recommended by Shelly and Moseley (1988) that this species be 

 moved from Category 2 to Category 1 for several reasons: (1) the 

 species has been extirpated from a large portion of its 

 previously known global range, (2) it has a narrow ecological 

 amplitude, (3) it lacks detectable inter- and intrapopulation 

 genetic variation, and (4) habitat alteration continues in a 

 major portion of its extant range. 



III. UPDATE OF GEOGRAPHIC DISTRIBUTION 



Upon conclusion of the 1990 field season, H. aquatilis was 

 documented from a total of 76 extant populations worldwide: 1 in 

 Idaho, 59 in Montana, and 16 in Washington. All known Montana 

 populations are located in the Swan River drainage (Lake and 

 Missoula counties) . Within this drainage, a total of 428 

 wetlands have been surveyed; H. aquatilis has been found in 59 

 (13.8%) of them. The Montana populations constitute 77.6% of 

 those known globally for the species. Thirty-eight populations 

 (50% of those known globally) occur wholly or partially on 

 Flathead National Forest lands. The land ownership status of the 

 Montana populations is summarized in Table 1, p. 3. 



Two new populations were discovered in previously unsurveyed 

 ponds (occurrence numbers 058 (Salmon Prairie) , and 059 (Lost 

 Creek-Cilly Creek Ponds) ) . Six other previously unsurveyed ponds 

 were also examined, but did not contain H. aquatilis . Element 

 occurrence print-outs and location maps for the two new 

 populations are included in Section VII, pp. 21-25. The 

 locations of the ponds that were surveyed, but do not support H. 

 aquatilis . are indicated on maps in Section IX, pp. 53-55. 



Although H. aquatilis has not been found to occur outside of the 

 Swan Valley in Montana, on the recommendation of Maria Mantas 

 (Flathead National Forest) , ponds which look suitable in the Lake 

 Five area near West Glacier, Montana, should be surveyed in 1991. 



IV. MONITORING STUDIES 



Details regarding population size and condition for the two newly 

 discovered occurrences are summarized in Table 2, p. 4. 



During 1990, 26 previously documented populations were re- 

 surveyed, and estimates of population size and percent of each 

 pond occupied by H. aquatilis were made. Updated occurrence 

 records for these ponds are provided in Section VIII., pp. 26-52. 

 Quantitative monitoring studies of five populations (008, 009, 

 013, 020, and 027) were continued. The locations of the 

 resurveyed ponds and the long-term monitoring ponds are in an 

 earlier status review (Shelly 1988) . The methods for the 

 quantitative monitoring studies are described in a report by 

 Shelly (1989) . 



