Recently, Jane Goodall reiterated her experience of seeking to name her chimpanzee subjects, at the start of her PhD writing-up:

“…the professors at Cambridge University who told me, in 1962, that the chimpanzees I was studying should be numbered not named…” (2023, p. xiii)

More than 60 years later, the situation has changed. So far as I know, not a single field project on wild chimpanzees uses numbers to identify known individuals. Similarly, studies of captive chimpanzees in laboratories, zoos, sanctuaries, etc. do the same. The scientific tradition of naming Pan troglodytes goes back at least to the pioneering work of Wolfgang Köhler (1929) on Tenerife. Moreover, I suspect that all field primatologists name their subjects of study, from dwarf lemurs to gorillas. In my 40+ years of primatology, I met only one case of numbering: At Cayo Santiago, Puerto Rico, in 1971, all the rhesus monkeys on the islet had three-digit numbers tattooed on their chests and inner thighs.

The naming systems used in chimpology vary, with no obvious rhyme or reason. They range from no apparent system at all to specific, multi-variate ones. The variables involved relate to various criteria, such as extent of habituation or lack of it, population size, level of specificity, etc. So far as I know, no one has attempted to compare and analyse these systems in terms of their utility. I know of no field study of chimpanzees that describes their naming system in sufficient detail to evaluate this aspect. The aim of this brief paper is to raise awareness of this absence, in hopes that someone else will tackle it properly, with a comprehensive, scientific analysis. Here, I will mention only a few cases, mainly to give example of pertinent issues.

Consider two of the oldest sites of ongoing study: Gombe and Mahale. Despite yielding many published articles and books, neither has offered a sufficient description of their method of naming, much less its rationale.

The names of Gombe chimpanzees are given in Goodall (1986), in a partial list of names and their abbreviations (no page number) and another list of 26 matrilines (pp. 62–63). The first list is alphabetical and provides two-letter codes for 85 names but no more. The names vary greatly; all but one are Western names, usually English language ones (e.g. Huxley, Melissa). The table with the second list provides entries for the matrilines, with offspring given in chronological order of birth. Eleven of the matrilines employ a simple system, with all names beginning with the same letter of the alphabet. (Readers of Gombe publications will know of the ‘F family’, ‘G family’, etc.) Four others link the names by other connections: classic Greco-Roman names (Athena, Atlas), alcoholic drinks (Vodka, Sherry), sweet taste (Caramel, Candy), and focus on the word ‘bee’ (Madame Bee, Bee Hinde). However, the other 11 matrilines show no obvious system of naming.

For Mahale, an appendix lists almost 300 names, and it is apparently comprehensive (Nakamura et al, 2015, Appendix VI). It lists the name, its two-letter code, sex, and unit-group. The origins of the names vary: About 60% are Tanzanian (Dar), Kiswahili (Tatu) or Kitongwe (Wabunengwa), about 30% are Western (Darwin) and about 10% are Japanese (Asahi). In the early days of naming K-group members, all females had names beginning with ‘W’ and males with ‘K’. Now, in M-group naming, all offspring’s names start with the same letter as the mother. Also, Kiswahili is now used in names, and these have few syllables (usually three). In the chapter on gerontology, Table 23.1 (pp. 328–329) lists the 22 female chimpanzees that lived to the age of 40 years, while Table 23.2 (p. 330) lists the same for 5 males. However, there is no list of matrilines.

For Bossou, Matsuzawa et al. (2011) provide Appendix A (pp. 404–405). Given names are short, mostly one or two syllables (the modal length of name is only 4 letters). None of the names is Western or Japanese. Each has a two-letter code, in which males are given as two upper-case letters, and females as one upper-case and one lower-case. Thus, the code incorporates sex. There are 7 matrilines, each headed by a female whose name begins with a different letter. In all cases, offspring bear the same first letter of their names as their mother.

For Budongo, Reynolds (2005) provides an appendix of the Sonso Community. Table A.1 lists 93 names alphabetically, mostly in 22 matrilines. Unlinked males are given on their own. All individuals have two-letter codes. About a third of names are Kiswahili (Jambo), or otherwise African (Kikinku); the rest are mostly Western, especially English language. Some chimpanzees are named after Budongo researchers (Vernon, Nick). The table provides much information about each individual: sex, date named, date of birth, and notes, e.g. father, permanent injuries, death or disappearance. Fifteen of the matrilines have offspring whose first name starts with the same first letter as the mother (Flora, Fred), but seven do not. Several matrilines have the same beginning letter; there are four M-families.

