FORUM is intended for new ideas or new ways of interpreting existing information. It provides a chance for suggesting hypotheses and for challenging current thinking on ecological issues. A lighter prose, designed to attract readers, will be permitted. Formal research reports, albeit short, will not be accepted, and all contributions should be concise with a relatively short list of references. A summary is not required.
Mauritianfolklore held that the seed of the tambalacoque (Sapotaceae: Sideroxylon grandiflorum [formerly Calvaria major]) needed to pass through a dodo's gut before it could germinate (see Durrell 1977), apparently because of the difficulty in germinating this seed, the seed's thick endocarp, and the rarity of the tree. This primary forest tree, like much of the native flora of Mauritius, is now seriously threatened (Cheke 1987). Vaughan and Wiehe (1941) had suggested that dispersal and germination of this tree might have been assisted by the dodo. Temple (1977) went further and formalized the folk notion to propose a coevolved obligate mutualism between the dodo and the tambalacoque. He argued that the seeds of the tambalacoque tree were unable to germinate naturally without abrasion in the gut of a dodo; his arguments for this obligate mutualism appealed to ecologists and have become textbook dogma (gon et al. 1990). However, there have been strong arguments against such an obligate mutualism by many biologists who have worked in Mauritius (Horn 1978, Owadally 1979, Cheke et al. 1984, Vaughan 1984, Cheke 1987). In spite of the serious doubts cast by these discussions, the notion that the seeds of the tambalacoque required treatment by a dodo's gizzard before they could germinate has thrived in the ecological literature (Pijl 1982, Wheelwright and Orians 1982, Armstrong 1985, Howe 1985, Murray 1988, Wheelwright 1988, as well as the previously cited texts). The hypothetical dodo/tambalacoque obligate mutualism is often used as an example of tight interdependence of species in ecology courses (pers. obs. MCW). As noted by Gould (1980) and Cheke (1987), attractive ideas, once entrenched, are difficult to change even in the face of contradictory evidence. In this note we review the evidence relevant to the hypothesized dodo/tambalacoque mutualism, discuss the natural history of the dodo and the tambalacoque, and review the literature on seed germination to assess what the ecological relationship between the extinct dodo and the endangered tambalacoque may have been. We conclude that there is little evidence that tambalacoque seeds required treatment by dodo guts to germinate.
