IES uses GPS devices for wildlife tracking

Institute for Environmental Solutions (IES) in cooperation with SIA “Forest Owners’ Consulting Centre” and Latvian State Forest Research Institute "Silava" develops new wild animal census approach using innovative technological solutions – drones, movement-activated camera traps and passive acoustic sensor networks. To provide reference data for technological solutions used in this research, as well as accurate deer migration and habitat evaluation, researchers also carry out tracking of four deer using GPS transmitters.

Red deer, roe deer, elk and wild boar are four dominant even-toed ungulates species in Latvia.  These animals have important role in our ecosystem, but they can also cause damage to the agricultural and forestry sectors. Furthermore, on average 750.000 vehicle collisions in Europe are reported with ungulates involvement, thus, indicating a problem related to the safety on roads. IES researchers in cooperation with partners will develop innovative ICT-based (data-driven) wild animal (ungulate) census methodology to support decision making on sustainable wildlife management and conflict resolution among landowners, hunters and society.

IES leading researcher Dr. Dainis Jakovels showcased the latest conclusions and described further steps of the research.


IES: In previous research season you continued collection of wild animal census data by using various technologies. Which technologies did you use, and what are the first conclusions?

Dr. Dainis Jakovels (D.J.): In the last research period (April – June 2020) we stopped using the unmanned aerial vehicles (drones). Spring and summer is a time when role of drones in animal census decrease, because animals are hiding under the tree crowns. During this period animals in drone data can be seen only when they cross the open areas. Therefore, we focus on processing of beforehand gathered data and automation of this process.

Data from the camera traps are gathered throughout the whole year. We are still trying out different types of camera trap solutions, but the most challenging part is the automatization of data processing. It is very important to collect enough data for development of computer vision algorithm – deep neural network. This algorithm will be able to automatically sort the images captured with camera traps and identify animals. For the training of algorithm, we need a large amount of data – more data means more precise results. In autumn 2020, we are planning to expand movement-activated camera trap network in the research area.

We are also working on identification of objects’ location by using passive acoustic sensor networks. At the moment, we are still testing the accuracy by using easily identifiable human made noises. If we know the source of the sound, we can easily assess, whether the acoustic sensors detected it and if it is possible to locate the object that made it. For now, we are using human made noises, because ungulates are silent animals, they are noisy only during mating season – autumn.


IES: This research includes red deer tracking with GPS transmitters. Why is it necessary?

D.J.: With red deer tracking we understand GPS collars that are put around the necks of the animals. These collars determines the GPS coordinates of each of the subject once every 30 minutes. We receive this information remotely. GPS tracking of animals are mainly a reference method for data validation of all the other technologies that we use in this research. One great example is camera trap case, where we have captured an image of red deer male Fabiāns equipped with GPS collar. If GPS transmitters gives us data about the migration paths, we can estimate how many times these animals have been close to the camera traps, how many times we have captured them and how many times camera trap sensors have not been activated.

Another important by-product from the GPS transmitters is determination of migration paths in the research area. This information allows us successfully plan the placement of camera trap and passive acoustic sensor networks to capture as many animals as possible.

In this research, we have also planned to start the red deer habitat modelling. By analysing gathered GPS data on the red deer movement, we get the migration profile of these animals. And if we add to this data, for example, ground coverage usage mapping or analysis of the tree types of the area, we can start to understand where and for how long these animals choose to stay. Of course, data about 4 deer migration habits is not enough, but it gives an insight for further research in cooperation with experts in other countries.

IES: To what kind of conclusions have you already come from the GPS data of 4 deer?

D.J.: Only 3 months have passed since deer have been equipped with GPS transmitters, thus, the amount of gathered data is still not enough to make scientific conclusions. Most valuable information that we have received is that all 4 of the red deer are healthy and are moving to and from the feeding sites. We expect the data to be much more interesting in the annual cut.

We already have had the first camera trap data validation – we captured the first image with one of the GPS collars equipped red deer. I am sure that we could find more than one similar cases, but camera trap data is gathered on site once every 3 months. After gathering data, we will compare them with the migration data of 4 red deer during the same time period. It will allow us to assess how many times we have captured animals that have been close to the camera traps.


IES: Why from all the researched animals you choose to equip (with GPS collars) only red deer?

D.J.: Many factors influenced our decision, for example, the migration area. Roe deer are not so interesting for this kind of data because they mostly stay at the same area. Red deer on the other hand cover several dozens of kilometres every day. Another important factor was different density of animal species. In Latvia red deer is spread almost 3 times more than elks. Moreover, also size of the animal was important – we just did not dear to approach large animals, such as elks.

