Despite an extensive search for the Western Black Rhino in 2006, experts failed to find any trace of rhino dung or footprints in its last known range state of Cameroon.
The IUCN had listed the Western Black Rhinoceros as "critically endangered" from 2000-2008 and officially declared the species extinct in 2011.
During their searches, researchers found evidence of widespread wildlife poaching. Local rhino monitors, paid to protect the animals from poachers, were caught faking rhino footprints.
"Given the wildlife poaching taking place, lack of political will and conservation effort by Cameroon conservation authorities in the past, and increasing illegal demand for rhino horn and associated increased commercial rhino poaching in other range states, it is highly probable that this subspecies is now extinct," says the IUCN.