Collective targeted migrations: a balancing act involving aggregation, group size and environmental clues: a simulation study

Abstract

What is behind the \emph{wisdom of the crowds} described by Simons (2004)? It has been showed that insects may use gravitational fields to travel (Dreyer et al 2018) and we may ask whether the use of gravitational fields is enough to secure the arrival of an individual to a relatively narrow spot thousands of kilometers away, as it is the case for example of monarch butterflies, which may travel 4,500 km to land in Mexico within an area of about 1/8 the size of Long Island. Here we show that if individuals budget a fraction of time to seek the target and the rest to maintain aggregation, the chances of landing within a narrow spot even under a weak signal are increased. Our model exhibits the existence of an equilibrium, the tradeoff that comes from maintaining group size, aggregation, and targeting. Whenever this balance is broken, the population may behave erratically. If this strategic balance between targeting and aggregation is prevalent then the possibility of destabilizing may be used to control or regulate the spread of undesirable organisms that navigate under this balancing set of mechanisms.