Since last I wrote, my field work has come to an end and analysis has begun. It has been a multidisciplinary wild ride. I’ll stick with the ecology and behavior components of my research for this first update.
Hyenas in fancy necklaces
After much government-level controversy and a decent amount of time, the ban on darting of wildlife in Kenya was finally lifted in February 2019 (I’ll save the juicy longer story for a future post). Because I had been geared up to collar since July 2018, I was one of the lucky few researchers to get my collaring plan re-approved right away- so I dropped everything and hopped on a plane to Nairobi almost immediately after hearing the news of the lifted ban. With much ado, drama (dare I say?), and effort by many parties, we ended up collaring seven spotted hyenas, representing 5 clans (two clans in Lake Nakuru National Park and three clans in Soysambu Conservancy). It was a great success.
The goal of this part of my study is to analyze the fine-scale (5-minute fix rates) movements of spotted hyenas in relation to linear barriers (fences, roads), other anthropogenic features and activities, land cover, livestock enclosures, and livestock predation events. Though spotted hyenas are heavily implicated in human-carnivore conflict, these aspects, especially at such a fine scale, have hardly been studied. Though the start-up effort was immense, there’s something inherently satisfying about having these hyenas out there collecting data for me, and looking at their movements each day on Google Earth hasn’t yet stopped being exciting. So far, the hyenas are showing us a few things: 1) the clans are using up every single inch of space in these two small protected areas (~180km sq each), 2) some of these hyenas are likely trying to disperse and failing due to linear barriers, resulting in some fascinating and unusual behavior, and 3) the Lake Nakuru National Park fence is currently not very effective at stopping hyena movements in and out of the park. Here’s where things get really fascinating.
Oh the places they’ll go…
Lake Nakuru National Park (LNNP) is one of only two fully-fenced national parks in Kenya (the other being the Aberdares). We’re talking a ~3 meter high, electric, parallel-wire fence. Some sections of the fence, particularly in the areas where the park directly abuts Nakuru city (one of the fastest growing cities in sub-Saharan Africa), have an extra reinforcement of woven wire extending a minimum of 1 meter underground, to prevent digging by wildlife. Like many barriers, the LNNP fence has a complex sociopolitical history. The fence was created not only to keep wildlife in the park and protect local communities from crop-raiding and livestock predation, but also to keep people out: the Kenya Wildlife Service (KWS) is concerned about poaching (especially of the endangered black rhinos living in the park), people gathering firewood inside the park, and other activities. KWS is trained to shoot on sight if they see any unauthorized people wandering in the park at night; when I would do night field work or travel through the park after dusk I had to warn my KWS ranger colleagues ahead of time so as not to get shot. The fence is complicated. People are grateful for its protection, yet sometimes do cut the wire to enter for resources. They illicitly graze their livestock in the perimeter (a grassy 2 meter space between 2 fences that’s technically a part of the park), yet express that as long as wildlife are blocked by the fence it’ll be fine to have large carnivores living just a stone’s throw from their homes.
As it turns out, just as the fence isn’t entirely keeping people out, it’s not keeping wildlife in either.
By walking, hiking, driving, and sometimes jogging along the entire LNNP fence several times, we discovered about 170 weak points where it was clear that wildlife were crossing in and out of the park. KWS rangers, who live in camps within the park, were integral to this effort since they see the fence every day. Using evidence such as fur and tracks (it was the rainy season the first time we did this, so, luckily for us, tracks were abundant), we chose 18 sites at which carnivores were definitely crossing. We posted camera traps (motion sensing cameras) at these stations to get a sense of the fence-crossing behaviors of carnivores and other wildlife, and monitored the cameras for a full year from June 2018-June 2019.
After the year was up, I had my work cut out for me (re-cut? was it ever not being cut…?): sorting the photos. Because most of the cameras had to be within the park facing the weak point or hole (to avoid theft outside of the park), the amount of erroneous grass photos was immense. My team of undergraduate students and I sorted through over 1 million photos, and were left with ~85,000 photos of wildlife doing all sorts of things at the fence line. I then reviewed each of the 85,000 wildlife photos (what better to do indoors on a winter day?) and assigned fence-specific behaviors to the wildlife in each photo (i.e. cross from LNNP, cross to LNNP, searching at hole, vigilant across fence, etc.). One of the first things that has become clear is that carnivores are crossing in and out of LNNP every single day. Baboons and vervet monkeys cross the fence with ease and constantly, warthogs aren’t too far behind the primates in their indifference to fences, and even large ungulates, such as cape buffalo, are also crossing the fence. Wildlife appeared at the fence line on every single camera, every single day. Final results are TBD, but it’s safe to say that the Lake Nakuru National Park fence will bring a new perspective to the current debate about whether conservation fencing is effective, economically viable, and ecologically sustainable.
Major funding for this project: National Science Foundation, National Geographic Society, Andrew & Mary Thompson Rocca Foundation