4380 End of the Reign? - webapps8

Of the 116 radio-collared moose in the research study, 85 have died—49 from unknown causes. This radio-collared,
3-year-old bull moose had abnormal antler growth. It died of an undetermined cause.
| of 2006 had 12 heat-stress days, and the
u
o spring survival rate among radio-collared
" moose dropped to 87 percent.
Summer heat-stress days, when temperatures
climb above 67 F, also elevate
the metabolic rates of moose. In 2002
and 2003, there were 111 heat-stress days
from March to October. Moose survival in
subsequent winters was below 80 percent.
During the same period in 2006 there were
125 heat-stress days, and moose winter
survival dropped to nearly 70 percent.
Lenarz stresses that six years of research
on radio-collared moose "is at the low end
of having enough data for analysis." But he
notes that heat stress in domestic cattle,
ungulate cousins of moose, has been shown
to cause impaired immune systems. And
he suspects that moose weakened by hot
summers and warm winters may be more
susceptible to parasites and diseases that
might not normally kill healthy moose.
Taking Action. Tom Rusch, DNR area wildlife
manager in Tower, has likewise noticed
hotter weather and fewer moose. And he
thinks habitat can help moose out.
"I think there's a general downward slope
in the moose population at the western
end of their primary range [in northeastern
Minnesota], but where they're hanging on in
the southwestern extent of that range, there
are large conifer bogs that provide summer
thermal cover," Rusch says. "I think we need
to have a better sense of forest history, of
the environment in which moose evolved.
We need to try to mimic the natural forest
composition that was created by fires,windstorms,
and other forest disturbances."
To that end, Rusch has dedicated some of
his wildlife management budget to helping
fund prescribed burns by the U.S. Forest
Service in the Boundary Waters Canoe Area.
Like Ingebrigtsen in Grand Marais, Rusch is
also favoring conifers in land management—
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