REPLY2: Moles and other Geophyte predators
DaveKarn@aol.com (Tue, 03 Jan 2006 05:44:19 PST)

In a message dated 12/30/2005 3:39:28 PM Pacific Standard Time, eob@peak.org
writes:

Ernie ~
Well, Dave, I hate to throw cold water on the statement that moles are only
carnivorous, but research has proven otherwise, right here in Oregon. An
excellent book on the subject of moles is: _Of Moles and Men: The Battle for the
Turf_ by Patrick H. Thompson.
Looks like obtaining and reading of this book will rank in the first five of
my objectives for 2006!

Interesting that this "ossified" description/understanding of moles (i.e.,
exclusively(?) insectivorous) is rather more widespread than realized, e.g.,
Webster defines Mole as an "insectivorous burrowing mammal."

As for throwing cold water (on statements, or otherwise!!), I spend the
winters at home in Northern California where we have been getting cold water from
the skies in near record amounts -- towns (Healdsburg, Guerneville) along the
Russian River (the appellation where some of the world's best pinot noir is
produced) are under as much as 45' of flood waters (Guerneville). Much of the
Napa Valley is flooded, as well. In this area, we have received nearly two feet
of rain this year, twice the normal amount -- and Winter is really just
getting started! I would imagine the local moles are using SCUBA to wait it out .
. .
"The Townsend's Mole eats tulips, tigridias, bulbous irises . . . and these
often form substantial portions of its fare. Under field conditions, Moore
documented the avidity of moles for tigridias. . . . In a study of commercial
tigridia planting near Smith River CA, Moore found that 600 bulbs were consumed
during a 10-day period. After two [!!! my comment] Townsend's Moles were
trapped in the plots, no further damage to the remaining bulbs occurred. The two
trapped animals contained 100 and 94% bulbs in their stomachs."
Loosely using the term "bulbs" in this thread, I feel, is misleading. The
cited research seems to indicate that corms and some "bulbs" (tulips) do form a
minor to major portion of this animal's diet. While I was just as guilty in
loosely using the term, my knowledge base is really tunicate bulbs, in
particular, Narcissus and Hyacinthus. I would certainly be the first to admit that I
know nothing about most of the plant material being discussed in this forum.

Growing several hundred thousand daffodils on several acres, I have dug the
occasional bulb that showed telltale incisor indentations indicating a gopher
had sampled the bulb and, apparently, just as quickly backed off when the
animal found it to be unpalatable. That is not to say I haven't lost bulbs because
of gophers, I have. When, in their tunneling, they encounter a daffodil
bulb, it is either moved out of the way into the spoil mound or transferred
somewhere else in the tunnel complex from which it is unable to grow.

Moles, on the other hand, are the scourge of a daffodil grower! Not because
they consume the bulbs but because their tunneling causes major problems. If
tunneling occurs beneath the bulb, the roots are knocked off (a daffodil will
grow only one set of roots each annual cycle); if above the bulb, the leaves
expand into the tunnel and are unable to photosynthesize. In either case, the
life of the bulb is seriously compromised. I have often dug bulbs later than
I should have and had to remove the layer of soil over the row of bulbs (when
the leaves are gone) to locate them before actually digging them. Thus, the
tunneling of moles becomes readily apparent. When the tunneling animal
encountered a daffodil bulb, it went around or, occasionally, dug and discarded the
(smaller) obstruction into the spoil mound. I have never found damage to a
bulb that could be attributed to consumption by a mole. If we were discussing
slugs, on the other hand, I'd have some really interesting tales of damage to
daffodil bulbs!!

The name "narcissus" descends from the Greek word narkissos meaning (broadly)
sleep-inducing. Narcissus bulbs contain an oxalate, the crystals of which
are needle shaped (raphides). When ingested, these crystals are released and
lodge in the mucous membranes lining the mouth and esophagus causing the tissue
to swell. Diffenbachia sp. also contain this compound. "Dumb cane" is a
colloquial term used for this plant. It has to do with an inability to speak and
not, necessarily, to the relative smarts of the person ingesting the plant!!
When chewed on by the unsuspecting (most frequently children under five
years), swelling of the mucous membranes is so great as to prevent speech (hence,
"dumb"). In the worst case, swelling could close off the airway causing death.

Oddly, the compound does not seem to be present in all tunicate bulbs,
however, even Amaryllidaceae. I also breed and grow Hyacinthus hybrids and have
found on several occasions where a gopher had gotten (unnoticed) into the
planting and devoured bulbs without suffering any ill effect (consumption of so great
a quantity had to occur over a significant amount of time) .

Dave Karnstedt
Silverton, OR (Mar-Nov)
Windsor, CA (Dec-Feb)