Love, hate, or somewhere in between?
It’s hard to tell whether the hyenas really love or really hate my cameras.
“Camera, you are going *down*”
Reconsidering…
Nope, definitely going down! (Inside of his mouth — see the canine tooth?)
To be fair, I have seen hyenas absconding with everything from flip-flops to sofa cushions – and there was an unforgettable night where our neighbors were awakened by the crashing about of a hyena who had gotten his head stuck in a mop bucket. The world is their chew toy.
One of our favorite things about camera traps is that they are relatively noninvasive – we think of them as candid cameras, unobtrusively watching the secret lives of Serengeti’s most elusive animals. We don’t bait our cameras to attract animals: we want to capture the natural behaviors of the animals to understand how they are using their landscape – what types of habitat features they prefer, and whether they alter their patterns of use at different times of day, at different times of the year, or in areas where there are lots of competitors or predators.
But it’s a fair question to ask whether the cameras affect animal behavior, and an important one. Stanford graduate student Eric Abelson, is hoping to answer it. If the animals are being attracted to or avoiding areas with cameras, that could change how we interpret our data. In wildlife research, this is known as being trap-happy or trap-shy. For example, say we want to estimate the population size of leopards in Serengeti. Since leopards have unique spot patterns, we can use what is known as Mark-Recapture analysis to calculate the total number of leopards based on the rates that we “re-capture” (or re-photograph) the same individual leopard. Because of the way that the math works out, if animals become trap-shy – avoiding camera traps after an initial encounter — then we would overestimate the total number of individuals in a population.
Fortunately, although researchers in other systems sometimes find trap-shy animals (baby tigers in Nepal, for example), our Serengeti animals don’t seem too bothered – at least not to the point where they avoid an area after encountering a camera trap. Even at night, with the flash firing away, we get photo after photo of the same bunch of playful lion cubs, or repeat visits by the same leopard, cheetah, lion, or hyena week after week.
Also, since the cameras aren’t baited, we don’t think that they’re drawn to the cameras from long distances. Instead, we think that once the animals are close to the camera, they come a little closer to investigate thoroughly.
Hope you enjoy the view!
The Snaran Story
You may have seen a snapshot of the lion Snaran when you were classifying:
The Lion Project is familiar with the individual lions in the area where the camera traps are set up, and so we can give you Snaran’s back story. Craig Packer writes:
Field assistant Ingela Jansson first saw Snaran on 22-Sept 2009 together with three other males along the Ngare Nanyuki River in a favorite area for two of our long-term study prides, the Loliondos and the Young Transects. The four new males were all shy, but Ingela eventually managed to get close enough to take photos and note down their ear notches and whisker spots. These identifying marks are how we keep track of individuals. She named them Snaran (Snare in Swedish), Faran (Danger), Karan & Twaran (made-up names).
Snaran had a fresh large scar around his neck, obviously caused by a snare, but it was impossible to tell if the snare was still there. Eight days later, Ingela found Snaran and his three brothers together with the Loliondo females. Ingela asked a veterinarian to come dart Snaran with tranquilizer and treat his snare wound. No wire was found, so Snaran must have wounded his neck while pulling himself free from the snare.
A year or so later field assistant Daniel Rosengren asked the vets to handle Snaran a second time, because his wound wasn’t healing. They worried that a snare may still be well dug into his flesh, but a metal detector found nothing. Snaran has otherwise remained in good shape, and the four males have stayed on as resident males for both the Loliondo and Young Transect prides.
The camera trap snapshot of Snaran is from March 25, 2011. Comment on it on Snapshot Serengeti’s ‘Talk’ pages.
Data from Seasons 1, 2, and 3
Last week Michael Parrish sent me all your classifications for Seasons 1, 2, and 3. At 4,374,368 classifications, it’s going to take me a while to fully analyze them. Nevertheless, I’ve taken a first look through and am happy to give you some feedback.
Snapshot Serengeti volunteers classified 512,585 capture events. (We call a set of images a “capture event,” regardless of whether it consists of 1 or 3 images.) Of these capture events, 30% were from Season 1, 40% from Season 2, and 30% from Season 3. Based on your classifications, 72% of these capture events were “nothing here” and less surprisingly, Season 1 had the highest share of “nothing here” images. Season 1 was when Ali was still trying to figure out how to animal-proof the cameras and plenty of cameras got knocked off trees. I still have to double-check accuracy for these “nothing here” images, but suffice it to say that you guys classified a lot of blowing grass. Thanks for your perseverance!
