Boyd Alexander was an African traveller and ornithologist. After his education at Radley College, Berkshire, during 1887-1891, he joined the army in 1893. He published his first papers, "On a new British petrel", and "Notes on birds in Kent", in the The Zoologist in 1896. During 1897 he visited the Cape Verde Islands twice to study their birds and wrote "An ornithological expedition to the Cape Verde Islands" (The Ibis, 1898). In 1898 he undertook an expedition up the Zambezi River from its mouth at Chinde, in Mozambique, to its tributary the Kafue, collecting some 914 bird skins representing 250 species. Several of the species were new, while many more were observed for the first time in southern Africa. He described his collection in the Bulletin of the British Ornithologists' Club (1899), and in an extensive paper entitled "An ornithological expedition to the Zambesi River", published in The Ibis (1899, Vol. 5, pp. 459-583; 1900, Vol. 6, pp. 70-109, 424-458). His field notes made the paper a valuable contribution to southern African ornithology. At the same time (1899) he donated a publication, "Descriptions of new South African birds", presumably an extract of one of the above, to the South African Museum.
Alexander continued his bird studies in various parts of Africa, visiting Ghana in 1899 and the island Fernando Po (Now Bioko, Equatorial Guinea) in 1902, where he also made ethnological observations, studied Spanish missionary work, and compiled a map. His detailed description of the island was published in The Ibis in 1903. In 1904 he undertook an expedition from the Niger River to the Nile delta with the object of showing that Africa could be crossed from west to east by means of waterways. He spent some months exploring Lake Chad and made valuable surveys of its periodically changing level. Traveling eastwards, surveying and studying the zoology of the region, he reached the Nile in December 1906. His book From the Niger to the Nile was published in two volumes in London in 1907. As a result of this journey he received a gold medal from the Geographical Society of Antwerp in 1907, and in 1908 the founder's medal of the Royal Geographical Society. Towards the end of 1908 he returned to Lake Chad but two years later was murdered by members of the local population in what is now eastern Chad. An account of this journey was published in Boyd Alexander's last journey, with a memoir by Herbert Alexander (London, 1912, 296p).