THANATOBASE

Derived from the name of the Greek god of death, Thanatos, thanatology is the study of reactions to death and dying, and its effect on the surviving individuals. Comparative thanatology aims to understand whether and how animals’ responses to and understanding of death differ from humans’ responses. Little empirical research has addressed how animals respond to death. This is remarkable because understanding animals’ responses to death can address fundamental questions about the evolution of cognition and emotion. For example, understanding how and why animals respond in the ways that they do to the deaths of others can shed light on the questions: Do animals understand the difference between life and death? And, can animals grieve?

To contribute, all that is needed is a non-human primate record of one or more responses to the death of another individual. Detailed observations about the deceased individual and respondent(s) would be wonderful, but even partial information will be useful. (See What if my record is incomplete? below.)

The long-term aim of this project is to build a 'living database'—one that grows as more records are added—that draws on the wealth of observations made by field researchers when conducting their research. In addition to building a 'living database of death,' contributors will be co-authors on a publication that describes this project after the initial call for contributions, following the examples of the PREDICTS and Ecological traits of the world's primates databases. After this point, the database will be published on Zenodo with a DOI, with all contributors listed as co-authors on the database. Thus, after the initial publication describing ThanatoBase, contributors will receive a citation any time the database is used through its DOI. (See also How will the data be used? and What is the timeline? below.)

Sharing these observations does not preclude researchers from publishing their own detailed case reports. Indeed, I hope that this project will provide motivation for researchers to collate and publish their own thanatological case reports where more detailed information can be provided than what can be entered into such a database. (We recently did this for our study site.)

Any accurate data will be useful to this project. This is because different analyses can include different types of data. For example, if the exact carrying duration of an infant's corpse is unknown, the presence/absence of infant corpse carrying can still be analysed. As long as the data are accurate, it can still be of use. This is particularly true for the less-well-studied primates.

In the first instance, the database will be described in a publication, with all contributors listed as coauthors. (See What do I get from contributing? above.) This publication will not test hypotheses, but will outline: the format of the data; the state of the current database, including the numbers of species covered; and the way these data could be used in the future.

At the time of this descriptive publication, ThanatoBase will also be published on Zenodo. It is important to be clear that data entered into ThanatoBase will be publicly available after the original publication describing the database. In the spirit of open science, anyone will be able to use these data however they would like once the database is published, which will generate a citation for the contributors.

It is my aim that contributions will be added to ThanatoBase in perpetuity. I will continue to curate contributions to and update ThanatoBase, with each new version having its own DOI. The list of authors will increase as contributions to the database increase.

The contributors' names and affiliations will also be accessible in the database as these will be important should anyone have a question about the observation, but contact details will be removed.

1. CONTRIBUTE: ThanatoBase will be open for contributions for 18 months (closing December 2021).

2. ANALYSE: After the first 18 months, a manuscript describing the database will be drafted and the draft circulated amongst the contributors for comment before publication.

3. ACCESS: On publication of the descriptive paper, ThanatoBase will move to a fully open-access living database, where all researchers can contribute to, search through and download entries from the database.

Together with a MSc student, Elisa Fernández Fueyo, I am in the process of collating published records of mothers' responses to infants. A similar project will collate others' responses to non-infant and heterospecifics' corpses in the future. We are trying to be as comprehensive as possible, but if you would like your data to be included, you can check whether we have it already in this list, and send me the relevant reference if it’s not listed (contact details below).

However, if you have further information to add to your published record, please get in touch to complete your record. The variables we are collating are listed on the data entry webpage.

More data currently exist for responses to death in non-human primates than in any other taxon. Although there are compelling case reports for both elephants’ and cetaceans’ responses to their dead, these cases are rare in comparison to the case reports for primates. Although this is probably due in part to a publication bias, primates’ responses to death, particularly to the deaths of infants, can be more prolonged and more elaborate than responses in other taxa. For example, primate mothers frequently carry their infants’ corpses, and groom and care for them, sometimes for weeks. This means that there is more variation and more power to test hypotheses. For these reasons, and primates’ shared evolutionary history with humans, this project will focus on responses to death in non-human primates. However, if you would like advice on creating a similar project for non-primate animals’ responses to death, please feel free to get in touch.

For reviews of the topic, see:

• Anderson, J.R. (2016). Comparative thanatology. Curr. Biol. 26, R553–R556.
• Anderson, J.R., Biro, D., and Pettitt, P. (2018). Evolutionary thanatology. Philos. Trans. R. Soc. B Biol. Sci. 373.
• Bercovitch, F.B. (2019). A comparative perspective on the evolution of mammalian reactions to dead conspecifics. Primates 1–8.
• Gonçalves, A., and Carvalho, S. (2019). Death among primates: a critical review of non-human primate interactions towards their dead and dying. Biol. Rev. 94, 1502–1529.
• Watson, C.F., and Matsuzawa, T. (2018). Behaviour of nonhuman primate mothers toward their dead infants: uncovering mechanisms. Philos. Trans. R. Soc. B Biol. Sci. 373, 20170261.

• Anderson, J.R., Gillies, A., and Lock, L.C. (2010). Pan thanatology. Curr. Biol. 20, R349–R351.
• Biro, D., Humle, T., Koops, K., Sousa, C., Hayashi, M., and Matsuzawa, T. (2010). Chimpanzee mothers at Bossou, Guinea carry the mummified remains of their dead infants. Curr. Biol. 20, R351–R352.
• Das, S., Erinjery, J.J., Desai, N., Mohan, K., Kumara, H.N., and Singh, M. (2019). Deceased-infant carrying in nonhuman anthropoids: Insights from systematic analysis and case studies of bonnet macaques (Macaca radiata) and lion-tailed macaques (Macaca silenus). J. Comp. Psychol. 133, 156.
• Fashing, P.J., Nguyen, N., Barry, T.S., Goodale, C.B., Burke, R.J., Jones, S.C., Kerby, J.T., Lee, L.M., Nurmi, N.O., and Venkataraman, V.V. (2011). Death among geladas (Theropithecus gelada): a broader perspective on mummified infants and primate thanatology. Am. J. Primatol. 73, 405–409.
• Lonsdorf, E.V., Wilson, M.L., Boehm, E., Delaney-Soesman, J., Grebey, T., Murray, C., Wellens, K., and Pusey, A.E. (2020). Why chimpanzees carry dead infants: an empirical assessment of existing hypotheses. R. Soc. Open Sci. 7, 200931.
• Masi, S. (2019). Reaction to allospecific death and to an unanimated gorilla infant in wild western gorillas: insights into death recognition and prolonged maternal carrying. Primates 1–10.
• Merz, E. (1978). Male-male interactions with dead infants in Macaca sylvanus. Primates 19, 749–754.
• Nakamichi, M., Koyama, N., and Jolly, A. (1996). Maternal responses to dead and dying infants in wild troops of ring-tailed lemurs at the Berenty Reserve, Madagascar. Int. J. Primatol. 17, 505–523.
• Sugiyama, Y., Kurita, H., Matsui, T., Kimoto, S., and Shimomura, T. (2009). Carrying of dead infants by Japanese macaque (Macaca fuscata) mothers. Anthropol. Sci. 117, 113–119.
• Trapanese, C., Bey, M., Tonachella, G., Meunier, H., and Masi, S. (2020). Prolonged care and cannibalism of infant corpse by relatives in semi-free-ranging capuchin monkeys. Primates 61, 41–47.
• Warren, Y., and Williamson, E.A. (2004). Transport of dead infant mountain gorillas by mothers and unrelated females. Zoo Biol. Publ. Affil. Am. Zoo Aquar. Assoc. 23, 375–378.