird were both only partially replaced. The outer primaries were replaced from P5-9, and the innermost secondaries S5-9. Another interesting thing we noticed on this bird was an asymmetrical molt when the right and left wings were compared. The left wing also had its P3 replaced. 

-Vincent

Citation: Eckerle, K. P. and C. F. Thompson (2020). Yellow-breasted Chat (Icteria virens), version 1.0. In Birds of the World (A. F. Poole and F. B. Gill, Editors). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.yebcha.01

 

  SpeciesCaptain Sam'sLittle Bear
NewRecapsNewRecaps
Downy Woodpecker
-
1
-
-
White-eyed Vireo
1
1
2
-
Red-eyed Vireo
2
1
1
-
House Wren
3
-
-
-
Carolina Wren
-
2
-
-
Gray Catbird
1
1
2
-
Northern Mockingbird
-
-
1
-
Yellow-breasted Chat
-
-
1
-
Baltimore Oriole
-
-
1
1
Ovenbird
1
-
-
1
Northern Waterthrush
3
1
1
-
Black-and-white Warbler
1
-
-
-
Common Yellowthroat
34
4
23
2
American Redstart
6
-
2
-
Northern Parula
1
-
-
-
Black-throated Blue Warbler
1
-
-
-
Prairie Warbler
1
1
2
-
Northern Cardinal
-
1
-
1
Painted Bunting
-
3
-
-



Today's Banding StatsCaptain Sam'sLittle BearTOTAL
# Birds Banded
55
36
91
# of Recaptures
16
5
21
# of Species
16
12
19
Effort (net-hours)
98.6
87.0
185.6
Capture Rate (birds/100 net-hours)
72.0
47.1
60.3
# of Nets
29
19
-




2020 Fall Cumulative Banding Stats Captain Sam'sLittle BearTOTAL
# Birds Banded
1224
546
1770
# of Recaptures
311
99
410
# of Species
42
38
49
Effort (net-hours)
4,314.31
2166.15
6480.46
Capture Rate (birds/100 net-hours)
35.6
29.8
33.6
# of Days3726
-

 

Banding Staff

Aaron Given (CS)
Sarah Mueller (CS)
Sarah Stewart (CS)
Dan Errichetti (CS)
Vincent Weber (LB)
Kristin Attinger (LB)
Josh Lefever (LB)