BC/Boreal Chickadee ranges

[Santner, Steven]

    Brian:
 
    When I lived in Pa, I lived right on the line between Carolina and
Black-capped.  There was an abrupt transition which corresponded to just
south of Blue Mt (actually not a mountain but a hill which topped out at
about 400-500 ft higher than the surrounding countryside).  The
Carolina's range extended a little further north along the Susquehana
River, though not nearly as far as Fish Crow and Black Vulture, two
other more southerly species.  In winter there would often be many
Black-capped Chickadees south of this line (numbers varied greatly from
year to year) while there would even be occasional Carolinas which moved
north a little from their normal range.  There was significant
hybridization of the two species in the overlap zone with some
individuals singing whichever song its nearest neighbor sang (I've
watched as they actually switched songs!).  The hybrid zone was probably
not more than 5-10 miles wide.  There was not always an obvious
difference between vegetation in the Black-capped and Carolina spots and
I always wondered why Blue Mt itself wasn't the dividing line.  Clearly
the chickadees see differences that we don't.  As far as Boreal
Chickadee goes, I haven't seen too much habitat that is truly boreal in
Michigan.  When I was in the Gaspe Peninsula, in Quebec, habitats there
had multiple types of spruce/fir and there were Boreals in these areas.
Michigan's boreal habitat looks more like some sort of "transition"
between true boreal and northern deciduous habitats.
 
    Steve Santner

	-----Original Message-----
	From: mich-chat-bounces at envirolink.org
[mailto:mich-chat-bounces at envirolink.org] On Behalf Of Brian A
	Sent: Tuesday, January 16, 2007 10:23 AM
	To: Mich-chat
	Subject: BC/Boreal Chickadee ranges
	
	
	Last weekend we dropped off my son at LSSU at the Soo and I did
a little birding in the morning at the Algonquin trails NE of the city.
	 
	This area appears very boreal to me, most of the trees are
spruce and birch with a few tamaracks.  The only mammal I saw was a
snowshoe hare  as I  crunched through the snow and the 11 degree morning
and about the only bird  I saw was Black-capped Chickadee.
	 
	Earlier this winter I visited in-laws in Columbus, Ohio and
enjoyed seeing the Carolina Chickadees there.  I have never seen a
Black-capped at that location.
	 
	Now I wonder why there is such a species cline between Ann
Arbor, Michigan with its forest (and climate) not too different from
Columbus, Ohio and only 3 hours away and yet in a boreal forest about 5
hours north of Ann Arbor it would be very unusual to encounter a Boreal
Chickadee?
	 
	Thank you for your response all you zoogeographers.
	 
	Brian Allen

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