Invasion of yellow crazy ant Anoplolepis gracilipes in a Seychelles UNESCO palm forest

By

Kaiser-Bunbury, Christopher
Cuthbert, Harrieth
Fox, Rebeckah
Birch, Darryl.
Bunbury, Nancy

Type

Article

Date of Publication

2014

Original Publication

NeoBiota : advancing research on alien species and biological invasions

Volume

22

Pages

43-57

Subjects

coco de mer palm , Endemic arboreal species , Geckos , invasive alien species , Islands , molluscs , Western Indian Ocean , World Heritage Site

Contributed by

Pensoft Publishers

Language

English

Published by

Sophia, Bulgaria Pensoft Publishers

Identifiers

DOI: https://doi.org/10.3897/neobiota.22.6634

 

Abstract

The mature palm forest of the Vallée de Mai, a UNESCO World Heritage Site, on the Seychelles island of Praslin, is a unique ecosystem containing many endemic species, including the iconic coco de mer palm Lodoicea maldivica. In 2009, the invasive yellow crazy ant Anoplolepis gracilipes was recorded for the first time within the palm forest, raising concern about its potential impacts on the endemic fauna. This research aimed: (1) to assess the current distribution and spread of A. gracilipes within the palm forest; (2) to identify environmental variables that are linked to A. gracilipes distribution; and (3) to compare endemic species richness and abundance in A. gracilipes invaded and uninvaded areas. Anoplolepis gracilipes was confined to the north-east of the site and remained almost stationary between April 2010 and December 2012, with isolated outbreaks into the forest. Infested areas had significantly higher temperature and humidity and lower canopy cover. Abundance and species richness of the endemic arboreal fauna were lower in the A. gracilipes invaded area. Molluscs were absent from the invaded area. The current restricted distribution of A. gracilipes in this ecosystem, combined with lower abundance of endemic fauna in the invaded area, highlight the need for further research to assess control measures and the possible role of biotic resistance to the invasion of the palm forest by A. gracilipes.