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Hi James & All,
I suggest we let John and Andrew deal with my question and go from =
there.=20
Balance in this context surely should consist of listing all known =
threats and and then ranking them to the extent possible.=20
On another matter, have you made any progress since June 9, 2013 on =
Google-earthing those elevations for possible ponds on Elderkin brook ? =
(My e-mails of June 9 and June 20, 2013.)
Yt, Dave Webster, Kentville
----- Original Message -----=20
From: James Churchill=20
To: naturens=20
Sent: Monday, June 30, 2014 11:44 PM
Subject: [NatureNS] Wood Turtle: long
Dave,=20
With respect, and in hopes of adding some balance here, I do not feel =
that your strong language here is appropriate and possibly, though I am =
not personally offended, it could be perceived as offensive to some. =
Science can move forward by rational argument, but how do you defend =
your use of the word 'delusion' in reference to the idea that collecting =
turtles could be one factor affecting turtle population viability? (To =
my knowledge no one has yet, including the Natural History Museum web =
site, suggested that collecting turtles is the main threat to turtle =
populations so your statement is misleading). 'Delusion' to me implies =
belief in a notion that is attractive but false. From what I've seen you =
have not provided any quantitative evidence supporting the notion that =
collecting turtles has no,or little, effect on turtle populations. Until =
then I feel you are not yet free to throw around the word 'delusion'.=20
One place I would suggest the discussion starts is with the COSEWIC =
status report on the Wood Turtle. If the discussion starts with research =
rather than anecdote there is possibility for making some headway in =
this discussion. Otherwise, in my opinion, your argument (as I =
understand it: that there is no harm and that we actually lose out by =
not collecting turtles), which is not yet based on evidence, and not one =
that to my knowledge many scientists agree with, is perhaps misdirecting =
our energies and misleading people that are listening to this =
conversation.=20
In the spirit of science and rational argument.
Cheers,
James
On Monday, June 30, 2014, James Hirtle <jrhbirder@hotmail.com> wrote:
Not threatened or endangered yet, but a painted turtle was crossing =
the Fisherman's Memorial Highway just outside of Hammond's Plains when I =
was coming home last night. I missed it as did the car behind me, but =
as to its fate after that who knows. =20
=20
James R. Hirtle
Bridgewater=20
=20
-------------------------------------------------------------------------=
---
From: dwebster@glinx.com
To: GILHENJA@gov.ns.ca; HEBDAAJ@gov.ns.ca; NatureNS@chebucto.ns.ca
Subject: [NatureNS] Wood Turtle: long
Date: Mon, 30 Jun 2014 19:13:41 -0300
Hi John, Andrew & All, =20
I noticed on a post to naturens recently that (from the NS =
Museum of NH site)--
"It may seem harmless to keep a turtle as a pet for a while, but =
this is not a good idea. Two of the province's four turtle species are =
already at risk in Nova Scotia. It is likely that removal of turtles by =
people is part of the reason, for Wood Turtles."
I expect this supposition rests in part on your 1984 statement =
(Amphibians and Reptiles of Nova Scotia p. 148) that--
"Another problem facing the Wood Turtle is the removal of many =
individuals from their habitat by people while on fishing trips or =
camping trips" which are then subsequently "released in the woods many =
kilometers from its natural habitat."
Perhaps you can provide some details of the observations on =
which your above statement was based.=20
To get a third viewpoint for comparison I went to Wood Turtle on =
Wikipedia and with some personal satisfaction note that much of their =
text, re Wood Turtles range wide, might have been written by me re =
turtles and amphibians in NS; e.g. emphasis on habitat loss, traffic =
fatalities, a plug for culvert underpasses and the observation that an =
overabundant Raccoon threatens WTs at all life stages. They quite =
rightly list commercial collections made for the international pet trade =
as a genuine threat. They note without commentary that "Brochures and =
other media that warn people to avoid keeping the wood turtle as a pet =
are currently being distributed."; a variant of damming by faint praise.
