Solar panels as novel nest sites for the European paper wasp Polistes dominula

Solar energy facilities are rapidly expanding in their land use footprint worldwide, with significant implications for biodiversity. Although impacts are often negative, it is possible for some species to take advantage of the novel anthropogenic structures and microhabitats provided by solar facilities.
We describe the frequent nesting of non-native European paper wasps (Polistes dominula) at two solar facilities in the Central Valley of California (USA), conducting nest censuses to further investigate population density and nest siting behaviour.
Active nests were found to occur at a density of 10-23 per hectare of solar facility, and paper wasps had a preference for nesting in sheltered metal torque tubes compared with the more exposed undersides of photovoltaic panels.
Our study shows that P. dominula might benefit from the construction of solar energy facilities, which could have a variety of impacts on native species and surrounding agriculture that warrant further study. The Euro..., To estimate wasp nest density at two GPV facilities, we conducted censuses by counting all nests of P. dominula along a randomly selected set of PV panel strings (rows of panels) in summer 2024. At the UC Davis facility 47 panel strings (5% of the total) were counted along their entire length between 09:30 and 14:30 on June 7th, July 9th and August 1st. At the SacSewer facility, 35 panel strings (10% of the total) were counted along their entire length between 08:40 and 11:30 on July 16th and August 21st.
Nests were categorized as active if at least one live adult wasp was present and inactive if no live adult wasps were present at the time of counting. PV panel strings were visually inspected for nests, with their location on the structure also recorded (torque tube or underside of panel). Reported values are likely an underestimate given that we could not fully examine hollow elements of the PV string infrastructure (e.g., metal torque tubes within the racking infrastructure that supp..., , # Data from: Solar panels as novel nest sites for the European paper wasp Polistes dominula

[https://doi.org/10.5061/dryad.0vt4b8h80](https://doi.org/10.5061/dryad.0vt4b8h80)

## Description of the data and file structure

**Nest counts** - We counted all nests of *Polistes dominula* along a randomly selected set of photovoltaic (PV) panel strings (rows of panels) in summer 2024, categorising them as active (at least one live wasp present) or inactive (no live wasps present) and recording their location on the PV infrastructure (torque tube or underside of panels). At the UC Davis facility, we randomly selected 47 panel strings (5% of the facility total) and counted nests along their entire length, with separate counts completed on June 7th, July 9th and August 1st. At the SacSewer facility, we randomly selected 35 panel strings (10% of the facility total) and counted nests along their entire length, with separate counts completed on July 16th and August 21st.

**Wasp counts** - During...