Archive | July 2013

Save the Memes

You have to check this out. Zooniverse has put together a hilarious web site called Save the Memes. It’s a light-hearted way of spreading the story about our Save Snapshot Serengeti campaign. And while it’s good for that… it’s perhaps a little distracting for us scientists, too!

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Give it a go with some pre-selected images. Or, you can turn your favorite Snapshot Serengeti image into a meme from the Talk pages now using the “Meme This!” button.

Fave photos?

Calling all camera trap captures!

BBC’s annual camera-trap ‘photo of the year’ contest is drawing a close – and we’re pretty sure Snapshot Serengeti has some winners. So we’re asking for your help to find them!

The contest has three relevant categories:

  • Animal Portraits Images taken during the course of research that capture the character or spirit of the animal
  • Animal Behaviour Images captured during the course of research that show interesting or unusual behaviour.
  • New Discoveries Images that show something new to science, such as a species never before photographed in the wild or outside its known range, or behaviour never before recorded. The caption must make clear what the discovery is.

We can submit up to 12 photos across these three categories. Long-time Snapshot Serengeti moderator lucycawte has already pinpointed a couple of fantastic photos:

…but we’d like your help to find some more!

So send us the subject ID’s or urls of your all-time favorite Snapshot Serengeti pics (via comments here). One of them just might wind up front and center in the next issue of BBC Wildlife or make Snapshot Serengeti the proud winner of a monetary prize to keep the cameras clicking.

And speaking of Snapshot Serengeti funding, I wanted to take a minute to say thank you all who have supported our Save Snapshot Serengeti campaign so far. Yesterday we passed our 20% mark, and we’re marching forward! For everyone out there who loves looking at these incredible photos, please take a look at our campaign — we have some really fun perks that you might enjoy. And whether or not you’re able to make a donation, please help us spread news of the campaign by sharing our link: igg.me/at/serengeti — the more people we reach, the better our chances of bringing you these photos for years to come. Thank you for your support, your effort, and for being as addicted to Snapshot Serengeti as we are!

Season 6: Snapshot Serengeti’s Final Season?

A lot has happened in the Serengeti over the last six months. The wildebeest migration, which appeared towards the end of Season 5, swept down onto the plains in pursuit of nutritious new grass. I improved my hyena-proofing strategies,

Spikes make the cameras less palatable...I hope....

Spikes make the cameras less palatable…I hope….

and Daniel found and collared the long-lost Transect Steady pride.

collarTS

And, although Season 6 marks my last field season as a graduate student, we on the Snapshot Serengeti team want to keep the cameras running for as long as we can. There is still so much to learn about the Serengeti, and many of its secrets can only be understood by long-term projects that capture both annual variability and unexpected events. The Snapshot Serengeti cameras let us study this incredibly dynamic system in a way that was never possible before – and we’re not ready to stop.

But we need your help. Our NSF funding has run out, and unless we raise enough money to keep the team going, there won’t be a Season 7.

So we’ve launched a crowd funding campaign on Indiegogo to meet our immediate funding needs. And we’re asking for support in any way you can give. We’ve got some fun “perks” in return for your donations, but the biggest perk of all will be having a Season 7 to look forward to.

So, if you too are addicted to pressing ‘play’ on the silly warthog close-ups or collecting images of baboon selfies, please share this campaign with your friends and family.

igg.me/at/serengeti

The more people we reach, the better our chances of meeting our goal and keeping our cameras running…and the better our chances of truly understanding what makes this incredible ecosystem work.

Unanticipated events and the need for long-term studies

In 1994, a terrible disease ripped through the Serengeti, killing lion after lion. By the end of the year, a third of the lions in the Serengeti were dead. The culprit was a virus known as canine distemper, and lions that died of the disease did not die quietly. The symptoms were clear to any observer: facial twitching, disorientation, and eventually convulsive seizures.

The lions in Craig’s study area were not spared, but the data he had been collecting over the previous decades proved invaluable in understanding what happened in 1994.

Radio-collared lion

Using archived blood samples that had originally been taken for genetic analysis, Craig and his colleagues were able to go back and test for a number of viruses. The earliest year blood had been sampled was 1984, but because some of the lions sampled had been ten years old or older, he was able to infer information about when lions had been exposed to viruses as early as 1970.

They found that there had been previous outbreaks of canine distemper in the lions in 1977 and 1981. Because the lions had been studied then, he knew that these outbreaks had not caused large die-offs like the one that occurred in 1994. Instead, he found that by 1994, essentially all lions in Serengeti were free from canine distemper antibodies, meaning that none of the lions had any immunity to the disease. This widespread lack of immunity and a mutation in the virus were thought to have caused so many deaths.

