[sci.bio] Killing for fun

milt@sgi.com (Milton E. Tinkoff) (02/27/91)

I've been told that there is only one animal (besides
humans) that kills for recreational purposes.  If this
animal exists, what is it?  Toying with prey and then
eating it or leaving it as a gift (house cats) doesn't
count.
--
-------------------------------------------------------------------------------
Milt Tinkoff				|	"Too much is always better
Silicon Graphics Inc.			|	     than not enough."
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bryans@ux1.cso.uiuc.edu (B. Charles Siegfried) (02/27/91)

milt@sgi.com (Milton E. Tinkoff) writes:


>I've been told that there is only one animal (besides
>humans) that kills for recreational purposes.  If this
>animal exists, what is it?  Toying with prey and then
>eating it or leaving it as a gift (house cats) doesn't
>count.

	Seems to me that this question has two big fallacies:
One, it assumes that there are other animals smart enough to 
actually separate recreational activities from its daily
life or that we can determine such recreational activity.
We discover how behaviors are integral to behavior all of the
time.  I doubt we can conclusively determine whether or not
any animal activity is recreational.  Secondly, you discount
any playing with unwanted prey.  doesn't it seem like if a 
cat kills a mouse when in fact it isn't hungry, that might be 
a recreational activity?  Maybe its just instinct - maybe its
recreation - how can we tell? (See above).  


__
Bryan Siegfried						   zig@uiuc.edu

schumach@convex.com (Richard A. Schumacher) (02/27/91)

On the other hand, seals all along the west coast are often
observed killing far more salmon and other fish than they
can eat. Why do they do it?

jokim@jarthur.Claremont.EDU (John H. Kim) (02/27/91)

In article <schumach.667616596@convex.convex.com> schumach@convex.com (Richard A. Schumacher) writes:
>On the other hand, seals all along the west coast are often
>observed killing far more salmon and other fish than they
>can eat. Why do they do it?

I can personally confirm this.  I watched a young (<6 ft) California
sea lion catch and toss around a mackerel for about two hours while
I was fishing in a harbor.  Every few minutes I'd hear a SLAP over the
water and see the mackeral go skittering across the surface.  The sea
lion would swim around a bit, retrieve the mackerel, and repeat the
process.  Eventually, it left the mackerel floating on the surface and
disappeared.  I hung around for about an hour longer and the sea lion
didn't return.

If you ask me, from what I've seen of my dog playing with rubber toys,
I'd say the sea lion was playing with the fish.
-- 
John H. Kim                 | (This space to be filled when I
jokim@jarthur.claremont.edu | think of something very clever 
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andrewt@cs.su.oz (Andrew Taylor) (02/27/91)

In article <1991Feb26.202248.26171@odin.corp.sgi.com> milt@sgi.com
(Milton E. Tinkoff) writes:
> 
> I've been told that there is only one animal (besides
> humans) that kills for recreational purposes.  If this
> animal exists, what is it?  Toying with prey ...

Californian Sea Lions will occasionally kill Marine Iguanas during play.
South American Sea Lions will kill Magellenic Penguins, apparently as play
and apparently quite deliberately. Neither eats the victim nor are they
normal prey. I'm sure there are other examples.

Andrew Taylor

geb@dsl.pitt.edu (Gordon E. Banks) (02/27/91)

In article <1991Feb26.202248.26171@odin.corp.sgi.com> milt@sgi.com (Milton E. Tinkoff) writes:
>
>animal exists, what is it?  Toying with prey and then
>eating it or leaving it as a gift (house cats) doesn't
>count.

If that doesn't count, why not and what would?
All cats do this, not just house cats.  Sometimes they will
not eat the prey or "leave it as a gift", but simply abandon
it if it is not appetizing or the cat is not hungry.
But they will rarely pass up the opportunity to take prey.
It looks to me like they are having fun.

sbishop@desire.wright.edu (02/28/91)

In article <1991Feb26.202248.26171@odin.corp.sgi.com>, milt@sgi.com (Milton E. Tinkoff) writes:
> 
> I've been told that there is only one animal (besides
> humans) that kills for recreational purposes.  If this
> animal exists, what is it?  Toying with prey and then
> eating it or leaving it as a gift (house cats) doesn't
> count.
> --

That's easy!  The domestic dog.  Any farmer can tell you that.  You really
don't want to see a flock of sheep after a pack of dogs has managed to corner
them.  They literally tear them up.  BTW, this problem is nearly always caused
by someone's 'precious pet' whom the owners believe must 'run free' since that
is their nature.  

