Monday, December 7, 2015

Last half of fall migration

We lost a whole week of monitoring the first week in October due to high winds and rain from the remnants of a hurricane. We finally got out on 5 October and captured 52 birds including our first Myrtle Warbler for the fall. By this date we are usually capturing many yellowrumps (Myrtle Warbler is the subspecies we typically see) but they meandered in slowly this year with good numbers not building up on Wing Island until the 17th. Shown below is a female above and male below her. Myrtle Warblers get their name from eating the berries off bayberry bushes, also called wax-myrtles. The coating on the berries is not a true wax but a substance containing fats, proteins, and carbohydrates.

Numerous Black-throated Blue Warblers were banded this fall, all in October. We had one gal that showed up on the 11th with very little fat. We captured her at least twice/week until the 27th when she was so full of fat that I'm sure she was ready to go and we didn't see her again.


We hear Red-breasted Nuthatches vocalizing most days but rarely catch them. This male was originally banded last year on 14 October and we recaptured him this year on the 6th.

On the 7th we banded one of three Lincoln's Sparrows for the fall and it was also the day of the highest diversity with 124 birds of 27 species handled.

Luckily I was so fortunate this fall to have an intern, Col Lazeau, helping me every day I went out, volunteering no less. Here she is getting a "hug" from a flicker.

Golden-crowned Kinglets, first captured on the 8th, were sparse this fall, we banded half as many as Ruby-crowned Kinglets.

Also on this day was our first of fall Northern Parula, a HY (hatch year) female. This was actually our only parula we banded this year. I thought for sure we would have captured some in the Punkhorn. They used to breed right where our nets were for the seven years we monitored that area but they were nowhere to be found this year. 

The Least Flycatcher banded on the 8th shown below was only the second one we banded on Wing Island in the past 16 seasons. This species is the smallest of the empids we typically see. 

Four more Black-throated Green Warblers were banded in October, a nice number since we typically only band one or two during the fall season. Shown below is a HY male.

Orange-crowned Warblers began showing up on the 11th and we banded seven in all. First fall females (top photo) are duller than males (bottom photo) and usually lack the hidden orange crown, although they can sometimes show a small area of orange. You can see it a bit in this photo of the male. 

Thrushes were few and far between this fall, even robins! We didn't start to hear bluebirds migrating through until the 25 Oct. We banded only a few Hermit Thrushes, no Swainson's, but did manage to capture a Gray-cheeked Thrush. We did careful measurements to rule out Bicknell's but this bird had a longer wing morphology and differing plumage characteristics from Bicknell's. Nice bird anyway!

Not only did we band a Gray-cheeked on the 14th, but also a White-eyed Vireo. Such beautiful birds! First year birds start off with a brownish iris that gradually turns gray, then white or white with a grayish wash. This bird was aged HY due to the molt limit (see arrow) between the replaced outer primary feathers (pp 5-9) and the retained inner browner-shafted and more worn juvenal feathers (pp 1-4).

One doesn't think of Northern Cardinals as migrants but every year we barely band any until October when they come through in large numbers on the island. The first year birds can go through a complete molt as the adults do so we often have to rely on other features to age them. Besides skulling, which I explained in my last post, we can look at their bill as the young are born with brown bills and change gradually to orange through the fall. By late October most have orange bills but this male may have been from a late brood with his mixed brown orange bill

and the appearance of 3 inner brown secondary feathers that had yet to be molted, shown by my white freehand drawing.

Brown Thrashers are a shy bird and compete with Gray Catbirds for territory. With the abundance and boldness of catbirds it is no wonder we only band a couple of this species per year.

I find Brown Thrashers tough to age by molt sometimes. The molt limit in the greater coverts can be hard to distinguish by color differences as the outer ones tend to have buffier tips than the inner ones almost creating a pseudolimit. But if you look at the photo below you can see a step between the longer replaced inner coverts and the three shorter retained outer coverts (where the arrow is). The color of the replaced coverts is also a richer brown. 

Black-billed Cuckoos must have been coming through this 3rd week of October as we caught one on the 17th and one the day after. Hatch year birds will have a yellowish color to the orbital ring through winter, unlike the adult which is bright red. It certainly was a year for cuckoos!

Another nice bird for the 17th was this Brown Creeper. The cryptic coloring of the feathers blends in so well with the bark of trees. If you notice a little brown bird climbing up the bark of a tree and then flying down to a tree beside it and repeating this behavior, it is most likely this little bird!

