Prospecting and informed dispersal: Understanding and predicting their joint eco-evolutionary dynamics

Abstract

The ability of individuals to leave a current breeding area and select a future one is important, because such decisions can have multiple consequences for individual fitness, but also for metapopulation dynamics, structure, and long-term persistence through non-random dispersal patterns. In the wild, many colonial and territorial animal species display informed dispersal strategies, where individuals use information, such as conspecific breeding success gathered during prospecting, to decide whether and where to disperse. Understanding informed dispersal strategies is essential for relating individual behavior to subsequent movements and then determining how emigration and settlement decisions affect individual fitness and demography. Although numerous theoretical studies have explored the eco-evolutionary dynamics of dispersal, very few have integrated prospecting and public information use in both emigration and settlement phases. Here, we develop an individual-based model that fills this gap and use it to explore the eco-evolutionary dynamics of informed dispersal. In a first experiment, in which only prospecting evolves, we demonstrate that selection always favors informed dispersal based on a low number of prospected patches relative to random dispersal or fully informed dispersal, except when individuals fail to discriminate better patches from worse ones. In a second experiment, which allows the concomitant evolution of both emigration probability and prospecting, we show the same prospecting strategy evolving. However, a plastic emigration strategy evolves, where individuals that breed successfully are always philopatric, while failed breeders are more likely to emigrate, especially when conspecific breeding success is low. Embedding information use and prospecting behavior in eco-evolutionary models will provide new fundamental understanding of informed dispersal and its consequences for spatial population dynamics.

Keywords: breeding failure; breeding habitat selection; conspecific breeding success; environmental changes; population dynamics; social information.

FIGURE 1

Flowchart of informed dispersal representing dispersal (red) and information acquisition and use in breeding habitat selection (blue). Breeding site 1 can be the natal or current breeding site. Depending on species life cycle, prospecting can occur before (Path 1 ‐ Best‐of‐n strategy) or after emigration decision (Path 2; sequential sampling)

FIGURE 2

Local number of adults (±SE) depending on the local environmental quality, emigration strategy, patch selection process, and per‐patch prospecting mortality cost. Pers is the use of personal information (individual breeding performance). Pers + public is the use of both personal and public information (conspecific breeding success) in emigration decisions. Results are shown after 20,000 years over 10 replicates

FIGURE 3

Mean (+SE) frequency of the number of prospected patches after 20,000 years over 10 replicates according to emigration strategy (columns), patch selection process, and prospecting cost per patch (rows) when only prospecting evolves. Bars left of the dashed red line correspond to random settlement (no prospecting). Blue numbers indicate the mode of the distributions

FIGURE 4

Mean (+SE) frequency of the number of prospected patches after 20,000 years over 10 replicates according to emigration strategy (columns), patch selection process, and prospecting cost per patch (rows) when both emigration and prospecting evolve. Bars left of the dashed red line correspond to random settlement (no prospecting). Blue numbers indicate the mode of the distributions

FIGURE 5

Emigration probability evolved under different patch selection processes and prospecting costs per patch after 20,000 years and over 10 replicates when both emigration probabilities and prospecting evolve. (a) Random emigration probability and emigration probability based on personal information of failed and successful breeders (error bars show ± SE) (b) Emigration probability based on personal and public information, where emigration probability is a function of the local breeding success. The bold lines represent the average reaction norm of failed breeders while thin dashed lines represent 20 random individual reaction norms. Emigration probability of successful breeders evolves to 0 independently of local breeding success