Artificial streams in the middle of the Mara

We set up our first artificial stream experiment in 2014, using a portable artificial stream array we built in Kenya. It was so exciting to be able to conduct rigorous experiments in the field, with controls and replication, which is usually quite difficult to do at the ecosystem scale at which we normally work. In 2014, we set up the stream array at the Mara River Water User's Association in Mulot, which is a grassroots water resource management group. Working there was a great way to stay in touch with local stakeholders in the basin and involve them in our research, and they had electricity and a water pump and holding tank that made running the streams fairly easy.

We were excited to use the artificial streams again this year, but we were hoping to stay closer to our camp, which is in the middle of the Mara Conservancy. We also planned to expand our stream array to 18 streams. But how could we get 18 streams full of water and running continuously at a remote field camp with no electricity or running water? Ah, a logistics challenge is hard for us to resist!

The first step, which is often the case, was to consult Brian Heath, CEO of the Mara Conservancy. In addition to managing the Mara Triangle, Brian is  a consummate naturalist, logistics expert, and supportive friend, whose advice and guidance has been critical to our success more times than I can count. Brian generously offered to let us use a vacant concrete pad located near the Conservancy headquarters, and we had a good start. The manager from the nearby Mara Serena lodge graciously allowed us to use their electricity for the experiment. Now, all we needed was water.

Crabs in the Mara?

During the food web short course, we had several great scientists from the National Museums of Kenya join us, including Laban Njoroge, Head of the Invertebrate Zoology section and an expert in aquatic macroinvertebrates, and John Kochey, a scientist in the Invertebrate Zoology section and a doctoral student studying freshwater prawns. John brought along some prawn traps to set in the river, and at the New Mara Bridge, on the border of Kenya and Tanzania, we caught a crab! We have seen a similar type of crab in the upper Mara, but we have never seen these in the lower Mara, and it turns out this is the first time this species has been documented in the Mara. It is Potamonautes niloticus, which is found within the Nile Basin, including Lake Victoria and its tributaries. It's a beautiful animal, with an olive green back and bright red claws tinged with blue. It's so exciting, after all the time we have spent in the Mara, to still be finding new animals there, especially one as unique as this.

Food Web Short Course

This year we taught our first short course on food webs and stable isotope ecology in the Mara River. The course was taught by myself, David Post, Emma Rosi-Marshall and Frank Masese, with funding from the National Science Foundation. We had 12 participants from Yale University, the National Museums of Kenya, Egerton University and Eldoret University. Some of the course participants were senior scientists or professors interested in learning more about these topics, and others were undergraduate or graduate students still planning their research. The course began with a day of lectures, followed by three days of a field sampling campaign, and then a final day of data analysis.

It was a really wonderful group of scientists and colleagues, all of whom work on different areas of freshwater ecology, and we had a wonderful time together in the field! The best part about the course was that everyone had different areas of specialization, so we all learned from one another.

Our outdoor laboratory

Searching for macroinvertebrates

Sorting bugs

Electroshocking for fish

Setting gillnets for fish

Streamside lecture

The requisite breakdown

Outdoor laboratory #2

Electroshocking for fish

Picking bugs out of hippo poop

Sampling with an armed ranger

Collecting wildebeest bones to sample biofilm

Lecture on aquatic macroinvertebrates

The team

Welcome to the Mara, James!

This summer we have two undergraduate students joining us in the Mara for the first time. They are part of a Research Experience for Undergraduates (REU) program through our National Science Foundation grant. The first student, James Landefeld, joined us in the Mara this week. James will be conducting research on the influence of hippo and wildebeest inputs on the Mara River food web, using both field sampling and artificial streams. Karibu James!

Bush baby

This summer we have a new field assistant joining us in the Mara... Lily will be coming along on her first field expedition! It will be a whole new adventure to have her in the Mara with us. I'm a little nervous (wildlife, malaria, equatorial sun, oh my!), but mostly excited! I hope she loves it as much as we do.

Invited lecture at the University of Antwerp

On our way to Kenya for our 2016 field season, we stopped by to visit our colleagues, Jonas Schoelynck and Eric Struyf, at the University of Antwerp. Jonas invited me to give a lecture at the Institute of Environment and Sustainable Development's Water in the World Series on the influence of large wildlife in the Mara River. It was a great honor and a lot of fun. 

Jonas and Eric visited us in the Mara in 2014 to study the influence of hippos on silica cycling in the system, and we're now working together on a paper on this topic. It was a short stay (and a little unnerving to leave 7 bags of research gear in a coin operated locker at the airport), but we covered a lot of ground and had a great time!

Jonas and Eric sampling silica in the Mara River

Graduation Day

Thank you so much to my advisor, Dr. David Post, for taking me on as a student, giving me unparalleled opportunities to grow as a scientist, and providing a supportive home for me here at Yale!

Huge wildebeest drowning in the Serengeti

Chris and I are currently back at Yale, but Geemi has been doing an outstanding job documenting wildebeest river crossings and drowning events this year in the Mara River. So far, there have been over 70 river crossings and just one drowning with 1,200 individuals. This is much fewer what we have documented over the past four years (an average of 5 drownings and ~7,000 individuals per year). All of our research thus far is on the Kenyan side of the border, but we just saw a report online of a huge wildebeest drowning that just happened on Sept. 29 in the Mara River on the Tanzanian side. From speaking with Mara Conservancy rangers, Geemi has learned the drowning happened fairly far downstream in the Serengeti, but we are still trying to find out more information. The original article was posted on Africa Geographic, and here's a photo from their story...

Wildebeest drowning in Mara River, Serengeti (photo from Africa Geographic)

ESA 2015

Amanda, Lily and I are at the Ecological Society of America meeting in Baltimore this year.  Amanda co-hosted a session called "Danse Macabre: The Role of Migrations and Mortality in Shaping our Planet" and presented on the "Causes and consequences of wildebeest mass drownings in the Mara River, Kenya".

I gave a poster on "Tracking flood pulses and their impacts on water quality using a low-cost, open-source monitoring network in East Africa."  Data from the network is available on Thingspeak.  If you're interested in the base code that I use in the water level stations and the weather stations (take a measurement and then upload to Thingspeak via a GPRS connection), you can get it here - https://github.com/cldutton/MaMaSe.

Geemi in Action

Some photos of Geemi documenting hippo aggregation numbers during extremely low flows (Thanks to Angela @ The Mara Conservancy for the photos!).