Being arboreal (tree-dwelling), orangutan populations are difficult to estimate. One way of estimating their numbers is by counting their nests combined with satellite imagery. According to one estimate, there are now c. 57,000 Bornean orangutans in the wild, 80% of which live outside of protected areas and so are vulnerable.
Bornean orangutan population is predicted to decline by 86% from 1950 to 2025, due to loss of habitat - Borneo has lost about half of its natural forests since 1985, and this could reach two-thirds by 2020. As a result, orangutans are classified as being ‘threatened’ in the wild.
The main threat to orangutans is deforestation, the two main causes of this being clearance for palm oil plantations and illegal logging.
Palm
oil is everywhere – it’s the most widely used vegetable oil in the
world and is contained in half of the packaged foods on supermarket
shelves. Global demand for palm oil has resulted in massive forest
destruction throughout Indonesia and Malaysia, which together produce
85% of the world’s palm oil and is a major industry and export for these
countries. The problem lies in its mass production, which necessitates
the clearance of vast areas of native rainforest and its replacement
with a monoculture crop. Millions of hectares have been converted in
this way, with devastating impacts on biodiversity. Deforestation also
cause soil erosion and, because most forests have been cleared through
the use of fire, air pollution from smoke. Much of the land on which
palm oil plantations have been established consists of peat swamp forest
– these are carbon sinks and the draining, burning, and conversion of
peat swamp forests to palm oil has been especially damaging to the
world’s climate, releasing massive amounts of stored greenhouses gases
into the atmosphere. Illegal logging has also had a major impact on forest areas. Until recently, up to 70% of timber produced in Indonesia was thought to be from illegal sources, and whilst this is no longer as prevalent it still occurs. Illegal logging removes high value trees from the forest – often the same species – and often large, long lived, seed producing trees. This alters the structure of the forest which can impact on the food resources available for orangutans and their ability to nests and move through the canopy. The act of logging also creates trails, waterways and breaks in the forest that can lead to other issues such as soil erosion, changing water levels, and increased human disturbance.
These two issues result in a loss of habitat
for orangutans, as well as habitat fragmentation. When their natural
habitat is removed, orangutans may resort to raiding crops and come into
conflict with humans. Those that are not rescued from such situation
may be persecuted or die of starvation. 
Where an adult dies or
is killed, youngsters are often (illegally) kept by local people as
pets, often in cramped cages. When known, such youngsters are rescued by
charities, then rehabilitated and returned to the wild. You can read
one such typical story on the Orangutan Foundation UK blog -
https://www.orangutan.org.uk/blog. In September 2018, Indonesia's president signed a moratorium on all new palm oil plantation development, effectively stopping any new land being made available for plantations. Whilst this is a positive move, a massive amount of land has already been lost to such developments. As well as protecting remaining areas of forest, future steps should seek to reinstate some areas of lost forest, re-connecting isolated habitats.
Tomorrow’s post takes a more positive tone and looks at the conservation efforts to save orangutans and their habitat.
#orangutans #redape
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