Meredith has been busy this past week attending the Citizen Science conference in St Paul, Minnesota. She reports back that it was a fantastically stimulating conference that confirms the high esteem that citizen science has grown within the science community.
The yearly conference sees a diverse group of people from researchers, educators and universities to the likes of NGO’s and museums get together to discuss the use and promotion of citizen science. Although we at Snapshot Serengeti have been aware of its great impact for some time citizen science is now emerging and is recognised as a powerful tool in the advancement of research by many.
Those attending the four day event collaborated by sharing their varied experience and ideas on a variety of topics. The collection and sharing of data and how to impact policy was discussed. There was focus on how to use citizen science as an engaging teaching tool, how to bring citizen science to a wider audience and how to involve citizens more in research. Those attending brought their joint experience and expertise together to discuss how citizen science impact on science could be measured and evaluated. If you want to find out more about the conference then visit this link.
We sometimes forget when working away at classifying our stunning images on Snapshot Serengeti that there is a lot of tech going on that enables us citizen scientists to be of use to the scientists. Meredith gave what’s known as a ‘project slam’ essentially a 5 minute presentation about our work on Snapshot Serengeti and how it has paved the way for helping other cameratrap citizen science projects. A quick look around Zooniverse will show just how many there are now.
The massive amount of data produced over several seasons through Snapshot Serengeti have allowed the development of a robust, tried and tested methodology that smaller projects would have taken years longer to develop. Just contemplate the work that went into developing interfaces, protocols, pipelines and algorithms for taking millions of classifications of untrained volunteers and turning them into a dataset which has been verified to be >97% accurate.
It is awesome to see that something we all find so truly engaging can translate into such serious stuff in the field of science. I think we, the citizen scientists, and the Snapshot team can be rightly proud of our work on this brand new branch of science
This weeks guest blog is from our moderator David Bygott who has been guiding us through Snapshot Serengeti images since the beginning.
I’ve been lurking here for years as a moderator, but Lucy Hughes invited me to come out of the shadows and tell you how I got my Serengeti creds.
As a country boy in England I was obsessed with nature and yearned to see more of the world’s wildlife. Reading “Serengeti Shall Not Die” by Bernard Grzimek, inspired me to go there. The dream took some years to achieve. First, I worked hard to get a zoology degree. Then, I wrote to anybody doing field research in Africa who might need a research student, assistant, or slave. I got lucky. A scientist, studying hyenas and wild dogs in Ngorongoro Conservation area, wanted me to work on her better-known chimpanzee project, which I had been following in the pages of ‘National Geographic’. Sounded good.
Thus in 1969 I pitched up at the camp of my new bosses, on the floor of Ngorongoro Crater. Ten days of getting to know Jane Goodall and her photographer husband Hugo van Lawick, and total immersion in African wildlife. Incredible nights of watching hyena packs run down wildebeest and tear them apart. Even a road trip into the heart of Serengeti.
A seed sown, my mind blown, I continued across Tanzania to the remote chimp camp at Gombe National Park on the beautiful forested shore of Lake Tanganyika. Here I spent 2 amazing years with a small team of young people, following the famous chimps through the forest and recording their behavior. Experiencing at first hand our closest kin was a life-changing experience for me.
David with a chimp group at Gombe, 1970
While at Gombe, I met more of my scientific heroes. Bernard Grzimek visited, so did Dian Fossey, and I travelled to Rwanda to see her gorillas. Jane’s doctoral advisor Robert Hinde came, and encouraged me to write up my fieldwork for a Cambridge PhD.
Two unexpected things happened at Cambridge. I met my wife, primatologist Jeannette Hanby. And we got to know Brian Bertram who had studied Serengeti lions for 4 years, following George Schaller’s pioneering work. Brian persuaded us that social carnivores were just as interesting as primates, and that there was still more to learn about lions. It was a change of direction, but we were tempted!
So in 1974 we joined the Serengeti Research Institute as lion biologists, thanks to support from the U of Cambridge. Our main mission was to census the lion population, as National Parks feared that lions were decreasing (they weren’t!). We also compared the lives of lions in different habitats (Serengeti Plains where prey abundance is seasonal, and Ngorongoro Crater where prey is always abundant). And we investigated lion pride dynamics – why do some individuals leave, and others stay?
