CHAPTER 4: KNVIRONMKNTAl. CONSEQUENCES 



interact, it is difficult to identify the impact associated with incremental differences in wolf numbers 

 statewide. 



Livestock Losses. Livestock losses were predicted using historical data for the Montana portion of the In- 

 state area from 1986-2001 (WS and USFWS unpubl.). As the wolf population in Montana increased 

 during those 15 years, the number of confirmed livestock losses generally increased as well, although 

 losses varied from year to year. FWP expects that general trend to continue as wolf numbers and 

 distribution increase. 



To predict confirmed wolf-caused livestock losses, FWP tallied the number of cattle and sheep killed for 

 every wolf in the population each year between 1986 and 2001 and then calculated a depredation rate for 

 each year (number confirmed livestock kills divided by total number of wolves). The annual rates were 

 averaged over all years to account for the variation year to year. Predicted loss in 2015 is the rate 

 multiplied by the predicted number of wolves under each alternative. Because each alternative calls for 

 different management philosophies and specific tools to resolve wolf-livestock conflicts, the loss rate was 

 adjusted to account for implementation of those tools, as described below. 



FWP recognizes that wolves have also been the suspected cause of some livestock losses in the past 

 because WS could not confirm a wolf as being responsible. FWP expects this will occur in the future. 

 Therefore, FWP examined the report forms completed by WS personnel upon investigation of a wolf 

 complaint for the calendar years 1999-2001 to discern whether wolves could have possibly been involved. 

 Cattle and sheep losses that were not attributed to some other obvious cause, such as disease, lightening, 

 or accidental death were tallied as "probable" wolf-caused losses. I^P then calculated the rate of 

 probable cattle and sheep losses. The probable loss rate multiplied by the predicted number of wolves 

 under each alternative equals the total probable losses in 2015. 



FWP also acknowledges that wolves have killed or injured other domestic animals such as guarding dogs, 

 llamas, or horses. While these losses have been intermittent and are more difficult to predict ba.sed on 

 wolf numbers, nonetheless, they do represent economic losses to the owner. To account for these other 

 domestic animal losses, the Defenders of Wildlife compensation records were examined. Historically, 

 payments for other domestic animals were about 8% of the total payments for confirmed and probable 

 cattle and sheep losses. The economic losses for other domestic animals are estimated for each 

 alternative by taking 8% of the predicted economic losses for cattle and sheep. 



FWP is also aware that livestock producers may experience losses for which little or no physical evidence 

 is ever found. These are referred to as undocumented losses, and they tend to be associated with remote 

 public land grazing allotments rather than private property. This EIS does not account for undocumented 

 losses because reliable data for Montana were not available. 



Under Alternative 1 , confirmed and probable livestock losses were estimated using historical data. 

 Management protocols essentially call for a reactive approach to livestock depredation, except for a few 

 specific circumstances. 



Under Alternatives 2 (Updated Council) and 3 (Additional Wolf), implcmcnlation of liberal management 

 tools is assumed to reduce the historic livestock depredation rate by 507^ and in direct proportion to the 

 50% reduction in the growth rate of the wolf population. Nearly all depredations in Montana to date were 

 on private lands. The management protocols of these allemalives should reduce the number of wolf- 

 Hvestock confiicts in general, but most specifically on private lands. 



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