BUFFLEHEAD DEPARTURES BREAK-UP ON THE MACKENZIE May 12, 2016

report by KJ Finley

There are still five yearling Bufflehead remaining, along with eleven Surf Scoters and two Common Goldeneye. The last Red-necked Grebe left last night. The latter three species are a suite of divers that co-habit lakes in the far northern boreal forest.
At Chick Lake ( 65 52 41 N, 128 01 32 W) where I conducted bird surveys in late May, 1973, Scoters, Barrow’s Goldeneye, Red-breasted Mergansers, Scaup and Red-necked Grebes were all common species, along with arctic species such as the Oldsquaw (Aha-alilk) and the Arctic Loon. There was only a single pair of Buffleheads, the most northerly breeding record then known, just beneath the Arctic Circle.
EOSDIS images show the the Big Bend of the Mackenzie where it cuts through the Gibson range, at the Ramparts, as it broke up on May 6th. In the latest image from yesterday, Wednesday the 11th, it runs muddy and the snow has cleared from the forest. Chick Lake is still covered with ice.
This spring the breeding pairs departed much earlier than usual, many on the 16th and 17th (see chart). A second exodus took place at month end, which is typical. But then a last group, comprised of some thirty yearlings, hung on and departed only last Friday night. Although Buffleheads are usually among the very last species to depart, averaging May 13th, the lingering presence of the Boreal Divers is unusual and indicates that they are not anxious to go north.
Meanwhile the southern boreal forest is unusually dry, with the Fort McMurray fire (May 4th) on everyone’s mind.
CheeDene Paysayquen
(Thanks to Rob Gray for monitoring numbers while I’ve been away on their interior breeding grounds.)
Mackenzie
Mackenzie Ramparts Breakup 6 May 2016

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DEPARTURE OF THE YEARLINGS – April 29th

As expected, many of the Buffleheads left last night as the pressure rose. It has just passed the peak at 1028 hPa, and it’s clear and calm. There are still fifty remaining, including an adult drake of a pair, and expect that more will depart tonight.
This departure date is the same as last year and 2012, and heralds a warm spell that will develop over the interior through the next week. Temperatures in the Mackenzie Valley are forecast to reach 18 degrees by Monday, so the snow will be retreating rapidly.
There are still a few other late lingering compatriots, including Red-breasted Mergansers (13), Surf Scoters (17), Red-necked Grebes (4), and one Horned Grebe. Like the Buffleheads most of these are yearlings and non-breeders, in various stages of moulting into adult plumage. It’s always a toss up between the Buffleheads and Mergansers to see who will linger the longest.
One of the essential characteristics of the Bufflehead’s life can be summed up as “Last to Depart, Last to Return” (from winter habitat), a phenological fact related to their small size and ecological requirements.
Buffleheads 4

Bufflehead Country in Spring 29 April 2016

It’s a fine clear day across the Bufflehead’s domain and the snow is receding into the southern boreal forest. The Mackenzie Valley is still frozen. They reach their northern most habitat near the Arctic Circle which is the north side of Great Bear Lake ( evident in the first image below.)
The Quill Lakes in eastern Saskatchewan stand out from space as the last waterbody within Palliser’s Triangle to hold its ice. At 640 square km, its one of the six largest saline lakes in North America. Its late break-up is related to its geo-chemical properties, and is a phenological standard by which to gauge the departure time of the yearling Buffleheads.
(The Quill Lakes are the site of the Great Bufflehead Crash of November 1940.)
The morning count gave 79, and that included only a single adult drake, and, very strangely, he was hauled up on the west beach. They rarely ever set foot on shore here, unless they’re in distress or injured, though this one seems healthy enough.
At present 17:20, some are resting / sleeping, but most are feeding intensively in a concentrated spot in the northwest corner of the bay. Its not been possible to get an accurate count yet, but two more drakes have appeared since the morning.
I’d say it’s looking like a go tonite.
satellite 1
satellite 2
Buffleheads 3