Behavioral adjustments in the social associations of a precocial shorebird mediate the costs and benefits of grouping decisions

Animals weigh multiple costs and benefits when making grouping decisions. The cost-avoidance grouping framework proposes that group density, information quality, and risk affect an individual’s preference for con- or heterospecific groups. However, this assumes the cost-benefit balance of a particular grouping is constant spatiotemporally, which may not always be true. Investigating how spatiotemporal context influences grouping choices is therefore key to understanding how animals contend with changing conditions. Changes in body size during development lead to variable conditions for individuals over short timescales that can influence their ecological interactions. Hudsonian godwits (Limosa haemastica), for instance, form a protective nesting association with a major predator of young godwit chicks, colonial short-billed gulls (Larus brachyrhynchus). Godwit broods may avoid areas of higher gull densities when chicks are susceptible to gull predation but likely experience higher risk...