[NatureNS] Re: Dovekie movements, and the Chebucto spectacle

Date: Sun, 13 Nov 2011 13:52:09 -0400
To: naturens@chebucto.ns.ca
From: Blake Maybank <maybank@ns.sympatico.ca>
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Hi All;

Birds move in response to breeding or hunger.  At=20
this time of year Dovekies are not breeding, of=20
course, so one can assume their general movements=20
are in response to seeking out food to survive=20
until the next breeding season.  They feed on=20
copepods by preference, and particularly seem to=20
enjoy finding them along the edge of, and=20
underneath, pack ice.  At the momemt the pack ice=20
is still quite far north, so I presume the=20
Dovekies are feeding in the open ocean.

At this point it might be useful to pass along=20
some info regarding Dovekie migration and=20
wintering habits.  The following is from "Birds=20
of North America", the on-line resource.

START QUOTE


Migration

Abandon colonies late Aug; start to leave n.=20
Baffin Bay Aug=96Sep, remaining at edge of pack ice=20
in Baffin Bay and Davis Strait, as far as eastern=20
entrance to Hudson Strait. By Oct, rare in n.=20
Baffin Bay but still common in Davis Strait, with=20
individuals dispersed south to Labrador Sea and=20
e. Newfoundland waters. Remain extremely abundant=20
on Grand Banks throughout winter. Generally reach=20
Scotian Shelf and Georges Bank in Nov=96Dec; from=20
this time, small numbers seen off northeast coast=20
of U.S., particularly Maine to Massachusetts.


Winter Range

In the Atlantic, most winter in low-arctic waters=20
of the Labrador Sea, Grand Banks, and coastal=20
Newfoundland. Distributions associated with=20
planktonic prey and sea ice, with concentrations=20
reported near shelf edges, particularly s. Grand=20
Banks. Generally reaches as far south as Scotian=20
Shelf, Gulf of Maine, and northern and eastern=20
edges of Georges Bank. Has been recorded in=20
Atlantic during winter south to s. Florida, Cuba,=20
Bahamas (Grand Bahama), and Bermuda. Major storms=20
have occasionally blown Dovekies to inland locations in e. North America.

Dovekies often show up out of range along the=20
east coast of North America and sometimes inland=20
in massive wrecks of stranded, starving birds.=20
Sustained, strong easterly winds have been=20
associated with some of these strandings, most of=20
which have occurred in early winter. Winds likely=20
make feeding conditions unsuitable and push the=20
weakened, emaciated birds landward, although=20
periodic fluctuations in prey availability could=20
also precipitate these strandings.



Winter Feeding

Off Atlantic Canada in winter, generally=20
concentrated at shelf edges and tidal upwellings,=20
as well as at edges of arctic pack ice, where=20
densest aggregations of zooplanktonic prey found.

END OF QUOTE

I have had the priviledge to witness such Dovekie=20
flights before, but in Newfoundland.

On 2 Jan 1985 we observed almost 74000 Dovekies=20
and 51000 Thick-billed Murres in the morning as=20
they flew southeast along the coast during the=20
L=92anse aux Meadows Christmas Bird Count.  The=20
wind was light, but there was a strong nor-easter=20
forecast, and the storm arrived in the=20
afternoon.  The birds seemed to be shifting in=20
anticipation o f the storm.  Three weeks later,=20
when a similar weather pattern occurred, we=20
observed more than 250,000 Dovekies in a=20
three-hour period off Quirpon, south of L=92anse aux Meadows.

Dovekies are not large, nor really strong fliers,=20
so when they encounter a furious gale such as=20
blew from the NE last Friday, they get swept=20
along with it.  Accordingly, they must have=20
already arrived in considerable numbers out on=20
the Scotian Shelf,  or perhaps in waters even=20
closer to Halifax.  It seems to me (though Ian=20
might correct me) that the Dovekies have moved=20
south earlier than is "normal", which would=20
account for their occurrence off Chebucto Head=20
during Friday's gale.  Perhaps there is a problem=20
with a food source for them, or they are=20
responding to the changing ice conditions further=20
north (it is above freezing in Iqaluit=20
today!).  One can only speculate, as no research=20
is being done, to my knowledge.  The winter=20
ranges and habits of alcids are not well=20
known.  It was only a few years ago that a large=20
Razorbill wintering population was found in the=20
Bay of Fundy, and no-one still really knows where=20
the mass of puffins spend the winter.

Regardless, the Dovekies put on a wonderful show=20
for Dave, Fulton, and Dominic.  Pity the gate to Chebucto Head is locked.

Cheers,

Blake

----------------------------------------------------------------------------=
-
Blake Maybank
maybank@ns.sympatico.ca
http://www.flickr.com/photos/blakemaybank/
902-852-2077

Editor, "Nova Scotia Birds"
http://nsbs.chebucto.org

Organiser, Maritimes Nature Travel Club
http://tinyurl.com/naturetravel

author, "Birding Sites of Nova Scotia"
http://tinyurl.com/birdingns
Downloadable Nova Scotia Maps for inside front and back covers:
http://tinyurl.com/mr627d

White's Lake, Nova Scotia, Canada =20
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Content-Transfer-Encoding: quoted-printable

