Risk-taking behavior in birds foraging along interurban roads

Abstract

Roads provide attractive but dangerous habitats for a wide variety of wild animals, including granivorous species feeding on road-spilled grains. The survival of those animals would imply risk-taking behaviors toward vehicles. We investigated these behaviors in a southern Tunisian crested lark (Galerida cristata) population, by using the flight and tolerance distances of flushed birds as assessments of motivation to take risks. Crested larks foraging on the roadside tolerated more risk compared to those foraging in road-free areas, which could reflect possible habituation of roadside individuals to road traffic. Moreover, crested larks tolerated closer approaches when they were in larger flocks, probably due to increased risk dilution and/or scramble competition. Finally, the studied birds took more risks in summer compared to winter, which could result from reduced time available for foraging during the hot season, or reflect a possible age effect since summer birds included many less-experienced fledglings, among other possible explanations. In sum, our findings highlight that roadside life imposes behavioral adjustments on seed-eating birds, and that seasonal effects may greatly affect birds’ behavioral responses to road-associated threats.