Monday, April 25, 2016

Lake St. Clair Metropark Bird Banding Report - April 23, 2016

This week, once again, I was able to band on only one day. This time, though, it was my fault as I did have volunteers for another day but my personal schedule changed at the last minute and conflicted with banding. Next week looks good for banding on two days!

Saturday, April 23, started out chilly at 37 degrees, and warmed up to 54. But the moderate north wind and cloudless sky may have reduced our catch because the nets were quite visible. The slow pace of leaf-out (non-existent so far), also made the nets visible to birds.

A second-year female Northern Flicker was a nice capture, and the second one so far this spring.
Second-year female Northern Flicker

Ageing woodpeckers is a bit tricky, and I will not claim to be an expert on this, but I am starting to get the hang of it thanks to a "key" that was distributed to banders a few years ago. Unfortunately, I don't remember who sent it out, but it has been very helpful. Woodpeckers are aged based on molt patterns, including primary coverts, primaries, and secondaries. There is variation in this pattern, which makes it more challenging. For example, the two Yellow-bellied Sapsuckers banded on April 3 had two different patterns on their primary coverts, but were both aged as after second-year. The brown plumage of flickers is also more challenging than the black plumage of most other woodpeckers. It appeared to me that this female had two different ages of primary coverts, with the outer two new and fresh, with the remaining ones worn and duller. In spring, flickers with a "molt limit" in the primary coverts, and only two ages (they can have up to three), indicates a second-year bird.
Second-year female Northern Flicker

Many of the flickers we catch seem to have soil encrusted on their bills, an indication of their partially terrestrial feeding habits.
Second-year female Northern Flicker

At the Point Rosa Marsh station, we banded a total of 14 Blue-gray Gnatcatchers over 10 years (10 in spring),with the earliest on 25 April, so it was nice to catch one today, beating that date by two days. As males of many species typically arrive first, it was interesting that this was a female.
After hatch-year female Blue-gray Gnatcatcher

It can be sexed as female, in the spring, by the lack of black eyebrow.
After hatch-year female Blue-gray Gnatcatcher

The kinglet captures today were all Ruby-crowned, and mostly males. So we are seeing a transition from Golden-crowned, which have mostly departed to the north, to the later-migrating Ruby-crowned. 

One expectation I had for this new banding site in the park was that because it was not marsh and swamp like the previous site, we would not catch very many Swamp Sparrows. So far, that expectation has been altered by the capture of several each day so far.
After hatch-year Swamp Sparrow

One assumption that some birders make is that the individuals with more extensive rufous in the crown are males, or older birds. But as banders, we do not have ANY plumage criteria that allow us to assign a sex to them, and ageing is done by the extent of skull ossification in the fall, and subtle molt criteria (in the primary coverts) in the spring. It is true that juveniles in late summer will never have rufous in the crown, but beyond that, birders should chalk the differences observed in crown color up to individual variation. The Swamp Sparrow shown below was also captured today, with obviously much less rufous.
After hatch-year Swamp Sparrow

When starting this new banding station, I wrestled with whether or not I'd band any European Starlings or House Sparrows. Some stations release these non-native (invasive) species unbanded. At the Point Rosa Marsh station, I was banding them because my predecessor (Ellie Cox) had banded them. I decided that I would band everything captured at this station, though if in the fall I end up catching too many I will likely release some if I get too busy. Today we banded one of each, including the male House Sparrow below.
After hatch-year male House Sparrow

This bird shows its black bib in transition from smaller in winter to larger in summer. Unlike many species, this is not because of molt, but due to feather wear. The broad pale gray tips on the throat feathers that are molted in the fall gradually wear off until in spring only the black bases remain.

Probably THE highlight of the day came in the form of a recaptured female American Goldfinch. Not only was it banded at the Point Rosa Marsh station, 0.4 miles away, but she was banded in 2010 as a second-year female. That makes her 6 years 10 months old!
7th year female American Goldfinch

Interesting birds observed, but not banded, included three flyover Common Loons,  two flyover Sandhill Cranes, a Yellow-bellied Sapsucker in a tree next to the banding table, and a singing Pine Warbler in the pines near the bike path.

It was nice having a couple of friends drop by and watch for a while; Janet Hug and Don Burlett.

Thanks to the many volunteers who helped out today, including: Andrea Charlebois, Jacob Charlebois, Caitlyn Hogan, Stevie Kuroda, Katie-Ann McKlinsky, Edie Schmitz, Joan Tisdale, and Blanche Wicke.

Bird Banding Results

April 23, 2016

Time open (E.S.T.): 5:30
Time closed (E.S.T.): 12:45
Hours Open: 7.25
Net Hours: 119.125
Temperature (F): 37-54
Cloud Cover: 0-10%
Wind Direction: N
Wind Speed (mph): 7-10
Barometer: 30.18 - 30.24
Precipitation: None
No. Banded: 50 (plus 13 recaptured)
Species Captured: 17
Capture Rate (#/100 net hours): 52.9
Banding Assistants (9.0 hours worked): Andrea Charlebois (2.0 hrs), Jacob Charlebois (5.5 hrs), Caitlyn Hogan (5.5 hrs), Stevie Kuroda, Kaitie-Ann McKlinsky, Edie Schmitz, Joan Tisdale, Blanche Wicke.

[Downy Woodpecker - 1 recaptured]
Northern Flicker - 1
Tree Swallow - 2
Black-capped Chickadee - 1 (plus 5 recaptured)
Ruby-crowned Kinglet - 14
Blue-gray Gnatcatcher - 1
Hermit Thrush - 1
American Robin - 1
European Starling - 1
Song Sparrow - 1 (plus 3 recaptured)
Swamp Sparrow - 7
White-throated Sparrow - 3
Northern Cardinal - 4 (plus 2 recaptured)
Red-winged Blackbird - 6 (plus 1 recaptured)
Common Grackle - 3
American Goldfinch - 3 (plus 1 recaptured)
House Sparrow - 1

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