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<body>
<font size=3D4>Hi All;<br><br>
Birds move in response to breeding or hunger.&nbsp; At this time of year
Dovekies are not breeding, of course, so one can assume their general
movements are in response to seeking out food to survive until the next
breeding season.&nbsp; They feed on copepods by preference, and
particularly seem to enjoy finding them along the edge of, and
underneath, pack ice.&nbsp; At the momemt the pack ice is still quite far
north, so I presume the Dovekies are feeding in the open ocean.&nbsp;
<br><br>
At this point it might be useful to pass along some info regarding
Dovekie migration and wintering habits.&nbsp; The following is from
&quot;Birds of North America&quot;, the on-line resource.<br><br>
START QUOTE<br><br>
</font><h2><b>Migration</b></h2><font size=3D4>Abandon colonies late Aug;
start to leave n. Baffin Bay Aug=96Sep, remaining at edge of pack ice in
Baffin Bay and Davis Strait, as far as eastern entrance to Hudson Strait.
By Oct, rare in n. Baffin Bay but still common in Davis Strait, with
individuals dispersed south to Labrador Sea and e. Newfoundland waters.
Remain extremely abundant on Grand Banks throughout winter. Generally
reach Scotian Shelf and Georges Bank in Nov=96Dec; from this time, small
numbers seen off northeast coast of U.S., particularly Maine to
Massachusetts.<br><br>
</font><h2><b>Winter Range</b></h2><font size=3D4>In the Atlantic, most
winter in low-arctic waters of the Labrador Sea, Grand Banks, and coastal
Newfoundland. Distributions associated with planktonic prey and sea ice,
with concentrations reported near shelf edges, particularly s. Grand
Banks. Generally reaches as far south as Scotian Shelf, Gulf of Maine,
and northern and eastern edges of Georges Bank. Has been recorded in
Atlantic during winter south to s. Florida, Cuba, Bahamas (Grand Bahama),
and Bermuda. Major storms have occasionally blown Dovekies to inland
locations in e. North America. <br>
&nbsp;<br>
Dovekies often show up out of range along the east coast of North America
and sometimes inland in massive wrecks of stranded, starving birds.
Sustained, strong easterly winds have been associated with some of these
strandings, most of which have occurred in early winter. Winds likely
make feeding conditions unsuitable and push the weakened, emaciated birds
landward, although periodic fluctuations in prey availability could also
precipitate these strandings</font>.<br>
&nbsp;<br><br>
<h2><b>Winter Feeding </b></h2><font size=3D4>Off Atlantic Canada in
winter, generally concentrated at shelf edges and tidal upwellings, as
well as at edges of arctic pack ice, where densest aggregations of
zooplanktonic prey found.<br>
</font>&nbsp;<br>
END OF QUOTE<br>
&nbsp;<br>
<font size=3D4>I have had the priviledge to witness such Dovekie flights
before, but in Newfoundland. <br><br>
On 2 Jan 1985 we observed almost 74000 Dovekies and 51000 Thick-billed
Murres in the morning as they flew southeast along the coast during the
L=92anse aux Meadows Christmas Bird Count.&nbsp; The wind was light, but
there was a strong nor-easter forecast, and the storm arrived in the
afternoon.&nbsp; The birds seemed to be shifting in anticipation o f the
storm.&nbsp; Three weeks later, when a similar weather pattern occurred,
we observed more than 250,000 Dovekies in a three-hour period off
Quirpon, south of L=92anse aux Meadows.<br><br>
Dovekies are not large, nor really strong fliers, so when they encounter
a furious gale such as blew from the NE last Friday, they get swept along
with it.&nbsp; Accordingly, they must have already arrived in
considerable numbers out on the Scotian Shelf,&nbsp; or perhaps in waters
even closer to Halifax.&nbsp; It seems to me (though Ian might correct
me) that the Dovekies have moved south earlier than is
&quot;normal&quot;, which would account for their occurrence off Chebucto
Head during Friday's gale.&nbsp; Perhaps there is a problem with a food
source for them, or they are responding to the changing ice conditions
further north (it is above freezing in Iqaluit today!).&nbsp; One can
only speculate, as no research is being done, to my knowledge.&nbsp; The
winter ranges and habits of alcids are not well known.&nbsp; It was only
a few years ago that a large Razorbill wintering population was found in
the Bay of Fundy, and no-one still really knows where the mass of puffins
spend the winter.<br><br>
Regardless, the Dovekies put on a wonderful show for Dave, Fulton, and
Dominic.&nbsp; Pity the gate to Chebucto Head is locked.<br><br>
Cheers,<br><br>
Blake<br>
</font><x-sigsep><p></x-sigsep>
----------------------------------------------------------------------------=
-<br>
Blake Maybank<br>
maybank@ns.sympatico.ca<br>
<a href=3D"http://www.flickr.com/photos/blakemaybank/" eudora=3D"autourl">
http://www.flickr.com/photos/blakemaybank/<br>
</a>902-852-2077<br><br>
Editor, &quot;Nova Scotia Birds&quot;<br>
<a href=3D"http://nsbs.chebucto.org/" eudora=3D"autourl">
http://nsbs.chebucto.org<br><br>
</a>Organiser, Maritimes Nature Travel Club<br>
<font color=3D"#0000FF"><u>
<a href=3D"http://tinyurl.com/naturetravel" eudora=3D"autourl">
http://tinyurl.com/naturetravel</a></u></font> <br><br>
author, &quot;Birding Sites of Nova Scotia&quot;<br>
<font color=3D"#0000FF"><u>
<a href=3D"http://tinyurl.com/birdingns" eudora=3D"autourl">
http://tinyurl.com/birdingns<br>
</a></u></font>Downloadable Nova Scotia Maps for inside front and back
covers:<br>
<a href=3D"http://tinyurl.com/mr627d" eudora=3D"autourl">
http://tinyurl.com/mr627d</a> <br><br>
White's Lake, Nova Scotia, Canada </body>
</html>

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