And what about the Snapshot Serengeti community itself? I want to preface this by saying that in the data I get, all volunteers have been anonymized. That is, each user name has been replaced by a gibberish string of letters and numbers, so I don’t know who is who. I can tell you that we have 14,352 volunteers who created a user name. They provided us with 84% of the classifications; the rest were done by people who didn’t create – or hadn’t yet created – user names.
The median number of capture events classified by each logged-in volunteer was 63. I find that pretty awesome. In case you need a refresher on what the median is: imagine we put all 14,352 Snapshot Serengeti volunteers in a line according to how many capture events they had classified. Those that made just 1 classification would be on the far left end, and those that had classified thousands of capture events would be on the far right end. Then we would find the volunteer in the very middle of this line; she would be the 7176th volunteer from the left (7176 is half of 14,352). And we would ask how many classifications she had made. The answer would be 63; that is, half of all volunteers (on the left) made fewer than 63 classifications and half (on the right) made more than 63 classifications. Sixty-three classifications is no small number; you’ve got to be sitting there a while to do that many, and yet over 7,000 different people did so. Wow.
The most number of capture events made by one volunteer? 8,431. That’s just for Seasons 1, 2, and 3, so I’m betting that number is higher now that Season 4 is underway. The 5,000 Club is pretty exclusive: 23 of you classified more than 5,000 capture events in Seasons 1 through 3. The 1,000 Club has 829 members. And an astounding 5,777 people classified more than 100 capture events.
I continue to be amazed and humbled by your dedication to this project. Thank you.
A note from the field
### I’m still getting sorted out in Tanzania – here’s a post I wrote from my first full field season when I learned how to drive a Land Rover. Excitement. ####
“Oh Dear God, We are going to DIE.”
I remember that phrase on constant repeat in my head during my unprepared and ill-advised ascent of the Polish Tatras. I had decided to climb a mountain in late May with little more than a t-shirt and ultralight rain jacket – the kind that costs an arm and a leg because it weighs no more than a paper clip and fits in a tea-cup – a coarse park map and no compass. Just as I was convinced of my imminent demise then, I am now. “Oh God, we are going to die.” I mutter it under my breath to myself as the ancient Land Rover steering wheel ricochets between my hands. We are on the long road from Arusha to Serengeti, and I am convinced that at any moment the wind will blow us straight off of the fresh tarmac. Even on the best road in the district, the Landy pulls and sways, as though yearning for the ditch along the road, and I constantly remind myself to breathe as I focus hard on staying straight. Dala dalas stuffed with passengers pass by effortlessly but I am scared to turn my head lest I lose my tenuous grip on our straight path forward.
It is June 22, 2010. Today I am 27 years old, crossing that bridge from “mid-20’s” to “late-20’s,” and while I joke about how my bones creak and short-term memory is fading, I am still too young to die. Meshack laughs quietly beside me – he is our prized fundi, our expert mechanic, and is making the long trek to Serengeti for no other reason than to make sure that I (and the car) make it there in one piece. “Twende!” he says, motioning forward. Let’s go. I gulp loudly and clench the wheel tighter. There really is no respite from the terror – on the open tarmac I have to go faster; as we slow for villages there are pedestrians and bicyclists, peddlers and Maasai and livestock that weave alongside the road erratically, and I am convinced that at any moment one of them will meander into the path of my Monster Truck. Winding up the gnarled and pockmarked Crater road are blind turns and oncoming trucks that only further the terror of the already perilous ascent. I am torn between the urgent need to reach the park gates before they close, and my desire to remain alive and in more or less one piece. When we stop at the Crater rim (in part for Patriki to take a picture, in part for me to try and restart my heart), Meshack glances at his watch nervously. Ever so gently, he offers, “Maybe it would be faster if I drive?”
I almost kissed him. The passenger seat in a Land Rover has never felt quite so luxurious – before or since – though I still question my lifespan on a daily basis from the driver seat. For example, George, my coworker on the Lion Project, has been teaching me to drive off road. “It is just fine,” he assures me as we begin to climb the veritable of dusty soil and clumpy vegetation. Except when it is not fine. As we circle and spin and weave through aardvark hole-ridden hilltops, I can see him clutch the window frame suddenly in panic, his foot involuntarily slamming down where the break pedal should be. The Landy falls into the abyss where ground once was. Ka-thunk. I hold my breath and resist the visceral urge to slam on the accelerator and clear away from the danger as fast as I can. The Landy keeps chugging forward, powered by the magic that is low-range. The rear tire plummets to the depths of hell and haltingly crawls back out. We are alive. Barely. George laughs. “Avoid that green grass!” he reminds me. I am lost – it’s all green. “That’s green!” I point, “and that! And that over there!” It is all green and it all looks the same, but George sees some magical difference. I’m told that in time I will see it too. In the meanwhile, however, I maintain my running commentary. “OH dear God, we are going to die!…Oh, okay, we’re okay. Oh that’s a hole! Oh, okay, we are alive. That’s just grass.” …Except when it’s not.
