Critically Endangered Species of the Week: Attenborough's Pitcher Plant!

About:
      Attenborough's Pitcher Plant, Nepenthes attenboroughii, is a species of insectivorous terrestrial shrub characterised by its large bell-shaped pitcher and narrow upright lid. It was discovered in 2007, and named in 2009 after Sir David Attenborough, because he is "a  keen enthusiast of the genus" [2; 6]. The stem can reach a height of 1.5m, and the pitcher may grow as large as 2 litres in volume [2].
     The pitcher of the plant holds water as two layers that do not mix: the lower region is viscous, and the upper is watery. The pitcher and liquid act as a trap; the plants often have slippery edges, meaning insects lured by colours and scents that land on the rim fall into the pitcher consequently drown and are digested by the enzyme-containing fluids.

Attenborough's Pitcher Plant, Nepenthes attenboroughii. The middle image displays the
huge amounts of liquid the pitchers hold. Images by A.S. Robinson, from [3].

Number left in existence:
     The plants grow singly, or in sparsely scattered groups, with few individuals in an area. This gives a population density of only one individual per ~20m², meaning the two-three known colonies only consist of a few hundred plants [1]. Actual population numbers are very low, but specifics are unknown.

Geographical Range in the wild:
     The species is known only from Mount Victoria, in central Palawan, Philippines. The plants grow on ultramafic slopes from 1,600m up to the summit [3; 6]. The actual area the species occupies comprises a few hundred square meters on each of the summit region, meaning the range is significantly below 10km2 [1].

Why they are endangered:

• The biggest threat to Attenborough's Pitcher Plant is poaching. Thankfully the mountain is mostly inaccessible, which means hiking and human development has little affect on populations. However the monetary value of this rare plants is high, notably on the Taiwanese and Japanese markets [1; 4].
• The species occurs only on ultramafic soils (nickel and magnesium-rich), and has separate male and female plants (dioecious). This means no single plant can reproduce just by itself, and so even light collection pressure and human influence can have a great impact on the reproduction of the species.
• The habitat of these endemic plants is under future threat from mining - a nickel mine operates at the base of the mountain, and the summit has been prospected for future potential [1].

What can we do to help?
     There are no current conservation measures in place for this species - Mount Victoria is mined, and the summit has no protected status (i.e. for National Parks) [1]. Control measures are in place for the trade of the endangered species of the genus Nepenthes, but these need to be better enforced, and the area made a designated protected zone [4].


BBC Wildlife and David Attenborough's documentary 'The Private Life of Plants' contains a clip full of excellent footage of the genus of Pitcher Plants, which is included below for interest's sake [5]!

References:
1. Robinson, A.S. & Madulid, D.A. 2012. Nepenthes attenboroughii. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.2. <www.iucnredlist.org>
2. Nepenthes attenboroughii. 2012. At Wikipedia. <http://en.wikipedia.org/wiki/Nepenthes_attenboroughii>
3. International Institute for Species Exploration. 2010. Attenborough's Pitcher. <http://species.asu.edu/2010_species01>
4. Malein, F. 2012. The 100 most endangered species on the planet - list in full. From: IUCN and Zoological Society of London. <http://www.guardian.co.uk/environment/2012/sep/11/100-most-endangered-species-planet>
5. Attenborough, D. 1995. The Private Life of Plants. BBC. <http://www.youtube.com/watch?v=trWzDlRvv1M>
6. Walker, M. 2009. Giant 'Meat-Eating' Plant Found. BBC. <http://news.bbc.co.uk/earth/hi/earth_news/newsid_8195000/8195029.stm>