Bird Banding Blog

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All banding, marking, and sampling is conducted under a federally authorized Bird Banding Permit issued by the U.S. Geological Survey’s Bird Banding Lab (BBL).
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Spring has begun, and the first week of April saw the beginning of the 2025 bird banding season at a new station for me, Belle Isle Bird Observatory in Wayne County, Michigan. This new site is at the east end of a road (Oakway Trail) that was removed about 3 years ago to improve the hydrology on the island. The site is also close to the Nature Center which allows for public education opportunities. It is hoped that this station will be operated long-term, and the plan is to train my replacement from the volunteers and interns of under-served communities in the Detroit area. The station consists of 12 nets set up in an area that is contained within a circle of approximately 10 acres. Six of the nets are on the edges of the removed roadside, and 6 are in an adjacent second-growth woodland. In the coming years, data will show how the regeneration of these roads affects the bird life using them. The banding table, currently operated out of the back of my car, is set up at the end of the parking lot for the ADA Playground, adjacent to the parking for the Nature Center.

To start, banding will be conducted two days each week, depending on weather and availability of volunteer assistants. The spring banding season will run from the first week of April to the first week of June, and the fall banding season will run from the first week of August to the first week of November. Nets will be opened for 6 hours, starting as early as is practical, attempting to be open by sunrise, or before. After getting the net poles set up on March 27th, we opened nets for the first time this spring on April 4th. What follows includes daily reports of results, and photo highlights.

 Friday, April 4, 2025

The weather in early April can sometimes be brutal, as winter is reluctant to give way to spring. My personal banding protocol early in the season is to not open nets unless it is at least 32 degrees. Mostly there are winter residents that can tolerate the cold, but care is always taken to avoid birds getting chilled, which can include more frequent net checks. Fortunately, this first day was chilly, but not cold, and we had a good opening day. I got to the site early to open 4 nets set up with audio lures to try to catch Northern Saw-whet Owls, which mainly migrate north during March, but my hope was that there might be some stragglers. That didn't happen this morning, but we had a good diversity of other species captured once the sun came up. As expected an over-wintering American Tree Sparrow was among the species captured.

After hatch-year American Tree Sparrow

With their rufous caps, they are sometimes confused with Chipping Sparrows, are almost non-existent in Michigan in winter. And in winter, Chipping Sparrows have a lot less rufous on their caps, and have pinkish bills (black in summer). The American Tree Sparrows have black-and-yellow bills, which can be seen well in the photo below.

After hatch-year American Tree Sparrow

Tree Sparrows also have a rufous stripe behind the eye, which is black in Chipping Sparrows. A more delicate species was an Eastern Phoebe, which is the northernmost wintering flycatcher species in eastern North America. None of them stay in Michigan during winter, but survive not too far south of us by feeding on berries rather than insects. This one did fine, and was banded and on its way in a few minutes.

After hatch-year Eastern Phoebe

A few Fox Sparrows overwinter in Michigan, but they are also early migrants. So it is not clear what the status was of this one banded today.

After hatch-year Fox Sparrow

A splash of color was provided by this Common Grackle, which is another early migrant with very small numbers over-wintering.

After second-year male Common Grackle

The most common species captured today was Red-winged Blackbird, followed by Song Sparrow and American Robin, all of which are early migrants. The two White-throated Sparrows captured today were almost certainly over-wintering as their spring migration typically peaks in the first week of May. 

After hatch-year Eastern Phoeb

We discovered some frog eggs in a small vernal pond in the middle of part of the removed road, which we determined were Wood Frog eggs. This photo shows one of the dozen or so egg masses.

