Cheetahs rocking the boat…again!
Cheetahs, it seems, just can’t stop shattering everything we believed to be true about them.
Scientists have long believed that lions (and hyenas to some extent) threaten cheetah conservation efforts — in large part because they kill so many cheetah cubs. But last year, researchers from South Africa revealed that lions probably don’t kill as many cheetah cubs as folks previously believed. And shortly after that, our research showed that regardless of the amount of lion-inflicted cheetah cub mortality, cheetahs do just fine around large lion populations.
Just last month, another story broke that shakes up how we think about cheetahs. It turns out that not only are cheetahs not as vulnerable to killing by lions, but they cheetahs aren’t nearly as vulnerable to non-lethal bullying either. It was thought that because cheetahs couldn’t fight back against lions – or hyenas – they lost a lot of their hard-earned kills to these ruthless scavengers. (Yes, both lions and hyenas do steal food from each other and from cheetahs.) We knew that wild dogs expend so much energy hunting that they can’t afford to lose even moderate levels of food, and assumed that cheetahs were similarly vulnerable. But, as a recent study from Bostwana and South Africa found out, they aren’t. It turns out that despite being super fast, cheetahs don’t expend all that much energy chasing down their prey. Researchers estimate that cheetahs could lose a full 50% of their kills to lions and hyenas, and still get all the calories they need!
All in all, it’s beginning to look a lot like the biggest threats to cheetahs aren’t lions and hyenas. Instead, availability of denning sites (as suggested by our research) and human destruction of habitat that forces cheetahs to travel far and wide in search of prey (suggested by this most recent study) are probably much, much greater threats to their survival.
Tidbits on wild dogs
One of our long-time Snapshot Serengeti members (thanks Reid!) sent me this NY Times article on African wild dogs. As you know, we don’t have wild dogs in the study area (though keep your eyes peeled! TANAPA did reintroduce them into the western corridor the other year, and I keep hoping we’ll catch one traveling through our grid).
But I am very interested in how dogs interact with the larger carnivore community. And these animals are just *so* cool – incredibly energetic and full of nerve. Watching a small group of dogs defend their kill against a hunting party of hyenas was one of the highlights of my trip to South Africa in June.
Photo by Ingela Jansson
The article points out that wild dogs may fare better when lions fare worse (which I’ve reported on here) — and that raises some questions about questions about how to target conservation efforts. Do we have to choose between which species to protect? I’d say “not necessarily.” My dissertation research suggests that although dogs fare worse in small reserves with lions, there are places where wild dogs seem to do just fine. Selous Game Reserve (TZ) and Kruger National Park (SA), for example – big areas that have complex habitat structures. So the answer to protecting the entire carnivore guild may lie in larger, diverse reserves.
There are currently efforts in place to do create a protected area the size of Sweden that spans five southern & east African countries. If successful, according to the NY Times, the Kavango-Zambezi Transfrontier Conservation Area will be the largest terrestrial protected area in the world. Now that’s something to celebrate.
I’m in the Zooniverse!
The Snapshot Serengeti science team has been a bit remiss at blog posts over the summer. Meredith has been battling tsetses in Serengeti for her first ever Serengeti field season, and I’ve been kept busy traveling on three continents – between finishing my dissertation, crewing for my partner in the world hot air balloon championships, and…moving to Oxford to join the Zooniverse!
Note that the red Zooniverse hoodie against the red sign is probably not the most flattering of photographic setups…
We’re still working out exactly what my job title and job description are (details!), but now that the dissertation is officially finished and I’m settling in here, expect more posts to come!
I am…
Dr. Swanson!
I have to admit that the defense was way easier than I had anticipated. In fact, I got to spend much of the two hour question session talking about possibilities for future citizen science projects and the cool things that could be done with camera trap surveys. Once things settle down on my end, I’m looking forward to sharing some of my most recent results here on this blog.
