Monday, June 15, 2015

Spring migration 2015

Our first banding day at Wing Island  on 16 April got off to a slow start with only 21 birds captured of 5 species. The day was cold with a starting temp of 38 degrees F although sunny. We banded goldfinches, numerous chickadees, a Northern Cardinal with probable avian pox on his bill as a piece of the upper mandible was broken off and a sore was seen on it too. Birds with healthy immune systems can clear their bodies of the virus eventually and I've even seen evidence of bills growing back. We once had a Pine Warbler that I documented as having the tip of the bill broken off and when this bird was recaptured the following year the bill had grown back and the line of new growth was seen.

Probably the best bird of the day was a handsome White-throated Sparrow.

Wing Island is quite exposed to the elements so with high winds and some rain we weren't able to band again until the 22nd. While it was another slow day, we did have a nice variety including a male Ruby-crowned Kinglet,

a female Eastern Towhee, 

and Savannah Sparrow. 

On the 29th we captured an Orange-crowned Warbler, our first ever for spring!

We sexed him as a male due to the large orange patch on his crown.

It was around this time that we began to see numerous foxes on the island and as you can imagine foxes and bird banding don't mix. I was forced to keep many nets closed and monitor those we had open constantly so I decided the best thing to do was to shut the station down sadly after 16 years. I see this as a temporary measure as populations ebb and flow. But I did notice a direct correlation between the banning of dogs on Wing Island for most of the year and an increase of foxes.We used to see minks and weasels, now they are nowhere to be found and it appears the foxes have eaten all the skunks too! Sometimes the good intentions by man can have unforeseen consequences...

On a happier note, I decided to reopen our field station in the Punkhorn Parklands that we used as a MAPS (Monitoring Avian Productivity and Survivorship) program but was closed down in 2009. This is on town-owned land in Brewster only a few miles from Wing Island and actually connects through waterways. The area is comprised of approximately 896 acres of fresh water swamps, overgrown cranberry bogs and upland forest. This is actually a better spring site than Wing Island because it isn't as exposed to the harsh coastal winds. We will miss our Prairie Warblers and Sharp-tailed Sparrows but will see plenty of Ovenbirds and Black-and-white Warblers; Scarlet Tanagers breed there also. For many years Northern Parulas bred at our site but I haven't heard or seen one yet this year in the banding area. 

It was a lot of work clearing net lanes and establishing new ones so we missed many days for set up. Our first banding day in Punkhorn was 10 May and we were pleased to capture 2 Black-and White Warblers, both females, the first being an ASY (after second year)

and a SY (second year) bird.
She was much duller with a molt limit seen at the alula covert (A1). The arrow is pointing to A2 and you can see the white at the tip is broken. On an ASY bird this white would travel around the feather forming a "V". 

Other birds banded today were chickadees, Common Yellowthroats, towhees, cardinals, catbirds, Ovenbird (below)

and a handsome ASY male Red-winged Blackbird. 

Here is a comparison of a SY male that we caught in June.

Our best day for the spring was on 17 May. We captured 74 birds of 13 species for a capture rate of 131 birds/100 net-hours. That number far exceeds our spring capture rate at Wing for a 15 year average on our best day of 45.2 birds/100 net-hours.  Some of the birds captured this day include an ASY female Black-throated Green Warbler,

one of the many Great-crested Flycatchers that have been serenading us,

a Lincoln's Sparrow, 

and both a female and male Ruby-throated Hummingbird. 

While we didn't have as many birds on the 19th, it was still a super day. It was the first day I started hearing Black-billed Cuckoos (shown below) and we were fortunate enough to capture one in the net. I've been hearing at least 3 in different directions most days I go out and also had a Yellow-billed one morning. There are plenty of caterpillars around for sure! We couldn't discern any molt pattern in this bird so we opted to age it as an AHY (after hatch year) since molt patterns can be tricky in this species.