Banding Results for April 4, 2025

12 nets open 6:45 - 12:45 (72.0 net hours), plus 4 nets open for audio luring from 5:45 - 6:45.
Temperature: 42-47
Cloud Cover: 0-100%
Wind Direction: N-NE
Wind Speed: 1-3-10 mph
Barometer: 30.29-30.35
Precipitation: None
Sunrise: 7:08

[Downy Woodpecker - 2 recaptured, banded last October]
Northern Flicker - 2 (plus 1 released unbanded)
Eastern Phoebe - 1
American Robin - 9 (plus 2 released unbanded)
[Black-capped Chickadee - 2 recaptured, banded last October]
American Tree Sparrow - 1
Fox Sparrow - 1
Dark-eyed Junco - 3
White-throated Sparrow - 2 (plus 2 released unbanded)
Song Sparrow - 9 (plus 1 recaptured - banded last October)
Red-winged Blackbird - 14 (plus 1 released unbanded)
Common Grackle - 1
Northern Cardinal - 1

No. of species captured: 13
No. banded: 44
No. recaptured: 5
No. released unbanded: 6
Capture Rate: 76.4 per 100 net hours

Bander: Allen Chartier
Banding Assistants: Marilynn Crowley, Mark Schaller, Leah Stafford, Erika Van Kirk, Blanche Wicke.

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Sunday, April 6, 2025

Today was a bit colder and windier than the first banding day, but with good diversity although lower numbers. Several volunteers came out to help today. Here is a photo of them happily making the rounds to check nets in their winter attire.

Audio luring for owls was done again this morning, but no owls were caught. But the early start allowed us to hear American Woodcocks displaying before dawn, and once the nets were open 30 minutes before sunrise, we had one in the nets!

Second-year female American Woodcock

I walked her over to the edge of the woods to release her, and she slowly walked off as if she thought I couldn't see her. To be honest, she's not that easy to see in the photo below.

Second-year female American Woodcock

Brown Creepers are expected early migrants, with our first two captured today.

After hatch-year Brown Creeper

Less expected was this Field Sparrow, which is extremely scarce in Michigan in winter, so this was clearly a migrant, a bit early.

After hatch-year Field Sparrow

Field Sparrows can be told apart from American Tree Sparrows by their pink bills and prominent white eye ring.

After hatch-year Field Sparrow

More American Tree Sparrows were banded today, and new arrivals incl8uded Golden-crowned Kinglet, Hermit Thrush, and Swamp Sparrow.

Banding Results for April 6, 2025

12 nets open 6:30 - 12:30 (72.0 net hours), plus 4 nets open for audio luring from 5:30 - 6:30.
Temperature: 38-42
Cloud Cover: 100-80%
Wind Direction: N-NE
Wind Speed: 7-10 mph
Barometer: 30.11-30.11
Precipitation: None
Sunrise: 7:05

American Woodcock - 1
Northern Flicker - 1
Blue Jay - 1
[Tufted Titmouse - 1 recaptured, banded last October]
Golden-crowned Kinglet - 1
Brown Creeper - 2
Hermit Thrush - 1
European Starling - 4
American Tree Sparrow - 3
Field Sparrow - 1
Fox Sparrow - 1
Dark-eyed Junco - 1
White-throated Sparrow - 3
Swamp Sparrow - 1
Song Sparrow - 10 (plus 2 recaptured)
Red-winged Blackbird - 2

No. of species captured: 16
No. banded: 33
No. recaptured: 3
No. released unbanded: 0
Capture Rate: 50.0 per 100 net hours

Bander: Allen Chartier
Banding Assistants: Shelly Andrews, Alexa Blankenship, Guadalupe Cummins, Mark Schaller, Ben Sehl, Blanche Wicke, Nicholas Yerkes.

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Friday, April 11, 2025

Today was another chilly and windy day, with lower numbers than the first two days. Little migration occurs this early in April. Three more Field Sparrows today were a pleasant surprise.

After hatch-year Field Sparrow

The day was dominated by winter residents and early migrants, including American Tree Sparrow, Dark-eyed Junco, Brown Creeper, and Fox Sparrow.

Banding Results for April 11, 2025

12 nets open 6:45 - 12:45 (72.0 net hours).
Temperature: 35-47
Cloud Cover: 100-20-40%
Wind Direction: N-NE
Wind Speed: 5-7-12 mph
Barometer: 30.17-30.18
Precipitation: None
Sunrise: 6:56

Brown Creeper - 2 (plus 2 recaptured)
American Robin - 2 (plus 3 recaptured)
American Tree Sparrow - 1
Field Sparrow - 3
Fox Sparrow - 1
Dark-eyed Junco - 1
White-throated Sparrow - 1 (plus 1 recaptured)
Song Sparrow - 2 (plus 3 recaptured)
Red-winged Blackbird - 2
Common Grackle - 1
Northern Cardinal - 2

No. of species captured: 11
No. banded: 18
No. recaptured: 8
No. released unbanded: 0
Capture Rate: 36.1 per 100 net hours

Bander: Allen Chartier
Banding Assistants: Shelly Andrews.Alexa Blankenship, Mike Charlebois, Marilynn Crowley, Diana Dugall, Erin Ford, Erika Van Kirk, Sue Wright.

