erage residence period more comparable with the figure from the short-term studies. Another factor that accounts for some of the difference between long-term and short-term average residence periods is the omission of spiders that were in aggregations from the former. Nevertheless, many of the studies listed in Table 1 also excluded moves caused by conspecific interactions, so this does not affect the within-table comparison. Finally, the life history of P. noblei, which often extends over more than one season, leads to the inclusion of winter records in the long term averages. Winter is a season of low general mobility and was not sampled in any other study listed in Table 1. Therefore, it can be seen that a realistic figure for the average residence period for P. noblei that is comparable to other studies lies somewhere between the short-term and long-term results reported here. Nevertheless, the long-term results provide information on maximum stays, the distribution of residence times, and some information on differences between spiders of different ages. In fact the single longest recorded stay of P. noblei, of approximately 263 days, seems remarkable for a silk recycling species. Unfortunately this cannot be compared to other species both due to the "snapshot" nature of most studies and due to the differing life-histories. All other species examined are essentially univoltine and this time period would have covered the entire life-cycle from emergence; for this P. noblei, however, this period accounted for approximately two-thirds of its growth, the record covering it from the small end of Medium, through to adult, probably around five instars.
An attraction for web sites with conspecific silk has been demonstrated in at least one orb web species (Schuck-Paim & Alonso 2001) which might indicate the further possibility of overestimation of the period of web site tenacity of Poltys if web site take-overs occurred frequently. This error is most likely to occur among records for smaller specimens that were not 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 structura