Range expansion drives the evolution of alternate reproductive strategies in invasive fire ants
Authored by Jackson A Helms, Eli S Bridge
Date Published: 2017
DOI: 10.3897/neobiota.33.10300
Sponsors:
United States Department of Agriculture (USDA)
Platforms:
R
Model Documentation:
Other Narrative
Model Code URLs:
https://github.com/Eli-S-Bridge/RIFA_ABM
Abstract
Many species are expanding their ranges in response to climate changes
or species introductions. Expansion- related selection likely drives the
evolution of dispersal and reproductive traits, especially in invasive
species introduced into novel habitats. We used an agent-based model to
investigate these relationships in the red imported fire ant, Solenopsis
invicta, by tracking simulated populations over 25 years. Most colonies
of this invasive species produce two types of queens practicing
alternate reproductive strategies. Claustral queens found new colonies
in vacant habitats, while parasitic queens take over existing colonies
whose queens have died. We investigated how relative investment in the
two queen types affects population demography, habitat occupancy, and
range expansion. We found that parasitic queens extend the ecological
lifespan of colonies, thereby increasing a population's overall habitat
occupancy as well as average colony size (number of workers) and
territory size. At the same time, investment in parasitic queens slowed
the rate of range expansion by diverting investment from claustral
queens. Divergent selection regimes caused edge and interior populations
to evolve different levels of reproductive investment, such that
interior populations invested heavily in parasitic queens whereas those
at the edge invested almost entirely in claustral queens. Our results
highlight factors shaping ant life histories, including the evolution of
social parasitism, and have implications for the response of species to
range shifts.
Tags
Agent-based model
phenotypic plasticity
Dispersal
Colonies
Population-dynamics
Size
Formicidae
Invasions
Range expansion
Dispersal evolution
Polymorphism
Social-organization
Dispersal polymorphisms
Reproductive polymorphisms
Social
parasitism
Solenopsis invicta
Solenopsis-invicta hymenoptera
Geminata
hymenoptera