Little Bear Ties Up the Species Count with Captain Sam's

Captain Sam's:

Hello everyone! While the muggy weather was the same, today was less slow than yesterday with 44 total captures (24 new birds, 20 recaptures). We did not have any FOS birds, but we caught another Blue-gray Gnatcatcher which was quite exciting. However, Little Bear tied Captain Sam's for total number of species today...so we're hoping to regain our lead and have some new migrants move through soon! 

This season, we've had a decent number of hatch-year Northern Cardinals find their way into our nets - 18 since 8/15, to be exact. Hatch-year Cardinals have dull, brown body feathers and a dark wash on their bill in their first few months out of the nest. Things get tricky for us later in the season, however, because hatch years start to look indistinguishable from adults. Why is this? Southern populations of Cardinals actually go through a complete pre-formative molt during their first fall 1, meaning they replace all body and flight feathers, as opposed to retaining some of their flight feathers through the winter. Thus, if a Cardinal is not exhibiting flight feather molt (meaning it is replacing juvenile feathers), brown body feathers, or darkness on the bill, we cannot confidently age it. We've already captured a few individuals that we've had to age as "Unknown", and this will only occur more often as the season goes on. 

HY Male Northern Cardinal. We call this guy "Alfalfa".
We were able to age this bird due to flight feather molt
and brown body feathers (Photo: SS).

HY unknown Northern Cardinal in full juvenile plumage.
This bird was young and had not yet begun replacing its
body or flight feathers (Photo: JL). 

1. Pyle, Peter, 1957-. Identification Guide to North American Birds : a Compendium of Information on Identifying, Ageing, and Sexing "near-Passerines" and Passerines in the Hand. Bolinas, Calif. :Slate Creek Press, 1997.

Little Bear:

We were met with another day of calm winds and warm weather. Unfortunately there wasn’t too much in the forecast that indicated many birds would be at the site. We ended our day with 23 new captures and 9 recaptures. Banding birds is always an exciting time, but we were met with the usual suspects save one first of season—a very fat after-hatch-year Swainson's Thrush (Catharus ustulatus). The amount of fat on this bird made it feel like a Mourning Dove in the hand!

A chunky after-hatch-year Swainson's Thrush (photo: Vincent)

Distribution of Swainson's Thrush

This species is a long distance migrant traveling all the way from northern Alaska south to northern Argentina. Like many paserines, they fly by night, but land for the day to refuel and regain fat reserves. A telemetry study discovered that they can travel up to 233 miles (375km) in a single night and maintain their flight for over 8 hours. During Spring migration they tend to head through the Central US and along the West Coast, but in Fall they are most concentrated in the East. The majority of the population funnels through Florida before making a nonstop flight across the Gulf of Mexico on their way to South America. We should be seeing a lot more soon. 

Oh yeah! We tied Captain Sam's for total species. They are determined to show Little Bear up. Place your bets now.

-Vincent

Citation: Mack, D. E. and W. Yong (2020). Swainson's Thrush (Catharus ustulatus), 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.swathr.01

Species	Captain Sam's		Little Bear
	New	Recaps	New	Recaps
White-eyed Vireo	-	6	-	1
Red-eyed Vireo	2	1	2	-
Carolina Wren	-	1	-	2
Blue-gray Gnatcatcher	1	-	-	-
Swainson's Thrush	1	1	1	-
Gray Catbird	2	1	-	1
Northern Mockingbird	1	-	-	-
Brown Thrasher	-	1	-	-
Yellow-breasted Chat	-	-	1	-
Ovenbird	2	1	1	-
Northern Waterthrush	-	1	1	2
Black-and-white Warbler	1	-	-	-
Common Yellowthroat	8	3	5	1
American Redstart	4	-	-	-
Yellow Warbler	-	-	1	-
Black-throated Blue Warbler	-	-	1	-
Palm Warbler	-	-	5	-
Prairie Warbler	1	-	4	-
Northern Cardinal	-	2	-	1
Painted Bunting	1	2	1	1

Today's Banding Stats	Captain Sam's	Little Bear	TOTAL
# Birds Banded	24	23	47
# of Recaptures	20	9	29
# of Species	16	15
Effort (net-hours)	138	87.4	225.4
Capture Rate (birds/100 net-hours)	31.9	26.3	29.1
# of Nets	30	23	-

2020 Fall Cumulative Banding Stats	Captain Sam's	Little Bear	TOTAL
# Birds Banded	1401	666	2067
# of Recaptures	371	126	497
# of Species	44	44	52
Effort (net-hours)	4824.31	2587.3	7411.61
Capture Rate (birds/100 net-hours)	36.7	30.6	33.7
# of Days	41	30	-

 

Banding Staff

Aaron Given (CS)
Sarah Mueller (CS)
Sarah Stewart (CS)

Dan Errichetti (CS)
Vincent Weber (LB)
Kristin Attinger (LB)