Mollusca of the Plains of Abraham

Search fails to find Monacha cantiana

Ever since writing the account of Monacha cantiana (Montagu, 1803) for the book Identifying Land Snails and Slugs in Canada … (Grimm et al. 2010), the question has been whether this species remains at Québec city. In the 1890s M. cantiana was reported in the thousands along the cliffs near the Plains of Abraham and below the citadel (Hanham 1897). This is a European introduction and is why it was featured in our book. We wrote that it was not found there recently, on the advice of others and notes written by Wayne Grimm on the subject. I hadn’t been able to visit Québec and check myself until now.

Plains of Abraham

The Plains of Abraham today.

Monacha cantiana, a European example

Monacha cantiana, a European example.

My first impression of the site(s) was that there’s little chance that Monacha cantiana is alive there today. The Plains of Abraham are largely mowed-lawn, gardens, and scattered shrubs, bordered on its lower flank by a wooded slope. The slope itself is shaded with hardwoods, but the understory is thinly vegetated and, while coarse woody debris is abundant, leaf litter is thin and the soil eroding in places. I would have expected M. cantiana not to be in the woods anyway; as we remarked in our book, M. cantiana is an open-land species, living along roads, railways, in quarries and field edges (Grimm et al. 2010).

The woods on the slope below the Plains of Abraham

The woods on the slope below the Plains of Abraham.

It is hard to say where “below” the citadel the original record came from, but not much habitat appropriate for this species occurs there today. There certainly wasn’t any dead shells of any large snails evident, including shells of Cepaea hortensis (Müller, 1774), which was recorded there by what may well have been Québec’s earliest malacologist, “Mrs. William Sheppard” (Sheppard 1830).

My list is only preliminary but found in the wooded slope were the snails Oxychilus draparnaudi (Beck, 1837) (shown below), Cochlicopa lubrica (Müller, 1774), Trochulus striolatus (C. Pfeiffer, 1828) and Haplotrema concavum (Say, 1829), and the slugs Deroceras reticulatum (Müller, 1774) and at least two Arion spp.

Oxychilus draparnaudi

Oxychilus draparnaudi.

Literature Cited

  • Grimm, F. W., R. G. Forsyth, F. W. Schueler, & A. Karstad. 2009 [2010]. Identifying Land Snails and Slugs in Canada: Introduced Species and Native Genera. Canadian Food Inspection Agency, Ottawa. iv+168.
  • Hanham, A.W. 1897. Notes on the land shells of Quebec City and District. The Nautilus 10(9): 98-102.
  • Sheppard, Mrs. W. 1830. Mrs. Sheppard of Woodfield on the recent shells which characterize Quebec and its environs. Transactions of the Literary and Scientific Society of Quebec for 1829 1: 188-198.