With respect to culvert underpasses I paste the following--
START OF PASTE\\\\\\\\\\\\\\\\\\\\\\\\\\\\
Hi Lisa & All, July 31, 2008
I dare say you are already moving in this direction, but a small =
animal underpass, suitably located (e.g. where you were escorting=20
toadlets in this instance) would be less labour-intensive and=20
consequently more practicable in the long run.
Why Conservation organizations have not lobbied for and made =
public=20
noises about small animal crossings beats me. Perhaps I have not =
been=20
paying attention but I have noticed that some have been installed in =
the=20
UK. Even modest highways with light traffic can be effective =
barriers to=20
movement of Reptiles and Amphibians, either by preventing access to =
the=20
roadway or by killing some that do make it.
Based on road kills observed while walking, I think snakes must =
sun=20
on gravel roads where they blend in nicely before and after being=20
flattened. And a 20-cm high ridge of gravel, thrown up by a road =
grader,=20
can stop a 30-cm snake from crossing. And a highway sand cut, at =
angle=20
of repose after about 25 years, acts as a solid wall to a toad (in =
dry=20
weather; wet might be different).
Yours truly, Dave Webster, Kentville
END OF PASTE\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\
And just one more example--
START OF PASTE\\\\\\\\\\\\\\\\\\\
Hi Flora & All, Apr 3, 2006
Traffic on our highways is unfortunately a very effective way to =
kill small animals; invertebrate & vertebrate. I dug out two responses =
to this spring rush (pasted below) and am struck by the agreement in =
timing. As noted in my post of Sept 17, 2005, underpasses can be very =
effective at least for snakes.
Thanks for the opportunity to flog a pet idea.
DW
Flora Cordis Johnson wrote:
Last night's rain, though undoubtedly needed, brought the first =
amphibian roadkills of spring to my neck of the woods, and a lot of =
them. In a 3/4 mile stretch of road that runs through a wetland east of =
my house on Cloverdale Road, near Middle Stewiacke, I counted three dead =
spring peepers, ranging in size from about a half inch to about an inch =
in length, and a large (about 2 inch) dark-charcoal coloured salamander =
with faint blue markings on its sides. In addition there were several =
unidentifiable splats -- which, judging from size and weather, were most =
likely ex-frogs. I brought the salamander home in a dead leaf and =
photographed it.
A sad Wild Flora in Birch Hill
START OF PASTES\\\\\\\\\\\\\\\\\\
Hi Anne & All, Mar 31, 2002
I recall hearing some years ago that toad (or frog ?) =
underpasses had
been installed on some British highways, really culverts at ditch =
level,
and had substantially reduced road kills.
I wonder if these salamanders would preferentially use a culvert =
if it
were available and how large it would need to be ?
Dave Webster, Kentville
\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\
Hi James & All, Mar 31, 2005
A lot of amphibians and reptiles don't get to the other side =
when=20
they attempt to cross a road.
I continue to wonder why Naturalist organizations don't pressure =
more for safe R&A underpass crossings. Is this a design problem or a =
motivation problem ?
Yours truly, Dave Webster, Kentville
END OF PASTES; really \\\\\\\\\\\\\\\\\\
=20
I don't like putting you and Andrew on the spot but remember =
"Iron sharpeneth iron", Prov. 27:17, I don't think the numbers add up =
and in my view, backed by Wikipedia as it happens (noted above), there =
are greater environmental problems that collectively shrink the odd =
turtle picked up on a fishing or camping trip to a value that is =
indistinguishable from zero.=20
According to Wikipedia, Wood Turtles live to 40 years in the =
wild (58 in captivity), become sexually mature at ages 14-18 and lay =
3-20 eggs per year. For simple mental arithmetic one can round this to =
20 egg-laying years and 10 eggs per year for a total of 200 eggs per =
female. So attrition must be severe to maintain a stable population and =
the range in egg production implies a control mechanism to avoid =
damaging intraspecific competition.
