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Ken McKenna
Box 218 Stellarton NS
B0K 1S0
902 752-7644
Hi Fritz
I have photos of a Harbour Seal eating rocks and gravel at Cribbons Wharf on Nov. 14, 2011- likely the same animal. I think the photos are still on a card that I have not downloaded as the photos are not on my computer. I will see if I can dig them up later. The seal did not look great at the time but it was alive and lethargic.
cheers
Ken
----- Original Message -----
From: Fritz McEvoy
To: NS NATURE
Sent: Monday, March 28, 2011 1:10 PM
Subject: RE: [NatureNS] seal eating rocks
Hi Randy and All,
I don't have any expertise to offer but I have an off the wall suggestion. Could this have been a post mortem event caused by tides washing gravel and small stones into an open mouth and down the throat?
I realize this would be exceedingly rare occurrence; if it's possible at all; but under very odd circumstances (open mouth & just right body position in just the right type of tidal zone) it might occur; providing the throat was open.
I have a very thick skin so if I'm out to lunch on this feel free to mock. All the best.
Fritz McEvoy
Sunrise Valley, CB
------------------------------------------------------------------------------
From: randy.lauff@gmail.com
Date: Mon, 28 Mar 2011 12:47:40 -0300
Subject: Re: [NatureNS] seal eating rocks
To: naturens@chebucto.ns.ca
Thanks James.
In general, carnivores don't use stones to grind food since meat is so easily digestible - anything swallowed can be acidified and enzyme-treated for digestion; bile helps with the prey's fats in the small intestine. I am aware of the debate of the functions of gut stones in crocodiles...ballast versus grinding (perhaps both...since crocs swallow bones), but have never heard of this in seals. However, the review article you supplied indicates that eared seals, but not earless seals (like the Harbour Seal), have them.
Additionally, this animal had a *full* stomach of stone and gravel, and the oesophagus was full, too, suggesting something out of the ordinary. At the time, I glanced at the teeth and didn't notice anything unusual - I'll look in more detail when I prep out the head.
Randy
_________________________________
RF Lauff
Way in the boonies of
Antigonish County, NS.
On 28 March 2011 11:17, James Churchill <jameslchurchill@gmail.com> wrote:
hey Randy,
found some theories on stress (http://www.dem.ri.gov/news/2007/pr/0423071.htm), consequence of eating snow/ice on beach (http://www.mysticaquarium.org/animals-and-exhibits/species-of-the-month/706-harp-seal) ...
Wikipedia also had some thoughts on Gastroliths... as a natural behaviour, for food grinding or for ballast...
And finally an article in Phil. Trans. R. Soc. B comparing these two theories of gastrolith function (grinding vs. ballast) in marine tetrapods
(http://www.jstor.org/pss/55808)
Any other clues Randy, like condition of the seal's teeth or whether the stones appeared to be recently ingested (local rocks) or worn/polished? (I suppose full esophagus suggests recent...?)
Be interested to hear what you find out!!
Cheers
James.
On Mon, Mar 28, 2011 at 10:13 AM, Helene Van Doninck <helene.birdvet@gmail.com> wrote:
Some animals can exhibit "pica", or the ingestion of abnormal things if they have metabolic issues or blood dyscrasias...just a thought
Helene
On 2011-03-28 8:54 AM, "Randy Lauff" <randy.lauff@gmail.com> wrote:
The surprise animal at the end of this year's Comparative Vertebrate Anatomy class was a Harbour Seal. The seal was found live in a "not good" condition at Cribbons Point, Ant. Co., last semester. Shortly thereafter, it died and was graciously delivered to me by DFO.
Last week, my students and I opened it up and found that its stomach and oesophagus were both full of stones...up to a bit bigger than golf ball size. Any ideas why a seal would eat rocks? My only guess was desperation...for some reason, it could have been hungry, but couldn't catch any thing? It had a decent layer of blubber, so I don't think it was starving. Nothing else seemed wrong with it, though I am no vet.
