Glenn DelGuidice planned to study the moose population of Minnesota’s northern forests, and in January, outfitted 49 moose calves with GPS tracking devices. He told people that they would see quick results from the study, and they did — just not the way they had expected.
Days after the Minnesota Department of Natural Resources captured the moose calves and placed the GPS tracking collars on them, 22 of them have died. The majority of those calves were killed by wolves and black bears. Of course, this is expected. The calves, in the first few weeks of life, are highly vulnerable to predators.
DelGuidice, lead moose researcher, said in an interview with the News Tribune, “Especially in the last few days, bear and to some extent wolves have just been hammering the calves. We knew that we would lose a lot of calves quickly. But to see it happening in real time like this is all new for us.”
All over the world, studies have been conducted that have discovered just over half of all moose calves will likely die in their first year of life, whether from predators, disease, or other reasons. Black bears are just waking from hibernation, and with berries, insects and nuts in low supply at the beginning of the season, the moose calves make an easy target.
The weather this year — snow late in the season, a cool spring, and delayed forest growth — have made it easier for the bears to find the calves.
DelGuidice points out that these numbers are actually expected. Studying the surviving calves will paint a truer picture into the reason the area’s moose population is declining. “You could have 100 percent of the calves survive and that wouldn’t solve our problem,” he said. “Our problem (in Northeastern Minnesota) is that too many adults are dying; not enough are surviving to reproduce to sustain the population.”
Thanks to the GPS tracking collars, researchers are able to respond quickly when a calf ceases movement. They have successfully retrieved 15 out of the 22 dead calves to figure out their cause of death. The other nine were eaten by predators. Sometimes, all that could be located was “the collar and tracks.”
As to what happened to them, they can’t be sure. Some could have died from the collaring process, while others may have been diseased or had a low birth weight. It will not be known for certain until lab results are released. “We’re not sure yet what killed some of them. It could have been capture-related, or it could have been they just weren’t viable; they couldn’t nurse or were sick,” said DelGuidice.
An interesting thing researchers have learned: 58 percent of the cows gave birth to twins, while experts only expected 20 to 30 percent. “That just blew us away. This may have its roots back in the (mild) winter of 2012, that more cows went into the rut and into this past winter healthy and with higher body weights and could sustain twins,” DelGuidice said.Google+