Gunung Leuser National Park is the habitat of one of the rarest great ape species on Earth. The population of Sumatran orangutans at Bukit Lawang consists of both wild and semi-wild (rehabilitated and released) orangutans, which are not 'tame'. Instead they have been 'habituated', which means that they no longer associate the presence of humans as an immediate threat and are therefore relatively relaxed in the proximity of people. However, they are free-ranging animals that have been given a 'second chance' at life in the wild, having been rescued from the illegal wildlife trade and reintroduced into the forest.

Inappropriate conduct by forest guides and visitors may have a negative effect on orangutan behavior. This in turn may place them at an increased risk of becoming stressed and/or of becoming ill and dying. By following these simple guidelines forest guides and visitors will be able to observe the Sumatran orangutans at Bukit Lawang as well as other sites such as Tangkahan, Ketambe, and Kuala Baru in a way which is both safe for themselves as well as the orangutans.

Group Responsibilities

As an individual in a group it is important to act responsibly, not only for yourself but for the group as a whole.

1. A maximum group size of seven visitors whilst in the forest.
   Visitor group size can affect the behavior of the animals and (as a result), the visitors’ experience. Where groups of visitors are too high in number, the animals become stressed and nervous and move away from visitor groups.
2. A minimum distance of 7 - 10 meters between the visitor group and the orangutans.
   The potential for disease transfer, both from humans to orangutans and vice versa, is very high due to the close genetic relationship we share with apes. Pneumonia, influenza, tuberculosis, hepatitis A, B, C, and E, cholera and even the common cold can all be passed between great apes and humans. It also protects you from the possible threat of attack from the orangutans: If an orangutan does move towards the visitor group, you must move back (maintaining the minimum distance at all times).
3. Maximum one hour in the presence of orangutans.
   When this period is over, the group is to leave the area where the orangutan is. Timing is at the guides’ discretion and the viewing period can NOT be extended. Remember that we are guests in the Gunung Leuser National Park, which is the orangutans’ home and what is best for the orangutans is to freely roam and forage naturally in the forest.

The Sumatran orangutan shares over 96.5% of its genetic DNA with us. They are like us in many ways. Orangutans are thinking, feeling beings and should be treated with due care and respect. Therefore, observe these ‘orangutan etiquette’ guidelines:

1. Do not touch the orangutans under any circumstances.
   Diseases, infections and even parasites can easily pass between orangutans and humans.
   Orangutans are approximately four times stronger than a human and are therefore capable of inflicting serious or fatal injuries if they feel threatened.
2. Avoid direct eye contact with the animals.
   Many great ape species use direct eye contact as a threat technique.
3. Do not place themselves between two orangutans, especially between a mother and her infant.
   Orangutan mothers are extremely protective towards their offspring and can become aggressive if they feel that their infant is being threatened.
4. Do not call out to the orangutans.
   Calling to the orangutans can cause stress and disrupt their natural behavior.
   Do not call/lure orangutans to the group or trail system. It deters the orangutans from behaving and foraging naturally. Do not make any sudden movements and do not try to gain the attention of the orangutans by waving your arms, etc.
5. Keep the noise down.
   Loud noise can be interpreted as a threat by the orangutans and they can respond either by fleeing or threatening back. If the orangutan begins to elicit kiss-squeak vocalizations and/or is breaking and throwing branches, this is a sign of disturbance, and it is best to move on and leave the orangutan alone.

Visitor Responsibilities

1. Do not go into the forest if you feel unwell.
   If you recently have had a sickness and/or diarrhea, do not enter the forest. It can seriously risk infecting the animals, which could easily result in their death (and the potential transmission of the disease to other orangutans). If the guide suspects that a visitor is not well, it is within his/her authority to deny the visitor entry.
2. Do not eat in the forest as it increases the risk of disease transmission and attacks from orangutans.
   Bring all rubbish out of the forest when you leave (this includes all fruits scraps). Bring as little as possible into the forest – only the essentials should be taken in. This will limit chances of loss/damage.
   Orangutans attack only if they know from past experience that visitors often carry food into the forest. If no food is brought in, the orangutans will learn that there is nothing to attack for. That will make it safer for all of the orangutans and all future visitors and guides.
3. If you need to urinate or defecate be sure that you are far from the orangutans. Dig a hole (at least 30cm deep) and fill it when ready.
   Try and wait until you are out of the forest.

Forest Responsibilities

Like any tropical forest, Bukit Lawang and its surrounding areas represent a complicated and diverse, but above all, fragile habitat. The whole rain forest ecosystem is a delicately balanced network of animal and plant species, many of which are heavily dependent upon each another. Therefore follow this simple guideline:

• Do not remove, damage, or alter any of the vegetation within the forest. Leaves, seeds and shells. All play a role within the forest ecosystem and should not be taken out.
• It is your responsibility to help ensure the survival of the critically endangered species and their habitat. Visitors should discourage other members in their group, including their guides if necessary, from acting in a way which contradicts these guidelines, and should express their disapproval and report any activity which puts either the visitors or the orangutans at risk.
• With your help and cooperation, the orangutan can continue to flourish in the Gunung Leuser National Park. Following these guidelines is much appreciated!