3. Changes in Conservation Status

The inventories provided critical information for assigning and modifying existing conservation status ranks for dragonfly species. Preliminary conservation status ranks were updated in 2000 after the first year of the northern surveys. Subsequently, we focused inventory efforts on the species considered at risk in order to more accurately determine their status. During these surveys, known ranges of many species were extended, knowledge of habitat requirements increased, and one new species was confirmed for the province. Many of the targeted species were more abundant than previously thought, and their conservation ranks were changed accordingly. Others were found only rarely or not at all.

Criteria for conservation rank assessments for 1995 were number of element occurrences, population trend, threats and protection. The latest assessments, made in 2004 separated threats into severity, scope and immediacy; the trends were divided into long and short term and environmental specificity and intrinsic vulnerability were added. The criteria are only used when the relevant information is known. A summary of changes for all BC species as of 2004 is given in Table 1.

The original list of Odonata from northern BC contained ten species that were probable inhabitants but which had not yet been recorded in the region. We were successful in recording all but three of these probable species and added nine. Ranking poorly known species is challenging, particularly if samples are small or habitats are difficult to access. By increasing our knowledge of these species and their requirements, we can assign them more accurate ranks, thus ensuring that conservation efforts will target the species and habitats that truly require them.

Between 2000 and 2003 we changed the rank of 15 species (17% of BC species) -- 14 are now less at risk and one is considered more at risk (Table 1). Appendix 3 contains the definitions of symbols and the complete list of conservation ranks for these and all other BC species. For more about conservation ranking and species and habitats at risk, see the CDC website at http://srmwww.gov.bc.ca/cdc/.

Table 1: Changes in the conservation status of British Columbia Odonata: 1995 to 2004. Species with scientific names in bold are found in northern British Columbia.

Figure 16. Aeshna tuberculifera, a species whose conservation rank was lowered after
collecting in northern BC showed it to be uncommon rather than rare.
Photo: Robert A. Cannings.RBCM.

Figure 17. Amphiagrion abbreviatum, a species reported from the
North for the first time during the surveys.
Photo: Robert A. Cannings and M. Brent Cooke, RBCM.