Higher predation risk for insect prey at low latitudes and elevations.
Tomas RoslinBess HardwickVojtěch NovotnýWilliam K PetryNigel R AndrewAshley L AsmusIsabel C BarrioYves BassetAndrea Larissa BoesingTimothy Carlton BonebrakeErin K CameronWesley DÁttiloDavid A DonosoPavel DrozdClaudia L GrayDavid S HikSarah J HillTapani HopkinsShuyin HuangBonny KoaneBenita C Laird-HopkinsLiisa LaukkanenOwen T LewisSol MilneIsaiah MwesigeAkihiro NakamuraColleen S NellElizabeth NicholsAlena ProkuratKaterina SamNiels M SchmidtEleanor M SladeVictor SladeAlžběta SuchankováTiit TederSaskya van NouhuysVigdis VandvikAnita WeissflogVital ZhukovichEleanor M SladePublished in: Science (New York, N.Y.) (2018)
Biotic interactions underlie ecosystem structure and function, but predicting interaction outcomes is difficult. We tested the hypothesis that biotic interaction strength increases toward the equator, using a global experiment with model caterpillars to measure predation risk. Across an 11,660-kilometer latitudinal gradient spanning six continents, we found increasing predation toward the equator, with a parallel pattern of increasing predation toward lower elevations. Patterns across both latitude and elevation were driven by arthropod predators, with no systematic trend in attack rates by birds or mammals. These matching gradients at global and regional scales suggest consistent drivers of biotic interaction strength, a finding that needs to be integrated into general theories of herbivory, community organization, and life-history evolution.