Search this journal:     Advanced search
Original Research

The alien invasive land snail Theba pisana in the West Coast National Park: Is there cause for concern?

Lizelle J. Odendaal, Tanya M. Haupt, Charles L. Griffiths

Koedoe - African Protected Area Conservation and Science; Vol 50, No 1 (2008), 93-98. doi: 10.4102/koedoe.v50i1.153

Submitted: 15 April 2008
Published:  10 December 2008

Abstract

The distribution, abundance, size distribution and diurnal activity patterns of invasive land snails, Theba pisana, in the West Coast National Park (WCNP), South Africa, were investigated. The park was divided into 1 km2 grids, within each of which five 1 m2 quadrat counts of live snails were recorded. Of 106 grids sampled, 19% contained live snails. The average density of snails was 4.04 m-2 ± 24.9, significantly lower than in disturbed habitats adjacent to the park (57 m-2 ± 96.25), but very high densities were recorded at two sites. Snails were most abundant along roadsides and densities decreased dramatically with distance from roads. T. pisana in the WCNP appear to have an annual lifecycle, breeding in autumn to winter and growing to adult size of about 14 mm diameter by the end of the following summer. Snails were observed on a wide variety of endemic and introduced plant species and appeared to have a catholic diet. They are active mostly at night and especially during periods of high humidity, irrespective of temperature. Given the very high densities that T. pisana can attain at some sites, plus their apparently catholic feeding habits, their potential impact on the vegetation of the park is cause for concern and should be further investigated. Control of the main colonies should also be considered.

Full Text:  |  PDF (765KB)

Author affiliations

Lizelle J. Odendaal, University of Cape Town, South Africa
Tanya M. Haupt, University of Cape Town, South Africa
Charles L. Griffiths, University of Cape Town, South Africa

Metrics

Total abstract views: 2759
Total article views: 1892

Cited-By

No related citations found

Comments on this article

Before posting your comment, please read our policy.
Post a Comment (Login required)


ISSN: 0075-6458 (print) | ISSN: 2071-0791 (online)Follow us on:

All articles published in this journal are licensed under the Creative Commons Attribution license.

©2014 AOSIS (Pty) Ltd. All rights reserved. No unauthorised duplication allowed.

AOSIS OpenJournals | Perfecting Scholarship Online
Postnet Suite #110, Private Bag X19, Durbanville, South Africa, 7551
Tel: 086 1000 381 
Tel: +27 21 975 2602 
Fax: 086 5004 974

Please read the privacy statement.