Fire!
Maybe you’ve seen fire in some of the images you’ve classified and thought “oh no!”
Fire is actually an important component of savanna ecosystems. Fire kills young trees and seedlings, reducing the number of big adult trees that grow over time. Since trees compete with grasses for light and soil moisture, fire actually helps the grasses and keeps the savannas open.
Dr. Rico Holdo, a professor at the University of Missouri, and his colleagues modeled and wrote about the interactions of fire, rain, grasses, trees, and the various animals in the Serengeti. The interactions get complicated quickly, but I’ll try to give you a run-down of how they see fire acting in this ecosystem.
First, as I’ve mentioned, fire suppresses trees and encourages grasses. If you have both fire and rain, but no animals, then something interesting happens: the rain encourages the trees, but it encourages the grasses, too. As the grasses get taller, there is more fuel for fire, and the fires become more widespread and more damaging. These fiercer fires really hurt the trees – in fact, the damage from fires (because of more rain) is more important than the extra boost the trees get directly from the rain. So more rain actually means fewer trees.
With me so far? We’re now going to throw animals into the mix – well, at least some of the animals. Let’s talk about the grazers. The grazers eat the grass, and this reduces the fuel available to fire. If you have a lot of grazers, like we do in the Serengeti, the grass height is reduced a lot. That means fewer fires and that rain once again helps the trees. Further, many of the grazers are migratory and move around the landscape a lot. They don’t eat the savanna grasses in a neat, tidy, organized way. Instead, they create a patchy mosaic of grass heights, and with those different grass heights come different susceptibility of patches of grass to burn.
With rain and fire and grazers, we now have a landscape of grasses of different lengths, patchy fires, and some areas dense with trees and some areas with fewer trees. All that variation means more diversity – more diversity of the grasses, plants, and trees, and more diversity of the animals that rely on them.
All that diversity due, in part, to fire.
You can read the scientific paper by Dr. Holdo and his colleagues here:
Holdo, Ricardo M., Robert D. Holt, and John M. Fryxell. “Grazers, browsers, and fire influence the extent and spatial pattern of tree cover in the Serengeti.” Ecological Applications 19.1 (2009): 95-109.
Season 4
Dear devoted Snapshot Serengeti ID-ers: I know the last couple weeks have been tough, especially with the appearance of those two words that strike fear into the heart of every Serengeti addict (I mean ID-er): “We’re done.”
Well, we’ve got good news for you: we’re not really done. Like Margaret wrote the other day, we expected to have several weeks (or more!) to prepare Season 4 for posting. We hadn’t really expected to you guys to process three seasons of images in one week. Clearly. So, it’s been a bit of a scramble…but we’re finally ready to give you Season 4. Even cooler? Yours will be the first eyes to really take a look at these photos.
Prior to launching Snapshot Serengeti, Seasons 1-3 had been looked at by a small group of volunteers on a prototype application called “Serengeti Live.” We’ve been able to use the preliminary data to start answering research questions, refine our analytical methods, and show funding agencies that this project is really cool and worth continuing. However, each image had only been looked at once, so there were a lot of mistakes, which is why we still needed your help with those Seasons.
But Season 4 has never been seen before. It contains all the photographs collected during my last field season in Serengeti – February through July 2012. The rains were pretty bad that season – I can’t tell you how many times I got stuck in the mud trying to get to those cameras. Oh, yeah, and the neighbor’s outdoor toilet (choo in Swahili) sunk. But with the rains came the wildebeest, who honked/mooed (I don’t think there is a word for the sounds they make) outside our homes at night. And in July I lugged back a huge, dust-covered hard drive full of photos.
Choo down!
With every SD card I collect, I do some basic error-checking – so I’ve taken a very cursory flip through the photos and tried to trim down the number of “broken camera” shots of the dirt, grass, or sky, as well as some of the “lawn-mowing” images. But other than that, this is unexplored territory. These photos are new, unseen, unexplored…you’re the first!
I’m excited to see what you find.
