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The Phantom Hogs of Kibale National Park

Rafael Reyna is a biologist fighting to protect the vanishing animals of eastern African rainforests. He studies them through a variety of methods in the hope that the information he gathers can help save them from extinction at the (often unwitting) hands of mankind. Written By Rafael Reyna El Colegio de la Frontera Sur, México Uganda’s...

Rafael Reyna is a biologist fighting to protect the vanishing animals of eastern African rainforests. He studies them through a variety of methods in the hope that the information he gathers can help save them from extinction at the (often unwitting) hands of mankind.

Written By Rafael Reyna

El Colegio de la Frontera Sur, México

Uganda’s Kibale National Park is host to many endangered creatures; pigs and cats, elephants and monkeys. To help conserve them at this critical time, we have undertaken a project to learn more about their habits and behaviors, which are crucial to understand if we are to save them.

This project, kindly supported by the Committee of Research and Exploration at National Geographic, is focused primarily on an endangered species of pig, the giant forest hog (Hylochoerus meinertzhageni), which is the largest species of suid still alive in the world. As a species, we know very little about its characteristics, such as group size, movement patterns, feeding habits, habitat preferences and population status. Yet, we know it is disappearing at an alarming rate, especially the eastern African subspecies (H. m. meinertzhageni) (1). In addition, the project is gathering a wide array of information on other endangered animals at the same time.

The original aim of this project was to follow group movements of hogs with the use of radio collars. However, after months of trying to capture hogs to attach collars to, we had failed to capture a single one, so in July 2013 we switched to monitoring them through the use of camera traps instead. We have succeeded in recording several families of giant forest hogs visiting wallowing points, salt licks, and crossing trails (a short article was published in the news section of the National Geographic website here). After this post was published, more photo-captures were obtained, revealing more details of the social lives of these giant pigs.


This information will, we hope, shed light on the social structure of the groups, social behavior and the population status of this species. For example, we have learned that the giant forest hogs visited the salt licks mostly in the hours of dusk (18:00–20:00) and that they live in groups of 8–12 individuals with an apparently dominant male, which always uses the salt lick first. Groups of giant forest hogs contain one to six juveniles and several females as well. The group seems to be cohesive most of the time; however, we have also observed individual males and females with newborns traveling separately.

…And It’s Not Just Pigs, Either

In addition to photos of giant forest hogs, camera traps allow us to glimpse the behavior of other species that live in the rainforest that are very secretive and difficult to see. Among these species are red and blue duiker (Cephalophus weynsi and Philantomba moniticola), Kibale-forest elephant groups with babies (Loxodonta africana), golden cats (Profelis (Caracal) aurata) and L’Hoesti monkeys (Cercopithecus lhoesti), among others.


Red duikers were the most common mammal captured with camera traps and their relative abundance is the highest of all terrestrial mammal species in Kibale National Park. Red duikers prefer to feed in early hours and again in the evening hours. Blue duikers were less abundant in relation to red duikers. The L’Hoesti monkey, a species thought to be very rare in relationship to other primate species, was recorded by almost all camera trap stations and its relative abundance was only surpassed by the red duikers.


Camera traps also revealed group size in elephants, with the observation of one group of six and one group of 12 members, mostly composed of females and some juveniles and newborns. These elephants like to wallow in the mud and spray their bodies with it—like a spa in the jungle. In addition, we were lucky enough to have recorded a playful interaction between a marsh mongoose (Atilax paludinosus) and a golden cat one night, with the apparent dominance of the space by the golden cat.



The Forest Is Crying Out

Ugandan rainforests, as well as all eastern African rainforests, are facing great pressure from the growing human population and are being encroached upon every day (2). In addition, all of the terrestrial mammals face great pressure from poachers because of snare traps, which are meant for pigs; these traps can harm other species such as chimpanzees, L’Hoesti monkeys and baboons, as well as elephants. For example, in a single patrol of Kibale’s snare-removal team, 59 snares were removed in just four days.

It is urgent that we study and protect the terrestrial mammal community of Kibale rainforest as it may be the final stronghold and conservatory of animals like the giant forest hog and L’Hoesti monkey in all of eastern Africa. Understanding how these species act and live is fundamental to building conservation plans designed for them. This study, with the great support of the Committee for Research and Exploration from National Geographic, intends to supply pieces of that information. In addition, through this report we intend to share our amusement and delight with more people about the secretive lives of African rainforest wildlife.


Rafael Reyna wants to acknowledge the following persons who, without their help, advisory, and assistance this project would likely not be possible: Edith Rojas, Alex Tukumunde, Colin Chapman, Martin Mukasa, Patrick Kwalsion, Wilson Ruikakara, John Akwilo, Patrick Omeja, Mauro Sanvicente and Sophie Calme.


Literature Cited

  1. d’Huart, J.P. and Kingdon, J. In press. Hylochoerus meinertzhageni, In: Kingdon, J.S. and
    Hoofman, M. eds. (In press) The Mammals of Africa. Vol. 6 Pigs, Deer, Giraffe, Bovids
    and Hippos. University of California Press, Berkley
  2. Plumptre, A. T. R.B. Davenport, M. Behangana, R. Kityo, G. Eilu, P. Ssegawa, C. Ewango, D. Meirte, C. Kahindo, M. Herremans, J. Kerbis-Peterhanse, J. D. Pilgrim, M. Wilson, M. Languy, D. Moyer. 2007. The biodiversity of the Albertine Rift. Biological Conservation 134:178-194

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Meet the Author

Robert Coburn
I've lived and traveled all over the United States and the world. I've been in Germany, Holland, Japan, New Zealand and Australia. I've completed sustainability projects in the latter two countries and studied and written on advanced theoretical biology and technology topics, like artificial life and the search for alien organisms in strange places. People say I am very funny and entertaining. I suppose I am. I am very passionate about a lot of topics and great at analyzing things to an interminable depth. I'm highly imaginative and daydream a lot—not on the job, mind you. Writing has always been my primary focus and greatest area of expertise. I'm currently involved in writing a monograph on first-line HIV treatments, as well as a fictional novel. My interests include biological and geological history, travel (but who doesn't say that, right?), weight training, nature, photography, romanticized historical movies and books, exploration and investigation. I help National Geographic explorers and grantees to publish blogs live from the field, and write original posts covering their work as well.