Males contest for the opportunity to mate so taking a male home =
would have no impact (apart from the positive one of decreasing demand =
on resources) and unless the population were really sparse the removal =
of a female would be soon offset by greater egg production as resources =
per adult increased.
On the other hand I have found no mention in your text for any =
species of the much greater threats of habitat destruction, road =
traffic and habitat fragmentation by highway embankments. Effective =
protection can be implemented only if the major threats are recognized.=20
And pushing the delusion that all will be fine if people just =
stop taking turtles home and releasing them far from the turtle's home, =
while downplaying or ignoring the much greater threats is in my view a =
good way to condemn the Wood Turtle to ultimate extirpation.
That is more than enough serious text for one communication so I =
will turn briefly to matters that are more fun.
In the plots of Eastern Painted Turtle (EP) and Wood Turtle (WT) =
distribution it is interesting (to me) that one distribution is almost =
entirely in the negative space of the other. Of 24 WT and 31 EP stations =
only 4 appear to be in common. By perhaps faulty probability reasoning =
(expanded below) I would expect 15 stations to have been in common (if =
these turtles had identical habitat requirements). Because only 4 were =
in common (and perhaps they were in the same general area and only =
appear to be in common) these two species approximate what used to be =
called a niche pair and consequently do not directly compete with each =
other.
The distribution of WT rang a bell so I compared it with =
Potamogeton robinsii in my 1954 MSc thesis; not identical but very =
close. This is interesting because P. robinsii was unique in that it was =
present only in water of unusual composition (high pH and low total =
mineral content). And to add one more twist, P. robinsii in Minnesota =
(Moyle, 1945) was exceptional by being only in waters of high pH and low =
alkalinity (which would imply low total mineral content). So there is =
possibly both physical and chemical differences between habitats of the =
two species.
PROBABILITY (P) CONSIDERATIONS:
Given 24 WT points, 31 EP points and 4 in common there are 51 =
stations.
P of WT at any station is 24/51; the sum over all 51 being 24.
P of EP at any one station is 31/51; the sum over all 51 being =
31.
Consequently P of both at any one station is (24 x 31)/(51 x 51); =
the sum over all 51 being (24 x 31)/51 =3D 14.59 rounding to 15.
With 15 stations having both there would be 16 having EP only =
and 9 having WT only for a total of 40 stations. Because it took 51 =
stations to obtain the observed 24 and 31 points one can consider =
distinct requirements to have been proven.
Note that these values of P are subject to iteration. Reducing =
the number of stations increases the number in which both should be =
observed. Whether this iterates to a stable value or all stations having =
both I am not sure. And I bet all are as wearied by this as I am; if not =
more so.
Yours truly, Dave Webster, Kentville
--=20
James Churchill
Kentville, Nova Scotia
jameslchurchill@gmail.com
(902) 681-2374
No virus found in this message.