Imagine this layer of mud on *everything.*
Earth Wolf
### Today’s post is a guest post from Lora Orme, an undergraduate conducting directed research with us at the University of Minnesota. ###
Often mistaken for a hyena, the aardwolf (whose name means “earth wolf”) of southern and eastern Africa is actually smaller and more docile than its carnivorous cousin (which belongs to a different sub-family). Both the striped and spotted hyenas primarily call large mammals “dinner,” but the aardwolf is more interested in a tasty termite column than meat. Because of its food choice, the aardwolf’s jaw is much less powerful and smaller than a hyena’s jaw, but the aardwolf has a specialized tongue that is longer and sticky. It licks up various insects (with a preference for termites) off of the ground, rocks, and trees with only minor digging with its front claws. For an aardwolf, a fully belly can mean as many as 300,000 termites! The aardwolf will memorize the locations of termite mounds to save the time and effort of finding new snack spots, and will be careful to leave enough of the population alive so that its food source will be “re-stocked.” At the end of a long night of dining on insects, the aardwolf returns home to an under-ground burrow.
At one point, the aardwolf’s burrow most likely was stolen from another small mammal such as a hare, aardvark, or porcupine. Although able to create a new burrow, it takes much less energy for the aardwolf to use a pre-existing one. The burrow provides a safe-haven in the daylight hours when the nocturnal aardwolf normally sleeps or relaxes.
Aardwolves, while primarily solitary, will coexist in groups of six to a dozen neighbor burrows. They congregate for safety in numbers (and more rarely to help rear young), but more often to find a mate. Males will seek females within their own territories and in those of neighbors, sometimes leading to male-male conflicts which are solved with barks, blunt-teeth gnashing, and musky scent-release from glands (the smell of which has been compared to a skunk).
A mating pair will form during the breeding season (spring or fall) and gestation lasts around 100 days, ending in a litter of three to five cubs. Usually birth occurs during the rainiest months of the year when termites are most available, providing plenty of nutrients for the growing young. The males contribute to the partnership by guarding the nest while the females nurse. Both parents supervise the cubs in their first foraging adventures about 3 months after birth.
Because the aardwolf acts as a control on the termite population, it often lives and scavenges near or on farms. Most farmers detest the termites that may destroy crops or infest homes, so they welcome the service of the aardwolves. Unfortunately, aardwolves are preyed upon by some larger carnivorous mammals such as the jackal. Even humans represent a threat to the species because the aardwolf is hunted for its unique fur.
Upon a closer look, aardwolves have distinctive pointed ears for acute hearing; after all, their prey is very small! The aardwolf’s paw is also distinctive from a hyena because it has five toes instead of four. The aspect you might notice first, however, is the bushy pointed tail that looks as if it has been dipped in a can of black or dark brown paint. In a confrontation, an aardwolf’s furry mane will raise from head to tail making it appear larger in size to (hopefully) persuade the opposition to back down.
See if you can spot one of these night-walkers as they prowl for termites!
It begins again.
### I’m traveling to Tanzania currently, about to begin my final field season (which will be Season 6 on Snapshot Serengeti). As usual, I’m running terribly behind getting ready to go – so thought I’d share a blog post I wrote while embarking on Season 2. ###
It Begins Again: Wet Season Survey 2011
As I leave Minnesota, winter seems to be already breaking. Amidst the national mid-winter heatwave, mountains of snow are melting, turning the roads into rivers and the hockey rinks back into lakes. For the third time, I am watching cheesy movies across the atlantic, fast forwarding through day and night, racing the sun eastward across the ocean and winning by 30 lengths like Secretariat in the Belmont Stakes.
Just some of the many casualties. Photo taken by Daniel Rosengren.
Except this doesn’t feel spectacular anymore. I am on my way to Tanzania, once again, with 240 lbs of luggage catapulting around the belly of the plane. My back feels thrown and the plane feels cramped, and the woman sitting next to me snorts and sniffles like some Sesame Street character.
After three weeks of delays, I’m finally heading…home? I’m dreading – just a bit – the madness that awaits me in Serengeti. A solid three weeks behind, I have 200 traps to place in the next 10 days….which happens to be humanly impossible.
See, my research relies primarily on camera traps – remote, automatic cameras that are triggered by heat and motion, attached to trees so that they take pictures of wildlife night and day. On the street they’re known as “hyena bait.” On my street anyway.
