[NatureNS] more on seasonal and other Bald Eagle movements,

Date: Wed, 26 Sep 2007 16:25:53 -0300
From: Jim Wolford <jimwolford@eastlink.ca>
To: NatureNS <naturens@chebucto.ns.ca>
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I left some stuff out in my answer below to Andy Dean.  And there was an
earlier question, also from Andy, about the timing of the seasonal
movements.  Often the build-up of numbers from seasonal immigrants is not
noticeable in the eastern Valley until mid to late November or early
December.  And we think that adult eagles start to depart from here during
February, in order to get back to wherever their nesting territories are.
Younger and unmated eagles are more leisurely about moving away from here in
Spring, and undoubtedly some or many of them linger into Summer, where they
would be undetectable among our nesting population plus their youngsters.

I believe there was a place in Maine where carrion was put out for eagles
and observers looked for banded and tagged eagles.

I have no recollection of any of our winter eagles having come from the deep
south of the U.S., e.g. Florida.  Perhaps someone can correct me on this?

Just for completeness?, I thought I would add something about the nesting
cycle for our bald eagles.  In western N.S., e.g. the Valley to Yarmouth
etc., eagles on noticeably on nests and presumably incubating eggs (up to 3
or 4) in mid-March.  I believe the incubation period is 35 days, and it
takes 12 weeks to go from hatching (tiny gray downy eaglet, really cute) to
absolutely full size (or a bit larger) and weights of 8 to 12+ pounds (up to
5.5 kg.).  Fledging occurs in early July in the Valley, but probably a bit
later in northern N.S.

Males are generally from 8 to 10 pounds, while females are 10 to 12 pounds.
There is a huge amount of variation in the immature plumages, especially in
the first two years, but with practice the sex can often be determined from
the size/weight of the bird, size of beak, and heaviness of flight.

Cheers from Jim in Wolfville
----------
From: Jim Wolford <jimwolford@eastlink.ca>
Reply-To: naturens@chebucto.ns.ca
Date: Mon, 24 Sep 2007 16:53:53 -0300
To: NatureNS <naturens@chebucto.ns.ca>
Cc: Mark Elderkin <ELDERKMF@gov.ns.ca>, Sherman Boates <boatesjs@gov.ns.ca>,
Randy Milton <miltongr@gov.ns.ca>
Subject: FW: [NatureNS] Bald eagle movement

Apologies to Andy Dean for not answering his query earlier, and thanks to
Richard and Randy  for responses.  I'm no expert, but I do have a long
history as a peripheral reader and interpreter and counts-compiler.  Andy's
question sounds simple, but there is no simple answer, and all the
tagging/banding etc. that was done was a very long time ago.  We used to
know a lot more details than we do now, because eagles are doing so well in
the province that they are not being studies any more.

As far as I know, there were never any radio-tagging studies, but for a long
time in the 1970s and 1980s the nests, primarily in Cape Breton then, were
monitored by Land & Forests (now Nat. Resources) personnel and the juveniles
banded, and sometimes colour marked with flags on the legs and wings.  Also
in at least two places, the Gaspereau Valley (Cyril Coldwell's farm) and
someplace near Yarmouth, carrion piles were monitored and observers actually
looked for tags and bands and often could read the band numbers with
telescopes (what frustrating work that must have been, getting zillions of
incomplete numbers!).  Thus the colour tags and leg bands produced a bit of
info' concerning just where certain birds had been banded while still in the
nest as juveniles.  Yes, I think a few were from Maine, and also I think
there were some from P.E.I. and N.B.? and perhaps Newfoundland, too?  But
the vast majority of eagles on the western mainland of N.S. in winter were
raised in Cape Breton.

Things have changed quite a bit in recent decades, perhaps partly from the
putting out of food in eastern King's County in winter having increased the
survival of young immature eagles.  The nesting population on the mainland
has increased steadily, I believe (comparing the two breeding bird atlases
in a few years will be very interesting), so that I'll bet the winter birds
we get now in eastern King's County are not so predominantly Cape Breton
birds.

