Biodiversity
No significant crazy ant-related invertebrate distribution
patterns could be detected except for ants
and one species of paussine carabid beetle (the first
record of this ant parasite subfamily from
Seychelles) (Tables 1 and 2). The single species of
paussine beetle was positively associated with the
crazy ant whilst other ant species were reduced in
areas with abundant crazy ant. Most ant species
were widespread, but the largest species, O. simillimus
(F. Smith) did not coexist with crazy ants.
In the woodland area the mean level of crazy ant
activity at mid-day was 5.4 active ants per square
metre, with the highest density in the densest woodland.
Leaf-litter samples (which also include ants
below the surface of the litter) contained over
10 times more ants (mean density of 60 m2). The
crazy ant was scarce in open woodland although it
does forage in open habitats at dusk. Differences in
woodland composition and cover in ant invaded
and ant-free areas are summarised in Table 3.
Active Lesser Noddy nests were found in ant
invaded and ant-free areas with no significant difference
between the two areas (in the 10 trees
studied in each area ant-infested trees supported
49 nests, whilst ant-free trees had 45 nests).
Nest success was difficult to determine, but
approximately 50% of nests in both areas
Table 2. Significant regressions predicting invertebrate abundance (derived from the data analysed in Table 1)
Regression t P
Cockroach Y ¼ 6.275–0.036 (cover) 2.12