The lion population recovered after the 1994 outbreak. Just years later, though, two “silent” outbreaks hit the population in 1999 and 2006. Unlike the 1994 outbreak, these ones were not noticed at the time because few lions died. They were only detected through blood sample testing. An analysis of the archived blood samples finally revealed the major difference between the canine distemper outbreak that led to massive death and those that did not. High death rates in the 1994 outbreak were due to the simultaneous infection with another disease — a protozoan parasite known as Babesia — that becomes increasingly common during and after major droughts. When Babesia is absent, lions contract canine distemper, but their immune systems fight it and they become immune. When lions are also infected with Babesia, they cannot fight off the canine distemper virus as easily, and more of them get sick and die.

The long-term lion data was also instrumental in understanding the spread of canine distemper in the 1994 outbreak. The disease showed up sporadically in the study area prides, suggesting that lions acquired the disease from an outside source, rather than spreading it from one lion to another. Sophisticated analyses revealed that the origin of the outbreak was likely in domesticated dogs in the human settlements around the Serengeti ecosystem. Further, it is likely that lions acquired the disease repeatedly from hyenas. Hyenas move great distances, use human-inhabited areas around the Serengeti more than lions do, and interact with lions at kills.

Scientists cannot predict major droughts. Nor can they predict wildlife disease outbreaks. It isn’t possible to recreate major droughts with experiments in vast wilderness areas. Nor is it ethical to introduce novel diseases into natural areas in order to understand more about the disease. It is ONLY through long-term research projects like the Serengeti Lion Project that we acquire the data necessary to understand what happens in nature during disease outbreaks, droughts, and other rare, but important events.

Ideally we would like to run Snapshot Serengeti for at least a decade. We want to be able to capture some drought years in our data set, and some years with unusually wet dry seasons. We want our cameras to be running when the next unexpected disease outbreak occurs — in lions or in other species. To those of you have already contributed to our crowd-funding campaign, a heartfelt thank you. If you haven’t yet, and are able, please consider a donation.

To read more about canine distemper, Babesia, and Serengeti lions, check out:

Munson, L., K.A. Terio, R. Kock, T. Mlengeya, M.E. Roelke, E. Dubovi, B. Summers, A.R.E. Sinclair & C. Packer. 2008. Climate extremes and co-infections determine mortality during epidemics in African lions. PLoS-One 3, e2545.

 

The life of a lion isn’t easy

Hopefully you’ve been enjoying the adventures of the lions that David Quammen has been writing about in this month’s National Geographic. David writes about the dramatic lives of C-boy and Hildur, two very good-looking male lions that roam the Serengeti, and the challenges that they face as male lions trying to survive in the Serengeti. I was in the car with Ingela that day that the Killers nearly destroyed C-boy — it was one of my first days in Serengeti, and one of the many moments that I fell in love with the dramatic lives of the animals there.

There’s a good chance you’ve seen C-boy and Hildur and Killers, as well as all the ladies they’ve been fighting over, in the camera traps. Below is a map of the pride territories overlaid on the Snapshot Serengeti cameras. There are a lot more prides than this, but these are the ones that Nick Nichols and Davide Quammen followed.

SnapshotSerengeti cameras and the lions that David wrote about in NatGeo

SnapshotSerengeti cameras and the lions that David writes about in NatGeo

Jua Kali, where Hildur and C-boy resided in 2009, control just a tiny patch of land in the center of the study area where the Seronera river begins. They spend most of their time in a marshy lowland where those two small tributaries, converge. The marsh has lush grass and standing water, but is just a tiny oasis in the otherwise dry and desolate grassland. It is not the best territory that a lion can have.

After C-boy and Hildure were deposed from Jua Kali, they eventually took over the Vumbi pride. It worked out pretty well for them in the end – the Vumbi’s are not only a bigger pride, but maintain control over the Zebra Kopjes, a suite of rocky outcroppings that provide shade, water, and a vantage point to watch for prey across the open plains. Despite C-boy’s brush with death and his inelegant retreat from power, C-boy and Hildur really haven’t done too badly for themselves.

North of Vumbi, the Kibumbu pride ranges along the Ngare Nanyuki river. When David was writing about our lions, the Killers had recently taken over the Kibumbu pride. Unfortunately, the Kibumbu females had had young cubs fathered by the previous coalition; the Killers would have killed these cubs to bring the Kibumbu females into sexual receptivity. Infanticide is a brutal, but natural part of a lion’s life.

So there it is. The lions that are gracing the pages of this month’s National Geographic magazine are the same ones that you see yawning, sleeping, and stretching in front of the Snapshot Serengeti camera traps. David’s story, and Nick Nichols’ photos, provide an amazing and detailed dive into their lives.

We’re currently raising funds to keep Snapshot Serengeti and the long-term Lion Research Project afloat. Thanks to everyone who has donated so far!

