Abandoned moose calves healthy at Minnesota Zoo
Apple Valley, Minn. — Six moose calves that were abandoned by their mothers after Minnesota DNR researchers placed GPS collars on them are doing well at the Minnesota Zoo.
Tony Fisher, animal collections manager at the zoo, said the calves could be going out for exhibit soon, perhaps this week.
While the abandonments were discouraging for the DNR’s research project – tasked with figuring out why the herd in northeast Minnesota is in decline – they came at a time when the Minnesota Zoo was down to only one adult moose in its collection, after two died in the past year.
“We were happy to get them,” Fisher said of the arrivals, which came in mid-May.
Of the six calves, four are female and two are male, he said. These are not the first calves to come to the zoo after having been orphaned, Fisher said. Of the 38 moose that have come to the zoo in the past 30 years, 12 have come as orphans from Minnesota, Canada, and Alaska, he said.
Fisher said the zoo plans to send one of the female calves to the Milwaukee Zoo soon.
“They need a moose, and we really can’t hold all six,” said Fisher, who added that while the calves likely will be exhibited together, they won’t share space with the adult cow anytime soon.
“She is just too big,” Fisher said.
The calves have been kept in groups of two and while they may be able to share exhibit space at the zoo’s Northern Trail during the day, as they grow into yearlings, they will need their own stalls at night, Fisher said.
DNR researchers had talked to the state-operated zoo ahead of time about the possibility of sending abandoned calves after several were abandoned last year during the first year of a multi-pronged moose study using GPS collars, said Glenn DelGiudice, the Minnesota DNR’s lead moose researcher.
To avoid abandonments from happening this year, researchers decided not to use helicopters in their approach since the adult moose appeared to scatter the second they heard or saw the aircraft. Researchers also cut down the number of team members on each operation from three or four people to two, DelGiudice said, noting that not all of the abandonments could be attributed to the capture and collaring effort.
But this spring, cows continued to abandon calves, even though in several cases the cows would return, only to leave again.
Seven calves were abandoned before DelGiudice decided to suspend that part of the project to consider another approach.
“We took a week to think about it,” DelGiudice said. “I thought, ‘maybe we need to stop the captures.’”
Of those seven calves, six were shipped to the zoo. The seventh ended up dying after researchers continued to monitor it, hopeful its mother would or had returned, since it was close, according to the GPS signals.
DelGiudice then resumed the study trying one last trick, in hopes of finding something that wouldn’t lead to the abandonments. The two-person team would go in and collar each calf within 60 seconds, foregoing the previous process of nearly five minutes that allowed researchers to weigh the moose and take a body temperature, among collecting other information.
“As researchers, we want to get as much information as practical,” he said. “But the collars are the most important thing. They allow us to get survival rates, natural causes of mortality, hourly locations, and proximity to their moms.”
It appears the new approach worked, DelGiudice said.
“The real positive thing is we found the approach where we can collar these animals quickly and stop abandonment,” he said.
Only one other set of calf twins were abandoned, and DelGiudice said it might be because it was a late birth. So he said the team would not collar late-birthed calves again.
“We wouldn’t learn nearly as much as we can from having the collars on them,” DelGiudice said. “Whenever you handle wild animals, there’s always a risk to some individuals. And when you start field studies like this, it’s not just about posing hypotheses and predictions and testing those, but you also have to figure out what methods and techniques will work well and safely at different locations and times.”