“They Were Pervasive” – Escalating Populations of Monkeys and Pigs Pose Human Disease Threat
Human-induced alterations to the natural habitats of Southeast Asia have triggered surges in the populations of wild pigs and macaque monkeys, thereby jeopardizing local ecosystems and elevating the risk of diseases affecting both livestock and humans. A recent study, led by The University of Queensland, sheds light on this concerning phenomenon.
Dr. Matthew Luskin, a researcher affiliated with UQ’s School of the Environment, and his team meticulously compiled and evaluated population data for various species across the region, some of which was collected using an array of surveillance cameras.
According to Dr. Luskin, “Macaques and wild pigs are rapidly colonizing the disturbed forests of Southeast Asia.” He attributes this expansion primarily to human activities such as logging and the establishment of palm oil plantations, which provide abundant food sources and optimal breeding environments for these animals. Dr. Luskin’s research revealed that wild boar and macaque populations near these plantations were a staggering 400 percent higher than in undisturbed environments. These creatures readily exploit the farmlands, raiding crops and thriving on calorie-rich fare.
The use of camera traps allowed Dr. Luskin to witness firsthand the explosion in these populations. “I encountered massive troops of macaques in Thailand, Malaysia, and Indonesia – they seemed to be ubiquitous along the forest edges, closely shadowing our activities and even interfering with our equipment,” remarked Dr. Luskin. Initially vexing, this experience soon took on an eerie dimension as they found themselves entirely surrounded by these animals.
Dr. Luskin underscores the substantial health risks posed by the burgeoning pig and macaque populations. “The origins of the COVID-19 pandemic traced back to wildlife in human-altered environments demonstrate that mammals in such settings often harbor a high load of pathogens, posing significant zoonotic disease risks,” he emphasized. “Both pigs and macaques are known carriers of diseases transmissible to humans and represent the most prevalent species in a region considered a global hotspot for zoonotic diseases.”
Collaborating researcher Professor Carlos Peres from the University of East Anglia (UK) pointed out that unnaturally high concentrations of wildlife species that serve as disease reservoirs frequently occur in human-modified tropical forests. “This study reinforces the notion that densely populated rural areas in Southeast Asia could potentially become sources of future human epidemics,” Professor Peres cautioned.
Jonathan Moore, a PhD candidate at the University of East Anglia and Southern University of Science and Technology (China), noted that the immediate consequences of these population surges were evident in the affected regions’ native flora. “Both pigs and macaques set off a chain of adverse ecological effects in these pristine ecosystems,” Mr. Moore observed. “They consume the seeds and seedlings of native plants and prey upon bird and reptile eggs. For instance, Malaysian pigs alone have been shown to reduce rainforest tree regeneration by a staggering 62 percent.”
The researchers stress the urgency of taking action to curtail the expansion of wild pig and macaque populations. Dr. Luskin acknowledged the challenges, stating, “Past attempts to manage these species’ populations have faltered due to their rapid reproductive rates and public opposition. While nobody advocates for unnecessary wildlife culling, the detrimental social and ecological consequences of hyperabundant pest species demand ethical and immediate management solutions.”
Reference: “The rise of hyperabundant native generalists threatens both humans 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 Reviews.
DOI: 10.1111/brv.12985
Table of Contents
Frequently Asked Questions (FAQs) about Wildlife Population Expansion
What is causing the increase in wild pig and macaque populations in Southeast Asia?
Human-driven habitat changes, such as logging and palm oil plantations, are altering the environment, providing abundant food sources and ideal breeding conditions for these animals.
What are the potential consequences of this population increase?
The rising populations of wild pigs and macaque monkeys threaten native forests, increase the risk of diseases spreading among livestock and humans, and negatively impact local ecosystems.
How significant are the population increases near palm oil plantations?
The study found that near palm oil plantations, wild boar and macaque populations were a staggering 400 percent higher compared to untouched environments.
Are there health risks associated with these expanding populations?
Yes, there are significant health risks. Both pigs and macaques can carry diseases that can be transmitted to humans, and Southeast Asia is considered a global hotspot for zoonotic diseases.
What ecological impacts do these populations have on the environment?
Both pigs and macaques have negative cascading effects on pristine ecosystems. They consume native plant seeds and seedlings and prey on bird and reptile eggs, significantly impacting local biodiversity.
What measures are suggested to address this issue?
Efforts to manage these expanding populations have faced challenges due to their rapid reproduction rates and public opposition. However, ethical and urgent management solutions are needed to mitigate the social and ecological consequences of these pest species.
