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HI Gayle,
I'm coming to this email a bit late. Reverse migration events occur among m=
igratory bird species all over the world. While migration routes of most sp=
ecies are hard wired (some species learn the route from their parents e.g. =
Whooping Cranes) their behavior en route is dependent on many factors. For =
example, temperature has an effect on how fast birds move north in the spri=
ng. These responses are also hardwired over the millennia their migration r=
outes evolved. However, sometimes this wiring gets mixed up. This may resul=
t in a bird going in the opposite direction to where it should go, usually =
with fatal results.
The case of the Yellow-rumped Warblers that Stuart is reporting on is not s=
uch a case. The simplest explanation for it is that the changing weather co=
nditions that he noted were also a signal to the birds that further migrati=
on to the northeast was hazardous and they turned around in response. Why t=
he birds didn't just drop into the vegetation at Cape Enrage I can't say bu=
t there must be some factor that the birds responded to that kept them from=
doing so. A reverse migration is not necessarily always that hazardous as =
Rick has noted. If it was, the genetics behind this reaction would soon be =
removed from the gene pool.
All the best,
Lance
From: naturens-owner@chebucto.ns.ca [mailto:naturens-owner@chebucto.ns.ca] =
On Behalf Of Rick Whitman
Sent: Friday, April 26, 2013 2:41 PM
To: naturens
Subject: EXTERNAL: Re: [NatureNS] Fwd: Large reverse migration of Yellow-ru=
mped Warblers off CapeEnrage - April 25, 2013
These birds may have made it across to Cumberland Co., the shortest distanc=
e from Cape Enrage being about 11 km. Or they may have turned around out of=
sight. After all, he does say visibility became "essentially zero". I feel=
that Stu was describing something that seemed very strange, and thus inter=
esting, but we don't know that it was a disaster and it most certainly was =
not suicidal.
Having said that, migrating birds make fatal "mistakes" somewhat routinely.
Cheers,
Rick Whitman
On Fri, Apr 26, 2013 at 9:33 AM, <duartess@ns.sympatico.ca<mailto:duartess@=
ns.sympatico.ca>> wrote:
Why would this occur if this would mean their demise? Aren't migration patt=
erns hard-wired into their brains? Not sure if I am asking this correctly.
Thank you,
Gayle MacLean
Dartmouth
---- James Churchill <jameslchurchill@gmail.com<mailto:jameslchurchill@gmai=
l.com>> wrote:
> interesting migration observations from naturenb (below).
> cheers,
> James.
>
> ---------- Forwarded message ----------
> From: Stuart Tingley <stubirdnb@gmail.com<mailto:stubirdnb@gmail.com>>
> Date: Thu, Apr 25, 2013 at 10:08 PM
> Subject: Large reverse migration of Yellow-rumped Warblers off Cape Enrag=
e
> - April 25, 2013
> To: NATURENB@listserv.unb.ca<mailto:NATURENB@listserv.unb.ca>
>
>
> I decided to head down to Albert County in mid-morning after receiving a
> text from Richard Blacquiere at Point Lepreau Bird Observatory with news =
of
> a substantial loon flight there.
>
> I arrived at Cape Enrage at 10:30am with reasonable visibility in light f=
og
> and drizzle and strong SW winds. Within a few minutes of arriving I saw a
> passing flock that included 630 Surf/Black Scoters and 210 Long-tailed
> Ducks. I also noted a few Red-throated Loons flying NE low over the water
> and a CASPIAN TERN flew by low over the water heading northeast. But what
> caught my attention most was the almost constant stream of small groups o=
f
> YELLOW-RUMPED WARBLERS coming from the northeast and heading out to the
> southwest into the fog and drizzle.
>
> Shortly after I arrived the fog and drizzle got heavier and with little
> visibility over the water I focussed my attention on the warbler flight a=
nd
> tried to keep track of numbers until I left the cape with zero visibility
> at 12 noon. In 90 minutes I counted 475 Yellow-rumps and only about 10 PA=
LM
> WARBLERS, all heading SW into what seemed like a suicidal flight as the
> drizzle became drenching and thick fog reducing visibility to essentially
> zero. I have little doubt that this flight began at first light and
> probably involved one or two thousand birds. Even when I left at noon I
> could still hear Yellow-rumps passing overhead and going southwest into t=
he
> thick fog.
>
> Surprisingly I didn't see any birds turn around or come back in from the
> southwest - they seemed determined to go SW! In fact the only bird I saw
> come in off the water from the southwest was larger and had me perplexed
> until I got a good view of it - an adult male Baltimore Oriole.
>
> Elsewhere in Albert County, the adult LITTLE BLUE HERON was easily seen
> close to Route 915 at the east end of Waterside marsh at high tide in ear=
ly
> afternoon. Almost the entire salt marsh was flooded at that time.
