Research updates

Quarter 2 Update: Apr. 1 – Jun. 30, 2025

Birth, black bear predation, first vehicle-collision mortality

Second mortality of collared moose

Researchers received a mortality alert from a collared calf on April 12. The body was recovered in a stream on April 13 but was too decomposed for a full necropsy. Signs of hemorrhaging on the neck and scavenging were present and suggested wolf bite marks that indicated predation.

Researchers used GPS data to compare the calf’s movements with that of nearby collared wolves. They found that one adult female wolf was at the same location as the calf at the time of death. The data clearly showed a chase event, confirming this as the first verified wolf predation among the collared moose in the study.

Wolf predation on calves is expected and has been documented in other states like Minnesota. This project will help determine how frequently such events occur in Michigan and under what conditions. Although the carcass was decomposed, researchers collected the femur bone for testing. The moisture content in the bone marrow can indicate whether the animal was in poor health before death, as drier marrow suggests malnourishment.

Researchers are also collecting information on local wolf pack sizes to better understand predator-prey dynamics. Out of the 20 collared moose in this study, this is the first confirmed wolf predation.

Calving season

^{A cow moose nurses a calf.} 

Spring also brought new life to the study. Serum samples collected during winter capture provided evidence that 8 of the 10 adult female moose were pregnant. All eight pregnant collared cows had given birth by June 19^th (birth dates from 10^th May to 19^th June). Four had single calves, and three gave birth to twins.

Births were confirmed using GPS data and heat-sensing drones. By watching each moose’s daily step distance, researchers could detect when the cows were likely going into labor. Shortly after her movement patterns dramatically slowed, heat-sensing drones were used to observe her and the calves.

The drones were flown >300 feet above ground level and use 200x zoom to get clear visuals without disturbing the cow or calves. This non-invasive technology is a big step forward in studying calf survival during the first six months of life, which historically has been difficult to study because it required field crews to approach the animal, which can potentially lead to the cow abandoning the calf.

Researchers noticed that one cow showed unusually high amounts of movements shortly after giving birth and learned through the drone footage that her calf had been killed by a black bear. Based on the puncture wounds and the way it was consumed; researchers confirmed the calf died from black bear predation.

The remaining nine calves were observed shortly after birth with their mothers. All cows gave birth in lowland conifer habitats.

It is exciting and encouraging to see twins born in Michigan and is certainly a good sign for the condition of the cow. With the use of thermal drones to observe calves shortly after birth we are learning more than ever before about twinning rates in Michigan.

Third Moose Mortality – Vehicle Collision

On June 17, the third collared moose mortality was confirmed. The female moose was struck and killed by a vehicle, confirming the first collared moose vehicle collision in this study. This moose had been the first of the study animals to give birth to twins this year on May 10.

The collision occurred around midnight but was not reported to local authorities. Although the moose was retrieved by 10 a.m., warm overnight temperatures (over 70°F) rendered the carcass unrecoverable for consumption or donation. A necropsy and tooth sample for age analysis were completed and submitted to the lab. The animal appeared to be in good health prior to the collision and both calves were confirmed alive days prior to the collision.

Given the twin calves’ young age and dependence on their mother, it is presumed both have since died, although neither has been located.

Moose-vehicle collisions are most common June and September, and this marks the third collision in 2025. Of those, this is the first involving a collared moose. For comparison, Michigan recorded 11 collisions in 2021, 20 in 2022, 16 in 2023, and 24 in 2024.

As of the end of Quarter 2:

• Collared adult males — 5 of 5 alive.
• Collared adult females — 9 of 10 are alive.
• Collared calves (yearlings) — 3 of 5 alive.
• Newborn calves — 8 of 11 alive.

Quarter 1 Update: Jan.1 – Mar. 31, 2025

Project launch: Moose capture and collaring

In late February, researchers successfully captured and GPS-collared 20 moose in Michigan’s western Upper Peninsula. This effort is part of a multi-year study to better understand moose health, calf survival, movement patterns and causes of mortality. 

After two days of safety training, planning logistics, and waiting for the winter weather to clear, the team took to their stations and the collaring effort began.  

The capture effort was led by a team from the Michigan Department of Natural Resources, Keweenaw Bay Indian Community and Northern Michigan University. Using survey planes, helicopters and ground crews, the team safely captured, collared and released 20 moose in just 13 hours. 

Ten females (cows), five males (bulls) and five calves were fitted with GPS collars that transmit location updates to researchers every hour. These collars provide a near real-time look at moose movement and survival.

During the collaring operation, researchers also collected blood, hair, parasite and fecal samples. These samples will help determine pregnancy status, identify diseases and provide other biological insights that will inform Michigan’s moose population model.

The GPS data will shed light on emigration and immigration patterns—where moose travel to and from. Researchers can also track daily step counts and activity levels, which may indicate key behaviors, such as calving. The collars send a mortality alert if a moose stops moving for a specified time, allowing teams to quickly investigate possible deaths.

Since then, the moose have transmitted more than 50,000 GPS locations, giving researchers a detailed look at their post-capture movements and well-being.

^{Moose movements mapped using GPS tracking data.}

Hair loss and winter tick monitoring

In March, researchers used thermal-sensing drones to capture aerial images of the collared moose and assess signs of winter tick infestation. Some moose had lost 25% to 30% of their coats due to intense grooming triggered by itching.

Despite their efforts, moose cannot easily remove attached ticks. Because moose are active and large, they’re easy targets for clusters of ticks. And unlike deer and elk, moose haven’t evolved strong grooming responses. According to Cornell University, moose can be infested with 100,000 ticks in a single season.

Unlike other ticks, winter ticks spend their entire life cycle on a single host. In the fall, larvae climb vegetation and wait for an animal—typically a moose—to pass by. According to Cornell University, a single moose can carry up to 100,000 ticks in one season.

While winter ticks do not carry disease, the blood loss, skin irritation and hair loss can be fatal, especially during cold winters. Calves are particularly vulnerable because they lack the insulating benefits of a full coat.

Winter ticks may be one of several potential factors impacting health and survival of Michigan’s moose herd – and these are the kinds of challenges this project is designed to investigate.

^{Drone image of a moose with hair loss.}

First mortality in collared moose

A collared calf moose died of unknown head trauma three weeks after being collared. A necropsy revealed the female calf had small puncture wounds in the neck and chest and cranial trauma. The moose had not been near any roads, and there were no signs of a predator attack. The cause of trauma remains undetermined.

The carcass of the calf was left in the field and a trail camera was installed to document scavenger activity. Photos showed that several scavengers visited the carcass over the following days, including common raven, fisher, and rough-legged hawk. No wolves have been photographed scavenging from the carcass.

As of the end of Quarter 1:

• Collared adult males — 5 of 5 alive.
• Collared adult females — 5 of 5 are alive.
• Collared calves — 9 of 10 alive.