When they die, in a wilderness version of the television show “CSI,” a signal alerts crews who rush in and recover the carcass to determine its cause of death. The crews include staff from the DNR, the U.S. Forest Service, and the Fond du Lac and Grand Portage bands of Ojibwe.
In springtime, when the GPS signals alerted the crews that the females were bedding down to give birth, specially trained crews that do the same work in western states and Alaska carefully moved in to collar 50 newborn calves.
Despite taking all the precautions they could think of, one frustrating and unexpected result of the calf collaring is that 11 died, said DelGiudice.
Nine of them were abandoned by their mothers. One died when a mother stepped on it during the attempt to collar it and one died for unknown reasons.
The timidity of the mothers surprised the wildlife experts who have done such collaring elsewhere, DelGiudice said.
In Alaska, the helicopters had to hover directly above the handlers on the ground to keep the mothers at bay. In one case, the pilot had to nudge a mother moose away with the helicopter strut.
“Here the mothers were skittish and would bolt for distances,” DelGiudice said.
In addition to those 11 deaths, four calves slipped their collars, leaving a total of 34 for the researchers to follow. By the end of the summer, 24 of them had died. Four were eaten by bears and another 16 most likely were killed by wolves, though researchers aren’t positive about four of those. One drowned, two were abandoned by their mothers well after being collared and one died for unknown reasons.
If the 10 that are left survive the winter, their chances are good, DelGiudice said.
Easy prey for wolves
Wolves also took about half of the 19 adults — eight were direct kills and two died from infections that developed from wounds, Carstensen said. Three apparently healthy moose died for unknown reasons.
That raises tantalizing questions about the predator deaths. Moose that are sickened or weak are easy prey for wolves, which then eat the evidence of what caused the decline in the first place, she said.
That may be what happened to one moose whose demise, by sheer chance, was witnessed by Amanda McGraw and others in a group of graduate students who were doing moose habitat research near Isabella, Minn., during the first week of September.
They saw an adult moose near the edge of a pond, and moved in to get a closer look and take photos. They crawled through the long grass on their bellies, and only as they got close did they realize that the moose was sick and injured.
It ignored them, and then stumbled into the water, where it couldn’t get up.
They called in the moose wildlife crew and left to finish their work. When the crew arrive two hours later, the moose already had been eaten by wolves that most likely were lurking in a nearby patch of poplars waiting for its collapse.
She realized only later, McGraw said, that while crawling through the grass she might have come nose to nose with a wolf.