Alaska Board of Game and Department of Fish and Game think
predator control is needed in the McGrath and Game Management
Unit 13 areas to boost allegedly low and/or decreasing moose
populations and harvests. There are major scientific, ethical
and other shortcomings with these objectives and associated
"remedies," at several levels. However, the allegations
themselves don't hold up.
McGrath, the state's moose-census ("count") area
almost certainly includes only small portions of the annual
ranges of the relevant populations. This means that the year-to-year
estimates of moose numbers and trends are at least as likely
to reflect temporary changes in distribution as anything about
actual population changes. There is heavy reliance on calf
to cow ratios even though without good census information
these ratios can falsely indicate that high, increasing populations
are low and decreasing, and vice-versa.
doubling of the state's moose estimates for McGrath from 2000
to 2001 (and even a tripling in the core "EMMA"
management area) is enough to demonstrate that they are unreliable,
because no realistic combination of birth and death variables
could produce such steep increases in only 12 months. Even
if these estimates were reliable, they would indicate that
the McGrath moose numbers are already at or above the objective
the board has set for this control program.
the same is true for annual harvests. Biologists and hunters
understand that the reported McGrath moose harvests are only
an unknown portion of the total annual harvests. When the
reported harvests are corrected with reasonable guesses as
to the unreported legal and illegal takes, the totals at least
closely approach the board's published harvest objective.
Moreover, for most of the last 10 years the percentage of
successful hunters of the total who reported success or failure
has remained relatively stable at 30 percent to 40 percent,
which is about the same as in GMU 20A, south of Fairbanks,
the state's best moose hunting area.
is census information for only a 1,500-square-mile portion
of 23,000-square-mile GMU 13. While this shows a 1994 to 2001
moose decline, it still leaves a relatively high level of
abundance -- probably too high for the state's own moose-harvest
objectives (moose populations typically generate their highest
sustainable yields 30 percent to 40 percent below their largest
do these census results say anything scientific about what
moose populations elsewhere in GMU 13 may or may not be doing,
especially given the likelihood that there are many, independently
changing populations and subpopulations across this large,
biologically diverse area. If they did, they would argue against
predator control, because the latest estimate -- one moose
per square mile -- extrapolated to the full 23,000 square
miles would indicate a total well above the board's unit-wide
objective of 17,600 to 21,900 moose.
the remaining 94 percent of GMU 13, the state is relying on
"trend counts" as well as calf ratios, a combination
that state and other biologists debunked decades ago as an
especially error-prone way to evaluate moose numbers and trends.
Indeed, it was this very approach in 1979 that misled the
state into recommending another aerial wolf control program
near McGrath, in the Nowitna area, because -- the state and
McGrath residents insisted -- moose numbers had declined from
2,000 to 1,000. But when state biologists finally undertook
a bona fide census, they found there were actually 3,500 to
5,000 moose in the Nowitna!
reported annual GMU 13 moose harvests have declined steeply
since the mid-1990s. But so too have the numbers of hunters
going afield each year, such that hunter success rates have
remained about the same. By now these rates almost certainly
would be declining sharply if the alleged unit-wide moose
decline was real.
The current predator control programs would never survive
quality scientific review. They are based on little more than
hobby "science," beginning with the claims that
there is even a problem.
Haber, Ph.D., is an independent, career wildlife scientist
who has studied wolves and prey in Alaska since 1966. His
research is supported by Friends of Animals.