Monthly Archives: September 2015

Interesting Still-Breeding-Plumaged Dunlin at Pine Point, 9-20-15


Earlier today, I found an interesting Dunlin at Pine Point, at the mouth of Scarborough Marsh. It flew in from across the channel on the incoming tide, and landed up Jones Creek, a couple of hundred feet away.

It was an adult bird, including an extensively black belly, and it appeared pale above and rather small. I needed a better look, but as I waited for the bird to slowly come closer, I posted to the Maine-birds listserve of a “…pale-backed Greenland (or other European-type)-like Dunlin,” mostly to alert other birders in the area (there were quite a few today as usual here). Based on the fact that this bird looked small, pale, and had not yet undergone molt, my mind immediately went to one of the “European” subspecies.

The bird had come considerably closer by the time Noah Gibb and Leon Mooney arrived, and it was clear that this was not a short-billed bird, perhaps on its own eliminating the Greenland subspecies arctica (one fitting this description was photographed this summer at Popham). But I will admit to not knowing the full range of variation in bill length among all of the 10 subspecies of Dunlin, so we went to work photographing and studying the bird.

We agreed that the bird appeared small (although the three other “typical” juvenile Dunlin that were present were never seen nearby, a comparison that would have been most helpful) and “not short-billed.” It wasn’t the longest, droopiest billed Dunlin that we’ve seen, but well within the range of our typical migrant subspecies, hudsonia.

As the bird came closer, plumage details and patterns blurred by heat shimmer and scope-shake in the 20+mph winds at a distance became more discernable. Arctica, the smallest and shortest-billed subspecies, also has a small belly patch. I don’t think this bird would be characterized as being short-billed or with a small belly patch.

Meanwhile, in response to my Maine-birds post, Louis Bevier chimed in that the subspecies arcticola which breeds in northwestern Canada and Alaska “is somewhat paler-backed than our typical hudsonia and delays molt until after migration.” That was not something I had remembered, but it’s been a while since I’ve done much reading on the subject. However, The Shorebird Guide by Michael O’Brien, Richard Crossley, and Kevin Karlson – which I grabbed as soon as I returned to the store – references arcticola as molting on the breeding grounds, as does our typical hudsonia. Bevier also stated that it is from “northern Alaska and the West Coast,” but that, I believe is actually referring to pacifica, which also molts on the breeding grounds (Arcticola winters in Japan, Korea, and China).

The Shorebird Guide cautions that “a few individuals of pacifica, arcticola, and hudsonia migrate before molting extensively.” While I could not see any signs of molt on the wings, back, scapulars, etc on this bird, of course some birds don’t always molt according to the book. Injuries (none obvious) or malnutrition (harder to decipher in the field) could delay molt, and some individuals can suspend molt for similar reasons – and others, such as simply being “screwed up!”

The only other reference I have handy here at the store is Richard Chandler’s Shorebirds of North America, Europe, and Asia which offers a similar array of caveats about subspecific identification. While saying “identification to race may be possible in favorable circumstances, most readily in breeding plumage,” it then goes on to warn that “At the end of the breeding season, separation will often be difficult, as feather wear renders the distinctions less obvious and upperparts become dull and blackish.”

It’s late September, and therefore it’s well past the end of the breeding season, making feather wear a serious issue. While I couldn’t see anything that suggested extreme wear (like on the flight feathers of a retarded 1st summer bird), there’s no doubt that any colors we were seeing were likely paler, and perhaps considerably so, than what the bird would be in fresh plumage.

Chandler takes the time to reason that “It is not easy to identify any of the races of Dunlin in breeding plumage away from the breeding grounds…Since races are established largely on the basis of the average characters of specimens taken on the breeding grounds, variation between individuals and differences between sexes, as well as variation with time owing to fading and wear as the season progresses, result in caution being needed when attempting to assign race to any particular individual. Consequently, there will always be more than an element of speculation with the racial identification of many migrant Dunlins in breeding plumage.”

So where does that leave me with subspecific identification? Completely and utterly unsure.

Is this simply a hudsonia that has not molted yet for some odd reason? Maybe. Is this an arctica, like my first impression? I don’t think so anymore (too long-billed and with too much black on the belly). The only thing that is definitive is that this is an interesting and educational bird. Hopefully, it will be seen again, and perhaps better photos – and photos with “normal” Dunlin – could be acquired. But for now, I am fine with saying “I don’t know.”

I present an array of phone-scoped images for you to ponder (or not). I’ll also send this link out to those who know more about Dunlin subspecies than I do. It’s going to be a busy two weeks for me (Birds on Tap!, Monhegan tour, than travel to a trade show), so I may not get back to an analysis of the analysis for some time, but if anything revelatory becomes apparent, I’ll discuss that here.

Thanks for reading!2
















IMG_6180_18 IMG_6181_19

9/23 UPDATE: Jeannette and I observed the bird again yesterday, 9/22 and Jeannette took excellent photos, as usual. It was also a whole lot closer, allowing for much more detailed study. You can ignore those awful photos above, this is what the bird really looked like!







