Data from: Ant mosaics in Bornean primary rain forest high canopy depend on spatial scale, time of day, and sampling method

Background: Competitive interactions in biological communities can be
thought of as giving rise to “assembly rules” that dictate the species
that are able to co-exist. Ant communities in tropical canopies often
display a particular pattern, an “ant mosaic”, in which competition
between dominant ant species results in a patchwork of mutually exclusive
territories. Although ant mosaics have been well-documented in plantation
landscapes, their presence in pristine tropical forests remained
contentious until recently. Here we assess presence of ant mosaics in a
hitherto under-investigated forest stratum, the emergent trees of the high
canopy in primary tropical rain forest, and explore how the strength of
any ant mosaics is affected by spatial scale, time of day, and sampling
method. Methods: To test whether these factors might impact the detection
of ant mosaics in pristine habitats, we sampled ant communities from
emergent trees, which rise above the highest canopy layers in lowland
dipterocarp rain forests in North Borneo (38.8–60.2 m), using both baiting
and insecticide fogging. Critically, we restricted sampling to only the
canopy of each focal tree. For baiting, we carried out sampling during
both the day and the night. We used null models of species co-occurrence
to assess patterns of segregation at within-tree and between-tree scales.
Results: The numerically dominant ant species on the emergent trees
sampled formed a diverse community, with differences in the identity of
dominant species between times of day and sampling methods. Between trees,
we found patterns of ant species segregation consistent with the existence
of ant mosaics using both methods. Within trees, fogged ants were
segregated, while baited ants were segregated only at night. Discussion:
We conclude that ant mosaics are present within the emergent trees of the
high canopy of tropical rain forest in Malaysian Borneo, and that sampling
technique, spatial scale, and time of day interact to determine observed
patterns of segregation. Restricting sampling to only emergent trees
reveals segregatory patterns not observed in ground-based studies,
confirming previous observations of stronger segregation with increasing
height in the canopy.