Since the first afternoon we arrived in Kenya, storm clouds had been threatening to bring an early start to the rainy season. We worked hard to get the prescribed burns for our research project finished before the rains, each day looking anxiously out across the valley where other ranches were getting isolated storms. Fortunately we were able to finish in time, and just a few days afterwards, multiple bands of storms thundered in. It was amazing to see the intensity of the rainstorms, and how quickly the land responded! Plants started greening up in just three days, and week after the first storm the whole landscape was transformed. Animals changed their behaviors too, with birds starting their breeding and nesting patterns for the new season, and insects emerging in droves out of the ground.
These young ones were hidden in the grass a little ways away from one of the areas we burned. Our hope is that the burned areas will attract lots of herbivores, which will in turn provide some tasty lunches for the cheetahs when they get a little bit older!
The only legal way to shoot wildlife in Kenya is from a car, with a camera. In the afternoons and evenings after the day’s fieldwork, we drove around to different parts of the reserve, stopping whenever we spotted something in the bushes, trees, or skies.
The diversity of wildlife here is mind-blowing. In just a few weeks, I’ve seen 34 different species of wild mammals, and more birds than I could begin to count. I’ve also gotten pretty good at taking pictures out of a truck window, aided by the best drive and tour guide imaginable (my advisor).
Fire–and what happens to plant communities after fire–is the core topic of my dissertation research. I’ve set up experiments in Sierra mixed-conifer forest and nutrient-poor but diversity-rich serpentine chaparral communities, and when my advisor discussed a project with prescribed fire in his study system in Kenya rangeland, I jumped at the opportunity.
For over twenty years, this project has been studying how the presence or absence of wild herbivores or cattle can affect this plant community–the acacia trees and understory grasses that grow on black cotton soil–and through them, the rodents, birds, and insects that also use this environment.
In 2013, the research team burned a section of each plot to test how past herbivory affected fire behavior, and how fire changed all of these interactions between wildlife, cattle, trees, grass, and insects. This year, we reburned all those sections to look at the effects of repeated fire, and burned a second set of sections in each plot to look at differences between fire in different years.
There were 36 burns total, each 30 x 30 meters. The whole process took our team of almost thirty people five days. Most of the crew was there not to light fire, but to keep anything outside of these sections from catching fire. In addition to the two main organizers and fire-lighters, there were people running two water tanks with hoses, people driving the trucks that pulled the water tanks, people running an even larger refill water tank–which was pulled by a tractor. Another crew wore backpacks full of water, to be able to spray any spot embers, and a final crew stayed behind after each burn, to rake apart coals or smoldering dung, and make sure all the hot spots were extinguished. Plus of course all the researchers recording temperature, wind speed, flame heights, bird movements, and tree survival.
For me, this project was a wave of experiences. This was my first time visiting anywhere in Africa and my first time working on a prescribed fire team. My original plan had been to arrive a week or so before the burning started, to have time to settle in and establish my own mini-experiment within the burn areas. However, due to concerns over the rains coming early, the entire project was moved forward, so we starting burning my second day after arriving. This meant that my first week I was trying to learn the system, help with the burns, keep ahead of the burning plan to set my experiments in the late afternoons or early mornings in the areas that would be burned the following day, and see and photograph as much nature and wildlife as I could. I didn’t have time to be jetlagged or tired from the 24 hour flight until over a week later!
From field assistants to coworkers, the team here has been absolutely amazing. Watching an unwieldy group of people with all these moving parts come together to accomplish all of these burns smoothly and safety was incredible. I’ve learned so much, and I’ve had a lot of fun along the way!
On Mpala Ranch is an area commonly referred to as the hippo pools, which is just upstream of a small dam, so the water level stays consistent even during the dry season. It’s one of the best places to go to see wildlife, including the hippos that give its name, and many other animals that take advantage of the predictable resource. We saw over fifteen hippos there on our first visit, as well as a small herd of elephants, a troop of vervet monkeys, two giraffe, a fish eagle, a little bee eater, and a hadada ibis. The big yellow-barked acacia that grow near the river are called fever trees.
Mpala Ranch has two main soil types–black cotton and red soil–which host vastly different plant communities. Our research takes place on the black cotton soil, where the plant community is dominated by one tree species, the whistling thorn tree (Acacia drepanolobum). Acacias in general are known for having thorny stems and hosting mutualistic ant colonies. The whistling thorn trees have many long, straight spines on the branches, some of which have a swollen, hollow base, which ants can live inside. They also secrete nectar from the base of their leaves that ants can eat. In exchange, the ants may defend the tree against herbivores ranging from other insects to elephants.
The whistling thorn gets its name from the sound the wind makes when it blows through the holes in the hollow thorns. Other trees grown on the black cotton soil, including other acacia species, but the whistling thorn trees dominate. Underneath them grows a variety of grasses.
Many different animals use the black cotton, including wildlife (elephants, giraffe, antelope, buffalo, cheetah, lions), domestic herbivores (cattle, goats, sheep, camel), reptiles, birds, rodents, and insects. Each species affects the plant community in different ways. Grazers eat the grasses, often singling out their preferred species. Browsers pull leaves from the trees. Wood-boring beetles carve tunnels through the tree stems. Elephants will even rip up or knock over full-sized trees, possibly just because just because they find it fun.
These photos were all taken during the dry season, when the grass is brown and the trees drop most of their leaves. In a month or two it will all be vibrantly green again.
Within the large wildlife reserve and research center that is Mpala, there’s a smaller area where researchers and staff live and lounge. This area is surrounded by electric fences that keep out the biggest of animals–elephants, hippo, giraffe, buffalo, and lions. Even just in this small space, though, birds and smaller mammals are abundant (and often very habituated to people). Also, the front porch of the kitchen/dining hall boasts sunrise views stunning enough to make jet-lagged 4:30am wakeups a blessing.
I was lucky enough to be invited to join my advisor on his 41st research trip to Kenya. For the next month I’ll be living at Mpala Research Center, helping with an experiment looking at the interaction between herbivory (by cattle or wildlife) and prescribed fires. We flew in to Nairobe late at night, and the next morning drove about four hours to the research station. The drive itself was incredible, seeing the change from drier lowlands to wetter uplands to dry again uplands–this time in the rain shadow of Mount Kenya, which remained shrouded by heavy clouds. I loved the alternating patches of farmland with towns, bright colored shops and roadside stands. The road itself boasted newer cars and Landrover-type safari vehicles, overburdened motorcycles and brightly colored buses with catchy shoutouts to Jesus painted on their sides.
The research station itself is incredible, with views looking out at the mountain range and an impressive diversity of wildlife. In just my first afternoon here I’ve seen eleven wild mammal species–zebra (Plains and Grevy’s), giraffe (reticulated), bush hyrax, warthog, dik dik, mongoose, bush baby, hare, vervet monkey, and bush buck–in addition to cattle, donkeys, sheep and goats. I wasn’t quick enough to get pictures of all of them, but I know there will be a lot more to see and many more opportunities! Our few hours in the field ended with thunderstorms in the distance and the setting sun lighting up the clouds over Mount Kenya.
We squeezed in a late-September backpacking trip up the Elwha. Despite a bit of chilly rain, it was a really beautiful trip, and we camped near a creek that feeds into the Elwha River. I’m really glad we managed this last-minute jaunt, as winter storms have once again destroyed the road leading to this trailhead, and it may not be passable next summer.