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Sunday, April 13, 2025

Warmer conditions today brought some (human) visitors to the station for the first time this spring, as well as our first Tree Swallow.

After hatch-year male Tree Swallow

For the 4th banding day in a row, a Fox Sparrow was banded. And another Northern Flicker today was more than I had been expecting.

After second-year male Northern Flicker

The eastern subspecies used to be considered a separate species, called the Yellow-shafted Flicker, which is obvious when you see its spread wings.

After second-year male Northern Flicker

This also allows a bander to evaluate the bird's molt, with older and newer feathers appearing subtly different, and allowing it to be aged.

Banding Results for April 13, 2025

12 nets open 6:45 - 12:45 (72.0 net hours).
Temperature: 43-58
Cloud Cover: 90-40-70%
Wind Direction: WSW-SW
Wind Speed: 5-7-12 mph
Barometer: 30.14-30.07
Precipitation: None
Sunrise: 6:53

[Downy Woodpecker - 1 recaptured]
Northern Flicker - 1
Eastern Phoebe - 2
Blue Jay - 1
Tree Swallow - 1
American Robin - 2
[European Starling - 1 recaptured]
American Tree Sparrow - 1
Fox Sparrow - 1
White-throated Sparrow - 1 (plus 1 recaptured)
Song Sparrow - 1 (plus 1 recaptured)
Red-winged Blackbird - 4 (plus 1 released unbanded)
Northern Cardinal - 1 (plus 1 released unbanded)

No. of species captured: 13
No. banded: 16
No. recaptured: 4
No. released unbanded: 2
Capture Rate: 30.6 per 100 net hours

Bander: Allen Chartier
Banding Assistants: Mike Charlebois, Danielle Hawkins, Wren Haynes, Vikay Kaz, Guy Lenk, Nolan Lenk, Mark Schaller, Sue Wright.

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Thursday, April 17, 2025

Winter asserted itself once again, with the coldest start so far. Volunteer assistants were still bundled up at the start of the day, but the temperatures reached into the 50s and the wind was not a factor for the first time this spring.

One of the highlights today was a nice female Yellow-bellied Sapsucker. Females have white throats while males have red throats.

Second-year female Yellow-bellied Sapsucker

Second-year female Yellow-bellied Sapsucker

Another highlight today was a female Eastern Towhee. This one had a reddish-brown eye but no signs of molt contrast, so was difficult to age more precisely than after hatch-year.

After hatch-year female Eastern Towhee

A few more Hermit Thrushes were banded today, and the streak of Fox Sparrows continued (5 days, 5 Fox Sparrows banded). More Field Sparrows and a Northern Flicker brought the season totals higher than was typical at my previous banding stations. A handful of visitors stopped by the station today.

Banding Results for April 17, 2025

12 nets open 6:45 - 12:45 (72.0 net hours).
Temperature: 34-55
Cloud Cover: 10-20%
Wind Direction: Calm-SE
Wind Speed: 0-5 mph
Barometer: 30.21-30.16
Precipitation: None
Sunrise: 6:47

Yellow-bellied Sapsucker - 1
Northern Flicker - 1
Golden-crowned Kinglet - 1
Brown Creeper - 1
Hermit Thrush - 3
American Robin - 3 (plus 3 recaptured)
European Starling - 1
Field Sparrow - 2
Fox Sparrow - 1
White-throated Sparrow - 3 (plus 3 recaptured)
Swamp Sparrow - 1
Song Sparrow - 5 (plus 3 recaptured)
Eastern Towhee - 1
Red-winged Blackbird - 2
Brown-headed Cowbird - 1
Northern Cardinal - 1 (plus 1 recaptured)

No. of species captured: 16
No. banded: 29
No. recaptured: 10
No. released unbanded: 0
Capture Rate: 54.2 per 100 net hours

Bander: Allen Chartier
Banding Assistants: Nancy Butler, Mike Charlebois, Marilynn Crowley, David Dimitrie, Mark Schaller, Nate Spala, Blanche Wicke.