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<DIV>Hi James & All,</DIV>
<DIV> I suggest we let John and Andrew deal with my =
question=20
and go from there. </DIV>
<DIV> </DIV>
<DIV> Balance in this context surely should consist of =
listing=20
all known threats and and then ranking them to the =
extent possible.=20
</DIV>
<DIV> </DIV>
<DIV> On another matter, have you made any progress =
since June=20
9, 2013 on Google-earthing those elevations for possible ponds on =
Elderkin brook=20
? (My e-mails of June 9 and June 20, 2013.)</DIV>
<DIV> </DIV>
<DIV>Yt, Dave Webster, Kentville</DIV>
<BLOCKQUOTE=20
style=3D"BORDER-LEFT: #000000 2px solid; PADDING-LEFT: 5px; =
PADDING-RIGHT: 0px; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px"=20
dir=3Dltr>
<DIV style=3D"FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV=20
style=3D"FONT: 10pt arial; BACKGROUND: #e4e4e4; font-color: =
black"><B>From:</B>=20
<A title=3Djameslchurchill@gmail.com=20
href=3D"mailto:jameslchurchill@gmail.com">James Churchill</A> </DIV>
<DIV style=3D"FONT: 10pt arial"><B>To:</B> <A =
title=3Dnaturens@chebucto.ns.ca=20
href=3D"mailto:naturens@chebucto.ns.ca">naturens</A> </DIV>
<DIV style=3D"FONT: 10pt arial"><B>Sent:</B> Monday, June 30, 2014 =
11:44=20
PM</DIV>
<DIV style=3D"FONT: 10pt arial"><B>Subject:</B> [NatureNS] Wood =
Turtle:=20
long</DIV>
<DIV><BR></DIV>Dave,
<DIV><BR>
<DIV>With respect, and in hopes of adding some balance =
here, I do=20
not feel that your strong language here is appropriate and =
possibly,=20
though I am not personally offended, it could be perceived=20
as offensive to some. Science can move forward by rational =
argument,=20
but how do you defend your use of the word 'delusion' in reference to =
the idea=20
that collecting turtles could be one factor affecting turtle =
population=20
viability? (To my knowledge no one has yet, including the Natural =
History=20
Museum web site, suggested that collecting turtles is the=20
main threat to turtle populations so your statement is =
misleading).=20
'Delusion' to me implies belief in a notion that is =
attractive but=20
false. From what I've seen you have not provided any=20
quantitative evidence supporting the notion that collecting =
turtles=20
has no,or little, effect on turtle populations. Until then I feel you =
are not=20
yet free to throw around the word 'delusion'. </DIV>
<DIV><BR></DIV>
<DIV>One place I would suggest the discussion starts is with=20
the COSEWIC status report on the Wood Turtle. If the =
discussion=20
starts with research rather than anecdote there is possibility =
for making=20
some headway in this discussion. Otherwise, in my opinion, your =
argument (as I=20
understand it: that there is no harm and that we =
actually lose=20
out by not collecting turtles), which is not yet based on evidence, =
and not=20
one that to my knowledge many scientists agree with, is perhaps =
misdirecting=20
our energies and misleading people that are listening to this=20
conversation. </DIV>
<DIV><BR></DIV>
<DIV>In the spirit of science and rational argument.</DIV>
<DIV>Cheers,</DIV>
<DIV>James</DIV>
<DIV><BR>On Monday, June 30, 2014, James Hirtle <<A=20
href=3D"javascript:_e(%7B%7D,'cvml','jrhbirder@hotmail.com');"=20
target=3D_blank>jrhbirder@hotmail.com</A>> wrote:<BR>
<BLOCKQUOTE=20
style=3D"BORDER-LEFT: #ccc 1px solid; MARGIN: 0px 0px 0px 0.8ex; =
PADDING-LEFT: 1ex"=20
class=3Dgmail_quote>
<DIV>
<DIV dir=3Dltr><FONT size=3D6>Not threatened or endangered yet, but =
a painted=20
