Puerto Rico manjack  (Cordia rupicola)

The Puerto Rico manjack is classified as Critically Endangered (CR) on the IUCN Red List (1).

The Puerto Rico manjack (Cordia rupicola) is a small, woody shrub which, despite its common name, is thought only to occur on the Caribbean island of Anegada, in the British Virgin Islands (1). Its leaves are roughly oval in shape, with a rounded base and a rounded or slightly pointed tip, and measure up to 9 centimetres long and 4.5 centimetres wide. The upper surface of the leaf is rough, and the underside is covered in whitish hairs (2) (3). As in other Cordia species, the leaves of the Puerto Rico manjack grow at alternating points along the stem, rather than in opposite pairs (2).

The flowers of the Puerto Rico manjack are white and grow in clusters of up to 20, with each cluster measuring up to one centimetre in diameter. The individual flowers are small, at around seven millimetres in length, and produce a red fruit containing a single seed (2) (3) (4). The fruit is a rounded drupe, and measures just four to five millimetres in length (2) (3).

Originally described as endemic to Puerto Rico, the Puerto Rico manjack was previously known from three sites in the south-western Guánica region of Puerto Rico, including on the island of Vieques (1) (3). Surveys in 1992 failed to relocate these populations, and the species is believed to be extinct there (1) (5), although it is possible that a few scattered individuals still remain (3) (4).

In 1987, the Puerto Rico manjack was found on the island of Anegada, in the British Virgin Islands (3), and this may now represent the only remaining population (1) (5). It is reported to be locally common on the western side of the island (1) (3), but occupies a total area of under five square kilometres (1).

The island of Anegada is unique among the British Virgin Islands in being made up of limestone and coral, rather than having a volcanic origin (6). The Puerto Rico manjack occurs on limestone and sand dunes around the ‘salt ponds’ of western Anegada, with a slight preference for limestone areas (7). These habitats are covered with dry, scrubby vegetation, usually dominated by cacti and dry thicket (5) (7) (8).

In Puerto Rico, the Puerto Rico manjack was known from subtropical dry forest, as well as from shrubland and forested hills with low, dense brush (2) (3) (4).

Relatively little information is available on the biology of the Puerto Rico manjack. However, it has been reported flowering and fruiting in December and January and June to July (3), and appears to produce flowers and fruits quite regularly and in abundance (1).

The main threat to the Puerto Rico manjack is habitat loss and fragmentation due to residential and tourist developments on Anegada (1) (3) (9). This habitat loss is only likely to accelerate over the next few years, and is compounded by other threats from road construction, invasive plant species, fire, and trampling and grazing by introduced cattle, goats and donkeys (1) (3) (9). As its highest point is no more than eight metres above sea level, Anegada is also highly vulnerable to the effects of climate change and associated sea level rise (1) (6) (8).

A study in 2004 estimated the total population size of the Puerto Rico manjack on Anegada to be in the region of several thousand individuals (7). However, with such a restricted range the entire population could be wiped out by any extreme event such as a hurricane (1) (3).

If it still occurs in Puerto Rico, the Puerto Rico manjack is likely to face continued threats from urbanisation and development. Individuals found beneath power lines may be threatened by maintenance activities such as cutting and burning, and even within protected areas this species is potentially vulnerable along the edges of trails and roads (3). The Puerto Rico manjack can be quite difficult to distinguish from Guettarda scabra, a common and widespread Caribbean plant, and so may also be affected by management and maintenance activities for this species (3).

Part of the Puerto Rico manjack’s preferred limestone habitat on Anegada occurs within a designated Ramsar site (1) (10), and legislation is being prepared to declare this a protected area (1). Protected Wildlife legislation for Anegada is also being revised (1) and an action plan has been produced for the island’s coastal biodiversity, as part of a Darwin Initiative Project (9).

Recommended conservation measures for Anegada’s plants include long-term habitat protection, the control of invasive species, seed collection and ongoing monitoring of key species (5) (9). Anegada has been suggested as a prime candidate for designation as a ‘Caribbean Important Plant Area’, but conservation measures urgently need to be implemented before the various threats have a lasting negative impact on the island’s biodiversity (3) (7).

Two of the locations in Puerto Rico at which the Puerto Rico manjack may still occur are within protected areas, the Guánica Commonwealth Forest and the Vieques Island National Wildlife Refuge (3). This species is also listed as a Candidate species for threatened status by the U.S. Fish and Wildlife Service (11).

Cuttings of the Puerto Rico manjack are held at the J.R. O’Neal Botanic Garden, on the island of Tortola (5), and experiments have been recommended to find ways to artificially propagate this species, which may allow conservationists to establish new populations (3). Studies are also underway into the Puerto Rico manjack’s distribution, abundance and biology (4), which may help to inform conservation efforts for this rare shrub.

ARKive is supported by OTEP, a joint programme of funding from the UK FCO and DFID which provides support to address priority environmental issues in the Overseas Territories, and Defra

Find out more about the Puerto Rico manjack:

• Center for Plant Conservation:
  http://www.centerforplantconservation.org/Collection/CPC_ViewProfile.asp?CPCNum=1048

Find out more about conservation on Anegada and the British Virgin Islands:

• McGowan, A., Broderick, A.C., Clubbe, C., Gore, S., Godley, B.J., Hamilton, M., Lettsome, B., Smith-Abbott, J. and Woodfield, N.K. (2006) Darwin Initiative Action Plan for the Coastal Biodiversity of Anegada, British Virgin Islands. Darwin Initiative, London. Available at:
  http://www.seaturtle.org/mtrg/projects/anegada/Anegada%20BAP.pdf
• UK Overseas Territories Conservation Forum - British Virgin Islands:
  http://www.ukotcf.org/territories/bvi.htm