GPS tracking of wild boar is interesting for IES as well as to Food and Veterinary Service. But in this research, we did not do it, because the process of equipping wild boars with GPS transmitter collars is much more complex.

Considering all the above-mentioned factors, we decided that red deer will be the most suitable option. Also, it was important to choose 4 animals from the same species not 4 individuals from different species. This approach gives us repeatability in data gathering, processing and analysing process.

IES: How the red deer equipping process with GPS transmitter collars was maintined?

D.J.: Beforehand we needed to get all the necessary permissions from the Food and Veterinary Service, as well as the State Forest Service. We needed to prove to these organizations that we will perform this activity according to the requirements. This activity was done in cooperation with the Institute of Food Safety, Animal Health and Environment “BIOR”.

Veterinarian who received an authorisation to perform this activity spent around 3 weeks in the ambuscade located next to animal feeding site until he caught suitable individuals to equip with the GPS transmitter collars.

These animals were put to sleep and then veterinarian placed the collar around animals’ neck. Collars were put on the necks with an estimation so that they are not tight. In the data we can see that all 4 animals woke up after they were put to sleep and returned to their daily activities. When we purchased these GPS transmitter collars we choose reliable Swedish company with great reviews from research institutions all over the world.

IES: How did you choose which red deer individuals to equip with the GPS transmitter collars?

D.J.: This process was random – which animals came to the feeding site those were chosen for this research. Veterinarian caught 3 red deer hinds and 1 male fawn. We also gave them names, hinds – Oļģertīne, Elmīra, Fiona and fawn – Fabiāns . For this research it was more suitable to have hinds. One reason is the size of the collars – the diameter would not be suitable for large individuals. Another reason was the migration area – red deer stags tend to wander longer distances, but in this research, we need the collared individuals to stay in our research area where animal census data gathering technologies are located. Migration area also play an important role in animal monitoring. In case of necessity we can determine their location and do the observation with drones.

IES: Did you experience any challenges during red deer equipping process with GPS transmitter collars? If so, how did you tackle them?

D.J.: Yes, we had few challenges. Spring is the time when red deer hinds are pregnant, and veterinarian had to choose individuals that are not carrying their babies. It was important not to create unnecessary stress to these animals. Timing we chose for red deer equipping with GPS transmitter collars was wrong because spring is a time when animals do not visit feeders so often. Therefore, veterinarian spent longer time in the ambuscade than we expected, until he caught suitable individuals.

After the process of equipping animals with GPS transmitter collars we haven’t had any challenges, but we have safety protocols designed. We are planning to periodically monitor these animals to assess the situation.

If we see that there is a problem with the collar, we have a remote drop-off option. With one text message the collar automatically opens and frees the animal.

It is planned that these collars will collect data of red deer migration habits around one whole year.

IES: Is this animal tacking method previously used in Latvia and the world? What future possibilities this method provides?

D.J.: Animal tracking with GPS transmitter collars in not a common practice in Latvia. When we went through the permission authorisation process, we found out that there is no information about similar cases.

We are the first ones in Latvia to use GPS transmitter collars for research of wild even-toed ungulate species.

This approach is commonly used in Scandinavia. The Institute for Environmental Solutions have had close collaborations with Inland Norway University of Applied Sciences (INN) where similar approaches were used in other research areas. INN  has a great experience in wild elk research by applying GPS transmitter collar method. That is a great approach to understand wild animal migration patterns, habitat preferences and behaviour models. In our research, on the one hand GPS transmitter data gives us reference data for other technological methods. On the other hand, it provides valuable and scientifically based information that describes wild animal behaviour and preferences. Animal tracking with GPS transmitter collars is costly and complex process that will provide us with data about 4 deer navigation information. This will allow IES to start cooperation with organizations that does similar researches in other fields and countries.

In the next research period, we will continue camera trap data collection and validation with the reference from 4 red deer tracking information. We will also continue the work on development of automatic solutions for data processing and testing of different passive acoustic sensors. In autumn 2020, we are going to expand movement-activated camera trap network in the research area.

The research is a part of the project “ICT-based wild animal census approach for sustainable wildlife management” (No. is part of European Regional Development Fund, 1.1.1 "Improve research and innovation capacity and the ability of Latvian research institutions to attract external funding, by investing in human capital and infrastructure" measure “Support for applied research”.

Find more about this project here.