METHODS

Field surveys were undertaken through the primary adult activity season from mid-June through at least August in order to cover all species' flight periods. We visited the widest possible array of habitats to identify and note adult dragonflies, emphasizing those habitats that were likely to support rare species. Sites were chosen on the basis of historical records and remaining aquatic ecosystems. The timing of visits to particular sites was determined by the known flight times of the species being searched for there. As specified in the Resource Inventory Committee's standardized arthropod sampling methodology, each site was visited for at least five hours (or for a shorter time if population estimates could be done more quickly) during fine weather during the period of the study to attempt to ensure that no species was missed.

Often, specimens were netted for close examination and voucher specimens were collected (Fig. 8) if we believed that their collection would not harm the viability of the population. These were deposited in the RBCM. Larval specimens or the cast skins of larvae were also used as indicators of a species' use of a particular site and were collected as needed. Both adult and larval specimens were prepared, labelled, identified and accessioned into the RBCM collections.

Details of numbers of dragonflies, their behaviour and ecology, as well as precise UTM grid coordinates were recorded on CDC field forms and cross-referenced to dragonfly specimens. The data were entered into an RBCM database. The physical and floristic characteristics of the wetland habitats were also described using CDC forms. Dominant plant species were recorded, and any rare plants (those taxa tracked by the CDC) found were documented by CDC field observation forms and voucher specimens deposited at the RBCM.

Distribution maps of each species have been produced using ArcView GIS. The distribution of larvae and breeding adults will be analysed to determine critical habitats. The English names of dragonflies used in this report are those adopted by the Dragonfly Society of the Americas (Paulson and Dunkle 1996, Catling et al. 2005). These names are not used in the body of the report but are listed in Appendix 1.

Figure 8. Andrew Harcombe drying dragonfly specimens in the sun north of Fort St. James.
Specimens are placed in envelopes and submersed in acetone for 24 hours to preserve colours.
The envelopes and specimens are later dried.
Photo: Robert A. Cannings.