Andy asked about seasonal movements.  The banding a few decades ago showed
us that there were substantial movements during the winter, especially
between the eastern Valley and the Shubenacadie River Valley (where there
was a pig farmer who put out carrion like Cyril did at Gaspereau, and the
Shubenacadie was also attractive because of spawning tomcod in winter plus
common mergansers that the eagles learned to hunt at certain stages of the
tide.

Sorry to be so verbose, and no doubt this will raise more questions -- ask
me either via NatureNS or off-list.

Cheers from Jim in Wolfville
----------
From: Richard Stern <sternrichard@gmail.com>
Reply-To: naturens@chebucto.ns.ca
Date: Mon, 24 Sep 2007 09:34:44 -0300
To: naturens@chebucto.ns.ca
Subject: Re: [NatureNS] Bald eagle movement

Bald eagles generally leave the Valley in March/ April and return in Oct/
Nov. More and more seem to be staying to nest each year, but that number
does not account for the 2-400 or so that we regularly see in Feb. on the
eagle counts. I believe that some early radio-tagged studies were done a
number of years ago, which showed that at least some of the wintering birds
here came from Maine and points farther south - even post breeding dispersal
from Florida. DNR may have that data somewhere. It would seem reasonable to
suppose that many of our wintering eagles are C.Breton breeders, but only
banding studies or satellite radio tags would be able to prove it.

Richard


On 9/23/07, Randy Lauff <randy.lauff@gmail.com> wrote:
Interesting question...I think that's the assumption, though I don't know if
anyone knows for sure. Eagles stay around Antigonish all year...hard to say
if there's any seasonal variation in numbers. It's also hard to say if the
same individuals are here all year round.

I had two adult eagles in my orchard this morning. My students are running
an entomology project here...unfortunately, the eagles are eating one of the
two bait sites (a road-killed deer); the other bait is in the woods for
comparison...although eagles will go into the woods, it's by no means as
common for them to do so.


On 23/09/2007, Andy Dean <aadean@ns.sympatico.ca
<mailto:aadean@ns.sympatico.ca> > wrote:
Can somebody enlighten me please......are there seasonal movements in the
the bald eagle population between the Annapolis Valley and Cape Breton. Do
they in fact breed in one area and migrate to the other?
Thanks
Andy
 
Andy & Lelia Dean
86 Baden Powell Drive
Kentville, NS. Canada. B4N 5P5
Tel: [902] 678-6243
 
aadean@ns.sympatico.ca

Randy
_________________________________
RF Lauff
Way in the boonies of
Antigonish County, NS.



-- 
#################
Dr.Richard Stern,  
70 Exhibition St.
Kentville, NS, Canada
B4N 4K9

Richard Stern, 
317 Middle Dyke Rd.
Port Williams, NS, Canada
B0P 1T0

rbstern@ns.sympatico.ca
rbstern@xcountry.tv
sternrichard@gmail.com
###################