Thoughts?
Randy
_________________________________
RF Lauff
Way in the boonies of
Antigonish County, NS.
--
James Churchill
Kentville, Nova Scotia
jameslchurchill@gmail.com
home: (902) 681-2374
--Boundary_(ID_3ejaBMkeJ1kVnRVq6E/Pnw)
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<DIV><FONT face=Arial></FONT> </DIV>
<DIV>Ken McKenna<BR>Box 218 Stellarton NS<BR>B0K 1S0<BR>902 752-7644<BR></DIV>
<DIV> </DIV>
<DIV>Hi Fritz</DIV>
<DIV>I have photos of a Harbour Seal eating rocks and gravel at Cribbons Wharf
on Nov. 14, 2011- likely the same animal. I think the photos are still on a
card that I have not downloaded as the photos are not on my computer. I
will see if I can dig them up later. The seal did not look great at the
time but it was alive and lethargic. </DIV>
<DIV>cheers</DIV>
<DIV>Ken</DIV>
<DIV> </DIV>
<DIV><FONT face=Arial></FONT> </DIV>
<DIV>----- Original Message ----- </DIV>
<BLOCKQUOTE
style="BORDER-LEFT: #000000 2px solid; PADDING-LEFT: 5px; PADDING-RIGHT: 0px; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px"
dir=ltr>
<DIV
style="FONT: 10pt arial; BACKGROUND: #e4e4e4; font-color: black"><B>From:</B>
<A title=fritzmcevoy@hotmail.com href="mailto:fritzmcevoy@hotmail.com">Fritz
McEvoy</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=naturens@chebucto.ns.ca
href="mailto:naturens@chebucto.ns.ca">NS NATURE</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Monday, March 28, 2011 1:10
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> RE: [NatureNS] seal eating
rocks</DIV>
<DIV><BR></DIV>Hi Randy and All,<BR> I don't have any expertise to
offer but I have an off the wall suggestion. Could this have been a
post mortem event caused by tides washing gravel and small stones into an
open mouth and down the throat? <BR> I realize this
would be exceedingly rare occurrence; if it's possible at all; but under
very odd circumstances (open mouth & just right body position in just the
right type of tidal zone) it might occur; providing the throat was
open.<BR> I have a very thick skin so if I'm out to lunch on
this feel free to mock. All the
best.<BR>
Fritz
McEvoy<BR>
Sunrise Valley, CB
<HR id=stopSpelling>
From: randy.lauff@gmail.com<BR>Date: Mon, 28 Mar 2011 12:47:40
-0300<BR>Subject: Re: [NatureNS] seal eating rocks<BR>To:
naturens@chebucto.ns.ca<BR><BR>Thanks James.