Imagine being part of a community of scientists studying every aspect of the ecosystem. We had a house in the centre of Serengeti and a Land-rover to go wherever we wanted, and we spent our days and nights with the great tawny cats.
Sometimes humans and lions are attracted to the same campsites
It was remote, but fortunately we were both used to that. Every month we made a supply run – either to Arusha or Nairobi, each at least 200 miles away, mostly on dirt roads. This took 2 days each way, plus several days of shopping and socializing. We learnt a lot about fixing cars, often in beautiful remote settings with primitive tools.
There was much less technology then. We had basic maps but no GPS, radio or mobile phones or internet. There were no computers, though we had cutting-edge hand-calculators. Radio-telemetry was in its infancy; we built our own radio-collars and darted and collared a few lions, but for most of our study we had no air support and ground-to-ground range was poor, so we had to rely on careful searching to find the lions – scanning with binoculars, driving, staying out at night to listen for roars. We identified the lions from natural markings and close-up photographs, on film of course. We developed a symbiosis with cheetah biologists, George and Lory Frame, photographing each others’ study animals whenever we saw them and trading ID photos to increase our sightings. We learnt as much as we could about what all our colleagues were doing, and often participated in ecosystem-wide aerial animal censuses.
We tried various methods of counting lions, including aerial and ground transects and individual recognition. The latter proved the most successful, but it was hard work to identify all the lions in our 1000 square study area. In addition, every second month we’d spend a week in Ngorongoro Crater. After finding as many lions as we could there, we would follow one pride for 4 days and nights, to observe their activity, range and hunting success. We did the same with a comparable pride living at Sametu on the Serengeti Plain. The story of the Sametu pride unrolled like a soap opera, and we couldn’t resist writing a book about them. “Lions Share” tells their story, but also incorporates much of what we knew about lion behavior and about the ecology of Serengeti. (Out of print, but look on Amazon).
Eventually we had to leave, and our friends Craig Packer and Anne Pusey took over the Serengeti Lion Project. Craig amazingly kept it going from 1978 to 2014, and Snapshot Serengeti is an offshoot of what has become one of the world’s longest running wildlife studies.
After writing up our 4 years of lion data, we returned to Tanzania in 1982 to work in conservation education; university teaching, producing guidebooks and interpretive displays, and guiding safaris. We built our home near Lake Eyasi, and experienced years of village life and culture clash, but that’s another story (in preparation). In 2003 we moved to Tucson, Arizona, but I still get back to Tanzania every year, mostly leading National Geographic Expeditions.
I’m organizing my own safari to visit Serengeti and other parks in February 2018. If you seriously want to see these wonderful animals in the flesh, send me a message!
Recently, as those of you who follow will know, I have been talking about the different people who work for the project in Tanzania. Reading about their daily lives working in ecology and conservation is about as close to visiting Africa as many of us will get. Their lives seem so fascinating I think because they are so different to most of ours (though that is a bit of an assumption of course!)
I talked to Ozward Nzunda, one of Dr Michael Andersons Tanzanian field assistants in the Serengeti. Michael’s project looks at vegetation and the interactions between herbivores and their savannah habitat. In order to study this a wealth of environmental data is needed and of course Michael, like many professors, is not based in the Serengeti. He relies on Nzunda to keep things running whilst he is not there. I asked Nzunda about his work and what it was like living in the famous Serengeti National Park.
He told me that most of his work in the field involves the collection of data from all over the study area. There are camera-traps that are checked once a month in order to down load the data and check for any maintenance issues. This is the data which we are busy classifying now on season 9.5. He must also collect weather and soil moisture data on a monthly basis in preset locations. He has to install the weather stations and soil moisture sensors and keep monitoring them until the data is collected. These jobs take up most of his time but he also has the unenviable job of keeping the project vehicles running. Tree and seedling surveys are done on a yearly basis.
So how does he manage all this and what does he think about it?