…But it might be a few weeks. Right now I’m in Brazil, crewing for my boyfriend in the world hot-air balloon championship. We are centered in Rio Clara, and this place is beautiful. Although more cultivated than some of the places we are used to flying (e.g. Serengeti), we have still managed to find some wildlife. When we (the chase vehicle) managed to find the landed balloon past a maze of 12-foot-tall sugar cane fields, the co-pilot looked at me nervously and said, “there are no hyenas in South America….right?” Because apparently they had seen a rather large canid ripping into some carcass on some abandoned hillside on the flight. And it turns out that there are maned wolves here, which is probably what they saw. Maned wolves actually vaguely resemble giant red foxes (~ 3 ft tall at the shoulder), and are in a genus all their own (Chrysocyon), and are considered “vulnerable” (as a species) by the Brazilian government. They are pretty cool.
Maned wolf; credit Mario Pineda flickr cc
Funny story. When I was applying to graduate school, long before I decided to work with Craig at the University of Minnesota, I had wanted to study maned wolves in the Brazilian cerrado (tropical savanna). And, in the end, I turned down an offer to do so in favor of coming to UMN. But wouldn’t you know it, 6 years later, here I was – right in the middle of maned-wolf country! Granted, *I* still haven’t seen a maned wolf here, as is usually the case. The balloon pilots, with their birds-eye view, always see the most spectacular things. We on the ground just hear about them.
But I’ve got nearly two more weeks here…and I’m on a mission to find me a maned wolf!
Quick update
Just a quick update on a room change for the seminar — it will be in Borlaug 365 at 1pm, July 11. The official announcement is below!
PhD Defense Seminar in the
Ecology, Evolution, & Behavior Graduate Program
Presented by
Alexandra Swanson
Advised by: Dr. Craig Packer
1:00 pm, Friday, July 11
365 Borlaug Hall
“Living with lions: spatiotemporal mechanisms of intraguild predator coexistence”
Top predators often suppress their smaller guild members and this can have profound consequences that cascade throughout the larger community. Suppression is mediated primarily through interference competition: direct aggressive interactions and behavioral avoidance by mesopredators to minimize the risk of aggression. These avoidance responses can be costly, especially when they result in large-scale displacement that reduces access of the subordinate species to resources. My dissertation explores the role of behavioral avoidance in driving intraguild predator dynamics, specifically hypothesizing that large-scale displacement drives mesopredator suppression, but that fine-scale avoidance strategies may promote coexistence by minimizing risk without costly large-scale displacement. Specifically, I examine how African lions affect spotted hyenas, cheetahs, and African wild dogs in Serengeti National Park, Tanzania. I first evaluate evidence for mesopredator suppression and large-scale displacement using long-term historical data. I then evaluate patterns of avoidance at fine spatiotemporal scales using novel camera-trapping methods and citizen science. Together, these studies identify large-scale displacement as a key driver of mesopredator suppression and fine-scale avoidance as a key mechanism for mesopredator persistence.
And the countdown begins
This Friday, July 11, I’ll be defending my dissertation. A little over a week ago, I hit the “send” button that submitted my dissertation to my committee members. At 124 pages, it falls smack-dab in the middle of most EEB (Ecology, Evolution & Behavior) dissertations (as my friend Marcus describes in this cool (albeit nerdy) post here). The defense itself consists of an hour-long presentation (open to the public – so karibu Borlaug 365*, July 11, 1pm) followed by 2 hours of medieval torture – whoops, I mean questioning – by my committee.
The last few days and weeks have been hectic. Since submitting my dissertation, I’ve been focused exclusively on preparing this seminar. An hour is a long time — but still somehow not long enough to talk about everything I’ve been doing for the past 6 years. Hell, I could talk for an hour about Snapshot Serengeti alone! And that’s just a part of my broader dissertation!
I’m excited and nervous and eager to be done with it all at the same time. Summer defenses are always a bit sad, as so many students and faculty are away in the field. Although I’m excited to finish my dissertation, I’m by no means done with Snapshot Serengeti. Not only am I preparing several Snapshot papers for publication, but…drumroll…I’ll also be joining the Zooniverse team in Oxford in the fall. As you probably know, Zooniverse received a Google Global Impact Award to build a generalizable tool so that science teams can build their own citizen science websites. I’ll be joining them on this adventure as their “resident ecologist” — to help make sure that such a tool makes sense for science teams asking questions about the natural world.
