Most people only know about one kind of orangutan.  For years we knew that there were actually two kinds, the Sumatran orangutan that we have living in a family group of three at the El Paso Zoo and the Bornean orangutan.   A few years ago scientists announced the discovery of a third species, the critically endangered Tapanuli orangutan.  This orangutan lives in a very small mountainous region of North Sumatra where the estimated wild population is less than 800 individuals.   Looking at a picture of one it’s really hard to see how they differ from the Sumatran and the Bornean, but there are anatomical differences and a big difference regarding their habitat.   Most orangutans live in lowland swampy areas, Tapanuli orangutans live in a mountainous region called Batang Toru.

Wildlife conservation efforts at the El Paso Zoo are often inspired by the animals we care for and exhibit.  Many of them are either critically endangered or endangered.   According to the IUCN a species is endangered when the best available evidence indicates that the species is facing a very high risk of extinction in the wild.  Critically endangered is when the best available evidence indicates that the species is considered to be facing an extremely high risk of extinction in the wild.

Last year the El Paso Zoo Conservation Fund earmarked a contribution to the AZA Orangutan SAFE program in support of efforts to help orangutans in Zoos and in the wild, including the Tapanuli orangutan.  The goal of this program is to manage AZA captive populations, by focusing specifically on the conservation of the wild orangutan population. The Orangutan SAFE Program aims to protect and restore the wild orangutan population and their habitats through public engagement, funding and field work.

The El Paso Zoo is helping to save this species in supporting the AZA SAFE program and other efforts in Indonesia, but what else can people do to help orangutans in Sumatra, both the Sumatran orangutan and the newly discovered Tapanuli orangutan? The Sumatran Orangutan Conservation Program is one grassroots organization that you can look into.  According to SOCP most of the Batang Toru Ecosystem, as the home of Tapanuli orangutan, is currently allocated as Protection Forest.  In order to decrease the rate of the illegal encroachments in the Batang Toru Ecosystem, @YayasanEkosistemLestari together with local government agencies, has carried out a lengthy boundary socialization program since 2009. Most local community members do not know where forest boundaries are, as they are not demarcated in the field. Yet at the moment, the hydro dam and the gold mining are the main and serious threats to the ecosystem. 

In many areas of the world building relationships with people who live near protected areas like the Batang Toru Ecosystem is often critical to the success of any effort.   But how does someone in El Paso or anywhere else go about doing that?  How can we support people living and working in this part of the world who care about these orangutans?  An online search of the mountain area using Google Earth revealed a city of about 200,000 people called Padangsidempuan, located about an hour’s drive from the mountain area where the Tapanuli orangutans live. Connecting with people in a city like Padangsidempuan is more easily said than done. It is difficult to know who to reach out to and the language is Indonesian.   Since I am a member of Rotary International I looked for a Rotary Club without success.   I then tried Facebook and using Google Translator and reached out to several people with a simple hello message.  I am still waiting for my first reply.  If I make any progress I will let everyone know, but right now it’s a long shot.

New orangutan research project

Recently the El Paso Zoo approved moving forward with an orangutan research project led Faye Harwell, a Boston University PhD Candidate.   Ms. Harvell recently sent us a summary of the new project involving our five year old baby Sumatran orangutan Khaleesi.

Like humans, orangutans are dependent on their mothers for a very long time. Despite many years of study, little is known about the timing of development in orangutans. For instance, when do girl and boy orangutans go through puberty? And, why don’t all male orangutans develop their cheek flanges at the same time? This study will examine growth and development in captive orangutans and fill some of these gaps in our knowledge of this critically endangered great ape.

To study developmental patterns and changes in orangutans, we are collecting urine on a weekly basis from young male and female orangutans. These urine samples will be used in hormonal analyses. We will investigate testosterone and estrogen in males and females, respectively. We will also look at cortisol and c-peptide, which can tell us if individuals are allocating a lot of their energy to growth and development.

To study their growth patterns, we are looking at weight records to see when they obtain their adult body size. Additionally, we are going to photograph the arm of these young orangutans to determine how fast their skeleton is growing. Like humans, great apes may go through a pubertal growth spurt when they are ‘teenagers.’ Additionally, male orangutans also go through a dramatic transformation called flanging, where they double in body size, develop cheek pads (flanges), develop a throat sac, can long call, and grow longer hair (often called dreads). This process is similar to puberty in the sense that there are a number of developmental changes happening at once. On the other hand, males experience flanging at different times meaning that not all males experience flanging at the start of their adulthood; some experience it much later.

Overall, orangutan growth and development are very interesting areas of research because orangutans are similar to humans in many ways, yet the unique characteristics of their development are very intriguing. 

Zoo Veterinarian, Dr. Victoria Milne, said that Khaleesi is one of the youngest orangutans being studied in this project. She is a superstar and has already learned to urinate into a collection cup and presents her forearm for keepers to measure.  Collection Supervisor Griselda Martinez will be supervising the data collection on our end over the next year.

Cover image on July 27, 2020 by Erwin Adriawan Perbatakusuma, Wikimedia Commons