Issues: Species loss
Habitat loss
Indicators: Number of threatened species
Ratio of area protected to maintain biological
diversity to surface area*
*MDG indicator no. 26 under Target 9, Goal 7

Threatened species

The number of threatened species serves as an indicator of overall threats to biodiversity. Of all the animal groups, mammals and birds have both the highest proportion and the highest number of threatened species. Altogether, more than 5 000 animal species are now threatened with extinction. At the same time, almost 6 800 plant species are endangered or vulnerable, 2.4 per cent of the total that have been described (Table 1). Of the threatened species, birds are concentrated in tropical Central and South America, and Southeast Asia, while mammals are concentrated in Central Asia, Central Africa and Meso-America (Figure 10). South and Central America, Southern Africa and South and Southeast Asia have the highest number of threatened plant species (Figure 11).

Table 1: Threatened species
Group	Number of described species	Threatened species in 2003	Threatened species in 2003 as percentage of described species
Mammals	4 842	1 130	23.3
Birds	9 932	1 194	12.0
Reptiles	8 134	293	3.6
Amphibians	5 578	157	2.8
Fishes	28 100	750	2.7
Insects	950 000	553	0.1
Molluscs	70 000	967	1.4
Plants	287 655	6 774	2.4
Source: IUCN 2003

Figure 10: Threatened animal species by sub-region in 2003

Figure 11: Threatened plant species by sub-region in 2003

Protected areas

The proportion of area protected to maintain biodiversity indicates the level of policy response to the issue. Noting that many important natural sites are not protected at all, and realizing that those under protection are not always very well managed and adequately recorded, the proportion of area under protection has increased since the 1970s and is now estimated to be more than 12 per cent of the earth’s land surface (or 18.8 million km²). Excluding those for which no starting data is known, the total is about 11 per cent (Figure 12).

Figure 12: Protected areas as percentage of total land area by region and global, 1975–2004

Approximately 1.64 million km² comprise marine protected areas – 0.5 per cent of the surface area of the oceans and less than one-tenth of the overall extent of protected areas worldwide. Marine areas remain under-represented in the global protected area system (Chape and others 2003).

About nine per cent of total land area is classified under IUCN management categories. The areas which are not classified account for about 35 per cent of the total number of sites, or 25 per cent of the total protected area.

The jump for West Asia between 1990–1995 is due to establishment of a single large protected area (640 000 km²) in Saudi Arabia in 1994.