Ngamba to consider vasectomy for male chimps

Authorities at Ngamba Chimpanzee Sanctuary are considering vasectomy for male chimps in order to reduce their growing population following failure of various family planning methods.

“We are considering two options; one is vasectomy for our male chimps, but the vasectomy for animals currently is still irreversible. We know that in humans there has been successful reversible contraception that is still experimental right now, but is something that’s new and we haven’t tried it in Apes. That’s an avenue we shall explore later because currently it would mean that if we do vasectomy in our male chimps, then  they  will never be able to induce conception in females which isn’t necessarily ideal,’’ said Dr Joshua Rukundo, the Executive Director of Ngamba Chimpanzee Sanctuary during the christening of the male baby chimp, Silver at the Island on February 23.

He added that whereas they would ideally want to have some chimps taken back to the wild, there are still on-going discussions about the process.

In the meantime, the Sanctuary may consider selective vasectomy to some of the males while putting implants in the females.

“The reason we use contraceptives at Ngamba is because it is an island with limited space and we want to maintain space in such a way that we can comfortably accommodate the existing chimps and still be able to accept and receive the rescued. We use contraception, which is reversible, so it is good for our population and health so as to revert back to normal recycling in case we need them,” he said.

He added that Silver is the Sanctuary’s newest baby chimp who was born on June 6, 2023 to one of the oldest Chimps called Cindy. “We were all surprised to see Cindy pregnant because she’s one of our female chimps who had never gone through estrus [a recurring period of sexual receptivity and fertility in many female mammals]. It was a bit of a surprise to see her getting into swelling and she conceived immediately.”

Dr Rukundo further noted that once the female tested pregnant, they did not intervene and Silver’s mother Cindy was confirmed pregnant after about two months.

“We found that she had removed her implant because we implant all our female chimps that are of child bearing age and we change these implants every two years. We use Norplant, which is currently also very good for humans. We insert it in the skin and it's very effective. We have had a recent uptake increase in the number of pregnancies in Ngamba after implant failures and so far there are seven chimps born in the process.”

He noted that they had earlier changed from a more common contraceptive, implanon used for many years, but later changed to the local one, Zadel, which is available in Uganda and cheaper.

“Implants on average cost 180 US dollars [about Shs 648000] per implant. While this implant was working at some sanctuaries, it appeared not to work for our Ngamba chimps to the extent that every year, we had few of our chimps conceive yet they had the implants. In some previous incidents, you would find that the females have removed the implants so we had to revert back to implanon or Nexplanon.”

Silver was adopted and named by Ms Silja Verhoeven from Silver HR in the Netherlands.

“In 2023, amidst the sanctuary’s silver jubilee celebrations, Ms Verhoeven bestowed the name silver upon Cindy’s son. This name not only pays homage to the first three letters of her firm’s name but also symbolises the era of his birth. Silver is described as a curious soul and always eager to explore his surroundings and investigate anything that catches his eyes, Ms Verhoeven said.

Ngamba  Sanctuary currently has 53 orphaned and rescued chimps  on 100 acres of rain forest situated on Lake Victoria. The seven chimps born on the island after implant failure include: Surprise, Eazy, Temba, Bolly, Tam-tam, Rupalleria and Silver.