individually distinctive and so I excluded aggregated spiders from the long term data if I became unsure about which spider was which at any time through the study. If present to a significant degree this error would be indicated by longer web site residencies for Small spiders than those of Large spiders, which were more recognizable as individuals. Instead the Small specimens show the most frequent movements, which is in agreement with the findings of other studies shown in Table 1. The lengths of some residence periods were further corroborated by observations of distinctive individuals that were using easily visible day-time hiding positions. Nevertheless, the spatial distribution of specimens in some cases, especially spiderlings, and reuse of sites, did suggest that P. noblei may be attracted by conspecifics, and/or that web sites were limiting. In the habitats where I found Poltys commonly, as in the areas where these studies were carried out, there were many more apparently suitable web sites than spiders. However the significance of spider spatial distribution was not tested here because of the complications of habitat heterogeneity, wind currents, and the structural suitability of different plant species for the webs and hiding places for spiders of different sizes.
The paucity of studies on nocturnal orb web spiders to some extent reflects the inconvenience of working odd hours, but nocturnal spiders may also make less ideal models than diurnal species due to differences in behavior. Diurnal species normally construct the new web within the frame of the previous one (e.g., Hodge 1987a). Thus, with no disturbance, the web will be in exactly the same place and repeated occupancy can be assumed to be a direct measure of the suitability of the web site for the spider. In contrast, nocturnal spiders such as Poltys, may spend up to 17 hours each day without a web, leaving in place only the bridging line, which is easily broken, and access lines between and along twigs. Except in an extremely simple structural situation, or in calm weather, the position of the web is therefore unlikely to be exactly replicated from night to night. In the observations reported here, I discounted small changes in web sites, as did, for example, Enders (1975) in the studies listed in Table 1 and possibly others who did not report on the precise details. However, in a habitat where supports are widely separated, even the relocation of a single support line may significantly change the web position and so could be considered as relocation (e.g., Nakata & Ushimaru 2004). Such heterogeneity in recording protocol and in spider behavior makes detailed comparisons between studies difficult. Nevertheless trends do emerge from this range of data and, in particular, the new data on Poltys add support to the findings of previous authors who suggested the connection between long residencies, random patterns of movement, and a high cost of relocation due to predation risks. Among the species with long web site residence times the precise modus operandi of the threat differs between the two diurnal species, N. clavipes and C. octotuberculata, but the requirement for effective camouflage may well be the key factor for both of the nocturnally active, diurnally cryptic species, T. elongata and P. noblei. Despite presenting interesting challenges, nocturnal and/or cryptic spiders provide useful insights into otherwise hidden facets of predator prey interactions.
New South Wales National Parks and Wildlife Service staff members were most helpful in arranging access to sites in Kuring-gai Chase NP. Mariella Herberstein kindly advised on thesis material and on an early draft of the current manuscript; Mike Gray was extremely helpful on a later draft. The project was supported by the Australian Museum, The University of Sydney, and awards from the Joyce W. Vickery Scientific Research Fund administered through the Linnean Society of New South Wales. Doctoral supervisors Mike Gray and Harley Rose and partner/colleague Graham Milledge provided help and support 