Abstract:
AIM : Foraging activity is critical for animal survival. Comprehending how ecological
drivers influence foraging behaviour would benefit our understanding of the link between
animals and ecological processes. Here, we evaluated the influence of ecological
drivers on ant foraging activity and relative resource use.
LOCATION : Six Brazilian biomes: Amazon, Atlantic rainforest, Caatinga, Cerrado, Pampa
and Pantanal.
TAXON : Formicidae.
METHODS : We assessed ant foraging activity and resource use by sampling across 60
sites. We placed baited tubes that contained one of five liquid resources (sugar, lipids,
amino acid, sodium and distilled water). We used model selection to assess the influence
of ecological drivers (temperature, precipitation, temperature seasonality and
net primary productivity) on ant foraging activity and relative resource use.
RESULTS : Foraging activity was higher in wetter, more productive and less thermally
seasonal environments. The relative use of amino acids increased at higher temperatures
while the relative use of lipids decreased. The relative use of sugar increased in
drier and less productive environments with high-temperature
seasonality while the
relative use of amino acid and sodium decreased in those environments. The relative
use of lipids was complex: increasing with increasing temperature seasonality and
decreasing with increasing precipitation. Furthermore, the relative use of sodium was
greater where the foraging activity was high.
MAIN CONCLUSIONS : We demonstrate how ecological drivers are correlated with ant
foraging activity and resource use in the field across large spatial scales. The search for resources encompasses different interactions involving ants with abiotic and biotic
components in the ecosystem. Thus, we suggest that changes in climate and NPP,
which influence the intensity and the way that ants search for resources, will result in
changes in ant-mediated
ecological processes.
