Spatiotemporal Variation in House Spider Phenology at a National Scale Using Citizen Science

Abstract

The seasonal appearance of Tegenaria and Eratigena (the best known of the UK genera termed house spiders) results in considerable public and media interest. Here, we present the largest dataset ever gathered on the occurrence of house spiders anywhere in the world. We collected almost 10,000 records from different locations within the UK (amounting to ∼250× more locations and 25× more records than any previous study) over a six-month period. Using this dataset, which contained details of sighting dates, times, location within UK, location within the home, location within rooms, and sex, we were able to investigate a number of aspects of house spider ecology. Eightytwo percent of records were males, supporting previous studies that showed house spider surges in autumn are predominantly males seeking mates. Sightings peaked in mid-September with a significant northwest progression across the UK as autumn progressed. Daily activity peaked at 19.35 hrs and spiders were seen more or less uniformly throughout different rooms; we discuss why this is more likely to be due to spider ecology than human behaviour. Within rooms, there was a sex-based difference in ecology with females more common on ceilings and doors/windows and males more common on walls, possibly because of sex-specific differences in mobility.