turtle was crossing the Fisherman's Memorial Highway just outside of =
Hammond's Plains when I was coming home last night. I missed =
it as did=20
the car behind me, but as to its fate after that who=20
knows. </FONT><BR><FONT size=3D6></FONT> <BR><FONT=20
size=3D6>James R. Hirtle</FONT><BR><FONT=20
size=3D6>Bridgewater <BR></FONT><BR> <BR>
<DIV>
<HR>
From: <A>dwebster@glinx.com</A><BR>To: <A>GILHENJA@gov.ns.ca</A>;=20
<A>HEBDAAJ@gov.ns.ca</A>; <A>NatureNS@chebucto.ns.ca</A><BR>Subject: =
[NatureNS] Wood Turtle: long<BR>Date: Mon, 30 Jun 2014 19:13:41=20
-0300<BR><BR>
<DIV>Hi John, Andrew & All, =
=
=20
=
=20
</DIV>
<DIV> I noticed on a post to naturens recently =
that (from=20
the NS Museum of NH site)--</DIV>
<DIV>"It may seem harmless to keep a turtle as a pet for a while, =
but this=20
is not a good idea. Two of the province's four turtle species are =
already at=20
risk in Nova Scotia. It is likely that removal of turtles by people =
is part=20
of the reason, for Wood Turtles."</DIV>
<DIV> </DIV>
<DIV> I expect this supposition rests in part on =
your 1984=20
statement (Amphibians and Reptiles of Nova Scotia p. 148) =
that--</DIV>
<DIV>"Another problem facing the Wood Turtle is the removal of many=20
individuals from their habitat by people while on fishing trips or =
camping=20
trips" which are then subsequently "released in the woods many =
kilometers=20
from its natural habitat."</DIV>
<DIV> </DIV>
<DIV> Perhaps you can provide some details of the=20
observations on which your above statement was based. </DIV>
<DIV> </DIV>
<DIV> To get a third viewpoint for =
comparison I=20
went to Wood Turtle on Wikipedia and with some personal satisfaction =
note=20
that much of their text, re Wood Turtles range wide, might have been =
written=20
by me re turtles and amphibians in NS; e.g. emphasis on habitat =
loss,=20
traffic fatalities, a plug for culvert underpasses and the =
observation=20
that an overabundant Raccoon threatens WTs at all life stages. They =
quite=20
rightly list commercial collections made for the international pet =
trade as=20
a genuine threat. They note without commentary that "<SPAN=20
style=3D"TEXT-TRANSFORM: none; BACKGROUND-COLOR: rgb(255,255,255); =
TEXT-INDENT: 0px; DISPLAY: inline !important; FONT: 14px/22px =
sans-serif; WHITE-SPACE: normal; FLOAT: none; LETTER-SPACING: normal; =
COLOR: rgb(37,37,37); WORD-SPACING: 0px; font-size-adjust: none; =
font-stretch: normal">Brochures=20
and other media that warn people to avoid keeping the wood turtle as =
a pet=20
are currently being distributed."; a variant of damming by faint=20
praise.</SPAN></DIV>
<DIV><SPAN=20
style=3D"TEXT-TRANSFORM: none; BACKGROUND-COLOR: rgb(255,255,255); =
TEXT-INDENT: 0px; DISPLAY: inline !important; FONT: 14px/22px =
sans-serif; WHITE-SPACE: normal; FLOAT: none; LETTER-SPACING: normal; =
COLOR: rgb(37,37,37); WORD-SPACING: 0px; font-size-adjust: none; =
font-stretch: normal"> =20
With respect to culvert underpasses I paste the =
following--</SPAN></DIV>
<DIV><SPAN=20
style=3D"TEXT-TRANSFORM: none; BACKGROUND-COLOR: rgb(255,255,255); =
TEXT-INDENT: 0px; DISPLAY: inline !important; FONT: 14px/22px =
sans-serif; WHITE-SPACE: normal; FLOAT: none; LETTER-SPACING: normal; =
COLOR: rgb(37,37,37); WORD-SPACING: 0px; font-size-adjust: none; =
font-stretch: normal">START=20
OF PASTE\\\\\\\\\\\\\\\\\\\\\\\\\\\\</SPAN></DIV>
<DIV><SPAN=20
style=3D"TEXT-TRANSFORM: none; BACKGROUND-COLOR: rgb(255,255,255); =
TEXT-INDENT: 0px; DISPLAY: inline !important; FONT: 14px/22px =
