TY  - JOUR
A1  - Sibly, Richard M.
A1  - Grimm, Volker
A1  - Martin, Benjamin T.
A1  - Johnston, Alice S. A.
A1  - Kulakowska, Katarzyna
A1  - Topping, Christopher J.
A1  - Calow, Peter
A1  - Nabe-Nielsen, Jacob
A1  - Thorbek, Pernille
A1  - DeAngelis, Donald L.
T1  - Representing the acquisition and use of energy by individuals in agent-based models of animal populations
JF  - Methods in ecology and evolution : an official journal of the British Ecological Society
N2  - Agent-based models (ABMs) are widely used to predict how populations respond to changing environments. As the availability of food varies in space and time, individuals should have their own energy budgets, but there is no consensus as to how these should be modelled. Here, we use knowledge of physiological ecology to identify major issues confronting the modeller and to make recommendations about how energy budgets for use in ABMs should be constructed. Our proposal is that modelled animals forage as necessary to supply their energy needs for maintenance, growth and reproduction. If there is sufficient energy intake, an animal allocates the energy obtained in the order: maintenance, growth, reproduction, energy storage, until its energy stores reach an optimal level. If there is a shortfall, the priorities for maintenance and growth/reproduction remain the same until reserves fall to a critical threshold below which all are allocated to maintenance. Rates of ingestion and allocation depend on body mass and temperature. We make suggestions for how each of these processes should be modelled mathematically. Mortality rates vary with body mass and temperature according to known relationships, and these can be used to obtain estimates of background mortality rate. If parameter values cannot be obtained directly, then values may provisionally be obtained by parameter borrowing, pattern-oriented modelling, artificial evolution or from allometric equations. The development of ABMs incorporating individual energy budgets is essential for realistic modelling of populations affected by food availability. Such ABMs are already being used to guide conservation planning of nature reserves and shell fisheries, to assess environmental impacts of building proposals including wind farms and highways and to assess the effects on nontarget organisms of chemicals for the control of agricultural pests.
KW  - bioenergetics
KW  - energy budget
KW  - individual-based models
KW  - population dynamics
Y1  - 2013
U6  - https://doi.org/10.1111/2041-210x.12002
SN  - 2041-210X
VL  - 4
IS  - 2
SP  - 151
EP  - 161
PB  - Wiley-Blackwell
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Liu, Chun
A1  - Sibly, Richard M.
A1  - Grimm, Volker
A1  - Thorbek, Pernille
T1  - Linking pesticide exposure and spatial dynamics an individual-based model of wood mouse (Apodemus sylvaticus) populations in agricultural landscapes
JF  - Ecological modelling : international journal on ecological modelling and engineering and systems ecolog
N2  - The wood mouse is a common and abundant species in agricultural landscape and is a focal species in pesticide risk assessment. Empirical studies on the ecology of the wood mouse have provided sufficient information for the species to be modelled mechanistically. An individual-based model was constructed to explicitly represent the locations and movement patterns of individual mice. This together with the schedule of pesticide application allows prediction of the risk to the population from pesticide exposure. The model included life-history traits of wood mice as well as typical landscape dynamics in agricultural farmland in the UK. The model obtains a good fit to the available population data and is fit for risk assessment purposes. It can help identify spatio-temporal situations with the largest potential risk of exposure and enables extrapolation from individual-level endpoints to population-level effects. Largest risk of exposure to pesticides was found when good crop growth in the "sink" fields coincided with high "source" population densities in the hedgerows.
KW  - Population dynamics
KW  - Pesticides
KW  - Ecological risk assessment
KW  - Habitat choice
KW  - Agent-based model
KW  - NetLogo
Y1  - 2013
U6  - https://doi.org/10.1016/j.ecolmodel.2012.09.016
SN  - 0304-3800
VL  - 248
IS  - 2
SP  - 92
EP  - 102
PB  - Elsevier
CY  - Amsterdam
ER  -