next message in archive
next message in thread
previous message in archive
previous message in thread
Index of Subjects
>>> My understanding is that irruption and migration
--_000_92470D8023567B4D8D50FBA6E5E9D00F0ECC1955BCHCXMSP1calmco_
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: quoted-printable
Jamie asked:
>If birds go south in the fall and return north in the spring on a regular =
basis aren't they migrating and not irrupting?
In the sense that migrating is the periodic movement from one region to ano=
ther yes it is. However as Randy wrote I think that we usually apply migrat=
ing to an event that takes place on a species wide basis and on an annual b=
asis. Using the term irruption implies to me that it isn't necessarily an a=
nnual event and that a variable number of the species engage in it. So for =
me, the northern species of owls 'irrupt' south periodically while Yellow W=
arblers migrate south to Central and South America annually (or more approp=
riately, Yellow Warblers migrate north where they spend 4-5 months breeding=
).
Also, migration isn't always restricted to a north-south movement, even in =
Nova Scotia. Local movements around the province or even concentrations at =
certain food sources have been brought up in discussions before on NatureNS=
. These qualify as migration under the above definition. There are also lon=
ger, west to east movements that for example, result in ducks, grebes, loon=
s, etc. wintering off of Nova Scotia's coasts.
All the best,
Lance
--_000_92470D8023567B4D8D50FBA6E5E9D00F0ECC1955BCHCXMSP1calmco_
Content-Type: text/html; charset="us-ascii"
Content-Transfer-Encoding: quoted-printable
<html xmlns:v=3D"urn:schemas-microsoft-com:vml" xmlns:o=3D"urn:schemas-micr=
osoft-com:office:office" xmlns:w=3D"urn:schemas-microsoft-com:office:word" =
xmlns:m=3D"http://schemas.microsoft.com/office/2004/12/omml" xmlns=3D"http:=
//www.w3.org/TR/REC-html40"><head><meta http-equiv=3DContent-Type content=
=3D"text/html; charset=3Dus-ascii"><meta name=3DGenerator content=3D"Micros=
oft Word 14 (filtered medium)"><style><!--
/* Font Definitions */
@font-face
{font-family:Cambria;
panose-1:2 4 5 3 5 4 6 3 2 4;}
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
@font-face
{font-family:Tahoma;
panose-1:2 11 6 4 3 5 4 4 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0in;
margin-bottom:.0001pt;
font-size:12.0pt;
font-family:"Times New Roman","serif";}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:purple;
text-decoration:underline;}
p.MsoAcetate, li.MsoAcetate, div.MsoAcetate
{mso-style-priority:99;
mso-style-link:"Balloon Text Char";
margin:0in;
margin-bottom:.0001pt;
font-size:8.0pt;
font-family:"Tahoma","sans-serif";}
span.hoenzb
{mso-style-name:hoenzb;}
span.BalloonTextChar
{mso-style-name:"Balloon Text Char";
mso-style-priority:99;
mso-style-link:"Balloon Text";
font-family:"Tahoma","sans-serif";}
span.EmailStyle20
{mso-style-type:personal-reply;
font-family:"Calibri","sans-serif";
color:#1F497D;}
.MsoChpDefault
{mso-style-type:export-only;
font-family:"Calibri","sans-serif";}
@page WordSection1
{size:8.5in 11.0in;
margin:1.0in 1.0in 1.0in 1.0in;}
div.WordSection1
{page:WordSection1;}
--></style><!--[if gte mso 9]><xml>
<o:shapedefaults v:ext=3D"edit" spidmax=3D"1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext=3D"edit">
<o:idmap v:ext=3D"edit" data=3D"1" />
</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-family:"Cambria","serif";color:#1F497D'>Jamie asked:<o:p></o:p></span><=
/p><div><div><p class=3DMsoNormal><b><span style=3D'font-family:"Cambria","=
serif";color:#1F497D'>></span></b><span style=3D'font-family:"Cambria","=
serif"'>If birds go south in the fall and return north in the spring on a r=
egular basis aren't they migrating and not irrupting?</span><span style=3D'=
font-family:"Cambria","serif"'><o:p></o:p></span></p></div></div><div><div>=
<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=3DMsoNorma=
l><span style=3D'font-family:"Cambria","serif";color:#1F497D'>In the sense =
that migrating is the periodic movement from one region to another yes it i=
s. However as Randy wrote I think that we usually apply migrating to an eve=
nt that takes place on a species wide basis and on an annual basis. Using t=
he term irruption implies to me that it isn’t necessarily an annual e=
vent and that a variable number of the species engage in it. So for me, the=
northern species of owls ‘irrupt’ south periodically while Yel=
low Warblers migrate south to Central and South America annually (or more a=
ppropriately, Yellow Warblers migrate north where they spend 4-5 months bre=
eding).<o:p></o:p></span></p><p class=3DMsoNormal><span style=3D'font-famil=
y:"Cambria","serif";color:#1F497D'><o:p> </o:p></span></p><p class=3DM=
soNormal><span style=3D'font-family:"Cambria","serif";color:#1F497D'>Also, =
migration isn’t always restricted to a north-south movement, even in =
Nova Scotia. Local movements around the province or even concentrations at =
certain food sources have been brought up in discussions before on NatureNS=
. These qualify as migration under the above definition. There are also lon=
ger, west to east movements that for example, result in ducks, grebes, loon=
s, etc. wintering off of Nova Scotia’s coasts.<o:p></o:p></span></p><=
p class=3DMsoNormal><span style=3D'font-family:"Cambria","serif";color:#1F4=
97D'><o:p> </o:p></span></p><p class=3DMsoNormal><span style=3D'font-f=
amily:"Cambria","serif";color:#1F497D'>All the best,<o:p></o:p></span></p><=
p class=3DMsoNormal><span style=3D'font-family:"Cambria","serif";color:#1F4=
97D'><o:p> </o:p></span></p><p class=3DMsoNormal><span style=3D'font-f=
amily:"Cambria","serif";color:#1F497D'>Lance<o:p></o:p></span></p></div></d=
iv></div></body></html>=
--_000_92470D8023567B4D8D50FBA6E5E9D00F0ECC1955BCHCXMSP1calmco_--