Pollinator-mediated isolation promotes coexistence of closely related food-deceptive orchids

Identifying the factors that contribute to reproductive isolation among closely-related species is key for understanding the diversification of lineages. In this study, we investigate the strength of premating and postmating reproductive isolation barriers between Disa ferruginea and Disa gladioliflora, a pair of closely-related species, often found co-flowering in sympatry. Both species are non-rewarding and rely on mimicry of different rewarding model flowers for attraction of pollinators. We constructed abiotic niche models for different forms of each taxon to measure ecogeographic isolation. Using experimental arrays in sympatry, we recorded pollinator transitions to measure ethological isolation. We performed hand pollinations to measure postpollination isolation. We found strong, but not complete, premating isolation associated with abiotic niches and absolute ethological isolation based on pollinator preferences in sympatry. Pollinator preferences among the orchids could be expla..., , , # Pollinator-mediated isolation promotes coexistence of closely related food-deceptive orchids

[https://doi.org/10.5061/dryad.rbnzs7hn4](https://doi.org/10.5061/dryad.rbnzs7hn4)

## Description of the data and file structure

This data was collected in the field at Boosmansbos Wilderness Area in the Western Cape of South Africa. The two experiments involved a preference experiment using floral arrays of the two closely related orchids with pollinators, this was used to confirm pollinator-mediated isolation. We also conducted a hand pollination experiment between the two orchid species to determine postpollination isolation. Furthermore, floral measurements were taken to compare floral traits between mimics and models. We also extracted environmental variables from point localities using QGIS to determine the abiotic niche of the two orchids.

### Files and variables

#### File: abiotic\_variables.csv

**Description:** Abiotic variables used to generate the PCA associated with the abiot...