There are numerous enhancement techniques (physical and chemical) which have been developed for the successful visualisation of latent fingermarks. Nonetheless, problems arise when latent fingermarks require enhancement on difficult surfaces such as human skin, food stuffs, fabric and animals. The ability to develop latent fingermarks on the surface of bird of prey feathers and that of their eggs was investigated. Red and green magnetic fluorescent powders proved to be most suitable on the surface of bird of prey feathers whereas black magnetic powder was the most suitable technique on the eggs. These powders produced the highest quality of visible ridge-detailed developments over a controlled period of time.
McMorris, H., Farrugia, K. J., & Gentles, D. (2015). An investigation into the detection of latent marks on the feathers and eggs of birds of prey. Science & Justice, 55(2), 90-96. https://doi.org/10.1016/j.scijus.2014.12.004