He told me that the days are long in the field, the drive to the study plots is long and so a lot of time is spent in cars and when you get to the study plots there is a chance you won’t be able to get out the car to do anything. Many a time he says, he has arrived to find lion sleeping or with a kill near his plot and is forced to wait for the lions to leave or move on to another plot. Of course so much time in the field also means he gets to enjoy seeing lots of game on a regular basis.
The study is a continuous study and that means that the data must be collected come rain or shine and in the wet season that means mud. Nzunda told me that the hardest part of the job is wet season driving when you can easily get stuck in the black cotton soils. The mobile signal is poor, as you can imagine, in the park and he has been forced to sleep in the car on occasions until help arrives the following day.
In fact he says they regularly camp out in order to visit the remoter plots and has some interesting stories to tell. Camping in an area with a full complement of wild animals is not for sissies! But on this particular occasion it was the ants that kept them awake. A swarm of biting ants invaded the campsite and had them jumping up and down, shaking out clothes and acting like mad men until they finally left. Itching and scratching they finally got to sleep only to be woken up a few hours later by a rampaging hippo careening between their two tents. Now a canvas tent is no match for a hippo but luck was on their side and the hippo kept running and didn’t return. He says he will never forget this night and they named the campsite “one eye open and one eye close” in honour of the fact no one really slept that night.
His family and friends think he is mad for working alongside wild animals, they think only of the risks but Nzunda loves the challenges field work brings and says that the Serengeti is a beautiful place to be.
Life in the field can be a little lonely. His family live almost 1000km away and he only see’s them about once a month if he is lucky. But they are all accepting of this and are happy. A good job is worth it. He prefers the park saying it is a very good place to live, far better than town where there is too much noise and pollution. He gets his fill of social once a month when he leaves the park to go on a shopping trip for supplies. The rest of the time there is a small shop that caters for the parks staff and resident researchers and the little community gets by fine.
So we all know there are millions of images on snapshot Serengeti and that it is us citizen scientists who do all the work classifying them. The scientists can then get on with the task of figuring out what’s going on out there in the animal kingdom, hopefully in time to save some of it from our own destructive nature.
But… have you spared much thought as to how the images go from over 200 individual camera-traps dotted around the Serengeti to the Zooniverse portal in a state for us to start our work.
Firstly the SD cards have to be collected from the cameras and as this is an ongoing study replaced with fresh SD cards. This is done about every 6 to 8 weeks. A camera traps batteries can actually go on performing far longer than this but as the field conditions can be tough you never know when a camera may malfunction. This time frame is a good balance between not ending up with months worth of gaps in the data and not spending every minute in the field changing cards.
The team are able to check about 6 to 10 sites a day so with 225 cameras in play it takes around a month just to get to each site. Mostly the cameras are snapping away happily but there are always some that have had encounters with elephants or hyena but actually some of the most destructive critters can be bugs, they like to make nests of the camera boxes. As well as checking the cameras themselves the sites need to be cleared of any interfering foliage, we all know how frustrating a stray grass blade can be.
So with a hard drive full of all the data it then has to wait for a visiting field researcher to hand carry it back to the University of Minnesota, USA. It means the data is only received every 6 months or so but it is far safer than trusting the post. Once safely received it is up to Meredith to start the painstaking work of extracting the date time stamps. As sometimes happens there are glitches and she has to fix this by figuring out when the camera went off line or when capture events got stuck together. She says it is much like detective work. The images are then assigned codes and stored on the Minnesota Supercomputer Institute (MSI) servers.
Once it is all cleaned up and backed up it is sent to the Zooniverse team who then format it for their system giving new identifiers to each image. Finally it is ready for release to all the thousands of classifiers out there to get to work on.
So as you can see it really is a team effort and a massive under taking. It is no good collecting tonnes of data if there is no one with the time to do anything with it. I will take this opportunity again to thank you for all your help with the project. Keep up the good work.
In my last blog I mentioned Ingela Jansson and the KopeLion project and promised to tell you more.
Ingela spent three years working for the Serengeti Lion project as a research assistant monitoring lions in the Serengeti National Park as well as the Ngorongoro Crater. Although working in the park was an amazing experience it was the work she did in the crater area that was to prove a more urgent calling. The very real conflict she saw between humans and lions persuaded her that if someone didn’t do something the Ngorongoro lions were headed towards extinction. And so KopeLion project was born in 2011.