So, the next session with the bird shows several pertinent details:
1) This bird IS in molt, as several new coverts and tertials are visible.
2) The outermost primaries (especially as you can see in flight) ARE indeed very heavily worn (it could be a 1st summer/2nd winter bird afterall?).
3) The size and structure looks more than fine for our typical subspecies, hudsonia.

Those, combined with the details of the plumage, show that this is undoubtedly NOT a European bird. Instead, it is either one of the North American subspecies in very retarded molt (or perhaps a vagrant East Asian bird). I’ll synthesis what I learn when I return in a couple of weeks, but for now, I wanted to get these much more useful photos posted for you to ponder, enjoy, and/or ignore.

Excellent Morning Flight at Sandy Point, 9/16/2015

Over 2,000 migrants. 45 species, including 17 species of warblers. Yeah, it was a good morning to be at Sandy Point!

Cape May Warbler, male.

I arrived, as usual, a few minutes before sunrise, but unlike most mornings, birds had already begun to cross. And once the sun crested the horizon, the floodgates open. OK, so it wasn’t “Warblergeddon” at Cape May, but it was fun for me and it was an excellent flight for here.

Well, mostly fun. A lot of birds were high, especially as the wind went calm. Big pockets of birds were just too high to identify. I did my best to just keep count. Birds were dropping into the trees on both sides of the road, others were zipping through underneath. As I focused on something in the elm, I am sure I missed birds overhead. It was tough to keep track, but I did my best.
Prairie Warbler, male.

By the time I departed at 9:30, the tally was the 7th highest I’ve had at Sandy Point (the 6th highest in September), and by far my best flight of the season to date. It also had some interesting birds, and I’ll analyze some of the numbers below.

61F, clear, West 6.3mph to calm.

940 Unidentified
403 Northern Parulas (3rd highest)
161 American Redstarts
155 Black-throated Green Warblers
61 Cedar Waxwings
55 Tree Swallows (record high)
34 Black-and-white Warbler (3rd highest)
30 Blackpoll Warblers
22 Northern Flickers
22 Magnolia Warblers
18 Yellow Warblers
16 American Goldfinches
13 Yellow-rumped Warblers
11 Red-eyed Vireos
11 Black-throated Blue Warblers
10 Chipping Sparrows
9 Blue Jays
9 Nashville Warblers
8 Ruby-crowned Kinglets
8 Tennessee Warblers (3rd highest)
8 Baltimore Orioles
6 Scarlet Tanagers
5 White-breasted Nuthatches (record high)
4 Purple Finches
3 Eastern Phoebes
3 Blue-headed Vireos
2 Black-capped Chickadees
2 Wilson’s Warblers
1 Osprey
1 American Kestrel
1 Downy Woodpecker
1 unidentified Empid
1 unidentified Vireo
1 Red-breasted Nuthatch
1 American Robin
1 Chestnut-sided Warbler
1 Cape May Warbler
1 Prairie Warbler
1 Bay-breasted Warbler
1 EASTERN TOWHEE (present in scrub; only 3 previous records here).
1 Savannah Sparrow
1 White-throated Sparrow
1 Rusty Blackbird (first of fall)
x Common Yellowthroat

Total = 2044

Black-throated Blue Warbler, male. Look at how the “pocket hankercheif” is blown out by the low sun angle.

Several counts were noteworthy, including the two record highs. Tree Swallows usually don’t bother crossing from the island to the mainland via Sandy Point, but more often continue on to the south, crossing the bay with little trouble. Plus, most swallows are probably moving through after I depart in the morning. These birds, mostly in one large and a couple of small groups, were funneling over the bridge along with the rest of the typical Morning Flight migrants. Meanwhile, the 5 White-breasted Nuthatches were noteworthy as I usually see no more than a couple all fall here. The previous record for a single morning was two.

As for the higher counts, I was surprised by how large of a percentage of identified migrants were American Redstarts compared to Blackpoll Warblers. However, I think this is an “identification bias.” Redstarts are the easiest warbler to ID for me in flight, and few pass through at almost any height without being identified. I doubt many of the overwhelming “unidentified” count were redstarts. However, I would wager that a sizeable percentage of them were Blackpoll Warblers. Based on the date and what I’m seeing in the woods these days, there should have been a lot more blackpolls. However, these strong fliers are often very high overhead on light winds, and my guess is that the diminishing westerly this morning was of little consequence for them, and that a lot of those little dots overhead were blackpolls.

Yesterday, I was lamenting not being at Sandy Point. The conditions were great in the morning, and the radar was quite good overnight. However, I was guiding in the Camden area, and at least a little morning flight (ca 100 birds) flew over and through Merryspring Nature Center Park in town. It was a tease to think what might have been going on at “my office” however.

But last night’s radar was even better! Here are the very active 10pm, 12am, 2am, and 4am radar and velocity images from the overnight. See how much was offshore, even as of 4am?
10pm radar

10pm velocity

12am radar

12am velocity

2am radar

2am velocity

4am radar

4am velocity

And come dawn, the winds aloft were perfect for a good Morning Flight at Sandy Point.
5am wind map

In other words, that’s what produced 2,000 birds at Sandy Point, and with a busy schedule this fall, I was quite pleased to catch one of the big ones.

