Juergen Freund / Wildlife carer Margit Cianelli with juvenile Lumholtz kangaroo (Dendrolagus lumholtzi) with radio collar. The tree kangaroo has a radio collar to allow her to explore her forest surroundings ready for...

Juergen Freund / Margit Cianelli wildlife carer with young Lumholtz kangaroos (Dendrolagus lumholtzi), one with a radio collar. The tree kangaroo has a radio collar to allow her to explore her forest surroundings read...

Nick Garbutt / Pack of wolves (Canis lupus). Yellowstone National Park, Wyoming, USA. January.

Laurent Geslin / Young male European lynx (Lynx lynx) running after release in Jura Mountaiins, Geneva canton, Switzerland, May 2013.

Laurent Geslin / Vet and KORA team putting a radio collar on wild European lynx (Lynx lynx) for translocation to Kalkalpen National Park, Austria from Switzerland. May 2011.

Laurent Geslin / Conservationists releasing radio collared wild European lynx (Lynx lynx) from Switzerland into Kalkalpen National Park, Austria, March 2013.

Laurent Geslin / European lynx (Lynx lynx) emerging from crate during translocation from Switerland to Kalkalpen National Park, Austria. May 2011

Hugh Pearson / Leopard (Panthera pardus) resting, Erindi Game Reserve, Namibia.

Doug Gimesy / Two researchers examining an anaesthetised platypus (Ornithorhynchus anatinus) and starting to glue a temporary radio transponder to its tail, allowing researchers to track its movements. Snowy River...

Doug Gimesy / Scientist surgically implanting Platypus (Ornithorhynchus anatinus) with radio transponder. Dartmouth, Victoria, Australia. May 2018. Model released.

Nick Upton / Lucy Bearman-Brown inspecting a Hedgehog (Erinaceus europaeus) with a transmitter attached she has found by radiotracking after dark, Hartpury University, Gloucestershire, UK, June 2019. Model release...

Nick Upton / Lucy Bearman-Brown radiotracking a Hedgehog (Erinaceus europaeus) with a transmitter attached, after dark, Hartpury University, Gloucestershire, UK, June 2019. Model released.