Taxonomy

endemique
protegee
UICN

Common name :

Hma (nengone)

Red List Status -

Critically Endangered (CR) , assessed in 11/12/2014

Protected species -

in Northern Province

Cyrtandra mareensis is an endemic shrub to the loyalty islands (Maré and Lifou) in New Caledonia. Two subpopulations are known in Lifou (path from Xodre to Mele) and Maré (between Kurin and Shabadran), making a total population size of ca 300. The subpopulations are 80 km apart. It is restricted to rocky zones on the southeast coasts of Lifou and Maré where it grows in coastal shrubland. It is sometimes found on sloping cliffs close to coastal forests dominated by Pisonia-Cycas, Pandanus or Araucaria. There is an evident threat due to feral goat browsing of mature and juvenile individuals. Feral goats have indeed caused the loss of a subpopulation in Xodre hinterland in Lifou. Traces of browsing on individuals have been observed on the two existing subpopulations. A second threat is linked to invasive plant species (Pluchea odorata, Tradescantia spathacea and Turnera ulmifolia) which progressively tend to alter and occupy the suitable habitat for Cyrtandra mareensis. Its area of occupancy is no more than 9 km2 while its extent of occurrence is 460 km2. It is considered severely fragmented as each subpopulation could go extinct with a very reduced probability of natural recolonization from the other subpopulation. A continuing decline has been observed and/or estimated for its extent of occurrence, area of occupancy, quality of habitat, number of subpopulations and number of mature individuals. Using criteria B, C. mareensis qualifies for CR B2ab(i,ii,iii,iv,v). Population size of mature individuals is estimated 300-1,000 with surely less than 1,000 individuals in each sub-population and with an estimated continuing decline of the number of mature individuals. Using criteria C, C. mareensis would qualify for VU C2a(i). Using criteria D, C. mareensis would qualify for VU D1.

Geographical area


Cyrtandra mareensis is an endemic shrub to the loyalty islands (Maré and Lifou) in New Caledonia. It is restricted to the southeast coast of these two islands.

Population


Two subpopulations are known in Lifou (path from Xodre to Mele) and Maré (between Kurin and Shabadran), while two other subpopulations were noticed in the past: one in Lifou in hinterland Xodre which would have disappeared (overgrazing) and one in Maré mentioned by Père Dubois (1939-1967) on the path of Leon

Habitat


Cyrtandra mareensis is restricted to rocky zones on the southeast coasts of Lifou and Maré. It grows in coastal shrubland. It is sometimes found on sloping cliffs close to coastal forests dominated by Pisonia-Cycas, Pandanus or Araucaria.

Threats


There is an evident threat due to feral goat browsing of mature and juvenile individuals. Feral goats have indeed caused the loss of a subpopulation in Xodre hinterland in Lifou. Traces of browsing on individuals have been observed on the two existing subpopulations. A second threat is linked to invasive plant species (Pluchea odorata, Tradescantia spathacea and Turnera ulmifolia) which progressively tend to alter and occupy the suitable habitat for Cyrtandra mareensis. The combination of these two threats will surely lead to a rapid decline of C. mareensis if no conservation measures are taken.

Conservation


No conservation measures have yet been implemented. However, the Province des Iles Loyauté (local institution in charge of conservation) was informed that Cyrtandra mareensis is a prioritary patrimonial species which deserves conservation measures. It could be wise to increase hunting pressure on feral goats in both stations and control invasive plant species.

Bibliography


Suprin B. 2008. Plantes du littoral en Nouvelle-Calédonie.

Butaud, J.-F. 2014. Flore des îles Loyauté (Nouvelle-Calédonie) : plantes patrimoniales, plantes envahissantes et espaces naturels remarquables.

Lormée N.; Cabalion P.; Hnawia E.S. 2011. Hommes et plantes de Maré.

Experts


Assessor(s): Butaud, J.

Contributor(s): Barrabé, L., Cazé, H., Fleurot, D., Butin, J., Birnbaum, P.

Facilitator(s): Schatz, G.


Geographical distribution