CITES -- a handbook for wildlife protection

The planet's endangered species may not be able to speak up for themselves but they do have a global treaty which seeks to protect them from the dangers threatening their future in a fast-changing world.

The Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), which meets in Bangkok on Sunday, is the framework by which trade in animals and plants is regulated.

While it does not directly manage wildlife populations -- and has faced pressure from conservationists to get tougher to combat high levels of poaching -- it can act to ban the sale of wildlife and associated products when a species is threatened.

Here are some key facts about the convention and how it works:

-- CITES was adopted on March 3, 1973 in Washington and entered into force two years later.

-- Some 35,000 species have since been placed under CITES protection.

-- In Bangkok, 70 proposals by 55 countries will seek to improve the conservation and sustainable use of various species, from sharks, rhinos and elephants to Ecuador's vicuna (a cousin of the llama), freshwater turtles, frogs, and ornamental and medicinal plants.

-- CITES protection is not always enough to save a species in the face of habitat destruction and increasingly advanced poaching networks. The tiger was added to Annex I in 1975, but it has still faced "substantial population declines" even since the late 1990s, according to the 2011 International Union for Conservation of Nature Red List report.

-- The convention recognises that the trade in plant or animal species may be necessary both for local populations and for the conservation of the species, provided such trade is sustainable.

-- When threats to a specific species are scientifically proven, the secretariat or CITES member states can propose adding it into one of the Convention's three appendices.

Appendix I bans international trade in the species outright. It includes some 600 animals, from big cats to sea turtles, and around 300 plants, including varieties of orchid and mahogany.

Appendix II imposes strict controls over the trade of named species, requiring export permits, for example. Currently 4,500 animals and 29,000 plants are on this list, while several species of shark are tipped to be added at this meeting.

Annex III covers unilateral initiatives by member states aimed at protecting local species by imposing strict controls on exports. It covers some 260 species.

-- When a species is added to one of the appendices all member states must adopt legislation and other scientific, legal or customs-related measures, to ensure the protection requirements are respected.

-- Each decision of CITES must be adopted by a two-thirds majority of those present. A member state can call for a secret vote if it is supported by 10 others, but some members wants to reform the process in order to increase transparency.