Gracia is a 40-year-old wild female orangutan who lives in the Sebangau National Park. She is a familiar face to many of BNF’s researchers, but there is something odd about her behaviour lately…
Abdul Azis, BNF Indonesia’s Orangutan Coordinator, watched Gracia with suspicion. Her behaviour was different, he thought. Azis had known Gracia and her family for several years and, after four hours of tracking her movements through the dense forest, his suspicions had grown even further.
An orangutan’s long call echoed out from a burnt patch of forest. This area had once been Gracia’s home range before it was consumed by wildfire in 2015, displacing her and her then-infant son Gara. At this sudden sound, Gracia turned away as if to avoid the male orangutan loudly advertising his presence.
“I suspect that Gracia is pregnant again, since she is behaving more and more like a pregnant mother. Tomorrow we will try to do a pregnancy test with her urine,” Azis informed fellow scientists Jalil and Jali, who had joined the orangutan follow that day.
The next day, the team waited for Gracia to urinate before swooping in to collect any salvageable drops from dry leaves on the forest floor. It was unglamorous work, but the pregnancy test results filled them with hope.
“The results are two lines, indicating a positive, but one is a bit faint. Next month, we will do another pregnancy test, just to be sure,” Azis told his teammates.
He explained that if Gracia was pregnant, this would be her fourth pregnancy since 2003, when Dr. Helen Morrogh-Bernard first began recording orangutan pregnancies. As for Azis, this would be the second pregnancy of Gracia’s he sees through development.
The pregnancy test result of Gracia
Photo by Abdul Azis | BNF
“I am very happy and touched to be able to follow her progress directly. This is Gracia’s fourth child after Georgia, Gretel and Gara, so she has done a fantastic job of raising the next generation of Bornean orangutans, one of Indonesia’s most important umbrella species,” he said, smiling.
See also: Orangutan family tree!
Azis added that, besides a confirmed test result, pregnancy can also be apparent from the orangutan’s behaviour – for example, avoiding males’ long calls, since she has already mated.
“When female orangutans are ready to mate, they are usually more aggressive in their search for males and always respond to the sound of long calls,” Azis explained.
There are also physical signs of pregnancy, such as a growing belly and becoming less active.
“Recently, Gracia’s average travel distance when searching for food is only about 200 meters per day. Growing a baby is tiring work, so she’ll need lots of rest,” he continued.
Azis appealed to community members to help protect this vital orangutan habitat, which is still under threat from forest fires like the one that destroyed Gracia’s home range eight years ago. The loss of their forests leads to food scarcity, resulting in increased fighting over resources.
Another of BNF Indonesia’s orangutan researchers, Ristafatul Ulya, explained that the day-to-day behaviour of pregnant orangutans changes dramatically, including the way they move through the trees. Normally, orangutans brachiate, swinging from branch to branch with big loping movements; however, pregnant females move more slowly, over shorter distances.
“There are other physical changes that develop over the course of pregnancy too, such as elongated nipples as the female prepares to breastfeed her newborn,” he summarised.
Gracia, the female orangutan in Sebangau National Park, already has a big belly with her fourth pregnancy
Photo by Vera Dwi Safitiri | BNF
Written by Yohanes Prahara, Content Creator and Media Liaison