The Ngorongoro conservation area was gazetted in 1959 and designated a multi use landscape. The pastoralist population were permitted to continue living there alongside the wildlife. Since this time the population has risen 10 fold and the once harmonious coexistence with lions has collapsed. Lions have disappeared from much of the area and the connection to the Serengeti lions is all but extinguished.
Enter KopeLion. The project aims to foster human – lion coexistence through community engagement, science and mentorship. One of the most successful outcomes so far is the recruitment of former lion hunters as lion protectors, we heard Roimen’s story last week.
But just how do you ‘engage with the community’ to try and change their minds about living with a dangerous predator. Well KopeLion do this in many ways. Firstly most of the employees are local which means they already have the community’s ear. To the Maasai their live stock are sacred so KopeLion spend a lot of time trying to reduce lion conflicts. They follow the model developed by Lion Guardians Ltd ( http://lionguardians.org )by helping local herders to build sturdy bomas, searching for missing livestock, treating injured livestock and warning herders when lion are nearby. The lion guardians or Ilchokutis are assigned an area of between 60 and 200km2 where they monitor lions or signs of lions scientifically. They also try to prevent young warriors or Morani from carrying out lion hunts. Part of their role is as mentors to the younger generation.
The Maasai still hold strong traditional beliefs and have strong community ties, recognising and embracing this is one of the reasons for KopeLion’s success so far on its mission to help humans and lions live in peace. The strong local ties mean KopeLion have won trust amongst the local herders and in 2016 they were able to stop more than 20 lion hunts from going ahead and have seen the evidence that their efforts are working in the fact that two of the monitored lion prides now show complete survival.
Ingela and her team at KopeLion are doing such valuable work that I urge you to head over to their incredibly informative website to read more about it.
If you have clicked through the seemingly endless captures on Snapshot Serengeti then you must have realized just how many cameras are snapping away out there in the Serengeti. Have you ever wondered who looks after those cameras?
Researchers sometimes go to extreme lengths to collect their data and not much deters them from their goal.
On a recent assignment working in Central African Republic I was tasked by our biologist to collect in an array of 40 camera-traps. The park was very large, the size of Wales and very remote, the nearest village was a 12 hours 4×4 drive away. It was also newly proclaimed and had little in the way of infrastructure like roads. Of course, Thierry wanted to survey the areas we didn’t yet know so obviously the cameras were nowhere near any of the smatterings of roads.
He presented me with a mobile phone resplendent with a mapping app which showed the camera trap locations overlaid with our rudimentary road network. I should really say temporal track system as these so called roads consisted of two tire tracks driven through the elephant grass and mud soon to grow over again in the coming wet season. The park consists of a mosaic of wooded savannah and tropical lowland rainforest so you are either struggling through 2 meter high elephant grass or deeply tangled riverine forest growth. Added to the physical challenges of working in the park was the fact of it harboring armed Sudanese cattle herders, poachers and Lord’s Resistance Army militia.
So equipped with the mobile phone, two trackers and 5 armed rangers off we went to collect the cameras. After three hours bumpy ride plagued with biting tsetse fly we got as close to the first camera as any road was going to take us. Using the phone to navigate I pointed us in the general direction praying that the battery would last. If it failed we would be completely lost with no landmarks. Two kilometers later we had narrowed down the camera location to about 20 meters and under the vigilant eye of the rangers myself and the two trackers began searching for the camera in the thick jungle tangle.
Once the camera was reclaimed it was bagged up and we set out for the walk to the next camera another kilometer or so away. The whole day was spent battling foliage and insects in the 40o c temperatures for a total of 8 cameras. We made camp for the night; the journey back to base was just too far with so many cameras still to collect. It took 4 days to collect half the array and it was with some relief that we trundled back into base camp having had no encounter with armed men. A hot shower, something other than sardines to eat and the excitement of examining the camera-trap pictures was a just reward for all our foot work
The cameras were being used to assess what species were present in the park and as such were left up for short periods in small arrays. In the Serengeti however, there are 225 camera traps permanently running in an area of 1125 km2. Just think of the logistics involved with changing batteries, keeping vegetation trimmed back and changing SD cards. Our researchers work tirelessly to keep the project on its toes and over the next few months I will try to bring you their stories about the work we support from the comfort of our homes. We each have our part to play but together we are a team dedicated to furthering a scientific cause.