Morning Flight Fail

Following yesterday’s cold front, a huge flight was underway come nightfall. It was by far the biggest of the season to date, and one of the stronger (by density) flights as you can see around here.

Here are the midnight radar and velocity images, for example:


Even as of 4:00am, with the eastern sky likely showing a little light, the flight was still strong:


So of course I was up early to go to Sandy Point. However, the winds were forecasted to be out of the northeast, becoming easterly in the morning. And, the local weather stations I looked at (and my windometer at home ) were all reading north or northeast when I awoke a little before 5:00 this am. The 6:00am Intellicast “Wind cast” image shows this coastal northeasterly wind very well:

After almost any night in the fall with a little migration, there will be a few birds at Sandy Point. And after a migration as strong as last night’s, there were bound to be some birds. However, due to a combination of geography and the instinct to fly into the wind to compensate for overnight drift (to oversimplify things a bit), there are just never a lot of birds at Sandy Point on northeasterly winds.

On the other hand, on both north and northeast winds, I have witnessed good morning flights (aka Morning Re-determined Migration” or “Morning Reorientation”) in the south-facing peninsulas that reach into Casco Bay, including the dual peninsulas of Harpswell.  What I have not figured out yet, however, is which point is best, how, and when. This is mostly because I can’t tear myself away from Sandy Point long enough to find out!

But this morning, as I reached I-295, something made me turn north instead of south. With what was supposed to be an increasing northeasterly wind and a huge flight, this should have been a perfect morning to test my hypotheses at the tip of Harpswell.  So, with no small feeling of impending regret, I drove down to Pott’s Point at the end of Rte 24 for the dawn.

As birds that were over and beyond Casco Bay at sunrise begin to work their way inland and compensate for that drift, island-hopping to the north and northeast deposits birds in the long fingers of the Mid-Coast. Unlike Sandy Point on Cousin’s Island, however, there isn’t a single leading line, perfectly-pointing peninsula, narrow crossing, and raised bridge (for visibility) that combine to offer a perfect morning flight observation location.

So I thought today would have been a perfect morning to see if Pott’s Point was the answer on a northeasterly wind, even if it meant missing a few birds at Sandy Point.

I was wrong.

I arrived at the end of Pott’s Point at 6:27, 20 minutes after sunrise, but found the wind to not be northeast, or even north, but to be north-northwest. Uh-oh, I thought.

But since I have yet to find a way to be in two places at once, I settled in for the next hour at Pott’s Point (it would have taken at least 45 minutes to get from Pott’s Point to Sandy Point), and counted…very, very little:
16 Cedar Waxwings
11 American Goldfinches
5 American Redstarts
5 Unidentified
2 Yellow-rumped Warblers
1 Pileated Woodpecker

Now, all of those birds were doing the “right” thing, flying from over the bay or from Haskell Island just to the south, then over Pott’s Point and northward up the peninsula.  There were just so few of them!

If I only had a boat…

The view of the top of the power plant at the other end of Cousin’s Island was a reminder of what could have been, as Sandy Point is excellent in a NNW wind. Was I missing a huge flight? Or, were the winds northeasterly on the other side of the bay, and only a light flight was passing through there (although it would have undoubtably been better than the “flight” at Pott’s, I will convince myself of the latter!)?

In other words, I was here:

But should have been here:

Besides, it’s a peaceful spot to spend the morning, with the only traffic being a few lobster boats.

And the narrow peninsula does have a Monhegan-esque feel to it and its birding (sometimes).

So if the migrants were not at Sandy Point, where was the Morning Flight concentration this morning?  Looking back at the radar images, there was not a ton of offshore drift (due to the lack of a westerly component throughout the night), so maybe there just weren’t a lot of birds offshore come sunrise.  But there still looks like more than enough for a good reorientation flight at sunrise.

Bascially, I am not only left without an answer to my pursuit of a good Mid-Coast morning flight spot, but now I will no doubt spend the rest of the season being over-cautious about missing a flight at Sandy Point and therefore miss the next huge flight through Pott’s Point on a northeasterly wind!

There wasn’t much else left to do but go birding, so I poked my way up the peninsula and into Brunswick, checking a few of the hotspots. Some day I will find a rarity at Stover’s Point, but today wasn’t the day for that either. However, I did have some pretty good birding at Mitchell Field, including a trickle of warblers overhead. A Yellow-bellied Flycatcher and a Lincoln’s Sparrow were highlights, and other migrants present included seven species of warblers. OK, it was small consolation, but at least there were some migrants around Harpswell today!

Unfortunately, the wind and weather forecasts for the coming days hardly look good for Sandy Point, so it might be as much as a week before I am back to spending the sunrise at “my office” where I should be!

P.S. It’s not too late to sign up for my “Morning Flight Phenomenon on Cousin’s Island” workshop for RSU5 Recreation and Community Education next week. More information and registration details are here.

9/5 UPDATE: I received an email this morning from Bill Hancock who was at Sandy Point on Friday and reported it was “dead” and did in fact have a northeasterly wind. Phew!  Meanwhile, I tallied 110 migrants on calm conditions on Saturday morning – a very light flight, as expected this time.