>
> Good Birding,
>
> Stu Tingley
>
> NatureNB guidelines http://www3.nbnet.nb.ca/maryspt/nnbe.html
> Foire aux questions de NatureNB http://www3.nbnet.nb.ca/maryspt/nnbf.htm=
l
>
>
>
> --
> James Churchill
> Kentville, Nova Scotia
> Email: jameslchurchill@gmail.com<mailto:jameslchurchill@gmail.com>
> Phone (h): (902) 681-237<tel:%28902%29%20681-2374>
--_000_92470D8023567B4D8D50FBA6E5E9D00F0E3AF09C5CHCXMSP1calmco_
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</o:shapelayout></xml><![endif]--></head><body lang=3DEN-US link=3Dblue vli=
nk=3Dpurple><div class=3DWordSection1><p class=3DMsoNormal><span style=3D'f=
ont-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>HI Gayle,=
<o:p></o:p></span></p><p class=3DMsoNormal><span style=3D'font-size:11.0pt;=
font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span><=
/p><p class=3DMsoNormal><span style=3D'font-size:11.0pt;font-family:"Calibr=
i","sans-serif";color:#1F497D'>I’m coming to this email a bit late. R=
everse migration events occur among migratory bird species all over the wor=
ld. While migration routes of most species are hard wired (some species lea=
rn the route from their parents e.g. Whooping Cranes) their behavior en rou=
te is dependent on many factors. For example, temperature has an effect on =
how fast birds move north in the spring. These responses are also hardwired=
over the millennia their migration routes evolved. However, sometimes this=
wiring gets mixed up. This may result in a bird going in the opposite dire=
ction to where it should go, usually with fatal results.<o:p></o:p></span><=
/p><p class=3DMsoNormal><span style=3D'font-size:11.0pt;font-family:"Calibr=
i","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=3DMsoNo=
rmal><span style=3D'font-size:11.0pt;font-family:"Calibri","sans-serif";col=
or:#1F497D'>The case of the Yellow-rumped Warblers that Stuart is reporting=
on is not such a case. The simplest explanation for it is that the changin=
g weather conditions that he noted were also a signal to the birds that fur=
ther migration to the northeast was hazardous and they turned around in res=
ponse. Why the birds didn’t just drop into the vegetation at Cape Enr=
age I can’t say but there must be some factor that the birds responde=
d to that kept them from doing so. A reverse migration is not necessarily a=
lways that hazardous as Rick has noted. If it was, the genetics behind this=
reaction would soon be removed from the gene pool.<o:p></o:p></span></p><p=
class=3DMsoNormal><span style=3D'font-size:11.0pt;font-family:"Calibri","s=
ans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=3DMsoNormal>=
<span style=3D'font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1=
F497D'>All the best,<o:p></o:p></span></p><p class=3DMsoNormal><span style=
=3D'font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p=
> </o:p></span></p><p class=3DMsoNormal><span style=3D'font-size:11.0p=
t;font-family:"Calibri","sans-serif";color:#1F497D'>Lance<o:p></o:p></span>=
</p><p class=3DMsoNormal><span style=3D'font-size:11.0pt;font-family:"Calib=
ri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=3DMsoN=
ormal><b><span style=3D'font-size:10.0pt;font-family:"Tahoma","sans-serif"'=
>From:</span></b><span style=3D'font-size:10.0pt;font-family:"Tahoma","sans=
-serif"'> naturens-owner@chebucto.ns.ca [mailto:naturens-owner@chebucto.ns.=
ca] <b>On Behalf Of </b>Rick Whitman<br><b>Sent:</b> Friday, April 26, 2013=
2:41 PM<br><b>To:</b> naturens<br><b>Subject:</b> EXTERNAL: Re: [NatureNS]=
Fwd: Large reverse migration of Yellow-rumped Warblers off CapeEnrage - Ap=
ril 25, 2013<o:p></o:p></span></p><p class=3DMsoNormal><o:p> </o:p></p=
><div><p class=3DMsoNormal>These birds may have made it across to Cumberlan=
d Co., the shortest distance from Cape Enrage being about 11 km. Or they ma=
y have turned around out of sight. After all, he does say visibility became=
"essentially zero". I feel that Stu was describing something tha=
t seemed very strange, and thus interesting, but we don't know that it was =
a disaster and it most certainly was not suicidal.<o:p></o:p></p><div><p cl=
ass=3DMsoNormal>Having said that, migrating birds make fatal "mistakes=