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Saturday, April 19, 2025

Finally, a day with normal temperatures for this time of year, although once again the wind was a factor. And rain was a factor too, although for most of the morning there were intermittent brief periods of light sprinkles, not lasting long enough to get out to close nets. But eventually the steady rain moved in, forcing us to close the nets an hour early. 

Today's highlights included some species we'd been hearing in the banding area for a couple weeks. One of those was a Brown Thrasher. 

Second-year Brown Thrasher

We had been hearing a Winter Wren singing for a couple weeks, and today finally caught one. It was overshadowed, though, by a rather early House Wren which we only started hearing singing today. Changes in bird names occur every year, and now our birds are called Northern House Wrens because those in South America are considered a separate species now (along with the ones on Cozumel, and on some islands in the Caribbean).

After hatch-year Northern House Wren

Yellow-rumped Warblers are among the earliest warblers to arrive, and we had been hearing them for about a week before finally catching one today.

After hatch-year male Yellow-rumped Warbler

Yet another Field Sparrow was banded today, along with several Hermit Thrushes and the first Ruby-crowned Kinglet of the season. The warm conditions brought out some dragonflies, all of them Green Darners which are migratory but also breed locally.

Green Darner (Anax junius)

The one caught in the nets today was quite fresh, so I'm guessing it was a local. Only a couple visitors came by today.

Banding Results for April 19, 2025

12 nets open 6:45 - 11:45 (60.0 net hours).
Temperature: 69-64
Cloud Cover: 100%
Wind Direction: SW-W
Wind Speed: 7-10-12 mph
Barometer: 29.78-30.00
Precipitation: Trace rain in a.m., rain forced early close
Sunrise: 6:43

Downy Woodpecker - 1
Northern Flicker - 1 (plus 1 released unbanded)
Ruby-crowned Kinglet - 1
Winter Wren - 1
Northern House Wren - 1
Hermit Thrush - 8
American Robin - 1
Brown Thrasher - 1
Yellow-rumped Warbler - 1
Field Sparrow - 1
White-throated Sparrow - 56 (plus 1 recaptured, 1 released unbanded)
Swamp Sparrow - 4 (plus 1 recaptured)
Song Sparrow - 3
Red-winged Blackbird - 2 (plus 1 recaptured)
[Northern Cardinal - 1 recaptured]

No. of species captured: 15
No. banded: 31
No. recaptured: 4
No. released unbanded: 2
Capture Rate: 61.7 per 100 net hours

Bander: Allen Chartier
Banding Assistants: Alexa Blankenship, Mike Charlebois, Guadalupe Cummins, Pierre hendricks, Nate Spala, Erika Van Kirk, Blanche Wicke.

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Thursday, April 24, 2025

The weather today swung to warmer than normal, resulting in good diversity that included three species of warbler, none of them the expected Yellow-rumped. Another early migrant warbler is the Palm Warbler, so the two banded today were pretty much on time.

 

After hatch-year male Palm Warbler

The extent of chestnut on the crown can be useful for determining the sex of Palm Warblers, but this is based on measurements not on an approximate visual assessment as there are many intermediates.

After hatch-year male Palm Warbler

The other two warbler species banded today were both somewhat early, including this Ovenbird. The pale fringes on the coverts and very narrow cinnamon edges on the tertials allowed it to be aged as second-year.

Second-year Ovenbird

A Northern Waterthrush today was also unexpected and early. 

After hatch-year Northern Waterthrush

The very similar Louisiana Waterthrush migrates earlier in April, with Michigan at the northern edge of its breeding range. But despite this bird's bright white supercilium, the spotting on the throat is diagnostic for Northern as Louisiana has a clean white throat (and a notably larger bill).

After hatch-year Northern Waterthrush

The first influx of migrant White-throated Sparrows came in today. Other highlights included a late American Tree Sparrow, and another Brown Thrasher. The season's second Eastern Towhee today was a male. 

