FOS Blue-winged Warbler

 CAPTAIN SAMS 

We were dodging rain showers again this morning and had to open later due to a quickly passing shower. We were able to get a full day of banding in but Little Bear was not so lucky. Storms continued to come ashore over Little Bear and they were not able to band this morning. The weather made for a slow day with 28 new birds and 15 recaptures of 12 different species. The highlight of the morning came during closing when we captured a first-of-the-season Blue-winged Warbler! This is only the 6th Blue-winged Warbler captured on Kiawah Island - the last one in 2023. We captured one in 2020, one in 2016, and the first two in 2015. 

Blue-winged Warbler (hatch year, female)

Blue-winged warblers breed from the Ozarks to the Appalachian Mountains in shrublands and scrubby fields. They breed in inland South Carolina but Kiawah Island represents part of their migratory route as they migrate to their nonbreeding grounds in Mexico, Central America, and the Caribbean.

Over the last 150 years, landscape changes from forest clearcuts and agricultural fields to scrubby fields have allowed Blue-winged Warblers to expand their range northward where they are now in regular contact and hybridize with Golden-winged Warblers that breed in the Northeast and upper Midwest. Hybridization and competition with Blue-winged Warblers has contributed to Golden-winged Warbler population declines. Hybridization creates two distinctive and commonly seen hybrids known as Brewster's and Lawrence's Warblers. Brewster's have golden wingbars and a white belly (Golden-winged features) but a white throat (Blue-winged feature). Lawrence's have a black throat (Golden-winged feature) but white wingbars and a yellow belly (Blue-winged features). See Table below from Ontario Breeding Bird Atlas.

Interestingly, Blue-winged and Golden-winged Warblers look different, sing different songs, breed in different habitats, and winter in different places; however, these species are 99.97% genetically similar! This is compared to the differences between humans with and without freckles, which may indicate that they are not separate species after all. The genetic similarities and the propensity for these species to hybridize indicate the likelihood that these species have been intermixing for thousands of years (pre-European) and may not be a recent, human-caused occurrence.

-Michael

 

Species	Captain Sam's		Little Bear
	New	Recaps	New	Recaps
Downy Woodpecker	-	1	-	-
White-eyed Vireo	-	2	-	-
Northern House Wren	-	1	-	-
Gray Catbird	16	1	-	-
Blue-winged Warbler	1	-	-	-
Swainson's Warbler	-	1	-	-
Common Yellowthroat	4	2	-	-
American Redstart	2	1	-	-
Black-throated Blue Warbler	1	-	-	-
Palm Warbler (Western)	1	-	-	-
Northern Cardinal	-	3	-	-
Painted Bunting	3	3	-	-

Today's Banding Stats	Captain Sams	Little Bear	TOTAL
# Birds Banded	28	-	28
# of Recaptures	15	-	15
# of Species	12	-	12
Effort (net-hours)	161.8	-	161.8
Capture Rate (birds/100 net-hours)	26.6	-	26.6
# of Nets	32	-	32

2025 Fall Cumulative Banding Stats	Captain Sams	Little Bear	TOTAL
# Birds Banded	2,761	1,916	4,677
# of Recaptures	376	346	722
# of Species	62	60	74
Effort (net-hours)	8,120.2	5,674.6	13,794.8
Capture Rate (birds/100 net-hours)	38.6	39.9	39.1
# of Days	52	44

Banding Staff

Michael Gamble (CS)

Liz Held (LB)

Arden Schneider (LB)

Camille Beckwith (CS)

Jeremiah Sullivan (LB)

Amy Nickerson (CS)

Note:  All banding, marking, and sampling is being conducted under a federally authorized Bird Banding Permit issued by the U.S. Geological Survey’s Bird Banding Lab.