While the cuckoo was exciting, perhaps the best bird of the day was an Alder Flycatcher! He was vocalizing very close to one of our nets and as I approached the net he flew right in. We've been hearing him every day at the time of this writing so I hope he attracts a mate, it would be a great breeding record for the cape. 

He had a very green back and the crown spots on his head were quite large.

We also captured a common bird we don't often get in the net, a White-breasted Nuthatch. I love the way their bill points upward.

The black head and nape is distinctive for a male, the female's head is gray and blends in with the back. 

Their very long hind claw and sharply curved front claws are adapted to help them go down tree trunks headfirst!

The 23rd was a very windy day and I normally wouldn't have banded had we been at Wing Island. Many of our nets are situated in gullies in Punkhorn and so are sheltered . We didn't have many birds but did capture a nice Blackpoll Warbler. The wind was blowing at a good clip around the banding table.

This was an interesting Common Yellowthroat we captured with yellow lores. 

And this guy below has the potential to be the oldest Common Yellowthroat on record according to the BBL (Bird Banding Lab) as right now they have the oldest as 10 years 11 months. He was first banded in 2004 during a MAPS banding day as a HY on 3 July. In June he would be 11 years old (but aged as 12Y because he is in his 12th year). All birds are considered to be born in June. So if we capture him again this year the BBL will have to update their age for yellowthroats! He had many yellow feathers above his black mask which was interesting too. 

We also recaptured an old Black-and-white Warbler, that we aged A9Y (after 9th year) since he was aged as ASY at first capture in 2008. We recaptured him a few times this spring. The BBL has the oldest Black-and-white Warbler as 11 years old.

We added a male towhee to our list too.

On the 25th we added a female Blackpoll Warbler. She looks very different from the male we captured a couple of days before. He will look more like her in the fall after molting into basic plumage.

A SY Tufted Titmouse we banded had a nice example of a molt limit in the greater coverts. The gray replaced inner coverts contrast with the browner outer greater and primary coverts.

 We've heard a Baltimore Oriole singing near the banding table since setting up and we captured the female on the 30th. She had a brood patch and was not far from his spot so maybe she is his mate.

She was aged as a SY due to a molt limit in her greater coverts (blue arrow) and replaced tertials (red arrow). 

WARNING! Skip over the Carolina Wren if you are grossed out by cloacal flukes! (this one is for you David Clapp, who tells me I like to post gross pictures on my blog!) This poor bird had the worst case I have ever seen in all my years of banding.

They covered the whole cloaca and traveled up to the uropygial gland.

The uropygial gland is located on the bird's back near the base of the tail. They rub their bill over the gland, which produces oil. It is thought birds use this oil to keep their feathers in good condition and I imagine it helps to repel water too. 

We weren't hearing Cedar Waxwings at Punkhorn until the 25th and finally captured a nice older adult female (ASY). She was sexed as female due to the minimal amount of black under her throat

and aged as an ASY due to the many waxy tips she sported.

Two Gray Catbirds  we recaptured on the 30th proved to be birds we first banded on Wing Island; one aged as a TY (third year) bird first banded on 25 May 2014 as a SY bird and the other aged as an A4Y (after 4th year) first banded on Wing Island as an AHY on 22 August 2012. The bird below is a photo of one of the catbirds we caught on Wing Island early in the season.

Our last spring banding day was 12 June. We captured 23 birds but that is still a good number for mid June! And we had our first baby of the season, a male Eastern Towhee, so cute! We aged him L for local as his feathers were still emerging and he probably just fledged that morning. A local bird is one who cannot sustain flight. We ran him right back and his parents were so happy to have him return.

Even though we had a late start at Punkhorn we still ended up capturing 343 birds, pretty decent considering we missed many good days. I was sad that we never did hear, see, or capture Northern Parulas that I was able to document as breeding from 2002-2009. Also missing was Eastern Wood Peewee. But I was happy that another cool species we've  captured in the past was still around, Ruffed Grouse. We flushed one up numerous times this May.