More lions at National Geographic

In addition to the main feature story on the Serengeti lions that I wrote about on Wednesday, there are a number of lion extras at National Geographic Magazine, too.

The article “Living With Lions” talks about the challenges of lion conservation, and brings up some topics I’ve written about before, including fences and trophy hunting.

There’s an interactive map, where you can see the fragmentation of wild lions. The Serengeti (‘C’ on the map) is one of only a handful of strongholds that contain at least 1,000 lions.

There’s a short interview with Michael Nichols, the photographer for the stories, and a fabulous slideshow of images that he took. (Although I have to say that I always think lions look very strange in black and white.)

And there’s a high-resolution download of this image of Serengeti lion cubs you could use for your desktop background if you wanted.

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Our lions in National Geographic Magazine

The August edition of National Geographic Magazine has a cover story on the Serengeti lions that Craig has been studying for decades. And because Ali set out the camera trap grid in the same place as Craig’s lion study area, you see the same lions (plus more) on Snapshot Serengeti as those featured in the article. In fact, photographer Michael Nichols was out in the Serengeti during Season 5, so his pictures are contemporaneous with the ones up on Snapshot Serengeti right now.

So if you have a moment, go check out “The Short Happy Life of a Serengeti Lion,” which is entertaining and gives a nice history of the foundational research on which the Snapshot Serengeti science rests. And take a gander at the editor’s note, which accompanies this picture.

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Crowdfunding Snapshot Serengeti

I recently returned from Serengeti with all of my limbs intact and hard drives full of camera photos in tow. The images on these drives comprise Season 6 – the season I welded spiky nails to the cases to discourage hungry hyenas from chomping on them, didn’t get stuck every 3 days for a change, and also my last trip as a Ph.D. student. (Now I’m back in Minnesota trying to make sense of all the data and write my dissertation!) The Season 6 images are slowly making their way through the cloud to the Zooniverse team, and we’re expecting to have them online by the end of the month.

Unfortunately, things are not all butterflies and rainbows for us. In fact, Season 6 will mark a rather dire situation for Snapshot Serengeti. As Margaret wrote back in May, our National Science Foundation funding has run out – and our application for renewed funding was rejected. Unless we raise enough money to keep our Land Rovers limping along, our cameras will turn off, and we’ll lose our secret window into this incredible world.

The good news is that we have a plan. Today we launched a crowdfunding campaign on Indiegogo, our first step in keeping the project going. We are asking people around the world to help us raise money to keep the Snapshot Serengeti cameras clicking for another three months after our funding ends in September. That will get us to the end of the year and give us a Season 7.

So, if you love Snapshot Serengeti and are able to contribute something, we’d love your support. And check out our perks. We’ve got some fun ones you might enjoy! If you’re unable to help out financially, please spread the campaign link around to your friends and family. The more people we reach, the more likely we are to make our goal. The link is

http://www.igg.me/at/serengeti

And meanwhile, happy hunting in Season 5. Thanks!

Meanwhile, happy hunting!

Weavers

Every once in a while, a camera gets knocked off a tree and ends up pointing up into the tree where there are many grassy balls hanging from the branches. We have one of these cameras in Season 5, and it is taking pictures like this one:

Weaver bird nests

What are those odd grassy balls? Why, they’re the nests of weaver birds. My Birds of East Africa book lists a dozen species of weavers in the Serengeti, and most of them have a yellow and black pattern. Here’s what some of these guys look like close up.



Several years ago, I watched through a Lion House window as a weaver bird build its nest from scratch. The bird started with just a branch, one with something of a knot at the end where a twig may have split off in the past. The weaver grabbed a long blade of grass and wrapped it around that knobby joint and tucked the blade under itself, as you might do if you were tying your shoe. Then it got another blade of grass and wove that through the loop it had created with the first blade, tucking it securely back under and through the loop a second time. It continued to add blades for the next twenty minutes or so, such that the grass formed two clumps, one sticking out of either side of the knot.

(Aside: the soundtrack is completely coincidental; field assistant John was cooking something in the kitchen while listening to music.)


Straddling the two clumps, with one talon hanging on to each, the weaver then took a long blade from one clump and wove its end back up into the other clump. The result was a loop. The bird pulled additional grass from one clump to the other and strengthened the loop. Bit by bit.


I watched for over a half-hour, but I had work to do, too. So I left the little weaver to its task, and checked in again that evening before the sun set. There it was, a hefty wreath of grass hanging from the end of a tree branch.

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I checked again a couple days later. The weaver had been working on filling in grass around the sides to form the ball shape.

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Three days later the ball shape was becoming apparent (and I finally decided to take pictures outdoors instead of through the window, so that they’re better in focus).