This is another guest post by Drs. Tom Morrison and Michael Anderson about the Snapshot Serengeti Special Edition and what their research hopes to uncover.
Seeing the forest for the trees
First, a big THANK YOU to everyone who has helped classified images at Snapshot Serengeti, both past and present. Without the continued help of this great online community, our research would come to a grinding halt! So thank you. A number of folks (and at least one giraffe) have asked about the new study currently up on Snapshot Serengeti, so here’s a fuller explanation of this work.
Photos from our newest Snapshot Serengeti Special Season come from a camera trap experiment in Serengeti involving friends and collaborators based at Wake Forest University (US), University of Georgia (US) and University of Glasgow (UK).
One of the exciting things about these new images is that they come from some of the more remote corners of the park, far beyond where past photos (Season 1-9) were (and continue to be) collected. So, keep an eye out for different species than past surveys. For instance in the north, you might see oribi, a small and elegant ungulate with a large dark scent gland below its eye. In the south, our cameras overlap the home ranges of some of the few black rhinoceros still living in the park, and we already know there are at least a few rhino images in our pile, like this:
We set these cameras at a slightly higher height (1.5 meters in most cases), which allows us to see species from new wider angles. Admittedly, this new experimental design makes animal classifications a bit harder because we can often see far into the distance. Our advice is to simply do your best, but don’t sweat it too much if you can’t figure it out. Better to see the forest than the trees.
Back to the research…
Speaking of trees, this new study is trying to unravel the secret lives of trees. We monitor hundreds of individually marked trees around the ecosystem and revisit them each year to measure growth, survival, disease and few other things. You may have noticed little cages in some of the camera trap photos (see giraffe above). These are part of our experiment and enclose four small native tree seedlings which we transplanted to the plots after growing them in a nursery for 6 weeks. In fact we planted over 800 seedlings around the ecosystem to study the relative importance of herbivory, fire and rainfall on seedling growth and survival. So, we need camera traps to monitor things when we’re not there.
For example, check out the following sequence captured on one of our game cameras in southern Serengeti involving one of our marked trees:
What’s amazing about this is that not only does an elephant kill an adult tree, he does it under 60 seconds. This tree is an Acacia tortilis, or the “umbrella acacia,” named for its characteristic flat top. Umbrella acacias are one of the most common trees in Serengeti and one of our main study species. Images like these help inform our study of trees, telling us how they died, or at least how many large herbivores were in the area to potentially kill and eat them. But this begs the question: if a tree falls in the Serengeti, will anyone hear it? At least we know that there’s a small chance that one of our cameras might see it.
Can’t get enough of these gnarly gnus? Head on over to our new spinoff project, Wildebeest Watch!
In collaboration with Dr Andrew Berdhal from the Santa Fe Institute, and Dr Allison Shaw at the University of Minnesota, we are taking a closer look at what the wildebeest are doing in the Snapshot Serengeti images to try and better understand the details of the world’s largest mammal migration.
Every year, 1.3 million wildebeest chase the rain and fresh grass growth down from the northern edge of the ecosystem down to the short grass plains in the southeast. We have a broad-scale understanding of where they are moving across the landscape, but don’t understand how they make these detailed decisions of where and when to move on a moment-to-moment basis. Wildebeest as individuals aren’t known for being particularly smart — so we want to know how they use the “wisdom of the crowd” to make herd-level decisions that get them where they need to go.
So while you’re waiting for more photos of lions, hyenas, and other sharp-toothed beasts, why not wander over to Wildebeest Watch to help us understand the collective social behavior of these countless critters?
Meredith: Our brilliant team of Snapshot Serengeti undergraduate volunteers at the University of Minnesota are perhaps even more on top of the lion literature than I am! This week, we have a guest post from one such student, Clayton Mazur, describing some recent work of Dr. Packer’s on lion disease spread in Serengeti Park. This post is a synopsis of a scientific paper that can be accessed in full here.
