Moose research

Research

Management


Adult moose mortality project

Complexities abound

GPS locations of Moose 192 for several days before her death.
GPS locations of Moose 192 for several days before her death.

Minnesota moose are some tough critters but research is showing that complex factors are combining to make their survival more and more precarious.

Just how tough are moose? And how complex can the situation become for the largest member of the deer family? Consider Moose 192, a 12-year old cow that DNR researchers collared in 2015 and died in April along a Superior National Forest road not too far west of Finland.

Twelve years is a relatively old age for a moose yet she was healthy enough to become fertile, be bred and carry a healthy male fetus to term.

View moose study deaths

That's an accomplishment for a healthy moose but Moose 192 did this while suffering from three serious health problems:

Despite these conditions, the cow settled down in late April to give birth. While calving, which made her extremely vulnerable, wolves attacked and inflicted massive injuries to her head and rump.

Moose 192 fought off her attackers though and, with her bull calf still in the birth canal, wandered about 1,000 yards north and laid down in a watery ditch along the roadside, tucking her front legs underneath. She likely drew her last breaths when under water as she and her unborn calf died.

The mortality study will consider Moose 192's official cause of death to be wolf kill. But facts gathered from the GPS collar and results of the necropsy show that this moose endured serious health conditions. Calving – not sickness – made her vulnerable to a wolf attack. But it's likely that health conditions eventually would have killed her.

Closeup of a puncture wound from a wolf bite in Moose 192's jaw.
Closeup of a puncture wound from a wolf bite in Moose 192's jaw.
Moose 192, a 12-year-old pregnant cow, fought off wolves while giving birth. After the attack she walked about 1,000 feet before laying down and dying in a watery ditch.
Moose 192, a 12-year-old pregnant cow, fought off wolves while giving birth. After the attack she walked about 1,000 feet before laying down and dying in a watery ditch.

Moose study deaths

Date Animal Cause
May 11, 2016 Moose 192, a 12-year-old cow collared in 2015 Wolf kill
April 28, 2016 Moose 21, a nine-year-old bull collared in 2013 Winter ticks
January 7, 2016 Moose 205, a six-year-old bull collared in 2015 Liver flukes

Anecdotal moose deaths
Click rows for details

Date Animal Cause
June 15, 2016 Adult female Vehicle

Cow had two twin newborn male calves when struck and killed by vehicle. Mother appeared healthy. Necropsy findings pending.

June 9, 2016 Adult female Vehicle

Cow struck and killed by vehicle. Moose appeared healthy. Necropsy findings pending.

June 7, 2016 Adult male Vehicle

Necropsy results revealed a mild liver fluke infection an mild encephalitis is the brain without an identifiable cause.

April 20, 2016 Adult female Vehicle

Cow pregnant with two twin males when struck and killed by vehicle. With the exception of a moderate liver fluke infection, no other significant health issues noted.

March 19, 2016 Adult male Sickness

A citizen reported a dead bull moose in northwestern Minnesota. The emaciated animal weighed only 490 pounds and suffered significant hair loss from a winter tick infestation. Necropsy results revealed liver fluke hepatitis and brainworm.

February 5, 2016 Male calf Brainworm

Loggers reported that a nine-month-old male moose calf was walking in circles, standing in open areas and unafraid of people. The team euthanized the animal and test results confirmed a brainworm infection.

Survial rate

The annual adult moose survival rate for 2016, the fourth year of the study, is 95 percent so far. Annual survival rates in previous years were:

The chart below provides an overview of all moose deaths in the study to date. Clicking an individual chart will display that chart's complete detail.

Causes of adult moose mortalities

February 2013 - June 2016 (n=49)

Arrow pointing down and to the left, representing information flow Pie chart showing overview and number of all moose deaths recorded since the study began in 2013. Arrow pointing down and to the right, representing information flow
Pie chart showing overview and number of all moose deaths from infection recorded since the study began in 2013. Pie chart showing overview and number of all moose deaths from parasites recorded since the study began in 2013. Pie chart showing overview and number of all moose deaths from wolves recorded since the study began in 2013.