West Mojave Plan FEIR/S - Desert Managers Group

Distribution of Symptomatic Tortoises: Four of the 12 (33%) tortoises with diseasesymptoms were found in the Superior-Cronese DWMA (Map 3-13). One was southeast ofCuddeback Lake, two were found in the Mud Hills area, and one was found in the northeastcorner of Coolgardie Mesa. All four were within several miles of recent die-off regions. Threeof the four were inside or within one mile of higher density tortoise areas.Ord-Rodman DWMA: Although three newer die-off subregions are described in thissection as being in the Ord-Rodman DWMA, only Region OR1 (5 mi 2 ) was actually foundwithin the DWMA (Map 3-13). Region OR2 (7 mi 2 ) was found north of Interstate 40 and east ofTroy Dry Lake, and OR3 (15mi 2 ) was found in the western part of the Johnson Valley OpenArea. Pertinent data are summarized in Table 3-23.Table 3-23Characteristics of Older and Newer Die-Off Regions in the Ord-Rodman DWMAREGION NO. &NAMEAGE OFDIE-OFFNO. MI 2 NO.CARCASSESRANGE AVERAGE(Carc/mi 2 )OR1. Newer 5 9 1 to 3 1.8OR2. Newer 7 4 1 0.6OR3. Newer 18 15 1 to 2 0.8TOTALS 30 28 1 to 3 1.1Observations: The three newer die-off subregions were between 5 mi 2 and 18mi 2 ,encompassing a total of 30 mi 2 . Only 28 newer carcasses were found, with about half of these(i.e., 15 of 28, or 54%) located in the Johnson Valley Open Area. Region OR1 is the mostsignificant, as it may indicate that ill tortoises have passed through the “corridor” from north tosouth (see “corridor” on Map 3-13). If this 5 mi 2 die-off area represents a contact zone forURTD or some other disease spread, it may have the potential to threaten tortoise populations onthe north-facing bajada between Dagget Ridge/Newberry Mountain and Interstate 40, where 19mi 2 of higher sign counts were found between 1998 and 2002.BLM Study Plots: There are three permanent study plots within and adjacent to the Ord-Rodman DMWA; the Stoddard Valley plot in the northwestern part of the DWMA and LucerneValley plot to the south; the Johnson Valley plot is found in the open area, to the east of theDWMA. Both the Stoddard Valley and Lucerne Valley plots are within higher density tortoiseareas. Interestingly, there was only a 5% decline on the Stoddard Valley plot (i.e., from 86 to 81tortoises/mi 2 between 1981 and 1991) and a 30% decline on the Lucerne Valley plot (i.e., 93 to65 tortoises/mi 2 between 1980 and 1994). For comparison, there was a 77% decline (i.e., 69 to16 tortoises/mi2 between 1980 and 1994), which is not associated with a higher concentrationarea. These findings further support Dr. Berry’s findings that tortoise trends on the individualthree square miles appear to represent tortoise trends for the three regions where the plots werelocated.Distribution of Symptomatic Tortoises: Four of the 12 (33%) tortoises with diseasesymptoms were found within or adjacent to the Ord-Rodman DWMA (Map 3-13). Two of thesewere within the DWMA, including one of the three observed with suspected evidence ofcutaneous dyskeratosis. One URTD-symptomatic tortoise was observed in the eastern portionsChapter 3 3-118