Second-year male Eastern Towhee

This one was a good lesson in using more than one character to determine a bird's age. Eye color can be helpful, with juveniles in fall having brown eyes which can be either brown or red by the following spring. This one with red eyes was showing some duller primaries and secondaries mixed in with blacker ones, and also had a couple of juvenile-type coverts with tiny spots on them (not, it isn't a Spotted Towhee!). 

Second-year male Eastern Towhee

Another Tree Swallow was banded today, and also two non-natives; European Starling and House Sparrow. Many stations do not band non-natives, but given our location within an urban setting, we will band whatever birds we catch in the hopes that we will learn something, and allows for educational opportunities with the public. A handful of visitors stopped by today.

Banding Results for April 24, 2025

12 nets open 6:30 - 11:30 (72.0 net hours).
Temperature: 41-77
Cloud Cover: 10-50%
Wind Direction: WNW-SW
Wind Speed: 1-3-5 mph
Barometer: 30.18-30.14
Precipitation: None
Sunrise: 6:36

Northern Flicker - 1
Blue Jay - 1
Tree Swallow - 1
Ruby-crowned Kinglet - 1
Hermit Thrush - 4
American Robin - 1 (plus 1 recaptured)
Brown Thrasher - 1
European Starling - 1
House Sparrow - 1
Ovenbird - 1
Northern Waterthrush - 1
Palm Warbler - 2
American Tree Sparrow - 1
White-throated Sparrow - 12
Song Sparrow - 2 (plus 2 recaptured)
Eastern Towhee - 1
Red-winged Blackbird - 4 (plus 1 recaptured, 1 released unbanded)
Brown-headed Cowbird - 3 (plus 1 recaptured)

No. of species captured: 18
No. banded: 40
No. recaptured: 4
No. released unbanded: 2
Capture Rate: 63.9 per 100 net hours

Bander: Allen Chartier
Banding Assistants: Mike Charlebois, Marilynn Crowley, Erin Ford, Blanche Wicke.

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Sunday, April 27, 2025

Today was near normal temperatures (a bit cool) with sunny conditions and yet again wind was a factor. A few warblers had come in since the 24th, as we had an increase in Yellow-rumped and Palms, along with two more somewhat early Northern Waterthrushes. A new species for the spring was a male Common Yellowthroat.

After second-year male Common Yellowthroat

Males with some mottled brown in the black mask are likely second-year birds, but those with all-black can be either second-year or after second-year. So, looking at the shape and wear of the primary coverts is necessary to determine their age more precisely. Some are intermediate so can only be aged as after hatch-year.

After second-year male Common Yellowthroat

The first Gray Catbird of the season was banded today, which had only recently arrived a few days before. 

Second-year Gray Catbird

A few visitors came by today, including the naturalist at the Nature Center with two dozen Girl Scouts. A noisy American Robin that I was banding at the time drew their attention, which allowed us to invite them over to watch it, and a recaptured Brown Thrasher, being processed at the banding table.

Banding Results for April 27, 2025

12 nets open 6:30 - 11:30 (72.0 net hours).
Temperature: 43-59
Cloud Cover: 0-20%
Wind Direction: W-NE
Wind Speed: 5-7-10 mph
Barometer: 30.32-30.33
Precipitation: None
Sunrise: 6:32

[Downy Woodpecker - 1 recaptured]
American Robin - 1
Gray Catbird - 1
[Brown Thrasher - 1 recaptured]
[European Starling - 1 recaptured]
Northern Waterthrush - 2
Common Yellowthroat - 1
Palm Warbler - 3
Yellow-rumped Warbler - 8 (plus 2 released unbanded)
Field Sparrow - 1
White-throated Sparrow - 8
Swamp Sparrow - 3 (plus 1 recaptured)
Song Sparrow - 1
Red-winged Blackbird - 9 (plus 1 recaptured, 1 released unbanded)
[Brown-headed Cowbird - 1 recaptured]

No. of species captured: 15
No. banded: 38
No. recaptured: 6
No. released unbanded: 3
Capture Rate: 65.3 per 100 net hours

Bander: Allen Chartier
Banding Assistants: Shelly Andrews, Alexa Blankenship, April Campbell, Mike Charlebois, Kaina Gonzalez, Guy Lenk, Nolan Lenk, Matthew Porter, Blanche Wicke.

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