Re: Fwd: Re: Carnivores and Packs

[larrys@zk3.dec.com]

>   Hunting juveniles IS the normal mode of hunting for most of the predators
>mentioned.  The number of kills of juveniles in any area is ALWAYS higher
>than the number of kills of adults of the same type.

I don't think Betty posted my original missive to which she was
replying:

Her original email replied to:
>>Even in this day and age, nothing hunts rhinos but man, not even 
>>lions willing to take on elephants and cape buffalo.

to which she replied:
>  Actually, this is sort of misleading.   Rhinos are hunted and killed by
>hyeanas, cape hunting dogs, lions, and man.  You seem to have skipped an
>entire age group in your estimate.

I noted:
>Well...deliberately so.  I take it as a given that predators will
>take relatively defenseless juveniles of virtually any species if
>given an opportunity.  What I am getting at is the "normal" mode
>of hunting - I don't think any predator specializes in juvenile
>rhinos.  But lions, to take the on-going example, _do_ specialize
>in cape buffalo and at least juvenile elephants many times their
>own weight.  That's the area I am driving at.  I'm sure a 'rex or
>an allosaurus would cheerfully take a juvenile sauropod, but what
>I am trying to get a handle on is how the made their living when
>such opportunities are _not_ present.

>Some others have mentioned cats other than lions, and polar bears
>as non-pack hunters, but they, too, tend to specialize in much
>smaller prey, from slightly more than their size on down.  What I
>am hunting for is the relative prey/predator size range.  Anything
>that routinely hunted something much larger than itself probably
>was a pack hunter is the hypothosis.  Now I'm trying to gather some
>opinions and data and see how plausible it is, and to figure arg-
>uments for/against.

To which Betty replied with the above paragraph.  I think that
syncs up the list on the discussion on that point.  At least, I
hope so, it is very confusing trying to figure out which messages
are from the list, going to the list, being copied to me and the
list, and so on.  At any rate, my response to her last reply is:

--
Can you point me to a reference for this?  According to my reading,
juveniles _are_ taken when opportunity presents, but that most
predators will try for adults in preference most of the time - I
gather because the "dress-out" weight makes them more cost-effective
in terms of risk - this is certainly the case in the lion prides
reported on in Nat'l Geo "Lions of Night" article.  Do you have any
documentation that shows that wolves and/or lions take more biomass
in juveniles than adults?  And how does the ratio change with env-
ironmental and seasonal factors?  Most herbivours will only have
juveniles at certain times of year, not even a majority of the time...
--

cordially,
Larry Smith