Northern Parulas were certainly the “bird of the week” at Sandy Point.
It was a special five-day run at Sandy Point Beach on Cousin’s Island in Yarmouth. It was a record-shattering run in fact, in which I tallied nearly 18,000 migrants engaging in the “Morning Flight,” or “morning re-determined migration” when nocturnally-migrating passerines relocate (to drastically oversimplify things) come sunrise.
(To learn more about Sandy Point, check out the site entry in Birdwatching in Maine: A Site Guide, and for more on nocturnal migration, interpreting the radar, and the “morning flight” phenomena, check out Chapter 5 in my first book, How to Be a Better Birder. Whaddya mean you don’t have these two books!?)
I’ve had a handful of four-day runs, but I cannot think of a time when conditions were favorable – and I was actually present, and not leading tours on Monhegan for example – for five straight days. But I have most certainly never had five days like this!
I recorded 72 species “deemed migrating” through here, not including migrants that were in the bushes, such as the Gray Catbirds and Song Sparrows that are so abundant in the brush here. It does not include species like Osprey, in which some of the many I saw this week were likely southbound, but impossible to separate from the still-locals. And this tally did not include all of the waterbirds, from Common Eiders to herds of dabbling American Black Ducks, and from Bald Eagles to hunting Great Blue Herons, as well as resident species.
I tallied 25 species of warblers, including a single Connecticut Warbler, one of the most sought-after parulids in Maine. A Northern Mockingbird was only my 5th ever noted here, and two passing Dickcissels are always a treat. But certainly the icing on the cake of this great week was the Lark Sparrow found by the group in the parking lot on the relatively quiet morning of 9/13. This was a first record for Sandy Point, and my personal 184th species here.
But it was the morning of the 11th that will go down in Sandy Point history! 8,185 migrants was not only a new record, but almost doubled the previous record (4,346 on Sept 21, 2010). It was incredible. More on that epic morning later.
A number of records for high counts for individual species were set, and I am sure even more would have been shattered if I had a higher rate of identification during the onslaught of the 11th. Other trends, typical of the season, were evident, such as the slow but steady change in the composition of the flight. The early migrants like Magnolia Warblers were giving way to a growing percentage of Yellow-rumped Warbles and Blackpoll Warblers for example. But it sure seems like we’re not yet running our of Yellow Warblers and American Restarts, however!
immature male American Redstart
Yellow Warbler, adult male
So first, here’s the numbers (bold font indicates a new daily record).
|Cape May Warbler||18||5||8||5||0|
|Black-throated Blue Warbler||8||7||4||4||0|
|“Western” Palm Warbler||1||0||0||0||0|
|Black-throated Green Warbler||118||63||73||57||26|
Now, let’s take a look at the radar. Here are the density and velocity images from 1am (as a sample) on 9/9 and 9/10. That’s a ton of birds on the radar.
And even as late as 4:00am on each day, a lot of birds were visible, and a lot of birds were offshore.
The night of 9/8 through 9/9 featured light westerly winds, shifting to northwest by sunrise. And on the next night, light north winds became northwest overnight. Both, as expected, produced great flights over and through Sandy Point some dawn.
Weather patterns, especially at this time of year, rarely produce three great nights for migrants in a row. And when they do, it often results in fewer birds overnight (and therefore at Sandy Point) come sunrise; essentially, the well temporarily runs dry.
And as you can see by the 1:00am radar image from September 11th, the density was nowhere near the previous two nights, despite mostly light westerly winds overnight.
And by 4:00am, it was rather quiet.
Light northwesterly winds in the evening slowly gave way to light north, before becoming light and variable. After midnight, they became west but didn’t really increase until after 2:00am. Coupled with a lackluster radar return, this was not a recipe for a huge flight.
Nonetheless with a light westerly wind at sunrise, I was heading to Sandy Point anyway. If only because it was a day off, and I won’t have many more chances to visit “my office” this month. A milky sunrise further clouded (sorry) my optimism for a big flight, but there were plenty of birds in the air.
And then all hell broke loose.
It was incredible. It was frustrating. It was beautiful. It was painful. It was amazing. It was indeed overwhelming, and at times, my only hopes at quantifying the flood was to skip attempting identification and just click my unidentified clicker as fast as I could.
And I really can’t explain it. It “shouldn’t” have been this amazing.
Come nightfall, with high pressure remaining in control, and with light westerly winds and clear skies once again, a moderate to strong flight occurred overnight. Here are the 1:00am and 4:00am radar images from the wee hours of 9/12:
With light westerly winds come dawn, I was once again stationed at the bridge, and what was – prior to three days ago! – considered a very good flight passed over and through. It was even downright relaxing – and manageable – after the chaos of the previous morning. I had fun.
Not surprisingly, after four consecutive nights, the flight was much lighter overnight on the 12th into the 13th, as evidenced once again by the 1:00am and 4:00am images.
And despite very light westerly winds in the morning, and clear skies, only a light flight was to pass through the point. Of course, that Lark Sparrow more than made up for it. It was also nice to enjoy a slower flight – and identify many more birds than not!
So almost every morning made sense: radar plus weather conditions correctly predicted the intensity of the flight. Except for one. The Big One. And I can’t explain it. But, I am OK (mostly) with that – it’s one of the fascinating and flabbergasting aspects of documenting the morning redetermined migration!
Winds turned to the south during the day on the 13th, and continued light and southerly overnight, bringing the streak of five great nights of migration to an end. Come morning, I also slept in – relatively speaking – and then went for a massage. As my therapist began to work on my aching neck, she simply uttered, “Wow” and got to work. I felt the same on Monday morning when the greatest flight I have ever recorded passed through Sandy Point.
Species, such as this Swainson’s Thrush, that can be rather secretive in migration, are sometimes seen really well at Sandy Point!