Mary Elizabeth Bowker was the eldest daughter of Miles Bowker and his wife Anna M. Mitford. At the age of two years she came to the Cape Colony with her parents and six brothers in a party of British settlers, while two more brothers followed in 1822. The family settled on the farm Tharfield in Lower Albany, overlooking the mouth of the Great Fish River. Here Mary received an elementary education at a farm school set up by her father and developed an interest in natural history and later in archaeology. Her mentor during the early years was her eldest brother, John M. Bowker, with whom she explored the local geology and fossils. Her interests were also shared by other members of the family, in particular by her younger brother James Henry Bowker*. Their names were commemorated in the names of the non-marine molluscs Gulella bowkeri, Prestonella bowkeri and Helix bowkeri. Two of her older brothers, Thomas Holden* and Octavius*, later became early collectors of archaeological artifacts. Mary married Frederick W. Barber in 1845 and some time after the seventh Frontier War of 1846-1847 they settled on the farm Highlands, near Grahamstown. Fred shared some of her interests and while staying near Graaf Reinett in 1847 the two collected some Karoo fossils in the area.
Mary's interest in botany was inspired by reading The genera of South African plants..., published in Cape Town by W.H. Harvey* in 1838. It included a description of the structure of plants, instructions for collecting and drying specimens, and an appeal for specimens to be sent to him. Collecting, painting and studying the plants of her district became an important aspect of Mary's life, and helped to ease the stress and hardship associated with having her house burnt down twice during the frontier wars. She started a scientific correspondence with Harvey, who had settled in Dublin, Ireland, in 1842, and over the years sent him her observations and about 1000 specimens. Harvey later acknowledged her scientific assistance in the preface to Volume 1 of the Flora Capensis (1860) by listing her as one of his South African correspondents and thanking her and her brother, James Henry Bowker*, "for several very interesting parcels of the rarer plants of the Winterberg and of the country extending thence eastward beyond the Kei". He also named the genus Barberetta (family Haemadoraceae) and the asclepiad species Brachystelma barberiae in her honour. Her water colour painting of the latter species was published in Curtis's Botanical Magazine in November 1866. In a lecture to the Albany Natural History Society by P. MacOwan* in October the next year, when describing a species of mistletoe, he said: "It is one of the numerous discoveries due to Mrs F.W. Barber [her husband's initials] of Highlands, whose name is as completely associated with South African botany as that of Zeyher* or Drege*".
Mary had a keen inquiring mind, an artist's eye for detail, and the ability to describe clearly what she had observed. Her interests included the economic aspects of her observations of plants and insects, such as the destructive effects of insects on crops and the use of certain plants as cattle feed. She was clearly a farmer's wife, rather than merely an inquisitive Victorian lady. Furthermore she passed on her enthusiasm for natural history to others, including her two sons Frederick* and Henry Barber*. Her first paper in an overseas journal "On fascination", published in the popular British journal Scientific Opinion in 1869, dealt with the hypnotic effect that snakes appear to have on their prey. This was followed by "The aloe, its habits and culture" in the Journal of the Royal Horticultural Society the next year.
She was particularly interested in the genus Stapelia and did her best to produce a complete series of illustrations of its species. She is credited with discovering two of these, Stapelia glabricaulis and Stapelia jucunda, both described and named by N.E. Brown*. Her notes on the genus were published after her death under the title "Stapelias" in Kew Bulletin in 1903. Meanwhile she also corresponded with the Colonial Botanist, John C. Brown*, and in September 1865 sent him a packet of seeds to be forwarded on to J. Hooker*, the director of Kew Gardens. In December that year, when Harvey was ill and the post of Colonial Botanist about to be abolished, she wrote to Hooker herself. This started a correspondence with Kew that was to continue on and off for some 30 years, during which she provided the institution with numerous plant specimens. Largely as a result of Hooker's contacts she got a number of scientific papers published in England. He passed on some of her papers to Charles Darwin*, who's book on Fertilisation of orchids (1862) triggered her interest in the fertilisation of plants. Her observations on this topic formed the basis of two papers in the Journal of the Linnean Society (Botany), one "On the structure and fertilization of Liparis bowkeri" (1870), the other "On the fertilization and dissemination of Duvernoia adhatodioides" (1871). These appear to have been the first contributions by a resident South African botanical observer to an overseas journal.
During the 1860s she became interested particularly in insectivorous plants. Her paper on the topic was read before the Albany Natural History Society in Grahamstown on 24 June 1869 and before the Linnean Society by Joseph Hooker in December 1870. Only an abstract was published, in the Gardeners' Chronicle (1871).
Mary also painted the butterflies and moths of Albany, often on the flowers that they frequented. The small book on South African butterflies published in 1862 by Roland Trimen*, Rhopalocera Africae Australis, had stimulated her interest. She started corresponding with Trimen in May 1863, sending him specimens and her observations on a fruit eating moth that had caused considerable destruction in the Grahamstown area. Her observations convinced Trimen that moths were capable of penetrating tough fruit membranes and he passed on her notes on this matter to Charles Darwin. She donated butterflies to the South African Museum in 1869 and was mentioned as one of the museum's regular contributers the next year. Trimen visited the Barbers at Highlands in 1870 and collected in the area with Mary and her sons. He named some new species after her and her brother James Henry, including the smallest known butterfly, the dwarf blue, Brephidium barberae. Some of her paintings of butterflies, with their larvae, pupae, and food plants, were later used as illustrations by F.L. Billinghurst* in a lecture on the butterflies of Grahamstown in February 1885. Trimen also acknowledged her contributions in the form of drawings, notes and specimens of butterflies from the Eastern Cape in the preface to his book South African butterflies... (1887-1889). Her "Notes on the peculiar habits and changes which take place in the larvae of Papilio Nireus", dealing with the colour changes she had observed in the larvae and pupae of this butterfly, was sent to Darwin and passed on by him to be published as "communicated by Charles Darwin" in the Transactions of the Entomological Society in December 1874. Darwin had meanwhile enlisted her help in his research on the expression of the emotions in man and animals and she was very flattered to receive a copy of the resulting book from him when it was published in 1872.
