Relying on animals for seed dispersal, many plants need to advertise their fleshy fruits and attract frugivorous birds and mammals—in accordance with the perceptual abilities of the dispersing clade. The disperser syndrome hypothesis (DSH) associate "contrastive colours" i.e. black, blue, red, with bird dispersal, while linking fruits of "cryptic" "colours" i.e. green, brown, yellow, with mammal dispersal.
In this study, researchers tested DSH, while attempting to flesh out a potential role of abotic factors on fruit colour evolution, as contrastive colouring of fruits by anthocyanins could also imply a means of simply protecting the photosynthetic apparatus against UV radiation—or the damaging effects of cold.
The authors set out with a dataset of fruit colouration for more than 3,100 fleshy-fruited plants. They used GBIF-mediated occurrences to determine the distributions of the plants and derive climatic factors. This was combined with bird and mammal breeding ranges and diet data to create a model to test the various hypotheses.
Their results found evidence for both biotic and abiotic variables contributing to the evolution of fruit colour. Cryptic colouration occur largely in warm environment where the relative bird frugivore prevalence is low. When wet season temperatures are low and/or bird prevalence is high, however, most fruits display contrastive colours.