Cameras reveal the secret lives of Chernobyl's wildlife
Automatic cameras in the Ukrainian side of the Chernobyl Exclusion Zone have provided an insight into the previously unseen secret lives of wildlife that have made the contaminated landscape their home.
Throughout 2015, the cameras will be positioned at 84 locations, allowing a team of scientists to record the type of animals passing through the area and where they make their home.
In the first four months since the cameras were deployed, the team has "trapped" more than 10,000 images of animals, suggesting the 30km zone, established shortly after the April 1986 disaster when a nuclear reactor exploded, ejecting radioactive material across the surrounding terrain and high into the atmosphere, is now home to a rich diversity of wildlife.
The network of cameras is gathering data that will help scientists choose the most appropriate species to fit with collars that will then record the level of radioactive exposure the animal receives as it travels across the zone.
"We want an animal that moves over areas of different contamination - that's the key thing we need," explained project leader Mike Wood from the University of Salford, UK.
"So we would consider some of the larger animals, such as wolves, because they would be ideal because the way the animal moves through the areas actually affects its contamination levels."
Commenting on the herds of Przewalski's horses, Dr Wood observed: "They seem to have adapted quite well to life within the zone.
"From the images from our cameras, they are clearly moving around in quite large groups," he told BBC News.
Dr Wood's team's project is part of a five-year research programme called Transfer, Exposure, Effects (Tree), which will aim to "reduce uncertainty in estimating the risk to humans and wildlife associated with exposure to radioactivity, and to reduce unnecessary conservatism in risk calculations".
Most of the fieldwork will be carried out within the Chernobyl Exclusion Zone (CEZ).
Late last year, one of Dr Wood's Ukranian colleagues - Sergey Gashchak - captured what was believed to be the first photographic evidence of brown bears within the CEZ.
But the tantalising glimpse of the bear is not enough to make it a candidate to fit with a collar.
Fitting collars to smaller animals, such as a fox, has disadvantages - such as limiting the size of the battery pack that can be fitted within the collar. Larger mammals are not without problems either.
"Once you start considering larger animals then it would be necessary to bring in a trained marksman," observed Dr Wood.
"There are difficulties with using firearms in Ukraine and will require additional permits to be put in place."
This means the team currently favours using bait to trap animals in cages, which will allow them to be fitted with the collars and for the individuals to be assessed by a vet before being released.
Illegal poaching is a problem within the CEZ, and one image captured by the cameras suggested that the elk in question had a narrow escape.
Dr Wood said that the team had to bear in mind the activity of poachers when they chose the most suitable species to wear the collars.
He explained that if the animal was killed then it would mean that the collected data would be limited or lost.
He added: "However, this is a concern that could be applied to any of the species because poachers going into the zone are unlikely to be overly selective."
"This image is a great example of how you could be going through an area and have a lynx just 20 or 30 yards away from you, yet you'd have no idea it was there," said Dr Wood.
"They can literally disappear into the background as they are so well camouflaged in this environment."
It also highlights why the camera traps, which will be capturing images until October 2015, are an important tool for the researchers.
They provide a more representative picture of what animals are found in an area, and whether they regularly visit particular locations.
Once the team has collected images from the 84 randomly selected locations across the exclusion zone, the next stage of the project - which is being undertaken by researchers from the University of Salford, the UK's Centre for Ecology and Hydrology, and the Chornobyl Centre - will be to fit tagging collars to the selected species.
This is expected to be carried out during 2016.