Asian Myrmecology, Volume 2, Ecology and Distribution
Remote detection and distinction of ants using nest-site specific LISS-derived Normalised Difference Vegetation Index
AJAY NARENDRA 1,2 * & T.V. RAMACHANDRA 1
1 Energy and Wetland Research Group, Centre for Ecological Sciences, Indian Institute of Science,
Bangalore 560012, India
2 ARC Centre of Excellence in Vision Science, Research School of Biological Sciences, Australian
National University, ACT 2601, Australia
Abstract. This study in Western Ghats, India, investigates the relation between nesting
sites of ants and a single remotely sensed variable: the Normalised Difference
Vegetation Index (NDVI). We carried out sampling in 60 plots each measuring 30 x 30
m and recorded nest sites of 13 ant species. We found that NDVI values at the
nesting sites varied considerably between individual species and also between the
six functional groups the ants belong to. The functional groups Cryptic Species,
Tropical Climate Specialists and Specialist Predators were present in regions with
high NDVI whereas Hot Climate Specialists and Opportunists were found in sites
with low NDVI. As expected we found that low NDVI values were associated with
scrub jungles and high NDVI values with evergreen forests. Interestingly, we found
that Pachycondyla rufipes, an ant species found only in deciduous and evergreen
forests, established nests only in sites with low NDVI (range = 0.015 - 0.1779). Our
results show that these low NDVI values in deciduous and evergreen forests
correspond to canopy gaps in otherwise closed deciduous and evergreen forests.
Subsequent fieldwork confirmed the observed high prevalence of P. rufipes in these
NDVI-constrained areas. We discuss the value of using NDVI for the remote detection
and distinction of ant nest sites.
Keywords: ants, NDVI, nest site selection, Western Ghats, canopy gap, Pachycondyla
rufipes