Researchers from the Royal Botanic Gardens, Kew, the Parc Botanique et Zoologique de Tsimbazaza, and the University of the Sunshine Coast, Australia, have discovered a new site for the Critically Endangered palm Tahina spectabilis. With its nearest living relatives in Asia and the Middle East, the discovery and publication of Tahina (Dransfield et al., 2008, Botanical Journal of the Linnean Society, 156, 79–91), a new monotypic fan palm genus in Madagascar, stunned the international palm community and intrigued the media (the latter dubbing the species ‘the Madagascan suicide palm’ as a result of the plant's hapaxanthic life history, whereby adults die after flowering).
Tahina spectabilis can reach up to 18 m in height, with leaves up to 5 m across, and the crown of the palm is so large that individuals can be seen in images on Google Earth. With fewer than 30 trunked individuals recorded in the wild, at a geographically restricted and vulnerable site on a remote peninsula in north-west Madagascar, T. spectabilis is categorized as Critically Endangered on the IUCN Red List. It is not understood what triggers the species' rare flowering events, but when the palm does flower, it has the capacity to produce enormous numbers of propagules. Kew worked with the local cashew plantation company VERAMA and the local community to collect seed from a successful fruiting event in 2007 and these were sold internationally, with the funds returning to the community to fund conservation and development activities at the site.
Ten years on, a Kew expedition set off in September 2016, with the support of the Mohamed bin Zayed Species Conservation Fund, to re-census the known T. spectabilis population and check on the progress of the conservation work. The team found that, although the population at the original site is still small, it is stable and probably increasing slowly, with nearly 700 individuals recorded. Five adults have flowered and died since the last census in 2008, but another five juvenile individuals have grown sufficiently to be classed as adults. The local community have been protecting the site, with a wide firebreak maintained around the population, and fences built to keep grazing zebu from trampling young plants. At a site nearby, the team found 170 seedlings, and the local community has agreed to monitor and protect this site as well. Income from seed sales has been managed by VERAMA, and has funded several infrastructure projects, including the construction of a school and the digging of a well for the village, and provided ongoing annual funding for the maintenance of the firebreak and fences.
After visiting the original type location of Tahina, the Kew expedition investigated reports of another population of T. spectabilis further inland, just 10 km from Madagascar's Route National 6 that connects the capital Antananarivo with Ambanja in the north. With the help of local people a small, but unmistakable, group of 25 individuals was discovered in a remote fragment of forest, including five adults, the largest being a medium-sized adult c. 12 m in height. Initial discussions with the local community about the importance of the species' conservation went well. A follow-up trip in October by another Kew team reinforced and continued these initial discussions, and investigated the needs of the community and how conservation and development work could be brought together at this new site. It is hoped that funding will soon be secured to help with the early stages of this work.
A demographic and genetic study across the two populations and a species conservation management plan are now being prepared. Species distribution models will be run using the currently known geographical range of T. spectabilis, and the results used to identify and explore other sites where the species could potentially grow. Although it is highly significant that a second Tahina population exists, it is unlikely that the Red List status of T. spectabilis will change as a result of this new discovery. Even with a much larger Extent of Occurrence for the species, the number of mature individuals known in the wild still remains extremely low at only 34, and therefore T. spectabilis remains Critically Endangered according to the IUCN Red List Criterion D.