So! Exciting times. And hectic times. I will try to keep posting over the next few weeks as I defend (*fingers crossed*), then head to Brazil to crew for my partner in the World Hot-Air Balloon Championships, then pack up the last six years of my life and head across the Atlantic. Lots to come — just have to survive July 11 first…Wish me luck!
* location has changed to Borlaug 365, not 335!
Almost there…
I’ve been a bit remiss in blog posts lately. I’ve just recovered from a whirlwind trip through South Africa (so much exciting data!!!), a visit to the Zooniverse team in Oxford, and, not least, my 31st birthday — and now I am rapidly approaching the end of my dissertation, and it is pretty much the only thing on my mind. I’ve already got a date – July 11th – on which I’ll give an hour long public presentation (anyone local is welcome to come) followed by 2 hours of inquisition by my committee members behind closed doors. But to make it there, I first need to hand in my dissertation and have them all agree that I’m ready to defend. I need to hand it in by Friday, and still have a *lot* of work to do!
So, I may have posted this before, but figured it was a good time to (re) share this clip of baby elephants learning to use their trunks. They remind me a little bit of me trying to learn how to do science…
Nyala are way prettier than impala
I’m in South Africa, getting a feel for the ongoing Panthera camera trapping surveys, collating data, falling madly in love with the country and South African bush, and scheming for how I need to find a way to come back.
Things are a bit of a whirlwind, but so far I am amazed and excited about the amount of monitoring that many of the small private and state-run reserves have been doing. There is an extraordinary amount of information that has been collected over the last decade on how all of the top predators move and live across these parks. There are parks with and without lions. Parks with and without hyenas. With and without wild dogs. Some parks are big and some are small. Some are very thickly treed, others are somewhat open. (Note that one thing I discovered very quickly is that pretty much all South African habitat, even the grassland, would equate to “woodland” in the Serengeti. So…”open” is a relative term.)
The amount of data here is enough to get any science nerd’s heart a flutter. But I am trying to focus on what is out the window instead of what’s on the computer for now. I’ve only a few days in South Africa, and endless time to analyze the data.
In the meanwhile, I thought I’d share one of my new favorite animals: the nyala.
These cousins to the waterbuck we capture in camera on Serengeti, and you can see it a bit in their pretty faces. But these animals are far more stunning than anything I’ve ever seen in Serengeti. The females are small and sport bright white stripes on their red fur, and the males have these incredible “manes” that run down the undersides of their necks and to their bellies. They are pretty awesome. As is everything I’ve experienced in South Africa so far. Yep, definitely need to find a way back!
South Africa, here I come! (cont’d)
A few weeks ago, I mentioned that I’d received NSF funding to carry out some research in South Africa.
Well, today, I leave to go do that!
I’m still frantically trying to finish up my dissertation, so this trip is only marginally prepared. I have tickets. I’ve started packing (still have 2 hours before heading to the airport, so I’d say I’m in good shape). I have a note to myself to *remember my computer charger*…
I’m excited (whoo! never been to South Africa!). I’m eager (I LOVE trans-atlantic flights because I get to watch movies for 20 hours straight and disappear into this weird twilight zone where time seems to stand still). I’m stressed (So much to do! Still haven’t finished my 3rd dissertation chapter so will need to work on the plane instead of watching all those crappy movies, darn). Sitting in my living room, surrounded by ziplock bags of socks and underwear, quick-dry field pants, power cords and extra batteries, I feel not-quite-ready for this new adventure — but I know it is going to be amazing and full of discovery nonetheless.
So with that, South Africa, here I come!
Just for fun
I know Mother’s Day was a week ago, but I stumbled across this little gem and thought it was worth posting. I’m currently frantically prepping for my trip to South Africa, so stay tuned for travel stories soon to come!
Snapshot Serengeti 