Original title: Competition drives excessive recruitment in collective search
Hyunjoong Kim, Gayashan Jayavilal, Joshua B Plotkin · September 2026
When animals forage in groups, one finder often recruits others to a food patch. Bringing more foragers helps the group, but overcrowding reduces the food each member gets. This means there is a sweet spot for how much to recruit. Problems arise when two groups discover the same food site. Researchers modeled two competing groups that interact only by sharing a patch where returns drop as crowd size grows. They found that groups fight over the site. A group recruits faster as its rival recruits faster to defend a monopolyOne group controls the entire foraging site, excluding the other.. However, if defending fails, it suddenly drops recruitmentCalling other members to a food source you found.. A group gives up its monopoly if the patch quickly saturatesReaches a point where adding more foragers gives no extra benefit. with few foragers or if the rival group is small. When groups match in size, both recruit excessively to compete. As a result, each individual gets less food than if they were all one big group.
Imagine two food trucks at a festival. Each truck sends out flyers to attract customers. But the more customers come, the longer the line, and each customer gets less food. Each truck tries to out-flyer the other to get more customers, but eventually both have such long lines that customers leave. In this paper, the trucks are groups recruiting foragers to a site, and the flyers are recruitment signals. The result is that both groups recruit too many foragers, and everyone ends up with less than if they had shared the site peacefully.
In any situation where groups compete for a limited resource—from ant colonies to human teams—this work shows that competition can lead to over-recruitment, wasting effort and reducing everyone's share. Understanding when this happens helps design better coordination strategies.
The model considers only two groups and a single foraging site. It does not account for multiple sites, dynamic environments, or empirical validation. The analysis assumes groups interact only through the shared return, ignoring other forms of competition.
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Competition drives excessive recruitment in collective search — Hyunjoong Kim, Gayashan Jayavilal, Joshua B Plotkin
Abstract licence: CC0
Explanation generated by Synthesis from the abstract — it is not the original paper. This is a preprint, so it hasn't necessarily been peer reviewed.