 As far as our site on Wing Island goes, I will monitor the number of foxes sighted there and if nothing changes we will continue our summer (once/week) and fall banding in the Punkhorn. In the future I will use Punkhorn as a spring site and hopefully flip over to Wing Island in the fall. Kudos go to all those who helped out with spring banding. We were sorry to lose Jo-Anna Ghadban due to her work schedule, but she'll be back at some point! Many thanks to (in order of hours donated): Doug McNair, Ronald Kielb, Donna Kucia, Jo-Anna Ghadban, Gretchen Putonen, Corey Accardo, Claire Revekant, Louise Vivona-Miller, Robert Finer, and others who helped out for a day.

The following is a list of birds seen, heard, or banded during spring migration (Punkhorn only):

Total birds netted: 343                              Total species: 62
Total species netted birds: 28                     Birds/100 net-hours: 60

Common Loon
Great Blue Heron
Mute Swan
Canada Goose
Turkey Vulture
Cooper's Hawk
Broad-winged Hawk
Red-tailed Hawk
Ruffed Grouse
Laughing Gull
Herring Gull
Great Black-backed Gull
Mourning Dove
Black-billed Cuckoo - 2
Yellow-billed Cuckoo
Ruby-throated Hummingbird - 3
Downy Woodpecker
Hairy Woodpecker
Yellow-shafted Flicker
Alder Flycatcher - 1
Eastern Phoebe
Great Crested Flycatcher - 7
Eastern Kingbird
Tree Swallow
Blue Jay - 1
American Crow
Fish Crow
Black-capped Chickadee - 54
Tufted Titmouse - 6
Red-breasted Nuthatch
White-breasted Nuthatch - 1
Carolina Wren -1
Blue-gray Gnatcatcher
Eastern Bluebird
Hermit Thrush
American Robin - 2
Gray Catbird - 87
Cedar Waxwing - 1
Red-eyed Vireo
Yellow Warbler - 2
Black-throated Green Warbler - 1
Pine Warbler
Blackpoll Warbler - 2
Black-and-white Warbler - 10
American Redstart
Ovenbird -11
Northern Waterthrush - 1
Common Yellowthroat - 120
Scarlet Tanager
Northern Cardinal - 6
Eastern Towhee - 6
Chipping Sparrow
Song Sparrow -5
Lincoln's Sparrow - 1
Swamp Sparrow - 1
Red-winged Blackbird - 7
Common Grackle
Brown-headed Cowbird - 2
Baltimore Oriole - 1
American Goldfinch - 2

Thursday, October 2, 2014

First half of fall migration

August has been an exceptionally busy month compared to previous years with productivity of some species such as Gray Catbirds, Yellow Warblers, Song Sparrows, and Downy Woodpeckers being quite a bit above average. The majority of these birds were not migrants but began their life on Wing Island.

Eastern Phoebes began showing up at the end of July and we banded 28 young birds in August. The cinnamon-edged coverts are present in young birds (shown below) before their preformative molt. After molting the edging will be a dingy gray color and the light colored breast will be more yellow.

Bander assistant Ron Kielb was excited to band his 1,000th bird, a Northern Waterthrush!

Numerous flycatchers were banded in August and September- Yellow-bellied, Acadian,but mainly Traill's (shown below).

We banded two Mourning Warblers in August, the first being on 16 Aug. This one was a puzzle as it had such a wide, almost complete eye ring, but it was really too small to be a Connecticut Warbler and it had an interrupted breast band. MacGillvray's Warbler has a wide eye ring but it too is partial. Any thoughts are greatly appreciated.

Pictured below is another Mourning Warbler with an eye ring more typical to the species, broken and thinner.

We banded 4 American Redstarts in August with the first showing up on the 16th, all HY (hatch year) birds. 

The 18th brought our first of only two Ovenbirds. We typically band more of these birds in fairly good numbers. 

Occasionally when I'm home trapping hummingbirds in my yard I get other visitors including Baltimore Orioles like this adult male and female that were coming into feed on the sugar water.