I once had a Siberian Husky kill twenty chickens, fifteen ducks, and a couple
of geese on my farm in just about fifteen minutes.  I caught the dog and called
animal control.

kuento@kuhub.cc.ukans.edu (02/28/91)

In article <2132@cluster.cs.su.oz.au>, andrewt@cs.su.oz (Andrew Taylor) writes:
> In article <1991Feb26.202248.26171@odin.corp.sgi.com> milt@sgi.com
> (Milton E. Tinkoff) writes:
>> 
>> I've been told that there is only one animal (besides
>> humans) that kills for recreational purposes.  If this
>> animal exists, what is it?  Toying with prey ...
> 
> Californian Sea Lions will occasionally kill Marine Iguanas during play.
> South American Sea Lions will kill Magellenic Penguins, apparently as play
> and apparently quite deliberately. Neither eats the victim nor are they
> normal prey. I'm sure there are other examples.
> 
> Andrew Taylor

Yes, there are, and they all have one thing in common which suggests
it is NOT purely for fun - the animals that are killed are either
normal prey items, or have characteristics similar to normal prey. The
answer is simple - the animal is *practicing* its hunting technique,
keeping itself sharp. *YOU* try catching a fish in your mouth some
time! Instinct does not necessarily confer *skill* automatically...
even a natural predator needs to practice. 
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young@alw.nih.gov (Jeff Young) (03/01/91)

I thought that it was the cat.  I think that feral cats have been seen killing
for no reason.
-- 

	jy 
	young@alw.nih.gov

mll@hpfcso.FC.HP.COM (Mark Luce) (03/01/91)

     Juvenile carnivores often engage in 'play' activities which are
actually learning experiences. They are practicing the predatory skills
which they will need to survive as adults. As such, these 'play' 
stalking, often stalking imaginary objects, because stalking abilities
are (or at least were, in the case of domesticated cats) essential to
their survival. If they get the chance to practice on living prey, they
will naturally do so, even if they are not hungry. Juvenile social
carnivores will practice social hunting skills. I would imagine that
juvenile hominids did much the same sort of thing...                                                                                                                                                                                               

andrewt@cs.su.oz (Andrew Taylor) (03/01/91)

In article <28836.27cc6593@kuhub.cc.ukans.edu> kuento@kuhub.cc.ukans.edu writes:
>> Californian Sea Lions will occasionally kill Marine Iguanas during play.
>> South American Sea Lions will kill Magellenic Penguins, 
>
> Yes, there are, and they all have one thing in common which suggests
> it is NOT purely for fun - the animals that are killed are either
> normal prey items, or have characteristics similar to normal prey. The
> answer is simple - the animal is *practicing* its hunting technique,

I disgree. Neither of the examples have similar characteristics to the normal
prey. Marine Iguana are slow surface-swimming targets which try to escape to
shallow water. Magellenic Penguins main evasive manoeuvres involve porpoising.
I can see no advantage for the Sea Lions learning to cope with these tactics.
Their prey does not do these things.  At least in the second case the
individual had been an adult for at least several years and hence presumably 
its hunting skill were well developed.

Other play by Sea Lions is does not develop hunting skills (e.g swimming
inverted below you while blowing bubbles at you).

Andrew Taylor

jokim@jarthur.Claremont.EDU (John H. Kim) (03/01/91)

In article <9560002@hpfcso.FC.HP.COM> mll@hpfcso.FC.HP.COM (Mark Luce) writes:
>
>     Juvenile carnivores often engage in 'play' activities which are
>actually learning experiences. They are practicing the predatory skills
>which they will need to survive as adults. As such, these 'play' ...

And I suppose kids 'play' baseball because of an instinctive desire
to increase their hand-eye coordination.

So how do we determine that an animal is doing something for fun (play)
and not for practice?  It seems where this is headed is that carnivores
kill for practice, but find it fun and consider it play.  In which case
the entire point of whether it is killing for fun or killing for practice
is moot.
-- 
John H. Kim                 | (This space to be filled when I
jokim@jarthur.claremont.edu | think of something very clever 
uunet!jarthur!jokim         | to use as a disclaimer)

anderson@lynx.cat.syr.edu (Joseph Anderson) (03/25/91)

In article <1991Feb26.202248.26171@odin.corp.sgi.com> milt@sgi.com (Milton E. Tinkoff) writes:
>
>I've been told that there is only one animal (besides
>humans) that kills for recreational purposes.  If this
>animal exists, what is it?  Toying with prey and then
>eating it or leaving it as a gift (house cats) doesn't
>count.
>--
	from anderson@cat.syr.edu
		I believe it is the Polar Bear


			Although recently Anthony Hopkins has demonstrated
			some new meanings to one of those words used
			above.