Due to very high winds on the 18th and 20th we decided to band in the Punkhorn instead of Wing as we hadn't taken down our nets there and it is protected from the wind. Most of the birds had dispersed from the area, there is no comparison between numbers of birds in fall between the two sites, but we did capture a first of the year Red-bellied Woodpecker, a female.

Males will have much more red on the head as shown below

Field Sparrows are aptly named preferring open areas. They are easily told by their bright pink bills, white eye ring and unstreaked underparts. The 'ping pong' song of the male can be heard loudly in the spring. I know we had the same individual back this year because he had an odd variation to his song that Jo-Anna and I heard often last year and he was smack dab in the same spot this year. We captured this bird on the 21st, a HY, probably not born on Wing but just passing through the area. This also happened to be our biggest day, with 192 birds processed. 

Numbers of Carolina Wrens were way down this year probably due to our previous harsh winter. We banded only 4 at Wing Island and 2 in the Punkhorn. 

Winter and Marsh Wrens didn't seem to fare much better as we banded only 1 of each this year but I imagine they are hardier species. Winter wrens are so tiny, the 'cutest' of the wrens! You might be able to tell their diminutive size by comparing my size of my fingers to the photo above.

The beautiful Marsh Wren below, who loves to spend time among the spartina grasses (and phragmities!) is easily told by the black-and-white streaked back feathers from the wrens above. Sedge wren is similar but has a streaked crown and rump.

On the 27th we banded a female Purple Finch (not the same bird pictured but looks similar because she was biting me too much!)

and  a male House Finch. 

I took a picture with the two of them to show the comparison of the shape of the bill and head between the two species, the House Finch in back and Purple Finch in front. The bill of the House Finch is more decurved. 

House Finches (right) have more streaking to the undertail coverts also. Purple Finches (left) have no to a few streaks.

We banded a number of juncos in October and November all HY birds. Here is a comparison between a male (left) with a dark gray head, throat, and upper breast and the much paler female (right).

Our last day of banding was 12 November because of predicted high winds for the following days. Overall we had a great year banding 3,181 birds of 81 species and not many days lost due to weather.

The highlight of the year was on Dec 1st. The day before I received an email about a hummingbird visiting a feeder in Harwich. I saw a picture of it and was quite intrigued! I was able to capture her and with pictures and measurements was able to identify her as a  HY female Black-chinned Hummingbird. Females of this species can look similar to female Ruby-throated Hummingbirds, the species that breeds in our area. Black-chinned Hummingbirds are a western species that typically winter in southern Texas and Mexico. Right now this is the 6th state record for Massachusetts. You can see how she resembles a Ruby-throated.
photo courtesy of Doug Meyer

Black-chinned Hummingbirds are longer-billed and longer-winged than Ruby-throated Hummingbirds and she was no exception. Her bill and wing measurements exceeded even the longest Ruby-throats. The crown of a Black-chinned is dull brownish-gray often extending to the nape and back is a duller green than seen on Ruby-throated Hummingbirds.

The shape of the outermost primary is more rounded in a Black-chinned

and more pointed in a Ruby-throated

The bill is very long on a female Black-chinned as you can see when I crop this photo

Still long on a female Ruby-throated but not as long as above.

During the banding operation I checked for fat and she had a large fat pad on her abdomen. She weighed almost 4.0 grams so I figured she probably wouldn't be around too long. After banding her and giving her a drink, I usually ask the homeowners if they would like to do the releasing and Doug agreed. Sometimes birds will sit for a few minutes before leaving but she was raring to go! Look closely above his hand and you will see her. She returned to the feeder within minutes of release. She was seen the rest of the day and the next day but then was gone. Doug said they saw her perched for about 10 minutes drinking, saw her one more time and that was it. She may have left during this stretch of warm weather. When I hosted a Rufous Hummingbird in my yard two years ago, he left the first week of December during a period of warm days.

A big thank-you to all who helped during the months of October and November. Looking forward to seeing many of you in the spring (in order of hours donated): Col Lazeau, Alex Cook, Matt Rothrock, Donna Kucia, Gretchen Putonen, Claire Revekant, Judith Bruce, Bradford Bower, Ronald Kielb, Keenan Yakola, Ben Lagasse, Maddie Nobili, Carrie Hisaoka, and Eric Russell. 

No comments: