In an attempt to record this amazing event that happened in May of 2018 in Tadoussac, Canada, I thought I'd make a blog post about it so I can go back and see it all in one place.
I'll start out with Ian's description of the over 9 hours of non stop birds flying by!
Link is here if you want to read more and see his excellent photos: https://ebird.org/view/checklist/S46116491
Mon May 28, 2018 5:45 AM
- Protocol:
- Traveling
- Party Size:
- 6
- Duration:
- 9 hour(s), 41 minute(s)
- Distance:
- 0.8 kilometer(s)
- Observers:
- François-Xavier Grandmont List , Ian Davies , Sarah Dzielski List , Thierry Grandmont List , Tim Lenz List , Tom Auer List
- Comments:
- [text by Ian Davies]
Today was the greatest birding day of my life.
Southwest winds overnight had led to high hopes for the morning, compounded by dawn rain in the area. Our first stop had been fruitless, with a handful of warblers moving, but nothing notable. We decided to head for the Tadoussac dunes anyways.
On our arrival (545a), it was raining. A few warblers passed here and there, and we got excited about groups of 5-10 birds. Shortly before 6:30a, there was a break in the showers, and things were never the same.
For the next 9 hours, we counted a nonstop flight of warblers, at times covering the entire visible sky from horizon to horizon. The volume of flight calls was so vast that it often faded into a constant background buzz. There were times where there were so many birds, so close, that naked eyes were better than binoculars to count and identify. Three species of warbler flew between my legs throughout the day (TEWA, MAWA, MYWA). For hours at a time, a single binocular scan would give you hundreds or low thousands of warblers below eye level.
The flight line(s) varied depending on wind direction and speed. All birds were heading southwest. When calm, birds were high, often inland or farther out over the river. High winds (especially from the W, or SW), brought birds down low, sometimes feet from the ground and water. Rain also lowered birds, and the most intimate experiences with migrants occurred during a rain squall and strong wind period. Hundreds of birds stopped to feed and rest on the bare sand, or in the small shrubs.
Counting birds and estimating species composition was the biggest challenge of the day—balancing the need to document what was happening with the desire to just bask in the greatest avian spectacle I’ve ever witnessed. A significant effort was made to estimate movement rates throughout the day, and those rates combined with species-specific movement estimates were used for the below totals. See the full checklist for species-specific notes.
Movement rate estimates were made by looking through binoculars at a flight line, and counting the number of individuals passing a vertical line in that field of view, per second. This was repeated multiple times for each bin view, and repeated throughout the sky so that all flight at that moment was accounted for. The average birds/second was then used for that time period, until another rate estimate showed a different volume of movement. Non-warblers were counted separately. I took a couple attempts at video, which are listed below under ‘warbler sp.’ These videos only hint at the magnitude of the spectacle.
These were my warbler rate estimates:
6:29-6:43 8/s — 6720
6:44-7:02 3/s — 3240
7:03-7:14 15/s — 9900
7:15-8:02 30/s — 84600
8:03-8:27 10/s — 14400
8:28-9:12 15/s — 48600
9:13-9:31 12/s — 12960
9:32-9:48 15/s — 14400
9:49-1038 25/s — 73500
10:39-11:03 40/s — 57600 (during and after a rain squall)
11:04-11:52 30/s — 86400
11:53-12:17 20/s — 28800
12:18-12:37 15/s — 17100
12:38-12:48 25/s — 15000
12:49-1:13 50/s — 72000 (winds switch to strong WSW)
1:14-2:36 30/s — 147600
2:37-2:56 20/s — 22800
2:57-3:04 10/s — 4200
3:05-3:14 3/s — 1620
3:15-3:18 1/s — 180
Total number of warblers: 721,620
To our knowledge, the previous warbler high for a single day in the region was around 200,000, which was the highest tally anywhere in the world. Other observers in the area today had multiple hundreds of thousands, so there were likely more than a million warblers moving through the region on 28 May 2018. Thank you to the Observatoire d’Oiseaux de Tadoussac (http://www.explosnature.ca/oot/) for monitoring these movements for decades, and sharing the wonder of this place with the global birding community.
There’s no place like Tadoussac.
- Submitted from eBird for iOS, version 1.7.4
Species
108 species (+3 other taxa) total
- May 31, 2018 New York Times