For Taï Forest, Boesch and Boesch-Achermann (2000) provide an appendix (Table A-1, pp. 277–281) for the community. There are 41 matrilines and 89 named offspring. In 24 of these, all members of the matriline start with the same first letter of their name, while 15 matrilines do not. With this many matrilines, some share the same first letter of their names; there are 4 M-families. Also, there are 15 individuals with no known offspring. None of the 145 named individuals has an African name, and the range of Western names is eclectic: researcher (Kummer), movie star (Brando), composer (Mozart), fictional character (Tarzan), cartoon character (Popeye), etc. Sex is indicated in the two-letter code: Females have two upper-case letters, while males have an upper-case first letter and a lower-case second letter.

Of course, naming systems may evolve over time, especially at long-term field sites. Goodall started with ad hoc naming, but it later became systematic, such as extending to 3-letter codes (Anthony Collins, personal communication). At Ngogo, individuals of both sexes were initially given surnames of jazz musicians (Coltrane, Fitzgerald). This evolved into opera singers or characters (Sutherland, Salome); then came ‘females of repute’ (Bronte, Curie). (It was proposed to extend naming to actresses, but this was not done.) Other individuals were named ad hoc, after researchers (Toshi, Kano), friends or donors (John Mitani, personal communication). Obviously, naming can be enjoyable, especially if a collective decision is required. (To be transparent, I named only one chimpanzee in my 40 years of chimpology: At Gombe, Miff’s son was born on or about the calendrical date of Michaelmas, which became his name.)

So, what can be derived from this brief survey of researchers naming wild chimpanzees? The sample of only 6 sites is biased toward long-term studies, and the range of data consulted varies in length and over time. Seven tentative conclusions can be drawn:

There is wide-spread variation in the form and extent of naming practices.

None of the sources give detailed descriptions of the rationales for their methods of naming.

The only factor present across (almost) all sites is a two-letter code for each name, but it varies in its use.

Matrilines are sometimes presented, but all have unnecessary complicating variation, which hampers their easy utility. Ideally, the first letter of a code should take you to a unique matriline, but only up to N=26 for the English language, although some letters are more challenging than others, such as ‘X’.

The sources for the names employed also vary from absence of African names to them being the majority.

The demographic information supplied by naming varies, but most give sex and matrilineal kinship.

Finally, combining and incorporating useful features of the various naming systems in use may assist researchers, students, and assistants, thus yielding better and more useful practices, especially for those new to primatology. As a simple example, why not give females names that end in consonants and males names that end in vowels. Therefore, sex is incorporated into the name itself, but this system would not work in Kiswahili or Japanese, as so few names end in vowels. Naming is not a simple process!

Many thanks to Anthony Collins, Kazuhiko Hosaka, Agumi Inaba, John Mitani, and Michio Nakamura for essential assistance.

Boesch C, Boesch-Achermann H 2000. The Chimpanzees of the Taï Forest: Behavioural Ecology and Evolution. Oxford University Press, Oxford.

Goodall J 1986. The Chimpanzees of Gombe: Patterns of Behavior. Harvard University Press, Cambridge MA.

Goodall J 2023. Foreword. In: Walking with Gorillas: The Journey of an African Wildlife Vet. Kalema-Zikusoka G (ed). Arcade Publishing, New York.

Köhler W 1929. The Mentality of Apes. 2nd ed. Kegan Paul, Trench, Truber, London.

Matsuzawa T, Humle T, Sugiyama Y (eds) 2011. The Chimpanzees of Bossou and Nimba. Springer, Tokyo.

Nakamura M, Hosaka K, Itoh N, Zamma K (eds) 2015. Mahale Chimpanzees: 50 Years of Research. Cambridge University Press, Cambridge.

Reynolds V 2005. The Chimpanzees of the Budongo Forest: Ecology, Behaviour, and Conservation. Oxford University Press, Oxford.