10.5068/D1J67R
Miller, Julie
0000-0002-2301-1955
University of California Los Angeles
Collective decision-making when quantity is more important than quality:
Lessons from a kidnapping social parasite
Dryad
dataset
2020
slave-making
Ants
optimal foraging
sequential choice
National Science Foundation
https://ror.org/021nxhr62
IOS-1406084
Huyck Preserve and Biological Research Station
https://ror.org/01asj1396
Sigma Xi
https://ror.org/04nmj5x57
2020-12-24T00:00:00Z
2020-12-24T00:00:00Z
en
403525 bytes
3
CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
Identifying the general principles that shape mechanisms of collective
decision-making requires studies that span a diversity of ecological
contexts. However, collective decision-making has only been explored in a
handful of systems. Here, I investigate the ecologically mediated costs
and benefits of collective-decisions by socially parasitic kidnapping ants
(Temnothorax americanus) over where to launch raids to steal host brood. I
first investigate their sampling strategies and preferences with
choice-tests. Using more realistic spatial scales, I confirm the findings
of others that colonies use a sequential choice strategy, and do not
compare options simultaneously. I then ask which ecological conditions
could favor the evolution of this strategy by testing the following
hypotheses from optimal foraging and mate choice theories: (1) raiding
decisions are time constrained or (2) search payoffs are low due to
resource uniformity. Spatial distribution and phenological data on nest
contents support the first hypothesis. Host nests contain an optimal ratio
of brood and workers for a brief period relative to discovery rates.
Colonies, therefore, benefit from raiding most nests they find in this
period rather than deliberating over the best choice, favoring host
quantity over quality. These findings contrast with best-of-n collective
decision-making in other systems and demonstrate that ecological
constraints on information acquisition can alter how collectives process
information.
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