» 



Fish and Wildlife Service has not issued a 

 decision on this recommendation. 



2. STATE STATUS: In Montana, the rank of H. 



aquatilis has been changed to S2 (6-20 sites in 

 the state) . 



B. UPDATE OP GEOGRAPHICAL DISTRIBUTION (MONTANA): Prior 

 to 1988, 348 wetland sites in the Swan Valley (Lake and 

 Missoula counties) had been surveyed for the presence 

 of if. aquatilis ; the species was found in 52 of them 

 (Shelly 1988). Field surveys were continued in 1988. 

 An additional 67 sites were surveyed, and three new 

 populations were found. Thus, ti. aquatilis is now 

 known from 55 populations, out of a total of 415 

 wetland sites that have been surveyed. These 55 

 populations are clustered in nine areas within the Swan 

 Valley. 



Element occurrence print-outs for the three new 

 locations are provided in Section V, pp. 9-11. The 

 locations of the 67 sites surveyed in 1988, and the 

 three new populations, are indicated on the maps in 

 Section V, pp. 12-15. 



C. POPULATION DEMOGRAPHY AND MONITORING STUDIES: Details 

 regarding population size and condition for the three 

 newly discovered occurrences are summarized in Table 1. 



During 1988, monitoring studies were initiated for five 

 populations (occurrence numbers 008, 009, 013, 020, and 

 027) . The locations of these occurrences are shown in 

 the previous status review (Shelly 1988, pp. 96 and 

 98). The goals of these studies are 1.) to assess the 

 suitability of the line-transect method for monitoring 

 H. aquatilis . and 2.) to begin collection of 

 information to assess the ecological relationships, and 

 responses to adjacent land use, of the species. 



METHODS: At each of the five ponds studied, a line- 

 transect was established, using steel posts for the 

 endpoints. The transects varied in length from 42.9 to 

 50.0 m. Within each pond, they were subjectively 

 placed through portions of the habitat that appeared to 

 be most representative of each occurrence. Measure- 

 ments of the length of canopy coverage bisected by the 

 tape, for H. aquatilis and the major associated 

 species, were recorded to the nearest centimeter. The 

 accumulated length occupied by a species out of the 

 total meter tape length used for the sample is 

 expressed as the percent cover for that species 

 (Mueller-Dombois and Ellenberg 1974) . In addition, 

 photographic slides of each pond were taken (Section 

 VI, p. 16), and measurements of pond depth were made at 



