Wednesday, March 9, 2011

Bornean Orangutan

There are just over 40,000 orangutans left on the island of Borneo. But history has shown that population could decline rapidly if forest habitats continue to be destroyed at the current rate. Poaching also continues to be a threat to Borneon orangutan populations. WWF is actively involved in global efforts to protect habitat and halt the illegal trade in orangutans.

Key Facts

  • Common names

    Bornean orangutan; Orangoutan de Borneo(Fr); Orangután de Borneo(Sp)
  • Habitat

    Tropical and Subtropical Moist Broadleaf Forests
  • Population

    Central Bornean = 38,000; NW Bornean = 3,000
  • Status

    Endangered (EN - A2cd; IUCN) CITES: Appendix I
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Little resilience in the face of logging and fire

The Bornean orangutan is now recognised as a different species from its Sumatra relative. Three subspecies are recognized: Pongo pygmaeus pygmaeus, P.p. morio, and P. p. wurmbii, the most common Bornean subspecies. Although extensive, the latter's habitat is increasingly fragmented in the remaining swamp and lowland dipterocarp forests of Central and West Kalimantan.

It is estimated that about one third of Borneo's orangutan populations were lost during the 1997/ 98 forest fires. On the Indonesian side of Borneo, populations of this subspecies are not faring well either.

Although some populations live inside protected areas, illegal logging still takes place within these areas and hence remains a major threat to the survival of this species.
Major habitat type
Tropical and Subtropical Moist Broadleaf Forests

Biogeographic realm

Range States
Indonesia, Malaysia

Geographical Location

Ecological Region
Borneo Lowland and Montane Forests 

Ecology and Habitat

High quality habitat critical to birth-rate

Social Structure

Adult orangutans are generally solitary, although temporary aggregations are occasionally formed. The large home ranges of males overlap the ranges of several adult females. Adult males are generally hostile to one another, although they do not display territoriality.
Life Cycle

After weaning at about 3.5 years of age, young individuals become gradually independent of their mother after she gives birth to a second young. The age of first reproduction in the Borneo orangutan is around 10-15 years of age, but there may be differences between the various sub-species.

Orangutans usually give birth to a single young, or occasionally twins, probably not more than once every five years. For the Bornean orangutan, the inter-birth interval can be as low as 5 years in high quality habitats.
The long period taken to reach sexual maturity, the long interbirth periods and the fact that orangutans normally give birth to just a single young mean that orangutans have an extremely slow reproductive rate. This makes orangutan populations highly vulnerable to excessive mortality, and means that populations take a long time to recover from population declines.

About 60% of the orangutan's diet includes fruit (e.g. durians, jackfruit, lychees, mangosteens, mangoes and figs), while the rest comprises young leaves and shoots, insects, soil, tree bark, woody lianas, and occasionally eggs and small vertebrates. They obtain water not only from fruit, but also from tree holes.

Priority Region

The Borneon orang-utan's habitat is part of the Heart of Borneo region, which is a WWF global priority region.

Population and Distribution

Kalimantan lost at least 39% of orangutan habitat within the species' range during 1992-2002

Previous population and distribution

A ten-year ongoing census of orangutans in the Sebangau Ecosystem recorded a 50% decline in numbers, from 12,000 individuals in 1995 to 6,000 in 2004. In Kutai National Park, perhaps only 10% of the area is still forested, and the orangutan population there was reduced from an estimated 4,000 in 1970 to 500 today.
Overall, analysis shows that Kalimantan (Indonesia) has lost at least 39% of its orangutan habitat within the orangutan's range over the 1992-2002 decade. 
Current population and distribution (click on map to the right to expand)

The Bornean orangutan is found in Kalimantan, and Sarawak and Sabah (Malaysia); most individuals occur in Kalimantan, where extensive areas of forest still exist, especially along the east coast.
The subspecies Pongo pygmaeus pygmaeus has been seriously affected by logging and hunting in its stronghold, Danau Sentarum, and a mere 1,500 individuals or so remain. Many swamps in the area are small, fragmented and are targeted by hunters. 
The largest population in Borneo is represented by Pongo pygmaeus wurmbii, especially in the large swamp areas of Central Kalimantan where at least 35,000 individuals are found. Major strongholds include Tanjung Puting, Sebangau and Arut-Belantikan, while an important population is found in Mawas, and a population further west in Gunung Palung. Elsewhere however, other once sizeable populations are disappearing fast.
The main stronghold of Pongo pygmaeus morio is the Berau/Gunung Gajah population, although remnants in what was once Kutai National Park may be worth protecting. New evidence suggests that P.p. morio has a strong presence in Sabah.
Densities and population sizes are in decline across the species range, and forest continues to be lost at a rapid rate.
Orangutan distribution on Borneo (Indonesia, Malaysia). The distribution of Orangutan on Borneo is rapidly decreasing, as mankind is reducing the available habitat for the apes. The loss of forest, through logging, clearing and burning, means reduced opportunities for hiding and food collection. In addition, orangutans are hunted for food and to be held in captivity.

