Those are pretty amazing things to find on rooftops Andrew! Your job certainly
sounds more interesting than my desk job - kind of a natural history field trip.
I have read a few articles about distribution of small freshwater snails on the
feathers of waterfowl, so maybe birds are responsible for some of the distribution
of some species.  The rooftop fish have me somewhat baffled unless the eggs were
stuck to bird feathers maybe.
I need to be cleaning out my gutters soon, so this could be some incentive,
unfortunately I don't think we have any land snails in this part of the country.

Nora
Calgary, Alberta
CANADA

Kay Lavalier wrote:

> Andrew Vik
> [log in to unmask]
>
> Dear Aydin:
>
> In my trade as a Roof Repairman, I am often amazed at how many different living
> things can be found on the harsh rooftop environment. Plants that I have found
> include grasses and freshwater sedges, numerous weeds and the saplings of palm
> and hardwood trees.
> In some more or less permanent puddling areas I have seen frogs, tadpoles and
> small fish.
> Many insects, arachnids, and lizards live out their entire lives on the roof.
> Leaf filled gutters also contain very healthy looking earthworms.
> As for molluscs, I have found at least four different species of pulmonates
> while at work.
> One species, Drymaeus multilineatus, is arboreal and probably fell out of
> overhanging trees. The other three were ground dwellers (Polygyra cereolus,
> Bradybaena similis, and Subulina octona). I have found the first two species
> very high up on walls during wet weather, but I have never seen Subulina climb
> anything very high. Perhaps these small snails are so light that a good wind
> storm could deposit egg bearing adults on top of a building.
>
> Yours, Andrew
>
> Orstan, Aydin wrote:
>
> > > -----Original Message-----
> > > From: G Thomas Watters [mailto:[log in to unmask]]
> > > Sent: Wednesday, March 29, 2000 07:54
> > > To: [log in to unmask]
> > > Subject: Re: Cocliocopa lubrica
> >
> > > I was once forwarded a jar of hundreds of Cochlicopa lubrica
> > > from a man who
> > > said there were millions of them in the wet leaves in the
> > > rain gutters of
> > > his house.
> >
> > That's interesting. How & why did they get up to his roof? I suppose
> > hatchlings are small enough to be wind blown.
> >
> > Aydin