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<HTML>
<HEAD>
<TITLE>more on seasonal and other Bald Eagle movements, plus timing of nest=
ing/fledging</TITLE>
</HEAD>
<BODY>
I left some stuff out in my answer below to Andy Dean. &nbsp;And there was =
an earlier question, also from Andy, about the timing of the seasonal moveme=
nts. &nbsp;Often the build-up of numbers from seasonal immigrants is not not=
iceable in the eastern Valley until mid to late November or early December. =
&nbsp;And we think that adult eagles start to depart from here during Februa=
ry, in order to get back to wherever their nesting territories are. &nbsp;Yo=
unger and unmated eagles are more leisurely about moving away from here in S=
pring, and undoubtedly some or many of them linger into Summer, where they w=
ould be undetectable among our nesting population plus their youngsters.<BR>
<BR>
I believe there was a place in Maine where carrion was put out for eagles a=
nd observers looked for banded and tagged eagles.<BR>
<BR>
I have no recollection of any of our winter eagles having come from the dee=
p south of the U.S., e.g. Florida. &nbsp;Perhaps someone can correct me on t=
his?<BR>
<BR>
Just for completeness?, I thought I would add something about the nesting c=
ycle for our bald eagles. &nbsp;In western N.S., e.g. the Valley to Yarmouth=
 etc., eagles on noticeably on nests and presumably incubating eggs (up to 3=
 or 4) in mid-March. &nbsp;I believe the incubation period is 35 days, and i=
t takes 12 weeks to go from hatching (tiny gray downy eaglet, really cute) t=
o absolutely full size (or a bit larger) and weights of 8 to 12+ pounds (up =
to 5.5 kg.). &nbsp;Fledging occurs in early July in the Valley, but probably=
 a bit later in northern N.S. &nbsp;<BR>
<BR>
Males are generally from 8 to 10 pounds, while females are 10 to 12 pounds.=
 &nbsp;There is a huge amount of variation in the immature plumages, especia=
lly in the first two years, but with practice the sex can often be determine=
d from the size/weight of the bird, size of beak, and heaviness of flight.<B=
R>
<BR>
Cheers from Jim in Wolfville<BR>
----------<BR>
<B>From: </B>Jim Wolford &lt;jimwolford@eastlink.ca&gt;<BR>
<B>Reply-To: </B>naturens@chebucto.ns.ca<BR>
<B>Date: </B>Mon, 24 Sep 2007 16:53:53 -0300<BR>
<B>To: </B>NatureNS &lt;naturens@chebucto.ns.ca&gt;<BR>
<B>Cc: </B>Mark Elderkin &lt;ELDERKMF@gov.ns.ca&gt;, Sherman Boates &lt;boa=
tesjs@gov.ns.ca&gt;, Randy Milton &lt;miltongr@gov.ns.ca&gt;<BR>
<B>Subject: </B>FW: [NatureNS] Bald eagle movement<BR>
<BR>
Apologies to Andy Dean for not answering his query earlier, and thanks to R=
ichard and Randy &nbsp;for responses. &nbsp;I'm no expert, but I do have a l=
ong history as a peripheral reader and interpreter and counts-compiler. &nbs=
p;Andy's question sounds simple, but there is no simple answer, and all the =
tagging/banding etc. that was done was a very long time ago. &nbsp;We used t=
o know a lot more details than we do now, because eagles are doing so well i=
n the province that they are not being studies any more. &nbsp;<BR>
<BR>
As far as I know, there were never any radio-tagging studies, but for a lon=
g time in the 1970s and 1980s the nests, primarily in Cape Breton then, were=
 monitored by Land &amp; Forests (now Nat. Resources) personnel and the juve=
niles banded, and sometimes colour marked with flags on the legs and wings. =
&nbsp;Also in at least two places, the Gaspereau Valley (Cyril Coldwell's fa=
rm) and someplace near Yarmouth, carrion piles were monitored and observers =
actually looked for tags and bands and often could read the band numbers wit=
h telescopes (what frustrating work that must have been, getting zillions of=
 incomplete numbers!). &nbsp;Thus the colour tags and leg bands produced a b=
it of info' concerning just where certain birds had been banded while still =
in the nest as juveniles. &nbsp;Yes, I think a few were from Maine, and also=
 I think there were some from P.E.I. and N.B.? and perhaps Newfoundland, too=
? &nbsp;But the vast majority of eagles on the western mainland of N.S. in w=
