A little push of birds

 CAPTAIN SAMS

A small push of birds last night brought a little more excitement than we've experienced the last several slow days and we ended up with 42 newly banded birds and 4 recaptures of 16 species. Some exciting captures include a few late migrants: Northern Parula, American Redstart, and Eastern Wood-Pewee. We also heard a couple Pine Siskins flying over the banding table but had no luck in capturing any. Flocks of Yellow-rumped Warblers were flying around and we managed to catch 23 in total. Yellow-rumped Warblers are one of my favorite late season birds to see in hand because their plumage is so variable even within the same age and sex class. Molt limits in hatch year birds can vary but there is usually an alula limit (A1) or a carpal covert limit (CC) present. We use several plumage characteristics to sex these guys including color of the lesser coverts, extent of black in the centers of the back feathers and upper tail coverts, amount of black streaking to the flanks, and amount of white in the outer tail feathers. Combining all of these traits allows us to separate sexes of both age classes. 

The photo above provides a glimpse into some of the plumage differences between hatch year and after hatch year males and females. The top two birds are both hatch years with A1 limits. The three overlapping feathers close to my finger make up the alula feathers with the smallest being A1, then A2 in the middle, and A3 is the largest underneath the other two. Note how A1 on both HY birds is darker with buffy/grayish edging whereas A2 and A3 are contrastingly brown with buffy tan edging. The two bottom birds are both after hatch years and have uniform plumage without any limits. Examining the alula feathers is a quick and easy way to age Yellow-rumped Warblers because the contrast in different feather generations is usually pretty extreme. Now onto distinguishing sex in these birds… the same plumage differences can be seen in both age classes but they are often more pronounced in after hatch years. Hatch year birds can have more intermediate features and sometimes require a closer inspection. One plumage clue to use is the color of the lesser coverts, which are the small scalloped feathers on a bird’s “shoulder”. Compare the brown lesser coverts on the females to the blueish gray lesser coverts on the males. You can also look at the greater coverts, which are located beneath the lesser coverts. The females have brownish greater coverts with buffy tan edging, while the males’ are blackish with white edging. AHY males are the most distinct of all with uniformly blackish alula feathers, large dark centers to the lesser coverts, and shiny blackish flight feathers. Since Yellow-rumped Warblers migrate in flocks, we sometimes catch many at once and it provides a great opportunity to compare the differences between them and I’m crossing my fingers we’ll have more days with lots of Yellow-rumps. 

-Olivia

LITTLE BEAR

Our first round was the busiest we've had in almost a week, but activity quickly waned as the wind picked up. We ended up with a total of 21 new birds and 4 recaptures of 13 species. Similar to Captain Sams, we saw a few late migrants today including a Northern Parula, a Blackpoll Warbler, 2 Black-throated Blue Warblers, and a stunning hatch year male Cape May Warbler. We heard small flocks of Yellow-rumps flying around but only 6 of them made it into our nets. 

-Liz

Cape May Warbler (hatch year, male)

Species	Captain Sams		Little Bear
	New	Recaps	New	Recaps
Downy Woodpecker	-	1	-	-
Eastern Wood-pewee	1	-	-	-
Golden-crowned Kinglet	1	-	-	-
Ruby-crowned Kinglet	7	-	3	-
Northern House Wren	1	-	-	-
Carolina Wren	-	-	-	1
Gray Catbird	2	1	1	2
Hermit Thrush	1	-	-	-
House Finch	1	-	-	-
White-throated Sparrow	1	-	-	-
Song Sparrow	1	-	-	-
Swamp Sparrow	1	-	1	-
Eastern Towhee	-	-	1	-
Common Yellowthroat	-	-	1	-
American Redstart	1	-	-	-
Cape May Warbler	-	-	1	-
Northern Parula	1	-	1	-
Blackpoll Warbler	-	-	1	-
Black-throated Blue Warbler	-	-	2	-
Western Palm Warbler	1	-	1	-
Myrtle (yellow-rumped) Warbler	21	2	6	-
Painted Bunting	1	-	2	1

Today's Banding Stats	Captain Sams	Little Bear	TOTAL
# Birds Banded	42	21	63
# of Recaptures	4	4	7
# of Species	16	13	22
Effort (net-hours)	128.8	107.55	236.35
Capture Rate (birds/100 net-hours)	35.7	23.2	29.6
# of Nets	33	28	-

2026 Fall Cumulative Banding Stats	Captain Sams	Little Bear	TOTAL
# Birds Banded	4,364	2,568	6,932
# of Recaptures	645	428	1,073
# of Species	84	76	98
Effort (net-hours)	11,294.6	8,082.55	19,377.15
Capture Rate (birds/100 net-hours)	44.3	37.1	41.3
# of Days	75	68

Banding Staff

Michael Gamble (CS)

Liz Held (LB)

Olivia DeMarchi (CS)

Jasmine Fu (LB)

Aiden Gifford (LB)

Nick Schleissmann (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.