Could foxes be surrogate seed dispersers of a megafaunal fruit vine in southern South America?

Abstract

Abstract Plants that bear oversized fruits, but do not co‐occur with present‐day large‐bodied frugivores to disperse their seeds, are considered to represent seed dispersal anachronisms. It is hypothesized that these plants were originally dispersed by the megafauna that became extinct at the end of the Pleistocene. Accordingly, many plant species in South America bearing the so‐called megafaunal fruits occur in ecosystems lacking native modern megafauna. In Chile, Lardizabala biternata is an endemic vine that produces a large edible fruit, with a morphology suggesting a megafaunal seed dispersal syndrome. This species grows across the Chilean Winter Rainfall‐Valdivian Forests and has a rather wide distribution, along which there are currently no large native vertebrates that could ingest its fruits and disperse the seeds. We hypothesized that foxes may be its present‐day surrogate dispersers, because they are the only remnant mesofauna across L. biternata's range that include fruits in their diet. We collected fox scats periodically for 1 year and analyzed their contents, which revealed the presence of intact L. biternata seeds. These results suggest that foxes may be acting as present‐day dispersers of this vine; however, it is unknown whether they provide effective dispersal. Our findings stress the fragmentary state of the knowledge of ecological interactions among species in Chilean ecosystems, opening new perspectives in terms of the role of terrestrial fauna in maintaining ecosystem functions.

Keywords

• anachronism
• fox
• Lardizabala
• Lycalopex
• megafaunal fruit
• seed dispersal