inter were raised in Cape Breton.<BR>
<BR>
Things have changed quite a bit in recent decades, perhaps partly from the =
putting out of food in eastern King's County in winter having increased the =
survival of young immature eagles. &nbsp;The nesting population on the mainl=
and has increased steadily, I believe (comparing the two breeding bird atlas=
es in a few years will be very interesting), so that I'll bet the winter bir=
ds we get now in eastern King's County are not so predominantly Cape Breton =
birds.<BR>
<BR>
Andy asked about seasonal movements. &nbsp;The banding a few decades ago sh=
owed us that there were substantial movements during the winter, especially =
between the eastern Valley and the Shubenacadie River Valley (where there wa=
s a pig farmer who put out carrion like Cyril did at Gaspereau, and the Shub=
enacadie was also attractive because of spawning tomcod in winter plus commo=
n mergansers that the eagles learned to hunt at certain stages of the tide.<=
BR>
<BR>
Sorry to be so verbose, and no doubt this will raise more questions -- ask =
me either via NatureNS or off-list.<BR>
<BR>
Cheers from Jim in Wolfville<BR>
----------<BR>
<B>From: </B>Richard Stern &lt;sternrichard@gmail.com&gt;<BR>
<B>Reply-To: </B>naturens@chebucto.ns.ca<BR>
<B>Date: </B>Mon, 24 Sep 2007 09:34:44 -0300<BR>
<B>To: </B>naturens@chebucto.ns.ca<BR>
<B>Subject: </B>Re: [NatureNS] Bald eagle movement<BR>
<BR>
Bald eagles generally leave the Valley in March/ April and return in Oct/ N=
ov. More and more seem to be staying to nest each year, but that number does=
 not account for the 2-400 or so that we regularly see in Feb. on the eagle =
counts. I believe that some early radio-tagged studies were done a number of=
 years ago, which showed that at least some of the wintering birds here came=
 from Maine and points farther south - even post breeding dispersal from Flo=
rida. DNR may have that data somewhere. It would seem reasonable to suppose =
that many of our wintering eagles are C.Breton breeders, but only banding st=
udies or satellite radio tags would be able to prove it.<BR>
<BR>
Richard<BR>
<BR>
<BR>
On 9/23/07, <B>Randy Lauff</B> &lt;randy.lauff@gmail.com&gt; wrote: <BR>
<BLOCKQUOTE>Interesting question...I think that's the assumption, though I =
don't know if anyone knows for sure. Eagles stay around Antigonish all year.=
..hard to say if there's any seasonal variation in numbers. It's also hard t=
o say if the same individuals are here all year round. <BR>
<BR>
I had two adult eagles in my orchard this morning. My students are running =
an entomology project here...unfortunately, the eagles are eating one of the=
 two bait sites (a road-killed deer); the other bait is in the woods for com=
parison...although eagles will go into the woods, it's by no means as common=
 for them to do so. <BR>
<BR>
<BR>
On 23/09/2007, <B>Andy Dean</B> &lt;aadean@ns.sympatico.ca &nbsp;&lt;mailto=
:aadean@ns.sympatico.ca&gt; &gt; wrote: <BR>
<BLOCKQUOTE><FONT SIZE=3D"2"><FONT FACE=3D"Arial">Can somebody enlighten me ple=
ase......are there seasonal movements in the &nbsp;the bald eagle population=
 between the Annapolis Valley and Cape Breton. Do they in fact breed in one =
area and migrate to the other? <BR>
Thanks<BR>
Andy<BR>
</FONT></FONT> <BR>
<FONT SIZE=3D"2"><FONT FACE=3D"Arial">Andy &amp; Lelia Dean<BR>
86 Baden Powell Drive<BR>
Kentville, NS. Canada. B4N 5P5<BR>
Tel: [902] 678-6243<BR>
</FONT></FONT> <BR>
<FONT SIZE=3D"2"><FONT FACE=3D"Arial">aadean@ns.sympatico.ca<BR>
</FONT></FONT></BLOCKQUOTE><BR>
Randy<BR>
_________________________________<BR>
RF Lauff<BR>
Way in the boonies of<BR>
Antigonish County, NS. <BR>
</BLOCKQUOTE><BR>
<BR>
<BR>
-- <BR>
#################<BR>
Dr.Richard Stern, &nbsp;&nbsp;<BR>
70 Exhibition St.<BR>
Kentville, NS, Canada<BR>
B4N 4K9<BR>
<BR>
Richard Stern, <BR>
317 Middle Dyke Rd.<BR>
Port Williams, NS, Canada<BR>
B0P 1T0<BR>
<BR>
rbstern@ns.sympatico.ca<BR>
rbstern@xcountry.tv<BR>
sternrichard@gmail.com<BR>
################### <BR>
<BR>
</BODY>
</HTML>


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