Fig 1.
Schematic representation of the breeding SB and natal dispersal strategy SN.
Under SB reproduction takes place before and after dispersal with a fraction 1-tE of offspring allocated to the natal patch and a fraction tE to the target patch. In contrast, under SN all reproduction always takes place either in the natal patch (with probability 1-p) or in the target patch (with probability p). In both scenarios dispersing individuals carry a certain mortality risk μ during dispersal—in case of mortality individuals will not reproduce in the target patch.
Fig 2.
The effect of patch capacity K and dispersal strategy on evolved mean dispersal as a function of dispersal mortality,μ(log scale).
(a) Density-independent (DI) scenario and (b) density-dependent (DD) scenario. Filled circles and diamonds represent small patches (K = 10) and empty circles and diamonds big patches (K = 100). Diamonds indicate natal dispersal (SN), circles breeding dispersal (SB). Other parameter values: environmental variability (σ = K)) and fecundity (λ = 2).
Fig 3.
The effect of patch size (K), dispersal probability and dispersal strategy (SB, SN) on coefficient of relatedness after 20 generations.
Different strategies SB and SN are represented by circles and diamond symbols, respectively. Small patch sizes (K = 10) are depicted with open symbols and big patch sizes (K = 100) with filled symbols.
Fig 4.
The effect of environmental variance (σ)), patch capacity (K) and dispersal costs (μ) on evolved dispersal rates.
Density-independent (DI) dispersal (graphs a,c) and density-dependent (DD) dispersal (graphs b,d). Small carrying capacity (K = 10, graphs a,b) and big carrying capacity (K = 100, graphs c,d). Empty symbols (σ = 0) and filled symbols (σ = K). Diamonds and circles stand for SN and SB respectively.
Fig 5.
Exemplary change in the proportion (SB/(SB+SN)) of individuals with the breeding dispersal strategy over time during evolutionary tournaments.
(a) Scenario with small patch size (K = 10) and (b) scenarios with large patch size (K = 100); environmental variability σ = K in all cases. Black and grey lines represent density-dependent (DD) and density-independent (DI) emigration scenarios, full and dashed lines represent mortalities μ = 0.001 and 0.5, respectively.