Northern Rockies wolf numbers rise while livestock depredations falls

Ed Bangs has released the mid-year estimate of wolf numbers. The final estimate is made for Jan. 1, and, of course, it has to be lower because the pups are born each April or May..

The wolf population continues to grow, most strongly in per cent terms in Montana, although in absolute numbers in Idaho which has the largest base population of wolves. There are a number of newspaper stories about this now, and a major point of confusion is due to the fact that the 2006 figures Bangs cites below are year end and 2007 figures are mid-year. Therefore, a story in a newspaper on Sept. 22 that says the population growth rate is 19% is wrongly overstated growth because wolves will die between mid-2007 and the end of 2007. Comparisons of wolves killed and livestock killed are also hard to directly compare with 2006 because more will come.

I didn’t realize this either, thinking at first it was mid-2006 compared with mid-2007.

Below are the data and an analysis by Ed Bangs.

TENTATIVE 2007 MID-YEAR WOLF POPULATION STATISTICS- Each year we give a
rough mid-year wolf population estimate for wolves in the northern Rocky Mountains [NRM].
There are no known wolf packs in the NRM outside of Montana, Idaho, or Wyoming. Our
official interagency estimates in our 2007 annual report will certainly be different and much
more accurate than these because of better wolf monitoring conditions in fall/winter and
increased levels of wolf mortality and dispersal later in the year. These figures do give some
insight into the likely trend of the wolf population, conflicts, and control relative to last year.
Overall, the NRM wolf population in 2007 will be higher, wolf control about the same, and
confirmed livestock depredations lower than that documented in 2006.

 

State    Year    # Wolves         Packs   B pairs     Cattle killed  Sheep    Dogs     Other    Wolves

 

MT      2006    316                      60          21                        32                        4            4            2          53

MT      2007    394                      71          37                        48                        19          1            1          50

 

ID       2006    673                      69          40                        29                        205        4            0          45

ID       2007    788                      75          41                        36                        150        7            0          40

 

WY     2006    311                      40          25                        123                      38          0            1          44

WY     2007    362                      33          27                        28                        16          2            0          45

 

Total   2006    1300                    172        86                        184                      247        8            3            142

            2007    1545                    179        105                      111                      185        10          1            134