" somewhat routinely. <o:p></o:p></p><div><p class=3DMsoNormal>Ch=
eers,<o:p></o:p></p></div><div><p class=3DMsoNormal style=3D'margin-bottom:=
12.0pt'>Rick Whitman<o:p></o:p></p><div><p class=3DMsoNormal>On Fri, Apr 26=
, 2013 at 9:33 AM, <<a href=3D"mailto:duartess@ns.sympatico.ca" target=
=3D"_blank">duartess@ns.sympatico.ca</a>> wrote:<o:p></o:p></p><p class=
=3DMsoNormal>Why would this occur if this would mean their demise? Aren't m=
igration patterns hard-wired into their brains? Not sure if I am asking thi=
s correctly.<br><br>Thank you,<br><br>Gayle MacLean<br>Dartmouth<br><br>---=
- James Churchill <<a href=3D"mailto:jameslchurchill@gmail.com">jameslch=
urchill@gmail.com</a>> wrote:<br>> interesting migration observations=
from naturenb (below).<br>> cheers,<br>> James.<br>><br>> ----=
------ Forwarded message ----------<br>> From: Stuart Tingley <<a hre=
f=3D"mailto:stubirdnb@gmail.com">stubirdnb@gmail.com</a>><br>> Date: =
Thu, Apr 25, 2013 at 10:08 PM<br>> Subject: Large reverse migration of Y=
ellow-rumped Warblers off Cape Enrage<br>> - April 25, 2013<br>> To: =
NATURENB@listserv.unb.ca<br=
>><br>><br>> I decided to head down to Albert County in mid-mornin=
g after receiving a<br>> text from Richard Blacquiere at Point Lepreau B=
ird Observatory with news of<br>> a substantial loon flight there.<br>&g=
t;<br>> I arrived at Cape Enrage at 10:30am with reasonable visibility i=
n light fog<br>> and drizzle and strong SW winds. Within a few minutes o=
f arriving I saw a<br>> passing flock that included 630 Surf/Black Scote=
rs and 210 Long-tailed<br>> Ducks. I also noted a few Red-throated Loons=
flying NE low over the water<br>> and a CASPIAN TERN flew by low over t=
he water heading northeast. But what<br>> caught my attention most was t=
he almost constant stream of small groups of<br>> YELLOW-RUMPED WARBLERS=
coming from the northeast and heading out to the<br>> southwest into th=
e fog and drizzle.<br>><br>> Shortly after I arrived the fog and driz=
zle got heavier and with little<br>> visibility over the water I focusse=
d my attention on the warbler flight and<br>> tried to keep track of num=
bers until I left the cape with zero visibility<br>> at 12 noon. In 90 m=
inutes I counted 475 Yellow-rumps and only about 10 PALM<br>> WARBLERS, =
all heading SW into what seemed like a suicidal flight as the<br>> drizz=
le became drenching and thick fog reducing visibility to essentially<br>>=
; zero. I have little doubt that this flight began at first light and<br>&g=
t; probably involved one or two thousand birds. Even when I left at noon I<=
br>> could still hear Yellow-rumps passing overhead and going southwest =
into the<br>> thick fog.<br>><br>> Surprisingly I didn't see any b=
irds turn around or come back in from the<br>> southwest - they seemed d=
etermined to go SW! In fact the only bird I saw<br>> come in off the wat=
er from the southwest was larger and had me perplexed<br>> until I got a=
good view of it - an adult male Baltimore Oriole.<br>><br>> Elsewher=
e in Albert County, the adult LITTLE BLUE HERON was easily seen<br>> clo=
se to Route 915 at the east end of Waterside marsh at high tide in early<br=
>> afternoon. Almost the entire salt marsh was flooded at that time.<br>=
><br>> Good Birding,<br>><br>> Stu Tingley<br>><br>> Natu=
reNB guidelines <a href=3D"http://www3.nbnet.nb.ca/maryspt/nnbe.html"=
target=3D"_blank">http://www3.nbnet.nb.ca/maryspt/nnbe.html</a><br>> Fo=
ire aux questions de NatureNB <a href=3D"http://www3.nbnet.nb.ca/mary=
spt/nnbf.html" target=3D"_blank">http://www3.nbnet.nb.ca/maryspt/nnbf.html<=
/a><br>><br>><br><span class=3Dhoenzb><span style=3D'color:#888888'>&=
gt;</span></span><span style=3D'color:#888888'><br><span class=3Dhoenzb>>=
; --</span><br><span class=3Dhoenzb>> James Churchill</span><br><span cl=
ass=3Dhoenzb>> Kentville, Nova Scotia</span><br><span class=3Dhoenzb>>=
; Email: <a href=3D"mailto:jameslchurchill@gmail.com">jameslchurchill@gmail=
.com</a></span><br><span class=3Dhoenzb>> Phone (h): <a href=3D"tel:%289=
02%29%20681-2374">(902) 681-237</a></span></span><o:p></o:p></p></div></div=
></div></div></div></body></html>=
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