Ageing and Sexing Hatch Year Baltimore Orioles

 CAPTAIN SAMS

We experienced the coolest morning of the fall with the thermometer reading 66.6 degrees at sunrise. Coupled with a stiff breeze, it was almost chilly! Despite a decent amount of bird movement on the radar last night, we had a pretty slow day with only 16 new birds and 4 recaptures of 9 species. The winds were out of the northeast which oftentimes is not very good for pushing migrants to us as they steered more inland. 

One highlight was a Baltimore Oriole. We only band a handful orioles each fall - mostly Baltimore and rarely Orchard. Today's bird was a young (hatch-year) male. Juvenile male Baltimore Orioles more closely resemble females and lack the distinct black head of the adult male however there are a few characteristics that we can look at to help us determine the sex.

1. Wing size - there is a fairly good difference in wing length with males above 91 mm and females below.  

2. Upper wing bars - in young males, the white wing bar will have a good amount of yellow in it compared to just whitish in young females.

3. Color of lesser coverts - the lesser coverts will be blacker in young males compared to a dusky or grayish color in young females.

4. Color of throat and breast - young males tend to be brighter orange compared to more yellowish in young females. However, young males can look similar to adult females. 

Baltimore Oriole (hatch-year, male)

Most of the time when we are ageing Baltimore Orioles, the molt limit is within the greater coverts (see below). The replaced preformative feathers are highlighted in yellow and the unreplaced juvenal feathers are highlighted in red. Note that the replaced greater coverts are slightly longer, and darker compared to the duller unreplaced feathers.
   

Baltimore Oriole  (hatch-year, male)

-Aaron

LITTLE BEAR

It was a windy day at Little Bear, with half our nets never even getting opened. This contributed to a very small number of captures with only a few new bands and a couple of recaptures. One of the recaptures, a young, and incredibly nippy, Northern Cardinal made herself memorable with several enthusiastic and well-placed bites. Hopefully the wind dies down soon and more birds work their way in soon!

-Jeremiah

Species	Captain Sam's		Little Bear
	New	Recaps	New	Recaps
Downy Woodpecker	-	1	-	-
Baltimore Oriole	1	-	-	-
Ovenbird	2	-	-	-
Northern Waterthrush	2	1	-	-
Common Yellowthroat	7	-	3	-
Hooded Warbler	-	1	-	-
American Redstart	1	-	1	-
Yellow Warbler	1	-	1	-
Northern Cardinal	-	-	-	2
Painted Bunting	2	1	1	-

Today's Banding Stats	Captain Sams	Little Bear	TOTAL
# Birds Banded	16	6	22
# of Recaptures	4	2	6
# of Species	9	5	10
Effort (net-hours)	137.1	55.3	192.4
Capture Rate (birds/100 net-hours)	14.6	14.5	14.6
# of Nets	32	14	-

2025 Fall Cumulative Banding Stats	Captain Sams	Little Bear	TOTAL
# Birds Banded	310	167	477
# of Recaptures	75	57	132
# of Species	30	23	35
Effort (net-hours)	2244.75	1012.25	3257.0
Capture Rate (birds/100 net-hours)	17.2	22.1	18.7
# of Days	16	9

Banding Staff

Aaron Given (CS)

Michael Gamble (CS)

Liz Held (LB)

Arden Schneider (LB)

Camille Beckwith (CS)

Jeremiah Sullivan (LB)

Aidan Given (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.