Thermal imaging cameras help count seal pups from the air

Image source, Terra Drone

Image caption, This photo shows the thermal image on the left and a normal aerial picture on the right. The heat detection camera makes it much easier to spot the seals in the water

The number of seals at the Farne Islands, a large nature reserve off the Northumberland coast, is being monitored using thermal imaging cameras for the first time.

Each year the number of pups born is recorded and the size of the colony monitored.

It is usually done using a special drone to capture aerial photographs. This lets researchers count lots of the mammals in a short amount of time.

Now thermal images will be used as well, which will help to identify the creatures from the air more easily.

Image source, Terra Drone

Image caption, A specially permitted drone is used by researchers. It is the fourth year drones have been used to count the grey seal population

A big job

Once the first pup is born the researchers begin their annual count.

This year the National Trust, which looks after the Farne Islands, is working with scientists from Newcastle University, Oxford University, the Sea Mammal Research Unit (SMRU) and drone company TerraDrone to count the seals.

The drones and thermal imaging make it much easier for them to spot the pups in more remote areas, like the smaller islands, which are hard to reach when the weather is bad.

Image source, Terra Drone

Image caption, The grey seals blend into the rocks making them harder to spot. The pups are the smaller animals with white fur

Numbers are up

The number of grey seals has gone up in recent years which is thought to be because of a lack of predators and disturbances to the colony.

In 2019 there was a record high of 2,823 pups - an increase of 62 percent over the last five years.

The teams weren't able to do the count in 2020 because of the coronavirus pandemic but it is hoped the upward trend has continued.

With a larger population to count this new technological approach is even more useful.

Ranger Thomas Hendry commented: "We are using a drone again this year which as well as filming the pups is fitted with thermal imaging technology to help make the count more accurate and less stressful for the seals.

"Having the extra thermal imaging technology is particularly useful now that the islands are supporting more and more pups and the population is denser."