[NatureNS] seal eating rocks

From: Ken McKenna <kenmcken@eastlink.ca>
To: naturens@chebucto.ns.ca
References: <AANLkTikyFiZPj16CNGKEN3UpkPr-Ca3r13PnO0HUwES4@mail.gmail.com>
Date: Mon, 28 Mar 2011 13:38:52 -0300
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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




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<DIV><FONT face=Arial></FONT>&nbsp;</DIV>
<DIV>Ken McKenna<BR>Box 218 Stellarton NS<BR>B0K 1S0<BR>902 752-7644<BR></DIV>
<DIV>&nbsp;</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&nbsp;are still on a 
card that I have not downloaded as the photos&nbsp;are not on my computer. I 
will see if I can dig them up later. The seal&nbsp;did not look great at the 
time but it was alive and lethargic. </DIV>
<DIV>cheers</DIV>
<DIV>Ken</DIV>
<DIV>&nbsp;</DIV>
<DIV><FONT face=Arial></FONT>&nbsp;</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>&nbsp;&nbsp; I don't have any expertise to 
  offer but I have an off the wall suggestion.&nbsp;Could this&nbsp;have been a 
  post mortem event caused by tides washing gravel and small stones into&nbsp;an 
  open&nbsp;mouth&nbsp;and down the throat? <BR>&nbsp;&nbsp; I realize this 
  would be exceedingly rare occurrence; if it's&nbsp;possible at all; but under 
  very odd circumstances (open mouth &amp; just right body position in just the 
  right type of&nbsp;tidal zone)&nbsp;it might occur; providing the throat was 
  open.<BR>&nbsp;&nbsp;&nbsp;I have a very thick skin so if I'm out to lunch on 
  this feel free to mock. All the 
  best.<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 
  Fritz 
  McEvoy<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 
  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>&lt;<A 
  href="mailto:jameslchurchill@gmail.com">jameslchurchill@gmail.com</A>&gt;</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>&lt;<A 
    href="mailto:helene.birdvet@gmail.com">helene.birdvet@gmail.com</A>&gt;</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" &lt;<A 
        href="mailto:randy.lauff@gmail.com">randy.lauff@gmail.com</A>&gt; 
        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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