Words On Birds by Steve Grinley

Another Amazing Day of Birding
June 02, 2023
By Steve Grinley
     With June’s arrival, the warbler migration is nearing its end. There were a good variety of species passing through Essex County throughout May – some days better than others. For me, the numbers of birds seemed to be less than previous years. Looking back over all my years of birding, the decline in birds is obvious. It certainly saddens.
     Then comes along another report from Massachusetts native Ian Davies.  Back in 2018, Ian reported “Today was the greatest birding day of my life.” He, and several companions were in Tadoussac on the St. Lawrence River in eastern Quebec and estimated 721,620 warblers migrating through in one day!  
     It happened again this year, well almost.  He reported another spectacular day in Tadoussac this past week. Here is his account:
     “There are some days that feel too good to be true, waking dreams filled with birds. Today was one of those days.  
     “A river of a quarter-million warblers. 12 hours. A dozen or so of us were able to witness this incredible spectacle today in Tadoussac, Quebec, a spectacle that has only happened at this magnitude once before—at the exact same place on 28 May 2018 (https://ebird.org/checklist/S46116491).  
     “Today started with cautiously high hopes, as the Tadoussac regulars had been eyeing this day since the weekend: southwest winds overnight (tailwinds good for migration), combined with a big cold front arriving right around dawn, bringing rain, strong northwest winds, and colder temperatures—the same setup that has resulted in flights of tens or hundreds of thousands of birds in past Mays. Despite the hope, you never know what will happen until you’re out there. 
     “The first couple hours of daylight featured drizzle and strong winds, and not many birds until about 6:45, when the rain became more light and intermittent. The trickle of warblers began to expand across the sky, increasing to 100 birds per minute, then 500 birds/minute by 7:30. The Tadoussac river of warblers had begun.  
     “This flight continued at 300-500 birds/minute until about 9:20, at which point the rain dropped significantly, and the flood gates opened, as many as 1345 warblers/minute raging past in a torrent of flight calls and glowing songbirds. Birds were everywhere, below eye level, flying between people, pouring through the bushes, landing on the sand, and one Cape May Warbler even tried to land on my arm. A Red-eyed Vireo flew into someone. It was madness.  
     “For the next four hours, tens of thousands of warblers raced past, sometimes inches off of the sand. For one period of time, the rate of warblers was 80,000/hour—similar to many points of the record day in 2018. 
     “The most common species of warbler was Bay-breasted, with an estimated 1 in 3 birds being of this species, followed by significant numbers of Cape May, Yellow-rumped, and Tennessee—all around 1 in 5. At one point, one branch in an isolated tree had 9 Cape May and 6 Bay-breasted Warblers on it. This was not unusual today. 
     “With so many individual birds, there are also always some oddities—most notably a Summer Tanager and a Red-shouldered Hawk, the tanager a first for the location and apparent 2nd for the county, and the Red-shouldered the first for the location since 1992 (second ever), and apparent 7th for the county. There were also significant numbers of Evening Grosbeaks, American Pipits, Horned Larks, and Cedar Waxwings—large flocks that would cut through the river of warblers—including the all-time high count for the location of Evening Grosbeak.  
     “As always, these massive events require balancing the need to document what is happening with the desire to just bask in the greatest avian spectacle I’m aware of. We tried our best, knowing that any method is imperfect, and all we can do is try.  
     “We arrived at total numbers of birds by estimating the rate of movement, since there is a constant ‘flow’ of birds moving to the southwest. Rate estimates were made by counting the number of individuals passing the count location in a one-minute period. Multiple observers would work to count the full sky (e.g., one person count towards the river, one inland, done in this list by Jessé and Ian), and those counts would be combined for a one-minute rate estimate. These counts were repeated every 10-20 minutes throughout the day. The counts are then used to interpolate counts between the timed counts… 
     “Rate counts were combined with our best estimates of warbler species composition from the field experience throughout the day…Species-specific numbers and comments are in the checklist. The estimated total number of warblers (rounded to nearest 500) is 258,500. This appears to be the second-highest total number of warblers recorded anywhere in a single day.”
     Some of Ian’s highest warbler estimates were 85,300 Bay-breasted; 56,900 Cape May; 51,700 Yellow-rumped; 46,500 Tennessee; 7,093 Wilson’s and 5,200 Magnolia. His full report, along with photos, can be found at: https://ebird.org/checklist/S139153079. Reading about such a birding event brightens our spirit. I guess we need to go to Quebec for our warblers next year!

Steve Grinley
Bird Watcher’s Supply & Gift
Port Plaza West Shops
45 Storey Ave, Suite 7B
Newburyport, MA 01950

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