Biology Reference
In-Depth Information
Figure 2.5.
A young mated
Pogonomyrmex barbatus
queen, shortly at er
shedding her wings, begins to excavate her founding nest chamber. Drawing by
John Dawson/National Geographic Stock.
rates of excavation, and found that in eight of nine pairs the queen that
did more digging when nesting alone also did more digging when
paired. In addition, the queen of the pairs that dug less when solitary
showed a signii cant reduction in digging behavior when she was
paired with a queen with a higher propensity to dig. h is looks like an
example of spontaneous division of labor with amplii cation of the dif-
ferences in behavior between the queens due to their responses to the
actions of each other (Figure 2.6).
Fewell set up parallel experiments using queens from a dif erent spe-
cies,
Pogonomyrmex californicus.
In some populations,
P. califor nicu s
queens form cooperative groups of up to 30 queens and cofound new
nests. With an evolutionary history of cofounding, one might expect
dif erences with respect to division of labor. However, division of labor
for digging (digging asymmetry) was no stronger in
P. califor nicu s
than
that observed for
P. barbatu s.
h is suggests that an evolutionary his-
tory of nest sharing is not necessary to get a demonstrable division of
