next message in archive
next message in thread
previous message in archive
previous message in thread
Index of Subjects
Index of Subjects
On 4/26/2012 11:46 AM, Angus MacLean wrote:
> I've often wondered that too, Peter. There must be an advantage for them
> but it difficult to imagine what it is!!
* the glib answer is that they come out to feed the Robins, but glib
answers aren't going to suffice for this, because we're dealing with a
diversity of species with biologies and life histories we know nothing
about beyond the fact that it occurs underground. One simple answer is
sex during whatever is the breeding season for a particular species.
Another is that in the absence of pavement there wouldn't have been
nearly so much mortality associated with surface movement, so the
benefits of surface movement would have had to be much less in order to
justify it than is required now when we see thousands crushed every
night when they move. Maybe they're like Leopard Frogs who go
"walk-about" on wet nights to exploit food that's remote from their
burrows. It's also important to remember that they don't have any
navigational information obtained from more than 5mm above the ground
surface. It would be an interesting experimental project to see if
Earthworms of the same species from narrow highway medians (where almost
every pavement wanderer has, for decades, perished) wander less widely
than those from golf courses or other extensively homogeneous habitats.
fred.
===============================================
> At 08:13 AM 4/26/2012, you wrote:
>> This morning I picked up about 100 live earth worms from the asphalt
>> in front of the house. We have about a 50ft x 80ft parking area that
>> slopes down to a brook from a small flower bed in front of the house.
>> At this time of the year after fairly heavy rain dozens of worms from
>> a few millimeters to about 15 centimeters leave the bed and start off
>> across the paving. They are accompanied by what appear to small
>> millipedes although in much fewer numbers, also some slugs that start
>> feeding on some of the dead worms in the morning.
>> They certainly don't get washed out of the bed and in fact have to get
>> over a lip and negotiate some pavers.
>> I guess my question is *why they would leave what would appear to be a
>> good habitat and head out for almost certain doom*.
>> Does anyone know if this is common behavior and why they do it.
>> I'm thinking of going into the bait business.
>> Thanks.
>> Peter Stow
>> Hubbards
--
fred
------------------------------------------------------------
Frederick W. Schueler & Aleta Karstad
Bishops Mills Natural History Centre - http://pinicola.ca/bmnhc.htm
Mudpuppy Night in Oxford Mills - http://pinicola.ca/mudpup1.htm
Daily Paintings - http://karstaddailypaintings.blogspot.com/
South Nation Basin Art & Science Book
http://pinicola.ca/books/SNR_book.htm
RR#2 Bishops Mills, Ontario, Canada K0G 1T0
on the Smiths Falls Limestone Plain 44* 52'N 75* 42'W
(613)258-3107 <bckcdb at istar.ca> http://pinicola.ca/
------------------------------------------------------------
------------------------------------------------------------
next message in archive
next message in thread
previous message in archive
previous message in thread
Index of Subjects