“They Were Everywhere” – Exploding Monkey and Pig Populations Pose Human Disease Risk

Human-driven habitat change in Southeast Asia is causing wild boar and macaque populations to increase, threatening ecosystems and increasing disease risk. Above is a pig-tailed baby in Malaysia. Credit: Ecological Cascades Lab

Research led by the University of Queensland shows that the increase in the number of wild pigs and macaques in Southeast Asia is a threat to natural forests and can lead to the spread of disease between livestock and people.

Dr Matthew Luskin, who works with UQ’s School of the Environment, and his team, collected and tested. species population data from different parts of the region,

some of it is collected through a network of cameras.

“Macaques and wild pigs occupy the disturbed forests of Southeast Asia,” Dr Luskin said. “Many people are now to blame for changing the forests by cutting down trees and establishing palm oil farms that provide food and suitable breeding conditions for these animals. We observed that wild boar and macaque populations were 400 percent higher in the forests near the plantations than in the untouched environment. These animals take full advantage of farmland, raiding crops and thriving on high-calorie food.”

Setting up and monitoring the camera traps gave Dr. Luskin a very close-up experience of the explosive numbers.

“I’ve encountered large armies of macaques in Thailand, Malaysia, and Indonesia – they were everywhere on the edge of the forest, following us and interfering with our equipment,” Dr Luskin said. “At first it was frustrating but then it was scary as we were completely surrounded.”

Dr Luskin said there were significant risks to human health from raising pigs and macaques.

“The origin of wild animals COVID 19 The epidemic shows that mammals in a dynamic human environment often harbor high pathogen loads and pose a high risk of zoonotic disease,” he said. Both pigs and macaques are considered carriers of diseases that can be transmitted to humans and are the most common animals in what is considered a hotbed of zoonotic diseases.

Collaborator, Professor Carlos Peres from the University of East Anglia (UK), said an unusually high number of wild animal species that are disease reservoirs often occur in rainforests that have been altered by humans.

“This study also shows that densely populated rural areas in Southeast Asia may be the source of future human epidemics,” he said.

The University of East Anglia and the South University of Science and Technology (China) PhD candidate, Jonathan Moore, said that the immediate effects of the population explosion can be seen in the natural flora of the affected areas.

“Both the pigs and the macaques are causing negative impacts of the decline in these favorable conditions,” said Mr Moore. “They kill the seeds and seedlings of local plants and eat the eggs of birds and reptiles. Pigs in Malaysia alone were found to reduce the growth of forest trees by 62 percent.”

Researchers say action is needed to slow the spread of wild pigs and macaques.

“Efforts to control populations of these species have failed in the past due to their ability to reproduce rapidly and the outcry of society,” Dr Luskin said. “Nobody likes the unnecessary killing of wild animals but the negative social and environmental impacts from predatory animals require ethical and urgent solutions.”

Reference: “The rise of hyperabundant native generalists threatens both people and nature” by Jonathan H. Moore, Luke Gibson, Zachary Amir, Wirong Chanthorn, Abdul Hamid Ahmad, Patrick A. Jansen, Calebe P. Mendes, Manabu Onuma, Carlos A Peres and Matthew Scott Luskin, 13 June 2023, Biological studies.
DOI: 10.1111/brv.12985