sans-serif; WHITE-SPACE: normal; FLOAT: none; LETTER-SPACING: normal; =
COLOR: rgb(37,37,37); WORD-SPACING: 0px; font-size-adjust: none; =
font-stretch: normal">Hi=20
Lisa &=20
=
All, =
July=20
31, 2008<BR> I dare say you are already moving in =
this=20
direction, but a small <BR>animal underpass, suitably located (e.g. =
where=20
you were escorting <BR>toadlets in this instance) would be less=20
labour-intensive and <BR>consequently more practicable in the long=20
run.<BR><BR> Why Conservation organizations have =
not=20
lobbied for and made public <BR>noises about small animal crossings =
beats=20
me. Perhaps I have not been <BR>paying attention but I have noticed =
that=20
some have been installed in the <BR>UK. Even modest highways with =
light=20
traffic can be effective barriers to <BR>movement of Reptiles and=20
Amphibians, either by preventing access to the <BR>roadway or by =
killing=20
some that do make it.<BR><BR> Based on road kills =
observed=20
while walking, I think snakes must sun <BR>on gravel roads where =
they blend=20
in nicely before and after being <BR>flattened. And a 20-cm high =
ridge of=20
gravel, thrown up by a road grader, <BR>can stop a 30-cm snake from=20
crossing. And a highway sand cut, at angle <BR>of repose after about =
25=20
years, acts as a solid wall to a toad (in dry <BR>weather; wet might =
be=20
different).<BR><BR>Yours truly, Dave Webster, =
Kentville<BR></SPAN></DIV>
<DIV><SPAN=20
style=3D"TEXT-TRANSFORM: none; BACKGROUND-COLOR: rgb(255,255,255); =
TEXT-INDENT: 0px; DISPLAY: inline !important; FONT: 14px/22px =
sans-serif; WHITE-SPACE: normal; FLOAT: none; LETTER-SPACING: normal; =
COLOR: rgb(37,37,37); WORD-SPACING: 0px; font-size-adjust: none; =
font-stretch: normal"></SPAN> </DIV>
<DIV><SPAN=20
style=3D"TEXT-TRANSFORM: none; BACKGROUND-COLOR: rgb(255,255,255); =
TEXT-INDENT: 0px; DISPLAY: inline !important; FONT: 14px/22px =
sans-serif; WHITE-SPACE: normal; FLOAT: none; LETTER-SPACING: normal; =
COLOR: rgb(37,37,37); WORD-SPACING: 0px; font-size-adjust: none; =
font-stretch: normal">END=20
OF PASTE\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\</SPAN></DIV>
<DIV><SPAN=20
style=3D"TEXT-TRANSFORM: none; BACKGROUND-COLOR: rgb(255,255,255); =
TEXT-INDENT: 0px; DISPLAY: inline !important; FONT: 14px/22px =
sans-serif; WHITE-SPACE: normal; FLOAT: none; LETTER-SPACING: normal; =
COLOR: rgb(37,37,37); WORD-SPACING: 0px; font-size-adjust: none; =
font-stretch: normal">And=20
just one more example--</SPAN></DIV>
<DIV><SPAN=20
style=3D"TEXT-TRANSFORM: none; BACKGROUND-COLOR: rgb(255,255,255); =
TEXT-INDENT: 0px; DISPLAY: inline !important; FONT: 14px/22px =
sans-serif; WHITE-SPACE: normal; FLOAT: none; LETTER-SPACING: normal; =
COLOR: rgb(37,37,37); WORD-SPACING: 0px; font-size-adjust: none; =
font-stretch: normal">START=20
OF PASTE\\\\\\\\\\\\\\\\\\\</SPAN></DIV>
<DIV><SPAN=20
style=3D"TEXT-TRANSFORM: none; BACKGROUND-COLOR: rgb(255,255,255); =
TEXT-INDENT: 0px; DISPLAY: inline !important; FONT: 14px/22px =
sans-serif; WHITE-SPACE: normal; FLOAT: none; LETTER-SPACING: normal; =
COLOR: rgb(37,37,37); WORD-SPACING: 0px; font-size-adjust: none; =
font-stretch: normal">Hi=20
Flora & All, =
Apr=20
3, 2006<BR> Traffic on our highways is =
unfortunately a=20
very effective way to kill small animals; invertebrate & =
vertebrate. I=20
dug out two responses to this spring rush (pasted below) and am =
struck by=20
the agreement in timing. As noted in my post of Sept 17, 2005, =
underpasses=20