In 1870 Fred Barber and other members of Mary's family, including her two sons, went prospecting for diamonds in the Kimberley area. She joined them during the next year. While there she studied the fertilisation of a species of Salvia and sent her description to Hooker. It was read before the Linnean Society in March 1872, but not published. Among the notable persons that she met on the diamond fields were the geologist Edward J. Dunn*, the explorer Frederick C. Selous*, and Cecil John Rhodes. Her interest was aroused by the stone artefacts found on the diggings and she collected a number of these and sent them to the South African Museum. In an article, "In the claims", published in the Cape Monthly Magazine (1872, Vol. 4, pp. 39-45), she gave a brief description of stone points, ostrich eggshell beads and pottery found at Colesberg Kopje and other sites. Though this was her only archaeological publication, she deserves note as the first woman to publish on southern African prehistory, and as one of the first persons in South Africa to recognise the prehistoric significance of stone tools. Early in 1876 she explored some of the old river diggings and found a variety of stone artefacts in the river gravels. She recognized early on that these differed from, and were much older than, the stone implements used by the more recent Bushmen. Two further articles by her in the Cape Monthly Magazine described life on the diamond fields: "Night at Du Toit's Pan" (1871, Vol. 3, pp. 331-333), and "The dark races of the diamond fields" (1873, Vol. 7, pp. 378-381). She published "The Kommetje Veldt of Kaffraria" (1874, Vol. 9, pp. 125-127) in the same journal.
When the South African Philosophical Society was founded in Cape Town in 1877 Mary promised Trimen that she would write a paper for it. She wrote "On the peculiar colours of animals in relation to habits of life", which was read at the meetings of 29 May and 26 June 1878 and published in the society's Transactions (Vol. 1, pp. 87-106). It was written in response to an article by Alfred R. Wallace in which he questioned Darwin's views on sexual selection. Mary was a devoted follower of Darwin and discussed numerous examples among insects, birds and mammals of fancy appearances in males for the sole purpose of being selected by females. Trimen invited her to become a member of the society - a singular honour for a woman at the time - and she was elected a corresponding member in June 1878. Soon she submitted a second paper, "Locusts and locust birds", which was published in the same volume of the Transactions (pp. 193-218) and dealt with the migratory locust swarms and the birds that prey upon them. A few years later this paper was read also before the Grahamstown Natural History Society. Meanwhile she had made a study of local birds, corresponding with E.L. Layard* of the South African Museum and sending him specimens. He acknowledged her help in his Birds of South Africa (1867) and other publications. Some of her paintings of birds had come to the attention of the Austrian ornithologist August von Pelzeln*. As a result she was elected a corresponding member of the Ornithologischer Verein in Vienna - probably the first female member of this august society.
Her husband Fred went on a visit to England in 1879 and from then on Mary led a rather unsettled existence, staying with her brother James Henry in Durban during the winters and following her sons around the country as they farmed or went prospecting for gold. In 1886 they joined the rush to the Witwatersrand, but Mary first visited Grahamstown and produced a paper on "Insectivorous birds in their relation to fruit and vegetable crops" which was read before the Eastern Province Literary and Scientific Society in July. It contained a strong plea for the preservation of insectivorous birds, which provided a natural control of the insects that damaged the colony's fruit crops. The paper was well received and published in pamphlet form as "A plea for insectivorous birds".
On the Witwatersrand she started collecting plants again and resumed her correspondence with J. Hooker. Among the many members of her family in Johannesburg were her daughter Highlie and son-in-law, Alexander C. Bailie*. In April 1889 she and her sons went to England and returned with her husband in October. Mary and Fred settled in Grahamstown, where Fred died in 1892. Mary moved to Natal and stayed with her brother in Durban and with her daughter in Pietermaritzburg. In 1898 her son Frederick was instrumental in having a collection of her poems, The Erythrina tree and other verses, published in England. The introduction contained a fine tribute by Trimen: "... wherever her lot for the time was cast, Mrs Barber has always been distinguished by her equanimity, cheerful self-reliance, fine sense of humour and cool courage, but more than all for her steady perseverance in the pursuit of natural history researches". She died at the home of her daughter the next year, at the age of 81. Before her death she had presented her herbarium, collection of butterflies, papers and illustrations to the Albany Museum; the pictures depict plants (30), butterflies (19), birds (12), moths (3) and reptiles (2), while 15 more plant illustrations are in the library at Kew. Her journal, Wanderings in South Africa by sea and land was published in the Quarterly Bulletin of the South African Library in 1962-1963. An ironic but significant tribute to her achievements is her inclusion in the biographical works Men of the times (1905, 1906).