Hatch year Black-and-white Warblers can be tricky sometimes to sex. We captured this female on the 20th. Both males and females can have white throats but usually males have darker streaking to the sides as opposed to the dull-colored streaking of this female. Her flanks and cheeks showed some buff coloration also.

We also captured a HY Saltmarsh Sparrow, maybe an offspring of the male we caught in July, 

and a Warbling Vireo with the rather indistinct facial pattern.  

The cardinal pictured below was suffering from a bad case of head lice or mites but I thought it showed a good picture of what birds' ears look like.

In the fall it is easy to tell young Red-eyed Vireos from the adults because their eyes are still brown. Shown first is the adult with the HY bird below.

The Brown Thrasher is another species that we can age by eye color. We were fortunate to have them breeding on Wing Island this year possibly due to the growth of the meadow that hasn't been mowed in a few years. They like to breed in thickets. The young have a grayish eye color

that becomes yellow as an adult like this female that we recaptured on 29 Sep. She was the same one we banded in July with a full brood patch. 

Adults can also have a pseudolimit in their greater coverts making them sometimes difficult to age in the spring. They have both white and buff-edged greater coverts.

As juveniles, Northern Mockingbirds will also start out with grayish eyes

that will become a dull yellow as they molt into preformative plumage and 

change to a brighter yellow as an adult. 

We heard very few kingbirds vocalizing this summer so we were happy to finally capture one on the 30 Aug. The young don't have the orange crown like the adults do.

We had our busiest day so far of the season on 31 August with 148 birds netted, half being Gray Catbirds of course! We also captured a young Marsh Wren still undergoing a preformative molt, our earliest ever for this species during fall migration.

August was quite a busy month with 1260 birds netted of 38 species. September then waned with numbers and variety of warblers and other species quite low possibly due to the many days of NE winds and quite breezy. We had our 2nd Acadian Flycatcher on the 3rd 

along with a Blackpoll Warbler (not shown), our first of two HY male Black-throated Green Warblers

and our one and only (so far) Black-throated Blue Warbler, a HY male, of the fall season.

Note the green-edged 2nd alula feather (A2) that had not been molted giving us a clear molt limit. 

7 September brought in two more firsts for the season, a HY female Yellow-breasted Chat

and a HY Veery of unknown sex. 

We had both male and female Wilson's Warblers, a female on the 8th with a very drab cap

and a male with a partial black that will fill in as he ages. 

A Nashville Warbler arrived in the middle of September, a HY male

as did a Western PalmWarbler, note the very drab coloration of the face,  

and a species we rarely get on the island, a Purple Finch!  We were unable to sex this HY bird at this time. 

Purple finches don't have the streaking on the undertail coverts 

like House Finches do.

I had to take a number of days off away from the station so we probably missed a number of nice species but I thought my son's wedding was a bit more important! Happily we were greeted to a nice Lincoln's Sparrow on the 23rd

and our first Brown Creeper for the season on the 24th. 

Our first of hundreds of Yellow-rumped Warblers (subspecies Myrtle) arrived on the 29th, we banded six that day and shown is a HY male.

Other special birds of the day was a HY female Indigo Bunting, 

a HY Savannah Sparrow 

and an adult female Prairie Warbler. I know, I know it looks like a male and fools us every year but she is now aged as an A5Y meaning that she was born sometime  in 2008 or before. We first captured her in May of 2010 as an adult (ASY) with an egg and have captured her many times in years hence with a full brood patch. Just when you think you know a lot, birds throw you a wrench.

On the 30th we captured a very late and quite dull Yellow Warbler, possibly a western race,

Many thanks to all the volunteers who helped out at the station during August and September, it is much appreciated- Jo-Anna Ghadban, Ron Kielb, Gretchen Putonen, Rose Scavotto, Megan Nepshinsky, Catie Porro, Judith Bruce, Claire Revekant, and many others who helped out for a day or two. I am now posting all our sightings on ebird so for further information on numbers, etc visit ebird- Brewster Wing Island.