Since I started to study for my first degree in biology, I heard a lot about Taï National Park (TNP) in Ivory Coast.
Indeed, this is the biggest primary rainforest of West Africa and different endemic species live there as the Jentink’s duiker (Cephalophus Jentinki), the white-breasted guineafowl (Agelastes meleagrides) and 8 monkey species as the western red colobus (Procolobus badius).
When I began to work for my Master’s thesis with IBREAM, I was very happy to go to this forest to study an endemic species of the National Park: the pygmy hippopotamus.
This animal is very solitary, nocturnal and rare to see in the forest. It was quite an exciting challenge to study it!
The objective of my Master’s thesis is to determine the diet of wild pygmy hippo living near the research stations of the TNP. More specifically it is to understand what it is eating to improve also its conservation both in a natural and in captivity environment
Ivory Coast, Taï National Park
I arrived in the Ivory Coast at the beginning of July 2017. On arrival in Abidjan I spent some nights in the Centre Suisse de Recherches Scientifiques (CSRS) before going to Taï City.
It was very important in order to prepare the investigation with my Ivorian colleagues, Karim Ouattara and Inza Koné before going to the forest.
The journey to Tai city was around 12 hours by car depending on the problems you may find (for example: we had to buy our own mattress for our forest camp).
I didn’t sleep during the trip so that I could admire the landscapes. Africa has plenty of colors!
We spend the first night in Taï City because it was too dark to go to the forest by car. The next day we drove for the first time into the forest. It was wonderful because everything was giant! You had to be really careful driving during the day to avoid fallen trees in the road.
Indeed, during the rainy season the trees are falling and we could be blocked for hours. The trees are huge and the road is not straight. But Bertin, our driver, drove carefully and we arrived safely at the camp which is situated more than a 1 hour drive to Taï City. There, I stayed in Camp Noe with the Taï Monkey Project (TMP) team.
The pygmy hippos need to protect their skin and like to hide and rest under the holes formed by roots trees.
Audrenisrou River as Nipla River or other little rivers are appreciated by them and we can found many tracks around it.
I spent the first three months trying to identify the habitat of the pygmy hippopotamus.
Then, I changed the focus of the project a little bit to look at the diet of this animal.
Just walking transects of 10 km didn’t help me to catch enough indirect observations as tracks and dung from this animal are very difficult to observe.
However, following the rivers or the human layons gave better results to catch pygmy hippo tracks and to my surprise there were a lot in my area!
We know now, thanks to camera traps, that the pygmy hippo spends 5 to 6 hours per day eating.[2,3] Knowing the diet needs of this animal will help to focus on the viability of its habitat.
Following the rivers, I also met different beautiful animals; frogs, monkeys and Dog Rivers and sometimes snakes! But the largest group I’ve seen was insects.
The most abundant and impressive I’ve seen were the “magnan” ants. The organization of the ants was amazing.
Sometimes they are organized and can make a strong bridge to cross a pool of water for example, and other times they just attack and they are dispersed everywhere!
When we met them in the forest we had to run because the biting is painful and it’s difficult to cast them away.
I had an admiration for them until they invaded my room one day.
By chance it was during the day… I was coming back from the field and I saw a quantity of black points moving quickly down the walls of my room. I didn’t understand first what these things were and why my walls were black. Then, I realized that it was the ants!
During my research, I collected pygmy hippo feces and plants of the forest for the project.
Indeed, because of its cryptic behaviour and way of living, we can only, until now, study the diet by indirect methods such as feces analysis.
To conserve the feces and to easily transport them, it is preferable to dry them.
I took also plant samples in the forest and made an herbarium in order to determine which plant fragments were found in the feces.
Pygmy hippos in zoo
Back in Abidjan, I went to visit the pygmy hippo in the zoo.
The objective was to check as well, in a captivity environment, what it was eating. Actually, it lives alone and eats local plants found around the zoo.
The zookeepers told me that they give local plants found around the zoo.
However, a friend came one month later and told me that the hippo was eating the same food.
I think more that this hippo has a monotonous diet of one kind of plants.
Then, back in Switzerland I went to visit the hippos of Basel Zoo as well. There are three pygmy hippos (a male, a female and a baby).
I collected their feces in the zoo to have some control samples and tests for the laboratory. In Basel Zoo the diet is varied ; they eat beets, carrots, fennel, food pellets (content of vitamins and mineral elements) hay and lettuce.
At present I’m analyzing by macroscopy and microscopy the plant fragments found in the feces of the pygmy hippos living near the research stations of the west part of the TNP.
I am very curious to see whether they are selective or not in their food and how to help them more for their conservation into the wild and also in the captivity.
Based on my experience, I understood why there is so little information about pygmy hippos because they are very difficult to observe (sometimes frustrating).
However, I really hope that my study will help also to improve the knowledge of this very special mammalian species.
This project has been funded by the CSRS with the « Willy Müller Award » and the Fond des Donations of the University of Neuchâtel, which I would like to thank as well as the Evolutionary and Genetics laboratory of Neuchatel which provided me the material for the lab analysis.
I also would like to thanks IBREAM for the support and all my supervisors Klaus Zuberbühler, Monique Paris, Karim Ouattara, Inza Koné and Bogui Elie to trust me in undertaking this project and to give me the ability to realize it.
References
- Google Maps. Google Maps Available at: https://www.google.com/maps/search/de+Abidjan+a+tai+passant+par+yamoussoukro/@6.0554212,-7.8929324,7z/data=!3m1!4b1. (Accessed: 6th September 2018)
- Robinson, P. . The reported use of denning structures by the pygmy hippopotamus (Choeropsis liberiensis). Mammalia, 45: 506–508. (1981).
- Eltringham, S. K. Les hippopotames. London: Academic Press (1999).