Behaviour (2016) DOI:10.1163/1568539X-00003332 brill.com/beh The wolf spider Pardosa milvina detects predator threat level using only vibratory cues Michael I. Sitvarin a,∗ , Shira D. Gordon b,∗∗ , George W. Uetz b and Ann L. Rypstra c a Department of Biology, Miami University, Oxford, OH, USA b Department of Biological Sciences, University of Cincinnati, Cincinnati, OH, USA c Department of Biology, Miami University, Hamilton, OH, USA * Corresponding author, current address: Department of Entomology, University of Kentucky, Lexington, KY, USA, e-mail: michaelsitvarin@uky.edu ** Current address: USDA/ARS, 9611 South Riverbend Avenue, Parlier, CA, USA Accepted 16 November 2015; published online ??? Abstract Predators may inadvertently signal their presence and threat level by way of signals in multi- ple modalities. We used a spider, Pardosa milvina, known to respond adaptively to chemotactile predator cues (i.e., silk, faeces and other excreta) to evaluate whether it could also discriminate predation risk from isolated vibratory cues. Vibrations from its prey, conspecifics, and predators (Tigrosa helluo and Scarites quadriceps) were recorded and played back to Pardosa. In addition, we recorded predator vibrations with and without access to chemotactile cues from Pardosa, indi- cating the presence of prey. Pardosa did not appear to discriminate between vibrations from prey or conspecifics, but the response to predators depended on the presence of cues from Pardosa. Vi- brations from predators with access to chemotactile cues from prey induced reductions in Pardosa activity. Predator cues typically occur in multiple modalities, but prey are capable of imperfectly evaluating predation risk using a limited subset of information. Keywords anti-predator behaviour, threat-sensitivity hypothesis, multimodal cues, vibration, Tigrosa helluo, Scarites quadriceps. 1. Introduction As predators and prey interact, a variety of cues are produced that can be used by both participants to inform behavioural decisions. In particular, prey species are capable of detecting predator cues and responding appropriately  Koninklijke Brill NV, Leiden, 2016 DOI 10.1163/1568539X-00003332