Mutualistic interactions among free-living species generally involve low-frequency interactions and highly asymmetric dependence among partners, yet our understanding of factors behind their emergence is still limited. Using individual-based interactions of a super-generalist fleshy-fruited plant with its frugivore assemblage, we estimated the Resource Provisioning Effectiveness (RPE) and Seed Dispersal Effectiveness (SDE) to assess the balance in the exchange of resources. Plants were highly dependent on a few frugivore species, while frugivores interacted with most individual plants, resulting in strong asymmetries of mutual dependence. Interaction effectiveness was mainly driven by interaction frequency. Despite highly asymmetric dependences, the strong reliance on quantity of fruit consumed determined high reciprocity in rewards between partners (i.e., higher energy provided by the plant, more seedlings recruited), which was not obscured by minor variations in the quality of animal or plant service. We anticipate reciprocity will emerge in low-intimacy mutualisms where the mutualistic outcome largely relies upon interaction frequency.

Dataset has been collected in the field, within Doñana National Park (Huelva, Spain) at two Pistacia lentiscus populations: La Macha del Rabicano at El Puntal site and Laguna de las Madroñas in Doñana's core Reserve.

Data gathering has involved different methodologies, see Supplementary Material of the associated paper for all the information. Below we provide a short summary:

- Frugivore animal-plant interactions come from DNA-barcoding analysis on collected bird sampled beneath individual Pistacia lentiscus plants (file: bc_indiv_lentisc.csv) and monitoring cameras recording individual P. lenticus plants (file: cam_indiv_lentisc.csv). We also extracted fruit feeding rates for different bird species using the monitoring camera's videos (file: lentisc_feeding_rates.csv). For seed predators, we also measured the number of fruits escaping predation (i.e. failure during handling; file: seed_predators_escape.csv)

- Microhabitat conditions were measured using the following methodology

• Microhabitat bird species' use - DNA-barcoding analysis on collected bird samples at each microhabitat (file: mh_combined_barcoding.csv)
• Microhabitat post-dispersal seed predation - seed offering experiments at each microhabitat (file: seed_predation.csv)
• Microhbaitat seed emergence and seedling recruitment - seed sowing experiments at each microhabitat (file: seedling_emergence.csv)

- Individual plant attributes - plant area was measured using a drone flight (dron_areas.csv), plants' initial crop was measured through fruit counts and we also measured fruit and seed weight at variable number of fruits (fruit_characteristics.csv).

Datasets are provided in .cvs and .rds format. See METADATA.csv for the explanation of all variables.

All analyses are in Rmd and can be run in R. See makefile.R with all the code available and the chronological order in which it was run.

Also see our GitHub repository for the manuscript: https://github.com/PJordano-Lab/MS_effectiveness