ions for locating spiders. The details of each Poltys seen along the route were recorded. The temperature was noted at the beginning of each survey, at the turn-around point, and again on return to the start. Because of public access to the area and not wishing to draw the attention of potential bird predators to the locations of spiders, web locations were not marked and I avoided seeking out the specimens during the day (although a few were easily visible, which allowed further confirmation that the same specimen was using the site throughout the putative period of residence). Instead, web locations were described or sketched in relation to vegetation features. No attempt was made to mark specimens for a number of reasons (see below), but abdominal shape was noted. The approximate size of each specimen was estimated by eye, without the aid of templates; hence the size ranges used in the analysis are approximate. Slight changes in web site within the same bush or tree (up to about 20-30 cm for a small spider or 50-100 cm for a larger specimen) were noted but were not considered moves unless there were other reasons to suspect that the specimen in the new site was not the original, or that the specimen was now using a different resting position.
Although the long term transects were initiated after only the pilot study of the short term surveys was completed, the further 10-day short term studies confirmed that these observations were valid. Overall, the short-term observations were found to indicate that (i) many spiders use the same, or a closely adjacent, web site night after night; and (ii) the likelihood of a similarly sized and shaped spider moving into a vacated web site soon after departure of the first was small unless there was a high local population density. Therefore, it was indicated that in general it was possible to monitor individual spiders without marking them, even though this introduced a small amount of uncertainty into the results. Marking spiders was decided to be unsuitable for this study because of the increased likelihood of relocation of disturbed specimens (and the likelihood of repeated disturbance when trying to get close enough with a bright light to confirm specimen identity), as well as potential disruption of camouflage and the likelihood of injury to small specimens.
Data analysis.--For the short-term transects, the average web site residence time for each transect site was calculated (in nights). Mean residence = total spider observation nights/total departures. For the long-term study, all calculations were performed using the average sample period as the unit of residence time (1 sample period = 8.49 nights). The sample mean and standard deviation were calculated for all spiders with unambiguous records. This excluded specimens for which the moving-in date was unknown (i.e., they were already present on the first transect night), or those for which there was likely to have been interference from conspecific spiders.
Two size classes were recognized, based on the field estimates. The "Small" class contained spiderlings, juvenile males (which cease making webs and become mobile when they mature), and juvenile females of a similar size. Therefore, small spiders in this context are those up to instar two or three (post emergence). This size-class cut-off point may be important as the abdomens of females are beginning to differentiate in shape at this size (Smith 2006b) and camouflage may begin to play a more important role. The "Large" class, therefore, comprised only juvenile and adult females. Some spiders grew from one class into the next while resident at a single web site. The class used here is the size at arrival.
The distribution of residence times of Small spiders was compared against those of the Large class using the [chi square] test on contingency tables and pooling most columns with expected values < 5 (note: it is not necessary to remove all expected values less than 5, Parker 1979). All subsequent tests used the two size classes separately.
For each size class the record