# Vibration as a New Survey Method for Spiders

## TL;DR

A new vibration-based method using a diesel tractor was tested to survey spider populations, showing promise alongside traditional methods like night collection and pitfall traps.

## Contribution

The study introduces a novel vibration-based survey method for spiders and recommends combining it with traditional methods to better capture diversity.

## Key findings

- Night collections captured the highest spider diversity and richness compared to pitfall traps and vibration-based methods.
- The vibration-based method captured unique spider species not found using night collections.
- Pitfall traps were biased toward ground-dwelling spiders, while night and vibration methods captured both arboreal and ground species.

## Abstract

Spiders play crucial roles in ecosystems as predators, prey, and indicators of environmental health, yet they have not been well-studied. This study compared different methods for surveying spider populations to understand their effectiveness and biases. A new vibration-based method, using an idling diesel tractor to attract spiders, was compared with the traditional methods of pitfall trapping and hand collection of spiders at night. Night collections yielded the highest species richness and diversity compared to the other methods. Pitfall traps were biased towards ground-dwelling species, while night collections targeted spiders in different vegetative strata. The study highlighted the importance of combining survey methods to accurately determine diversity in spider populations and emphasized the need for further research to better understand spider ecology. As the night collection and vibration-based methods were similar in labor required and material costs, we recommended a combination of these methods be used as there were species of spiders captured using the vibration-based method that were not captured in night collections. Further research is needed to refine the vibration-based method to better understand the underlying mechanism of how vibration attracts spiders and to improve the portability of the vibration source.

Spiders have important ecological roles as generalist predators, are a significant source of food for many other species, and are bioindicators of environmental health. However, spiders are poorly studied. Given their importance, a comparison of spider survey methods used to determine differences in spider diversity and abundance is required to understand their limitations and biases. A new survey method to attract spiders, based on vibration from an idling diesel tractor, was tested and compared to the traditional methods of pitfall trapping and hand collection of spiders at night. Across the three survey methods, there were, in total, 2294 spiders in 34 families, 138 genera, and 226 species identified. Spider species diversity and richness were significantly greater for spiders collected at night than from the other two methods (spiders collected in pitfall traps and attracted to vibration). The collection of spiders using the night collection and vibration-based methods were very similar in terms of labor required and material costs. Of all spider species identified, 80% were captured during hand collection, 30% through pitfall trapping, and 30% from vibration-based collection. Most species of spiders caught in pitfall traps were species known to be primarily ground-dwelling, whereas both arboreal and ground-dwelling spiders were collected at night and as a result of being attracted and collected using the vibration-based method.