Healing Hanuman's Army: Veterinary Care as a Core Component of One Health Principles in a Southeast Asian Monkey Forest

Abstract

Wildlife that inhabit urban landscapes face the dual challenge of negotiating their positions in their group while navigating obstacles of anthropogenically modified landscapes. The dynamics of urban environments can result in novel injuries and mortalities for these animals. However, these negative impacts can be mitigated through planning, and onsite veterinary care like that provided by the Ubud Monkey Forest in Bali, Indonesia. We examined 275 recorded injuries and mortalities among six social groups of long-tailed macaques (Macaca fascicularis) brought to the veterinary clinic from 2015-2018. We fit the probabilities of injury vs. death among macaques brought to the clinic using a multilevel logistic regression model to infer the relationship between injury vs. death and associated demographic parameters. Males were more likely to sustain injuries and females were more likely to die. The frequency of injuries and mortalities changed over the four-year study period, which was reflected in our model. The odds of mortality were highest among young macaques and the odds of injury vs. mortality varied across the six social groups. We categorized injuries and mortalities as "natural" or "anthropogenic". Most injuries and mortalities were naturally occurring, but powerlines, motorized vehicles, and plastic present ongoing anthropogenic threats to macaque health. Most wounds and injuries were successfully treated, with healthy animals released back to their group. We suggest other sites with high levels of human-alloprimate interplays consider the Ubud Monkey Forest veterinary office as a model of care and potentially adopt their approaches.

Keywords: Macaca fascicularis; One Health; Padangtegal; Ubud Monkey Forest; anthropogenically disturbed habitats; human–alloprimate interplays; injury; long-tailed macaques; mortality; veterinary care.

Figure 1

Social media posts and signs developed by the Ubud Monkey Forest. (A) Social media post informing the public of their commitment to the health of the long-tailed macaques (M. fascicularis) at the site; (B) Guidelines sign posted in the forest informing visitors how to behave around the macaques and lower the likelihood of an aggressive interaction.

Figure 2

Map of the Ubud Monkey Forest. The red arrow shows the location of the Ubud Monkey Forest Veterinary Clinic which is labelled “animal clinic” on the map.

Figure 3

Long-tailed macaque (M. fascicularis) wounds at the Ubud Monkey Forest. (A) Young adult male with lacerated lower lip from fighting; (B) Adult male self-grooming slashed tail wound from fighting; (C) Young adult female with open wound on left arm; (D) Young adult female with missing upper lip lacerated off from fighting.

Figure 4

Long-tailed macaques (M. fascicularis) inhabiting an urban environment. (A) Adult males walking along powerlines situated outside the Ubud Monkey Forest; (B) Subadult male licking necrotic tail that was struck by the motor scooter.

Figure 5

Plastic bottle caps lodged in long-tailed macaque (M. fascicularis) cheek pouches. (A) Juvenile macaque, red arrow refers to a bottle cap lodged in the cheek pouch; (B) Macaque with lodged bottle cap perforating cheek pouch. The bottle cap was surgically removed and treated by the veterinarians at the Ubud Monkey Forest.

Figure 6

Posterior predictive check $p\left(\tilde{y}\right|y)$ showing how well the model predicts an injury vs. death across the sample.

Figure 7

A point range plot demonstrating the estimate and 95% CI of the odds of death at each social group across all four study years. The line at 1 is baseline and assumes equal odds of death vs. injury.