can be very effective at least for snakes.<BR> =
Thanks for=20
the opportunity to flog a pet idea.<BR>DW<BR><BR>Flora Cordis =
Johnson=20
wrote:<BR></SPAN></DIV>
<BLOCKQUOTE>
<DIV><SPAN>Last night's rain, though undoubtedly needed, brought =
the first=20
amphibian roadkills of spring to my neck of the woods, and a lot =
of them.=20
In a 3/4 mile stretch of road that runs through a wetland east of =
my house=20
on Cloverdale Road, near Middle Stewiacke, I counted three dead =
spring=20
peepers, ranging in size from about a half inch to about an inch =
in=20
length, and a large (about 2 inch) dark-charcoal coloured =
salamander with=20
faint blue markings on its sides. In addition there were several=20
unidentifiable splats -- which, judging from size and weather, =
were most=20
likely ex-frogs. I brought the salamander home in a dead leaf and=20
photographed it.</SPAN></DIV>
<DIV><SPAN>A sad Wild Flora in Birch Hill</SPAN></DIV>
<DIV> </DIV></BLOCKQUOTE>
<DIV>START OF PASTES\\\\\\\\\\\\\\\\\\<BR>Hi Anne &=20
=
All, &nb=
sp; =20
Mar 31, 2002<BR> I recall hearing some years ago =
that toad=20
(or frog ?) underpasses had<BR>been installed on some British=20
highways, really culverts at ditch level,<BR>and had substantially =
reduced=20
road kills.<BR> I wonder if these salamanders =
would=20
preferentially use a culvert if it<BR>were available and how large =
it would=20
need to be ?<BR><BR>Dave Webster,=20
Kentville<BR><BR>\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\<BR>Hi James =
&=20
=
All, =
Mar=20
31, 2005<BR> A lot of amphibians and reptiles =
don't get to=20
the other side when <BR>they attempt to cross a=20
road.<BR><BR> I continue to wonder why Naturalist=20
organizations don't pressure <BR>more for safe R&A underpass =
crossings.=20
Is this a design problem or a <BR>motivation problem ?<BR><BR>Yours =
truly,=20
Dave Webster, Kentville<BR><BR>END OF PASTES; really=20
\\\\\\\\\\\\\\\\\\</DIV>
<DIV><BR> </DIV>
<DIV> </DIV>
<DIV> I don't like putting you and Andrew on the =
spot but=20
remember "Iron sharpeneth iron", Prov. 27:17, I don't think =
the=20
numbers add up and in my view, backed by Wikipedia as it happens =
(noted=20
above), there are greater environmental problems that collectively =
shrink=20
the odd turtle picked up on a fishing or camping trip to a value =
that is=20
indistinguishable from zero. </DIV>
<DIV> </DIV>
<DIV> According to Wikipedia, Wood Turtles live to =
40=20
years in the wild (58 in captivity), become sexually mature at ages =
14-18=20
and lay 3-20 eggs per year. For simple mental arithmetic one can =
round this=20
to 20 egg-laying years and 10 eggs per year for a total of 200 eggs =
per=20
female. So attrition must be severe to maintain a stable population =
and the=20
range in egg production implies a control mechanism to avoid =
damaging=20
intraspecific competition.</DIV>
<DIV> </DIV>
<DIV> Males contest for the opportunity to =
mate so=20
taking a male home would have no impact (apart from the positive one =
of=20
decreasing demand on resources) and unless the population were =
really=20
sparse the removal of a female would be soon offset by greater egg=20
production as resources per adult increased.</DIV>
<DIV> </DIV>
<DIV> On the other hand I have found no mention in =
your=20
text for any species of the much greater threats of habitat=20
destruction, road traffic and habitat fragmentation by highway=20
embankments. Effective protection can be implemented only if =
the major=20
threats are recognized. </DIV>
