 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 recorded pattern of residence times was compared with a random hypothesis, following the methods of Janetos (1982a) and Hodge (1987a, b). This method is based on the expectation that compounded random events such as web damage or disturbance by a predator should result in spider movement events that can be explained by a Poisson process (Janetos 1982a). A negative exponential series was generated (using the "expondist" function in Microsoft Excel), which models the expected distribution of spider movement events over time according to this random hypothesis. This distribution of class frequencies was then compared with that collated from the recorded data.
Seasonality of spider relocations.--In order to compare differences in spider relocation as a function of season, the same size classes were used as for the calculation of residence periods except that the Large spider size class was split into Medium and Large. Thus, Large in this context only contains adult and subadult females; these were split off because all adults die by winter and will therefore leave a web site. Data were extracted for each residency from the long-term observations at Waitara Creek--the season a spider moved into a position and its size, the seasons during which it was resident at a position, and the season and size at which it moved on (Smith 2006b). If a spider had grown between size-classes during its period of residence, the original data were examined to separate the seasons in which the two different size classes were present. For each kind of move, in or out, and for each size class of spider, the total number of moves per season was calculated as a proportion of the numbers of spiders in that class recorded during the season.
Short-term observations of residence time.--The residence period through each short-term transect period is 24.9 nights, averaged over all three sites. Per site the averages are: Myall, 26.3 nights; Waitara Creek, 23.5 nights; West Head, 23.9 nights. The presence of individual spiders through the recording period