Yeah, that’s right. I’ve discovered that hyenas are like big ugly puppies – the world is their chew toy. However, unlike your neighbor’s cute, squirmy blue heeler, hyenas have no responsible owner to say “No! No demolishing the $200 camera trap!” Last year alone, hyenas ate nearly $8,000 in cameras. I would arrive at my excruciatingly selected camera site to find bits and pieces of plastic, the stray LED, a fragment of circuit board…just no camera. Elephants took down about $5,000 in cameras, but with minimal destruction. They typically ripped the offending trap from the tree and flung it out of site. Those cameras usually worked, with some minor case modifications. But the hyena victims? Beyond repair.
Given the abysmal loss rates from the first year of this ambitious (crazy?) camera trapping study, I am now returning to the Serengeti with replacement cameras and heavy duty steel protective cases…which happen to weigh about 1.35 tons apiece. That might be an exaggeration, but the point is that they are very, very heavy. And hopefully hyena-proof.
It is dark outside, though the fancy seat-back TV map says we are smack dab over the Atlantic. I feel like my mind should be racing with plans for my research, or meandering down memory lane – but mostly I am thinking about how good the red wine tastes, and how tired my eyes feel. The night outside seems endless, the world feels far away and frozen in time – like Zach used to do on “Saved by the Bell” – and in my alternate reality I slip guiltlessly into mass-market movies, into staring blankly out the window, the wine wrapping its velvet fingers around my fraying neurons.
I have a million things to do by…yesterday, but my brain is tired and does not want to work. I do not want to think about where on earth I put my hard drive, or the fact that I have not yet filed my taxes despite my imminent disappearance into the bush. I want to fade into the bright, apoplectic flashes of the action movie’s runaway trains or the feel-good underdog story of the horse that could. When I get to Serengeti, it will be a flat-out race against the rains. I want to get my cameras set before the rains keep me hamstrung for days at a time. Today is Feb 19; the rains start at the beginning of March. Can it be done? I guess we’ll see when I get there.
Lions: Lazy or just very, very patient?
Lions have a reputation for being profoundly lazy. To the list of inert elements of neon, krypton and argon, it is tempting to add lion. But while lions do sleep for most of the day, they are not idle slackers; they are profoundly patient.
Lions are ambush predators: they lie in wait. There is no need to be antsy during those long hours between hunting opportunities. If a group of lions has caught something recently or failed in a chase, they’ve given away their location, which all the prey in the vicinity will avoid for the rest of the day. But the Serengeti is a moveable feast, and any prey animals that slowly drift in to the area will have little idea of the precise location of danger, if the lions are hiding quietly in tall grass.
On the other hand, lions do tend to wait around near river courses and rocky outcrops, and herbivores will avoid these spots as much as possible. But if there is only one waterhole in the vicinity, the wildebeest, zebra, warthog and buffalo will have to weigh their thirst against the risks of being eaten, should there be lions hiding in those bushes over there. And if nothing stumbles blindly towards them, hungry lions will eventually have to emerge and actively search for their prey – but not until after dark.
Either way, it’s a game that predators and prey must play every day of their lives, but since lions can easily wait 3-4 days between meals, they have a fundamentally different perspective on the passage of time than the rest of us.
And that’s what makes the camera-trap data so incredibly exciting for me. In the mid-1980’s, I took turns with one of my former graduate students, David Scheel, watching lions 96 consecutive hours twice a month for several years – we were out with the lions for four days in a row just before and after each full moon, squinting through night-vision goggles whenever the moon was above the horizon. I nearly went out of my mind waiting for the lions to catch their next meal. We wanted to find out why lions live in social groups – and we were able to dispense with the myth that lions evolved to become social because of advantages from cooperative hunting: individual females in foraging groups didn’t feed any better than solitary females.
But there were so many more questions that we couldn’t hope to address without a better idea how lions and their prey play that spatial game of cat and mouse around the waterholes. And maybe the prey take advantage of the lions’ territorial behavior by finding refuge in the no-man’s land between pride ranges, or maybe the prey somehow move randomly from nowhere in particular to nowhere else in particular just to keep the lions guessing. A few years ago, Ali Swanson and I found that the Serengeti lions consistently fed better during the dark phase of the moon – what extra steps do the prey take to try to keep safe on those dark, dark nights?
We will finally be able to tackle these ideas with the camera-trap data. In the coming months and years, we will overlay the camera-trap grid on to maps of high-risk features in the landscape and of lion-telemetry sightings, and then we will finally see how the Serengeti herbivores cope with the uncertainties of living with the hidden dangers of those not-so-lazy lions.
Have you spotted a zebra today?
This video is from my first research trip to Serengeti in 2009. I bet you’ve already found some photos of zebras at Snapshot Serengeti. Here’s what they look like moving. (And yes, it was quite windy; sorry for the noise.)
Snapshot Serengeti 