With the support of the Geographical Society of Hamburg he visited the Maasai country in 1882 and penetrated from the mouth of the Pangani River to Lake Naivasha. The Maasai prevented him from advancing further. Equipped with funds by the brother of Wilhelm Junker, an explorer, who with Emin Pasha and Gaetano Casati had been lost in the equatorial provinces, he organized a relief expedition which, however, was compelled to return after reaching Lake Victoria. Shortly after his return to Germany in 1886 he died of a bilious fever contracted during his journey.
He is commemorated in the names of a number of animals, including Fischer's lovebird, Agapornis fischeri Fischer's starling (Lamprotornis fischeri) and also a number of plants, including Gutenbergia rueppellii var. fischeri and Ligularia fischeri (Fischers ragwort).
- Mehr Licht im dunkeln Weltteil (1885)
- Das Masai-Land (1885)
- This article incorporates text from a publication now in the public domain: Gilman, D. C.; Peck, H. T.; Colby, F. M., eds. (1905). . New International Encyclopedia (1st ed.). New York: Dodd, Mead.