<DIV><BR></DIV>
<DIV>In general, carnivores don't use stones to grind food since meat is so
easily digestible - anything swallowed can be acidified and enzyme-treated for
digestion; bile helps with the prey's fats in the small intestine. I am aware
of the debate of the functions of gut stones in crocodiles...ballast versus
grinding (perhaps both...since crocs swallow bones), but have never heard of
this in seals. However, the review article you supplied indicates that eared
seals, but not earless seals (like the Harbour Seal), have them.</DIV>
<DIV><BR></DIV>
<DIV>Additionally, this animal had a *full* stomach of stone and gravel, and
the oesophagus was full, too, suggesting something out of the ordinary. At the
time, I glanced at the teeth and didn't notice anything unusual - I'll look in
more detail when I prep out the head.</DIV>
<DIV><BR></DIV>
<DIV>Randy<BR clear=all>_________________________________<BR>RF Lauff<BR>Way
in the boonies of<BR>Antigonish County, NS.<BR><BR><BR>
<DIV class=ecxgmail_quote>On 28 March 2011 11:17, James Churchill <SPAN
dir=ltr><<A
href="mailto:jameslchurchill@gmail.com">jameslchurchill@gmail.com</A>></SPAN>
wrote:<BR>
<BLOCKQUOTE style="BORDER-LEFT: #ccc 1px solid; PADDING-LEFT: 1ex"
class=ecxgmail_quote>hey Randy, <BR><BR>found some theories on stress (<A
href="http://www.dem.ri.gov/news/2007/pr/0423071.htm"
target=_blank>http://www.dem.ri.gov/news/2007/pr/0423071.htm</A>),
consequence of eating snow/ice on beach (<A
href="http://www.mysticaquarium.org/animals-and-exhibits/species-of-the-month/706-harp-seal"
target=_blank>http://www.mysticaquarium.org/animals-and-exhibits/species-of-the-month/706-harp-seal</A>)
...<BR><BR>Wikipedia also had some thoughts on Gastroliths... as a natural
behaviour, for food grinding or for ballast...<BR><BR>And finally an article
in Phil. Trans. R. Soc. B comparing these two theories of gastrolith
function (grinding vs. ballast) in marine tetrapods <BR>(<A
href="http://www.jstor.org/pss/55808"
target=_blank>http://www.jstor.org/pss/55808</A>)<BR><BR>Any other clues
Randy, like condition of the seal's teeth or whether the stones appeared to
be recently ingested (local rocks) or worn/polished? (I suppose full
esophagus suggests recent...?)<BR><BR>Be interested to hear what you find
out!!<BR><BR>Cheers<BR><BR>James. <BR>
<DIV>
<DIV></DIV>
<DIV class=h5><BR><BR>
<DIV class=ecxgmail_quote>On Mon, Mar 28, 2011 at 10:13 AM, Helene Van
Doninck <SPAN dir=ltr><<A
href="mailto:helene.birdvet@gmail.com">helene.birdvet@gmail.com</A>></SPAN>
wrote:<BR>
<BLOCKQUOTE style="PADDING-LEFT: 1ex" class=ecxgmail_quote>Some animals
can exhibit "pica", or the ingestion of abnormal things if they have
metabolic issues or blood dyscrasias...just a thought<BR><FONT
color=#888888>Helene</FONT><BR>
<DIV>
<DIV></DIV>
<DIV><BR>
<BLOCKQUOTE>On 2011-03-28 8:54 AM, "Randy Lauff" <<A
href="mailto:randy.lauff@gmail.com">randy.lauff@gmail.com</A>>
wrote:<BR><BR>The surprise animal at the end of this year's Comparative
Vertebrate Anatomy class was a Harbour Seal. The seal was found live in
a "not good" condition at Cribbons Point, Ant. Co., last semester.
Shortly thereafter, it died and was graciously delivered to me by DFO.
<DIV><BR></DIV>
<DIV>Last week, my students and I opened it up and found that its
stomach and oesophagus were both full of stones...up to a bit bigger
than golf ball size. Any ideas why a seal would eat rocks? My only guess
was desperation...for some reason, it could have been hungry, but
couldn't catch any thing? It had a decent layer of blubber, so I don't
think it was starving. Nothing else seemed wrong with it, though I am no
vet.</DIV>
<DIV><BR></DIV>
<DIV>Thoughts?</DIV>
<DIV>Randy<BR clear=all>_________________________________<BR>RF
Lauff<BR>Way in the boonies of<BR>Antigonish County,
NS.<BR></DIV></BLOCKQUOTE></DIV></DIV></BLOCKQUOTE></DIV><BR><BR
clear=all><BR></DIV></DIV><FONT color=#888888>-- <BR>James
Churchill<BR>Kentville, Nova Scotia<BR><A
href="mailto:jameslchurchill@gmail.com">jameslchurchill@gmail.com</A><BR>home:
(902)
681-2374<BR><BR></FONT></BLOCKQUOTE></DIV><BR></DIV></BLOCKQUOTE></BODY></HTML>
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