In the study of animal signals, spiders have emerged as a classic example of signalling using substrate-propagated vibrations (Barth, 1998). The vibrations propagated through the delicate webs of orb-weaving spiders are clear examples of signalling through vibrations (Barth, 1998;Finck, 1981;Frohlich and Buskirk, 1982;Klarner and Barth, 1982;Landolfa and Barth, 1996;Masters, 1984;Masters and Markl, 1981;Vollrath, 1979), but the majority of spiders may also use substrate-propagated vibrations in such varied substrates as water, soil, leaf litter or plants (Barth, 1985(Barth, , 1998(Barth, , 2002Bleckmann and Barth, 1984;Bristowe, 1929;Fernandezmontraveta and Schmitt, 1994;Rovner, 1968;Stratton and Uetz, 1983;Uetz and Stratton, 1982). Three types of substrate-borne vibration-production mechanisms have been described in spiders: percussion, stridulation and vibration (tremulation; Uetz and Stratton, 1982). Percussion is produced by the drumming of body parts against the substrate and has been described in a variety of species (Dierkes and Barth, 1995;Stratton, 1983;Uetz and Stratton, 1982). Stridulation occurs by the rubbing of two rigid body structures relative to each other (Dumortier, 1963) and seems to occur commonly in spiders (Legendre, 1963), particularly in wolf spiders (Family:Lycosidae; Rovner, 1975;Stratton and Uetz, 1983;Uetz and Stratton, 1982). Tremulation (Morris, 1980) is the third method of substrate-borne vibration production found in spiders (Barth, 2002;Dierkes and Barth, 1995;Rovner, 1980;Uetz and Stratton, 1982) and occurs by the oscillation of body parts, without a frequency multiplier (i.e. stridulation), coupled to the substratum, usually by adhesive hairs on the tips of one or more of the legs. All of these mechanisms can be used to produce substrate-borne (seismic) signals (Aicher et al., 1983;Aicher and Tautz, 1990;Narins, 1990).Jumping spiders (Family: Salticidae) are unique among spiders in that they are visual 'specialists', having two large, prominent frontal eyes that are specialized for high spatial resolution, as befits their predatory habits as stalker-hunters (Forster, 1982a;Land, 1985). Not surprisingly, vision also plays a prominent role in their signalling behaviour. Males, unlike females, have evolved conspicuously ornamented and coloured appendages that they wave like semaphores during courtship, producing stereotyped, species-specific visual displays that unfold over periods of seconds to minutes (Crane, 1949;Forster, 1982b;Jackson, 1982). These displays function in species isolation, species recognition and female