Black panthers are in fact regular leopards (Panthera pardus) with an excessive expression of a dark pigment called melanin (in Leopards it is resesive inheritance pattern, whereas in Jaguars it is dominant). These melanistic black leopards still have the stereotypic spotted coat, but it is masked by the dark fur. This has made camera-trapping studies of the cats very difficult, as without the visible spots to identify unique individuals (like finger prints), a true idea of 'black panther' populations is near impossible.
Well, that was until Hedges et al. 2015 noticed using an infra-red flash with camera trapping (usually used for night-time photography) actually revealed the hidden spots, allowing for a team of scientists to identify and estimate the population of black panthers in Malaysia (~ 3.00/100 km2, SE 1.02).
This new technique and findings is vital for the Malaysian leopard population, that has been sadly understudied. The reason for little study is partly due to the fact that there is a large proportion of the Malaysian leopard population being melanistic. This research will open up new population and ecological studies in this population of cats.