I propose we play a word-association game. I will offer a word and you think of what comes to mind. “Africa.” Did you imagine Mt. Kilimanjaro, or the towering, lush rain-forests of the Congo? “Wildlife.” Did you envision the sprawling savannas of Tanzania, home to hundreds of thousands of migrating wildebeest? If so, I would bet that your savanna also included the enigma of Africa: the African lion. Was he a graceful figure standing upon Pride Rock looking out over his kingdom? Perhaps he was laying in the shade, his dark mane flowing in the breeze as he waits for the females to return with a kill. I would argue that elegant images such as these are what come to mind for the majority the public. The portrayals of lions in the media- from Lion King to the MGM Lion- support this notion. As elegant as these images are, reality is less than elegant for the lions living in Serengeti National Park in Tanzania, Africa.
African lions have unique social structures that help them brave the tough conditions of the savanna. Lions live in families called prides; one to two male lions rule a pride. The roles of female and male lions within a single pride are vastly different. While females hunt, raise the cubs, and reproduce, male lions defend the pride from attack by other predators such as hyenas. Living in a large family group offers lions protection, but it also comes with costs. One cost is that females need to supply a large number of individuals with enough food for survival. Female lions coordinate hunts whereby they stalk prey and then give chase, but this technique only yields about 26% success. The low success rate forces large prides to split or starve. Perhaps a more interesting difficulty of living in a large pride is the spread of disease within lion populations. As Dr. Craig Packer has found, disease prevalence is a threat to the current lion population.
A fatal disease that persists in the carnivores of Serengeti National Park is Canine Distemper Virus (CDV). CDV infects a range of carnivores, from dolphins to rodents and even some primates. The viral infection causes encephalitis, pneumonia, anorexia and eventually, death. You may be familiar with CDV if you own a dog, for many owners in the US vaccinate their dogs for CDV. In Serengeti National Park, where local villages cannot afford to vaccinate their dogs, CDV is a conservation concern for African Lions who contract CDV from domestic dogs. To try to remedy the concern, an intense vaccination regime started in 2003. Packer and colleagues attempted to characterize the progression of CDV in both domestic dogs and African Lions. Their goal was to determine if domestic dogs were responsible for the infections observed in African Lions. The team also wanted to determine if the 2003 vaccination program had any effect at reducing CDV in the domestic dogs and/or African Lions.
The scientists worked with blood plasma collected from both domestic dogs (obtained from 1992-2012) and from African lions (obtained from 1984-2012). After collecting the blood samples, the team ran serological tests to detect for the presence of the CDV virus in individual dogs or lions. Using a Bayesian model, the scientists then calculated the probability that an individual lion or dog would contract CDV in one year. The scientists also used sensitivity models to determine the extent at which domestic dogs transmit CDV to lions. From the results of these models, the scientists were able to comment on the fate of the lions with regard to CDV.
The research team drew results by interpretation of the two models. They found that CDV had persisted in the populations of both dogs and lions for more than 25 years. Outbreaks of CDV occurred in 1981, possibly in 1976, and in 1993. Not only do these results suggest a historic presence of the fatal disease in the national park, the dynamics of each outbreak of the disease was unique. The scientists found that the year in which CDV infected the most dogs differed from the year in which CDV infected the most lions. The researchers proposed that this pattern identified domestic dogs as initial vectors for CDV in the park. After a 1994 outbreak in the lion population, the dynamics of the outbreaks become more disjoint. The disjointed dynamics between the domestic dog and lion populations suggest that after 1994, infections cycled through the dog population and the lion population separately. However, the spread of CDV between dogs and lions was not eliminated after 1994.
With domestic dogs established as an initial vector of CDV, the scientists wanted to know transmission rates between domestic dogs and lions. Again, they used a sensitivity model to predict this factor. The scientists found that domestic dogs were ten times more likely to spread CDV to lions than lions were to spread CDV to domestic dogs. With such a high prevalence of CDV in the domestic dog population and the tendency for CDV to spread from dog to lion, the effects of the 2003 vaccination effort were an important factor to analyze for the conservation of the Serengeti National Park lions. The scientists first analyzed the effects of the vaccine on the domestic dog population. Before 2003, there had been very sparse vaccination in villages surrounding Serengeti National Park. As was expected, this vaccination effort did little to curb CDV infection in either lions or domestic dogs. It was not until after 2003 when all villages to the east of Serengeti National Park and all villages within 10 km to the west of Serengeti National Park vaccinated their dogs against CDV did there exist a decrease (~5%) in CDV infections.
