Opinion:

Bull moose with broad antlers standing in a dense green forest in Norway.
Counting moose using drones could improve wildlife management. A pilot study shows how the technology could strengthen future moose and wildlife management, according to the author.

Moose hunting season is in full swing. Here's how hunters can make better decisions

OPINION: Drones equipped with thermal imaging cameras could provide more accurate estimates of moose populations and population density, the author writes.

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Martin Mayer Martin Mayer Researcher, University of Inland Norway
Published

Drones are increasingly used in wildlife management, because the view from above gives a much better overview of animals and their habitat.

In a recent pilot study, researchers from the University of Inland Norway tested whether drones can be used to count moose and monitor their population density to provide hunters and wildlife managers with more reliable numbers for decision‑making.

Drones may improve counting

When we think of drones, the first thing that comes to mind these days is often war zones and destruction. But drones can also be used for many other purposes, such as filming nature documentaries and monitoring wildlife. For wildlife managers and hunters, knowledge about population density, reproduction, and mortality is essential to make informed decisions.

Aerial view of dense coniferous forest in Finnskogen, with a bull moose and cow among the trees.
A moose bull and cow photographed during a drone flight in Finnskogen area, Inland Norway.

In practice, however, these numbers are often missing, because large animals like moose can be difficult to observe directly in the forest. Managers therefore use different indices to track how a population changes over time.

In moose management, common indicators include hunting statistics and browsing damage. These data come with considerable uncertainty and are usually demanding to collect. New technologies, such as drones, may help provide more concrete population counts.

Happy hunters, happy foresters

Researchers from the University of Inland Norway have recently published a new study in which they developed and tested the use of drones to count and monitor moose, with the aim of obtaining more precise population estimates.

This is important because moose are highly valued for hunting but can also cause damage to young forest stands, which requires balanced management to keep both hunters and foresters happy.

More accurate counts can help set hunting quotas, reduce browsing damage, and improve dialogue between hunters, landowners, and forest managers.

Works best under cloudy conditions

To test the method, the researchers first flew drones over moose that were wearing GPS collars from a previous project. This allowed them to determine the optimal conditions for finding moose and the probability of detecting a moose in the forest from a drone.

Map of drone flight paths in Finnskogen with a thermal forest image showing a detected moose.
Overview of the drone grid flights to record moose in Finnskogen and an example picture of a moose detected using a thermal infrared camera.

The drones were equipped with a thermal infrared camera, which detects heat signals and makes it easier to spot animals than with a normal camera. Detecting moose worked best under cloudy conditions, with around 80 per cent of GPS‑collared animals detected. In sunny weather, heated rocks and other surfaces made it harder to distinguish moose from other warm objects.

Importantly, a previous study showed that moose are not disturbed by drones as long as the drone flies higher than 70 metres. The flights for the present study were conducted at an altitude of 100 metres.

After establishing the most suitable flight conditions and obtaining an estimate of detection probability, the researchers carried out 33 grid transect flights in Finnskogen, Inland Norway, with the aim of covering as large an area as possible to estimate moose density in the area.

They detected 20 individual moose distributed across 9 of the grids.

Results are promising

After correcting for detection probability, this corresponded to a moose density of roughly 2.3 moose per square kilometre. The key message is that drone flights will miss some moose, and raw counts will therefore underestimate the true density in an area.

The degree of underestimation will depend on factors such as tree cover density, weather conditions, and time of year, and this needs to be considered when using drones to estimate moose densities.

In addition, drones may be used to detect calves and estimate calf-to-cow ratios and sex ratios. For example, in a previous study, the same researchers showed that drones can also be useful for detecting moose calves without disturbing the animals.

Composite image showing a moose and thermal detections in the Finnskogen forest.
A thermal image showing a cow moose with calf. The small image shows another cow moose with calf photographed with the zoom camera (500 mm) from an altitude of about 80 metres.

Even though this pilot study covered only a small area, mainly because the drone had to remain within sight and its battery capacity limited flight duration, the results are still promising.

They suggest that drones can be a time-saving, low‑disturbance, and safe tool for monitoring moose population density, especially at smaller scales such as local moose management units. Drones may therefore become an important future tool for monitoring and researching moose and other wildlife. 

Read also:
environment animal kingdom moose researchers zone opinion hunting technology
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