[obol] Cascara Tree- Empid

[Arch McCallum]

So, I can't help but asking, does it have the same effect on birds? I 
would guess not,
with all those species of birds gobbling up the berries. More likely, 
it has the
well-known relaxing effect on mammalian digestive systems "intentionally," to
prevent mammals from eating the berries. Apparently, to continue this 
adaptationist
line of reasoning, cascara wants its seeds spread by birds, not mammals. Why?
Perhaps to move them farther away from home than mammals are likely 
to roam, i.e.,
to increase dispersal distance, e.g., to open areas (see mention of 
"brush line" below).
This is a hypothesis with a lot of assumptions, e.g., the birds 
swallow the seeds, cascara
is a laxative for nonhuman mammals in its range, etc. I would love to hear any
supporting or refuting observations. There's no more fun way to learn.

I do know of one similar situation. I've read (don't remember when or 
where) that capsaicin,
the hot ingredient in peppers, is not hot to birds, but is to mammals 
in general.
The hypothesis that goes with that observation
is that the capsaicin is put in the pepper fruit to deter mammals 
from eating it,
saving it for the birds, who will wait until the seeds are mature 
when the fruit is red,
which is a signal visible to birds but not mammals that dinner is served.

Thanks to John Thomas for sharing chittem lore with us.


Arch McCallum
Spinning just-so stories in Eugene



At 02:00 PM 8/4/2007 -0700, John Thomas wrote:
>There are some Cascara up and down our "brush line" out here in farming
>country. Will have to watch more closely for unusual birds. A Hermit Warbler
>or Pacific Flycatcher would be great!
>
>When we were kids picking Logan berries for a local farmer, we played a
>dirty trick on a town kid by telling him over and over how good those
>Cascara berries on the tree were. In those days, we country kids called 'em
>"Chittem Bark" and knew the tree well as we could peel the bark, dry it, and
>sell it to a local hardware store for pickup by some company making
>laxatives. Being into sustainable pipe dreams (after killing scores of
>"Chittem Bark" trees), we even tried leaving a quarter of the trunk bark up
>the tree to keep it alive for future harvest. I doubt many made it but at
>least our hearts and minds were getting into keeping things alive and not
>leveling all to the ground.
>
>Back to the town kid: he spent the afternoon in the outhouse after chewing a
>handful or two. So ... beware. I imagine one berry would not be that potent
>however.
>
>John Thomas
>Silverton
>
>
>
>
>_______________________________________________
>obol mailing list
>obol at lists.oregonstate.edu
>http://lists.oregonstate.edu/mailman/listinfo/obol
>
>To unsubscribe, send a message to:
>obol-leave at lists.oregonstate.edu.