Gorongosa and Sasagamine: intra-species behavioral variation in baboons and Japanese monkeys
In August 2018, I had the opportunity to spend a week in Gorongosa National Park in Mozambique. Mozambique, formerly a Portuguese colony, gained independence in 1975. During the civil war that followed (1977–1992), animals in Gorongosa were targeted by soldiers as food. After the war, the number of animals started to recover, partly through a reintroduction program sponsored by the Carr Foundation, founded by Mr. Gregory Carr (Wilson 2014).
The field study of primates at Gorongosa is run by two Oxford scholars, Susana Carvalho and Dora Biro, both ex-students of mine. They invited me to accompany them on their field research. Guided by their PhD students, I had the opportunity to observe two troops of chacma baboons (Papio ursinus). The two troops are separated from each other only by a few kilometers, but live in very different environments: One lives in the woodland, the other on a grassland flood plain that it shares with waterbuck, impala, and even lions.
The flood plain where the grassland troop lives will turn into a huge lake in the rainy season. What will happen then? We do not know the details yet, but the baboons must migrate from the flood plain to the neighboring dry area. Their annual activity cycle is waiting to be studied.
Baboons, the genus Papio, are predominant across Africa and the southern part of the Arabian Peninsula, inhabiting various environments across the continent. There is another successful group of nonhuman primates that adapts to various environments, namely macaques, the genus Macaca.
I got a job in the Primate Research Institute in 1976. During the first winter, I went to Shiga Heights to see wild Japanese monkeys, often referred to as snow monkeys (Macaca fuscata). I studied the wild monkeys there (Matsuzawa et al. 1983; Wada and Mastzuawa 1986). In 1977 I started to focus on chimpanzee research in the laboratory and in the wild. However, I tried to take opportunities to visit the natural habitats of Japanese snow monkeys. Starting in the north, I have been to Shimokita Peninsula, Shiragami Mountains, Kinkazan Island, Shiga Heights, Myoko Heights, Kurobe valleys, Mt. Hakusan, Arashiyama in Kyoto, Shodoshima Island, Kohshima Island, and Yakushima Island. Thus, I have visited wild monkeys that have adapted to living in 11 different environments. The variation in behavior within the same species is enormous. Depending on where they live, the monkeys love to wash sweet potatoes (Schofield et al. 2018), bathe in a hot spring in Shiga Heights (Matsuzawa 2018), form extra-large clusters in Shodoshima (Zhang et al. 2007), and ride on deer in Yakushima (Pelé et al. 2017).
In the genus Macaca, the rhesus monkey (Macaca mulatta) has the largest geographic distribution, occurring from Afghanistan to China via India. The eastern limit of the distribution of Macaca is the Japanese monkey. The western limit is a species sometimes called the Barbary ape (Macaca sylvanus); due to its very short tail, it lives in the northern part of Africa, not far from the Mediterranean. Thus, a large area of the Old World, meaning Asia and Africa in this case, seems to be occupied by baboons from the west and macaques from the east.
The common characteristics of baboons and macaques are as follows. First, they form large troops containing both males and females. Second, they are omnivorous, feeding on diverse resources including plants, animals, insects, etc. Third, they adapt readily to various environments, from the seashore to high altitudes.
Some Japanese monkeys live high up in the Japanese Alps, reaching 2500 m. They are known to capture and eat birds called rock ptarmigans (Lagopus mutus). They use caves to shelter from heavy snows in winter in the Kurobe valleys (Kashiwagi et al. 2012). The key here is adaptation to various environments. They invaded new habitats and started to eat new and varied items. This reminds me of the case of human evolution and our species’ adaptation to new environments. We might be the most extreme case of adapting to various environments on the planet.
I am grateful to Drs. Susana Carvalho and Dora Biro of Oxford University. They gave me the opportunity to visit Gorongosa. Thanks are due to Prof. Richard Wrangham of Harvard University who was visiting Gorongosa with me at the same time, and Mr. Gregory Carr who welcomed us to the park. Financial support for preparing the manuscript came from MEXT-JSPS Grants #24000001, #16H06283; the Japan Society for the Promotion of Science (JSPS) Core-to-core Program CCSN, and the Leading Graduate Program of Primatology and Wildlife Science (U04) to the author. I also thank Dr. Shigeru Sugiyama for guiding me in Sasagamine, and Drs. Jim Anderson and Dora Biro for editing the English text.
- Wilson EO (2014) A window on eternity: a biologist’s walk through Gorongosa National Park. Simon & Schuster Inc, New YorkGoogle Scholar