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Aha! I caught a decent shot of the builder. My bird appears to be a Vitelline Masked Weaver male. (Although, my book also says that the top of the head ought to be rather chestnut color and this guy has maybe only a little bit of chestnut and rather brown markings on the back instead of black. Maybe it’s a young male?) These guys generally are found solitary or in pairs, which explains why I saw just one of them building a nest in a tree all alone. And their nests are “distinctive onion-shaped nests with an entrance hole at the bottom.” Looking good…

Five days later Mr. Vitelline’s work was looking very much like a nest.

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Five days later was also my last day in the Serengeti, so I didn’t see further developments of this nest. But I suspect it was completed and became a comfortable abode for its industrious builder.

Lions, cheetahs, and dogs, oh my! Part 2.

Last week, we left off with this crazy biological paradox: lions kill cheetah cubs left and right, yet as the Serengeti lion population tripled over the last 40 years, cheetah numbers remained stable.

As crazy as it sounds, it seems that that even though lions kill cheetah cubs left and right, it doesn’t really matter for cheetah populations. There are a number of reasons this could be. For example, cheetahs are able to have cubs again really quickly after they lose a litter, so it doesn’t take long to “replace” those lost cubs. It’s also possible that lions might only be killing cubs that would probably die from another source – say, cubs that would otherwise have died from starvation, or cubs that might have been killed by hyenas. Whatever the reason, what we’re seeing is that lions killing cheetah cubs doesn’t have an effect on the total number of cheetahs in the area.

I think this might hold true for other animals, not just cheetahs. It’s a bit of a weird concept to wrap your head around – that being killed, which is really bad if you’re that individual cheetah, doesn’t actually matter as much for the larger population – but it’s one that seems to be gaining traction among ecologists who study how different species live together in the natural world. Specifically, ecologists are getting excited about the role that behavior plays in driving population dynamics.

Most scientists have studied this phenomenon in predator-prey systems – say, wolves and elk, or wolf spiders and “leaf bugs”.

Wolf spider. Photo from Wikipedia.org.

“Leaf bug” from the Miridae family. Photo from Wikipedia.org.

What scientists are discovering is that predators can suppress prey populations not by eating lots of prey, but by causing the prey to change their behavior. Unlike many spiders, wolf spiders actively hunt their prey – sometimes lurking in ambush, other times chasing their prey for some distance. To avoid being eaten, leaf bugs may avoid areas where wolf spiders have lots of hiding places from which to stage an ambush, or leaf bugs may avoid entire patches of land that have lots of wolf spiders. If these areas are the same ones that have lots of mirid bug food, then they’ve effectively lost their habitat. Sound familiar?

Back to Africa – what does this mean for wild dogs and cheetahs? Interestingly enough, lions do not displace cheetahs from large areas of the Serengeti. We’ve discovered this in part from historic radio-collar data that was collected simultaneously on both species in the late 1980’s.  Below is a map that shows average lion density across the study area. Green indicates areas with higher densities. The black “+” symbols show where cheetah were tracked within the same study area. They are overwhelmingly more likely to be found in areas with lots of lions. This is because that is where the food is – and cheetahs are following their prey, regardless of the risk of encountering a lion. The Snapshot Serengeti data confirm this – cheetahs are way more likely to be caught on cameras inside lion territories.

Lion density is mapped per 1km x 1km grid cell. High density areas shown in green, lower in pale orange/gray. Cheetah locations are the black +'s.

Lion density is mapped per 1km x 1km grid cell. High density areas shown in green, lower in pale orange/gray. Cheetah locations are the black +’s.

Unfortunately, we don’t have radio-collar data on the Serengeti wild dogs from the 1980’s. But we do have radio-collar data for the wild dogs that have been living in the larger Serengeti ecosystem for the past 8 years. As you can see in the map below, wild dogs regularly roam within just 30km of the lion study area. But they don’t settle there – instead, wild dogs remain in hills to the east of Serengeti – where there are local people (who kill wild dogs), but very few lions.

DogMapcrop

Other researchers in east and southern Africa are starting to pick up on the same patterns in their parks.  From Tanzania, to Botswana, to South Africa, researchers are finding that wild dogs get kicked out of really large, prime areas by lions…but that cheetahs do not. What they’re finding (since they have all these animals GPS-collared) is that cheetahs are responding to lions at a very immediate scale. Instead of avoiding habitats that have lions, cheetahs maintain a “safe” distance from the lions – allowing them to use their preferred habitats, but still minimize their risk of getting attacked.

Carnivore researchers are only really just beginning to explore the role of behavior in driving population-level suppression, but I think that there’s good reason to believe that large scale displacement, or other behaviors, for that matter, have greater effects on population numbers of cheetahs and wild dogs, as well as other “subordinate” carnivores – not just in African ecosystems but in systems around the world. It’s a new way of thinking about how competing species all live together in one place, but it’s one that might change the way we approach carnivore conservation for threatened species.