With CDV slightly decreased in domestic dogs due to the vaccination effort, was there a similar decrease in CDV infections in the lion populations? Unfortunately, the sample size of lion serum that the scientists could obtain was not enough to comment on the updated magnitude of dog-lion CDV transmission. Overall, the scientists determined that CDV was still able to cycle in the lion population with very little reduction in the prevalence of the disease. However, not all is hopeless for the lion populations of Serengeti National Park. Dr. Packer’s team suggests that direct vaccination of lions may be more effective at preventing the disease. Additionally, the team suggests that advances in serological techniques would allow for increased accuracy when researching episodic diseases, such as CDV. Implementation of safe vaccines coupled with more accurate serological tests could minimize the effects of CDV outbreaks and ensure the health of the Serengeti lions.
As evident from the work of Dr. Packer and colleagues, there are threats to the conservation of the lion populations of Serengeti National Park. Not only do prides run the risk of individuals starving to death, splitting, and human-lion conflict, disease is another risk factor of living in a pride. Yet, these prides, these perfect families, come to mind when the public thinks about lions. Idealistic images of cubs play fighting or suckling from their mother are important for generating interest and compassion for African lions. One can be content with the image of the brave, courageous, elegant male lion standing on Pride Rock overlooking his kingdom, but one must simultaneously recognize the reality of the lion’s plight. Only then will conservation for lions be truly feasible.
Okay, so by now you’ve heard dozens and dozens of times that you guys produce really good data: your aggregated answers are 97% correct overall (see here and here and here). But we also know that not all images are equally easy. More specifically, not all species are equally easy. It’s a lot easier to identify a giraffe or zebra than it is to decide between an aardwolf and striped hyena.
The plot below shows the different error rates for each species. Note that error comes in two forms. You can have a “false negative” which means you miss a species given that it’s truly there. And then you can have a “false positive,” in which you report a species as being there when it really isn’t. Error is a proportion from 0 to 1.
We calculated this by comparing the consensus data to the gold standard dataset that Margaret collated last year. Note that at the bottom of the chart there are a handful of species that don’t have any values for false negatives. That’s because, for statistical reasons, we could only calculate false negative error rates from completely randomly sampled images, and those species are so rare that they didn’t appear in the gold standard dataset. But for false positives, we could randomly sample images from any consensus classification – so I gathered a bunch of images that had been identified as these rare species and checked them to calculate false positive rates.
Now, if a species has really low rates of false negatives and really low rates of false positives, then it’s one people are really good at identifying all the time. Note that in general, species have pretty low rates of both types of error. Furthermore, species with lower rates of false negatives have higher rates of false positives. There aren’t really any species with high rates of both types of error. Take rhinos, for example: folks often identify a rhino when it’s not actually there, but never miss a rhino if it is there.
Also: we see that rare species are just generally harder to identify correctly than common species. The plot below shows the same false negative and false positive error rates plotted against the total number of pictures for every species. Even though there is some noise, those lines reflect significant trends: in general, the more pictures of an animal, the more often folks get it right!
This makes intuitive sense. It’s really hard to get a good “search image” for something you never see. But also folks are especially excited to see something rare. You can see this if you search the talk pages for “rhino” or “zorilla.” Both of these have high false positive rates, meaning people say it’s a rhino or zorilla when it’s really not. Thus, most of the images that show up tagged as these really rare creatures aren’t.
But that’s okay for the science. Because recall that we can assess how confident we are in an answer based on the evenness score, fraction support, and fraction blanks. Because such critters are so rare, we want to be really sure that those IDs are right — but because those animals are so rare, and because you have high levels of agreement on the vast majority of images, it makes it really easy to review any “uncertain” image that’s been ID’d as a rare species.
Pretty cool, huh?