Orangutan distribution on Borneo (Indonesia, Malaysia). The distribution of Orangutan on Borneo is rapidly decreasing, as humans reduce the available habitat for the apes. The loss of forest, through logging, clearing and burning, means reduced opportunities for hiding and food collection. In addition, orangutans are hunted for food and to be held in captivity.

Inspired by Krista Oragutan

Saturday, March 5, 2011

STOMA ('Parastomal') HERNIAS

Stoma Hernia

A Hernia is a weakness or split in the muscle wall of the abdomen which allows the abdominal contents (usually some part of the intestine) to bulge out. The bulge is particularly noticeable upon tensing the abdominal wall muscles - such as occurs when coughing, sneezing, straining or simply standing.

Stomas   pose an additional problem.  When a stoma is brought out to the surface of the abdomen it must pass through the muscles of the abdominal wall, thus a potential site of weakness is immediately created. In the ideal situation the abdominal wall muscles form a snug fit around the stoma opening. However, sometimes the muscles come away from the edges of the stoma thus creating a hernia - in this case, an area of the abdominal wall adjacent to the stoma where there is no muscle.
Factors that can contribute to causing a stoma hernia to occur include coughing, being overweight or having developed an infection in the wound at the time the stoma was made. The development of a stoma hernia is often a gradual phenomenon, with the area next to the stoma stretching and becoming weaker with the passage of time. This weakness, or gap, means that every time one strains, coughs, sneezes or stands up, the area of the abdomen next to the stoma bulges, or the whole stoma itself protrudes as it is pushed forwards by the rest of the abdominal contents behind it.
As with all hernias the size will increase as time goes by. Stoma hernias are rarely painful, but are usually uncomfortable and can become extremely inconvenient.
They may make it difficult to attach a bag properly and sometimes their sheer size is an embarrassment as they can be seen beneath clothes. Although a rare complication, the intestine can sometimes become trapped or kinked within the hernia and become obstructed. Even more seriously the intestine may then lose its blood supply, know as strangulation. This is very painful and requires emergency surgery to untwist the intestine and prevent the strangulated part of the bowel from being irreversibly damaged. Regardless of inconvenience or pain, hernias are defects in the abdominal wall and should not be ignored simply because they might not hurt. There are surgeons who advocate that small stoma hernias that are not causing any symptoms do not need any treatment. Furthermore, if they do need treatment it should not be by operation in the first instance but by wearing a wide, firm colostomy/ileostomy belt. This is probably true with small hernias, in people who are very elderly and infirm or people for whom an anaesthetic would be dangerous (serious heart or breathing problems, for example).
We feel that nowadays operative repair of the stoma hernia should be given more serious consideration to improve the quality of life, prevent progressive enlargement of the hernia with time and make it easier to manage the stoma.



If symptoms are severe enough, the hernia is repaired. The repair of a stoma hernia requires that the abdominal wall tissue is made to fit back snugly around the stoma, leaving no weakness. Over the years many different surgical approaches to this problem have been tried. There are two options. One can move the stoma to a new site on the abdomen, i.e., create a new opening elsewhere and repair the hernia at the old site as one would any other hernia, or one can try to repair the hernia around the stoma, leaving the stoma where it is. 
Repair of the hernia without moving the stoma involves opening the abdominal wall over the hernia adjacent to the stoma and re-suturing muscle and supporting tissues in the area.  Although this may appear to be the most straight-forward way of doing it, this is not always a successful method. If the original stoma site is unsatisfactory for other reasons, or if the hernia is very large it may be necessary to re-site the stoma, making a new stoma through fresh, healthy tissue. The area of the hernia, together with the site of the original stoma is then repaired, usually by stitches.
This can be a more successful procedure regarding repair of the hernia, but is a more major operation because of the many technical, surgical difficulties in dismantling the existing stoma and transferring it from one side of the abdomen to the other.

A Modern Approach

Whether one chooses to leave the stoma at its original site or to move it, we feel that the hernia itself should be repaired with mesh over and beyond the weakened area to reinforce the whole weakened muscle structure. This is an improvement over the original stitching method and our technique usually enables us to avoid the more major procedure of re-siting the stoma.
Once inserted, the mesh rapidly becomes incorporated within the muscle and surrounding tissue and forms the core of a much stronger area within the abdominal wall. This is very similar to the way builders put a steel mesh inside reinforced concrete.
Although the mesh we use is wafer-thin, lightweight (yet extremely strong), the principle is the same, in that the mechanical load becomes spread over the whole area rather than pulling on any individual stitches through the muscles. 

This use of mesh, rather than stitches, serves to avoid future recurrences, which happen when the stitches used with other methods are pulled away from the tissue. Once the bowel is seen to function normally, our kind of mesh repair generally requires 1 or 2 days in hospital following which a rapid recovery with a more reliable repair can be expected. Because the reinforcing effect of the mesh gives strength to the repair without the tissue distortion and tension of other methods, most patients are able to be completely mobile and engage in normal levels of exercise within a very few days.
Whilst there can be no guarantee of the permanence of any stoma hernia repair, it is felt that this technique offers the least risk of recurrence.
As this is a highly specialised area of surgery, one should take care to seek surgeons with the appropriate level of experience with hernias, and specifically stoma hernias and this technique of repair.