<DIV> </DIV>
<DIV> And pushing the delusion that all will =
be fine=20
if people just stop taking turtles home and releasing them far from =
the=20
turtle's home, while downplaying or ignoring the much greater=20
threats is in my view a good way to condemn the Wood =
Turtle to=20
ultimate extirpation.</DIV>
<DIV> </DIV>
<DIV> That is more than enough serious text for =
one=20
communication so I will turn briefly to matters that are more =
fun.</DIV>
<DIV> </DIV>
<DIV> In the plots of Eastern Painted Turtle =
(EP) and=20
Wood Turtle (WT) distribution it is interesting (to me) that =
one=20
distribution is almost entirely in the negative space of the other. =
Of 24 WT=20
and 31 EP stations only 4 appear to be in common. By perhaps faulty=20
probability reasoning (expanded below) I would expect 15 stations to =
have=20
been in common (if these turtles had identical habitat =
requirements).=20
Because only 4 were in common (and perhaps they were in the same =
general=20
area and only appear to be in common) these two =
species approximate=20
what used to be called a niche pair and consequently do not directly =
compete=20
with each other.</DIV>
<DIV> </DIV>
<DIV> The distribution of WT rang a bell so I =
compared it=20
with <EM>Potamogeton robinsii</EM> in my 1954 MSc thesis; not =
identical but=20
very close. This is interesting because P. robinsii was unique in =
that it=20
was present only in water of unusual composition (high pH and low =
total=20
mineral content). And to add one more twist, <EM>P. robinsii</EM> in =
Minnesota (Moyle, 1945) was exceptional by being only in waters of =
high pH=20
and low alkalinity (which would imply low total mineral =
content). So=20
there is possibly both physical and chemical differences between =
habitats of=20
the two species.</DIV>
<DIV> </DIV>
<DIV> PROBABILITY (P) CONSIDERATIONS:</DIV>
<DIV> Given 24 WT points, 31 EP points and 4 in =
common=20
there are 51 stations.</DIV>
<DIV> P of WT at any station is 24/51; the sum =
over=20
all 51 being 24.</DIV>
<DIV> P of EP at any one station is 31/51; the sum =
over=20
all 51 being 31.</DIV>
<DIV>Consequently P of both at any one station is (24 x 31)/(51 x =
51); the=20
sum over all 51 being (24 x 31)/51 =3D 14.59 rounding to 15.</DIV>
<DIV> With 15 stations having both there would be =
16=20
having EP only and 9 having WT only for a total of 40 stations. =
Because it=20
took 51 stations to obtain the observed 24 and 31 points one can =
consider=20
distinct requirements to have been proven.</DIV>
<DIV> Note that these values of P are subject to=20
iteration. Reducing the number of stations increases the number =
in=20
which both should be observed. Whether this iterates to a =
stable=20
value or all stations having both I am not sure. And I bet all are =
as=20
wearied by this as I am; if not more so.</DIV>
<DIV> </DIV>
<DIV>Yours truly, Dave Webster,=20
Kentville</DIV></DIV></DIV></DIV></BLOCKQUOTE></DIV></DIV><BR><BR>-- =
<BR>
<DIV dir=3Dltr>James Churchill<BR>Kentville, Nova Scotia<BR><A=20
href=3D"mailto:jameslchurchill@gmail.com"=20
target=3D_blank>jameslchurchill@gmail.com</A><BR>(902)=20
681-2374<BR><BR><BR><BR></DIV><BR><A></A>
<P align=3Dleft color=3D"#000000" avgcert??>No virus found in this=20
message.<BR>Checked by AVG - <A=20
href=3D"http://www.avg.com">www.avg.com</A><BR>Version: 2014.0.4714 / =
Virus=20
Database: 3986/7771 - Release Date: =
06/30/14</P></BLOCKQUOTE></BODY></HTML>
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