Publication Date:
2022-05-26
Description:
Author Posting. © The Author(s), 2017. This is the author's version of the work. It is posted here under a nonexclusive, irrevocable, paid-up, worldwide license granted to WHOI. It is made available for personal use, not for redistribution. The definitive version was published in Journal of Animal Ecology 87 (2018): 36-46, doi:10.1111/1365-2656.12658.
Description:
The rate at which a population grows and spreads can depend on individual
behaviour and interactions with others. In many species with two sexes,
males and females differ in key life history traits (e.g. growth, survival, dispersal),
which can scale up to affect population rates of growth and spread. In
sexually reproducing species, the mechanics of locating mates and reproducing
successfully introduce further complications for predicting the invasion
speed (spread rate), as both can change nonlinearly with density. Most models of population spread are based on one sex, or include limited
aspects of sex differences. Here we ask whether and how the dynamics of
finding mates interact with sex-specific life history traits to influence the rate
of population spread.
We present a hybrid approach for modelling invasions of populations with
two sexes that links individual-level mating behaviour (in an individual based
model) to population-level dynamics (in an integrodifference equation
model).
We find that limiting the amount of time during which individuals can search
for mates causes a demographic Allee effect which can slow, delay or even
prevent an invasion. Furthermore, any sex-based asymmetries in life history
or behaviour (skewed sex ratio, sex-biased dispersal, sex-specific mating behaviours)
amplify these effects. In contrast, allowing individuals to mate
more than once ameliorates these effects, enabling polygynandrous populations
to invade under conditions where monogamously mating populations would fail to establish.
We show that details of individuals' mating behaviour can impact the rate
of population spread. Based on our results, we propose a stricter definition
of a mate-finding Allee effect, which is not met by the commonly used
minimum mating function. Our modelling approach, which links individual and
population-level dynamics in a single model, may be useful for exploring
other aspects of individual behaviour that are thought to impact the rate of
population spread.
Description:
This material is based upon work supported by the National Science Foundation under Grant No. OISE-1159097
to AKS and Grant No. DEB-1145017 to MGN.
Keywords:
Integrodifference equations
;
Invasion speed
;
Mate-finding Allee effect
;
Mating functions
;
Sex-biased dispersal
;
Spatial spread
Repository Name:
Woods Hole Open Access Server
Type:
Preprint
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