Wednesday, May 9, 2012

Late March-30 April

We had a mild winter on Cape Cod this year with temps warm enough that I could have banded throughout the winter. I had no nets set up at my yard feeders so I was chomping at the bit by March. We did have numerous turkeys visiting our yard in March and it was fun being so close to displaying males. The pictures aren't the best as they were taken through a window.

Many people put their feeders out in March with reports of early migrating Ruby-throated Hummingbirds. I had a call from a person in Dennis who had a hummingbird at her feeder the day after she put hers out. She recognized it as a Selasphorus since I had banded a Rufous Hummingbird at her house in 2007. I went over the next day (25 March) and it turned out she had an Allen's Hummingbird, which I believe is our 4th state record. This After Hatching Year male had an all green back,

a lancelot shaped r2 and very thin r5 measuring 1.2mm,

and a very beautiful orange colored gorget.

Our first official banding day on Wing Island was 13 April. We still had two nets to install with others needing to be reset so we opened on the later side and couldn't open all of our nets. We captured two American Goldfinches together, a probable pair, both SY (second year) birds. The male was halfway finishing up his prealternate molt into breeding plumage.

We also banded our first of numerous Swamp Sparrows

and five birds returned to us from previous years including a 5 year old Song Sparrow

and a SY Carolina Wren of unknown sex.

The next day we recaptured a Hermit Thrush first banded last year

as a HY (hatch year) bird. The teardrop buffy edging to the coverts indicate a SY bird.

Our first White-throated Sparrows graced the nets and could be heard singing all around the island. White-throats are just moving through at this time as they head further north to breed.

The 16th proved to be our best day with 52 birds handled including our first ever Brown Creeper in the spring.

A handsome ASY (after second year) Gray Catbird was captured, the first of many! We didn't capture another one until May.

Young Northern Cardinals can go through a complete molt as adults do so in the spring unless we see a molt limit, birds are aged as AHY (after hatch year). We captured a female cardinal and were able

to age her as a SY due to retained juvenal tertials (s8 and 9), those two brownish flight feathers closest to my thumb.

Warblers this day include yellow-rumps, or Myrtle Warblers, one of our earliest warblers to migrate north. Many yellow-rumps spend the winter on cape. Pictured below is an ASY male.

Yellow Palm Warblers were passing through too, banding six new birds.

Pyle says that most Palm Warblers cannot be sexed by plumage alone except for possibly the length of the crown patch, but more study is needed. In this case the crown patch measured 21mm, on the highest end for an older adult male. We will send his sex in the BBL as unknown with a note that we suspect male. 

Other birds gracing our nets were an unwelcomed guest, a male House Sparrow, although if he didn't have such a bad reputation we would consider him quite handsome!

After our 'big' day on the 16th, numbers of birds plummeted to 20 or less per day, numbers more consistent with April. Additional unwelcomed guests were found on the 17th, male (first below) and female (second below)Brown-headed Cowbirds.

Cowbirds can have a complete molt as a first year bird so we typically age them as AHY (after hatch year) at this time of year. The male appeared to have a retained juvenal greater covert (the brownish feather among the other black coverts) so we aged him as SY.  

We can also look to see if there is a molt limit in the underwing coverts. We found more brown juvenal feathers among one of the feather tracts (above the middle of my thumbnail).

Eastern Towhees arrived on the 20th, both SY males. The male below appeared to have a lack of melanin showing a washed out appearance.

They were aged SY by a molt limit in the wings, retained primary coverts and replaced greater coverts.

Although we've heard them singing all around us, we didn't capture a Pine Warbler until this day a SY female.

The most interesting bird on the 20th was a Savannah Sparrow.
Reading about molt in Pyle, Savannah Sparrows have a partial molt in their first year, replacing all median and greater coverts, 1-3 tertials (secondaries 7-9) in most birds, and no rectrices (tail feathers). The photo below shows juvenal rects with a growth bar. As far as the tertials go, the bird replaced s8 and 9 on  the right wing, but only s9 on the left wing all pointing to a SY bird.
But on examination of the whole wing, it appeared this bird had replaced some inner primary coverts which were much wider, darker, edged in buff while the retained pcovs were very abraded, lighter and lacked edging. The same pattern appeared in both wings. It was hard to get a great picture of this as lighting wasn't very good. Some of the primaries/secondaries looked replaced too. Some birds just leave me stumped!

Thanks very much to those who helped out this month- Jo-Anna Ghadban,  Jessica Rempel, Alice Wynne, and Judith Bruce.
The following is a list of birds seen, heard, or captured (with numbers) during April.

Total birds: 166                                           Total species: 58
Total banded species: 20                             Birds/100 net-hrs: 23

Great Blue Heron
Canada Goose
American Black Duck
Common Eider
Turkey Vulture
Red-tailed Hawk
Northern Bobwhite
Greater Yellowlegs
Solitary Sandpiper
Laughing Gull
Ring-billed Gull
Herring Gull
Great Black-backed Gull
Mourning Dove-1
Great Horned Owl
Mourning Dove
Belted Kingfisher
Red-bellied Woodpecker
Downy Woodpecker-2
Hairy Woodpecker
Yellow-shafted Flicker
Eastern Phoebe
Tree Swallow
Blue Jay
American Crow
Fish Crow
Black-capped Chickadee-40
Tufted Titmouse-7
Brown Creeper-1
Carolina Wren-9
Golden-crowned Kinglet
Eastern Bluebird
Hermit Thrush-6
American Robin
Gray Catbird-1
European Starling
Yellow Warbler
Yellow-rumped (Myrtle) Warbler-5
Pine Warbler-2
Yellow Palm Warbler-6
Northern Cardinal-11
Eastern Towhee-2
Chipping Sparrow
Savannah Sparrow-1
Song Sparrow-30
Swamp Sparrow-4
White-throated Sparrow-14
Red-winged Blackbird
Common Grackle
Brown-headed Cowbird-7
House Finch
American Goldfinch-13
House Sparrow-4


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