uncoated metal hardware cloth. Each foraging tray contained a freezer-killed mealworm
(cut in half) and a 1-ml Eppendorf tube filled with sugar water-soaked cotton placed on
top of a 7.6cm x 12.7cm white card. Each colony unit in the control treatment was
connected to a unique foraging tray, while each pair of competing colony units shared a
foraging tray. The set Ofhardware cloth bridges attaching competing colonies to the
foraging tray also allowed for the movement of ants between nest boxes. Each bait was
removed, weighed, and replaced with a fresh bait item on days 3 and 5 of the experiment.
The average desiccation of control baits (without ant access) was subtracted from the
difference between the initial and final weight of each bait item to determine the mass of
bait consumed during the 48-hour period. This calculation method sometimes led to
negative values for overall resource consumption.
Behavioral data were collected every 15 minutes for 1 hour and 45 minutes
beginning 10 minutes after the bridges were first put in place at 1400h CST on July 3,
2008. Data was then collected each hour until 3 hours and 55 minutes after the start of
the experiment and at 24-hour intervals from the start of the experiment until its
completion on day 6 (July 8,2008). On both days 3 and 5, behavioral data were also
collected after sugar water and mealworms were replaced, at 51 hours and 10 minutes
and 99 hours and 10 minutes after the start of the experiment. During each data
collection, the number of ants of each species at the sugar water and at the mealworm
was recorded for all colony units. In addition, for paired competition units, we recorded
the number of ants of each species involved in fights, as well as the number of ants in the
nest box of the competing species. After the last data collection event at 1400h on July 8,
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