Observing frugivores or collecting scats: A method comparison to construct quantitative seed dispersal networks

Mutualistic interactions form the basis for many ecological processes and are often analyzed within the framework of ecological networks. These interactions can be sampled with a range of methods and first analyses of pollination networks sampled with different methods showed differences in common network metrics. However, it is yet unknown if metrics of seed dispersal networks are similarly affected by the sampling method and if different methods detect a complementary set of frugivores. This is necessary to better understand the (dis-)advantages of each method and to identify the role of each frugivore for the seed dispersal process.

Here, we compare seed removal networks based on the observation of 2,189 frugivore visits on ten focal plant species with seed deposition networks constructed by DNA barcoding of plant seeds in 3,094 frugivore scats. We were interested in whether both methods identify the same disperser species and if species-level network metrics of plant species were...