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Cheetah Tactics?

 

Here at Snapshot Serengeti we are lucky to get regular good images of all the big cats. Lions feature the most frequently followed by cheetah with leopard being the rarest. This is not surprising when you think that lions like to spend the day sleeping and resting after their night-time prowling. This means they make a bee-line for the shade of trees. Cheetah have the same idea, staying out of the sun during the day. Leopard of course tend to be up those trees and so its harder to capture them on camera trap. We are still waiting for the day that we get a capture of a fury belly as a leopard leaps up over the camera on its upward trajectory. Imagine how hard that could be to identify!

Looking through some of the recent images from the most recent batch we came across this series of three images of a cheetah walking right up to the tree the camera-trap was on, presumably to settle down for a nice nap, but is that all there is to this tree/cat relationship?

 

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Cheetah, as I am sure you are aware are at the bottom of the big cat chain. They don’t do well in a fight against lion, leopard or hyena for that matter so they have to stay alert to danger. They need time to slink away or flee at speed.

So now picture this, a cheetah is sleeping in the grass, it wakes up and wants to survey the plains to see if there is either prey or danger about. It sits up and bang! its seen by anything that happens to be near by. Now rewind a bit, the same cheetah has a nap under a tree. This time it sits up to survey and its slender body is masked by the trunk of the tree. Its not nearly so easy to spot from a distance.

Ok so its just a theory and probably cheetah primarily spend time underneath trees from a purely physiological perspective but it would be nice to think they were also using their tree as a point of tactical surveillance. Certainly in the hot shimmering air of the Serengeti it is hard to see a cheetah that is sitting upright under a tree until you are pretty close by. In my experience although lions like a tree too its just as likely that you will find them lounging in the shade of an erosion channel or small bush but cheetah always seem to by in that classic pose under a sturdy tree when resting.

It gets you thinking!

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Machine Learning Update

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Hartebeest through a dislodged camera-trap cover.

It has been just over a year now since Snapshot Safari was launched. Snapshot Serengeti as the original Zooniverse citizen science camera trap project has remained the flagship project but there are now several other projects under the Safari banner.

 One of the good things about joining forces with all these other projects is that collaboration tends to bring perks that operating on your own doesn’t. For example, different areas of expertise that some of us would just never have thought of, being somewhat far from the mind of field researchers and ecologists.

 I am talking about the computer learning side of things, ML (Machine Learning) in particular. The team behind Snapshot Safari have been working hard on this aspect essentially to help speed up the rate of classification needed now that there is so much data across different projects.

 They have recently engaged a specialist in machine learning at the University of Minnesota who is helping them to develop ML for use with the Snapshot Safari projects.

 The idea is to run an algorithm on the data prior to uploading it to the Zooniverse, this will identify most of the misfire and vegetation only images meaning us volunteers will be left with more of the good stuff, the actual animal images.

 The algorithm has been trained on millions of images from Snapshot Serengeti, now for these latest batches the team have asked the ‘machine’ to predict which species it is seeing, how many and what the behaviour of the animals is. Don’t panic we really are in the early stages and the idea is to compare what it came up with against the actual results from the volunteers whom we already know are pretty darn accurate. The team doesn’t expect great things yet from the ML and doesn’t foresee computers taking over any time soon but it will be interesting to see how the ML goes.

 So, for now things will be continuing as normal, no changes in how you classify or what you do but hopefully there will be fewer blank images with no animals. As the team stresses, they are a looonnng way from machines taking over.

 For those of you who enjoy being part of this developmental side of the project the Safari team will soon be launching a side project called Snapshot Focus. It is designed to also look at how well the ML is at recognising animals in trickier images, especially those with multiple animals. If you feel like helping out as a break from the usual work flow it couldn’t be simpler. All you have to do is answer yes/no as to whether the computer has managed to put a bounding box around every animal in the image.

 Look out for updates from the team over the coming months to learn more about these developments but meanwhile there are still lots of images to classify on Snapshot Serengeti.

Merry Christmas from the Snapshot Serengeti Team

The last month has seen a new batch of Snapshot Serengeti Images uploaded to the Zooniverse. There seems to be a high portion of really stunning images amongst the 40000 odd that were uploaded in this batch. Now there is no rhyme nor reason for this as the camera-traps are impartial, they simply snap away when an animal triggers them. It is pure luck if the resultant image is a perfect portrait or a tip of a horn or tail.

Of course, as scientists we don’t so much care about pretty pictures as being able at least to id the animals involved but no one is immune to a great image and so we at Snapshot Serengeti give a great big thanks to the animals of the Serengeti for being so cooperative when it comes to our camera-traps.

As you classify the images do remember to flag any really special ones for everyone to enjoy.

Christmas is approaching and so from all the team at Snapshot Serengeti Merry Christmas. Its been a big year for us moving over to the new system and joining up with Snapshot Safari, thanks for sticking with us through the teething problems and a big thank you for all your classifications over 2018.

 

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A Team Effort

Snapshot Serengeti has been on the go since 2010 in one form or another and over those years a team of dedicated people has kept it running. The base of the effort is the 225 camera-traps that have been snapping away continuously for that whole period. Of course for that to happen there needs to be researchers and assistants on the ground physically looking after camera-traps, a scientific team who coordinate all data processing and analysis, a management team running the administration of the project  and generous funders to keep everything alive and kicking.

Snapshot Serengeti could also not work without all the thousands of volunteer citizen scientist who generously give their time and energy to classifying all the millions of images, ultimately helping the researchers to answer scientific questions we hope will aid in the conservation of all that we love about the Serengeti.

Here in these blogs we have celebrated all these people but it dawned on me recently that there is one group of people that seem to have been forgotten, our moderators.

Our amazing team at Snapshot Serengeti deserve a special mention. They, like our citizen scientists are volunteers, dedicating their time and expertise for free. Contrary to what some may think they are not part of the scientific team in as far as they are not university students who do the job as part of their studies. No, they are a mixed bunch in terms of back ground and do the job plain and simply because they love the Serengeti and love the project. They spend a huge amount of time online helping other users with their classifications, guiding new users through some of the pit falls they know only too well and sharing their collective knowledge through prompt responses to questions and great information posts helping others with less experience to understand the Serengeti and its wildlife. They also have to deal with the odd, luckily very infrequent, troll which is a thankless task in diplomacy. We are privileged to have such an amazing team and I know that they are greatly appreciated by Snapshot Serengeti’s participants.

So thank you to davidbygott, maricksu and tillydad who have been with us since the beginning and welcome to parsfan and nmw. You Guy’s are the best and Snapshot Serengeti would not be the experience it is without all your help.

 

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Hartebeest through a dislodged camera-trap cover.

Vulture Culture

Lappet-faced vulture

 

Of all the large birds out there on the Serengeti plains the vultures are probably the most recognisable, with their long barely feathered necks and large hooked beaks, you can’t miss them. For a lot of people they are ugly birds and their behaviour makes people shudder, all that frantic plunging of necks inside messy carcasses. Some cultures revere the vulture, instilling magical attributes to them whilst others vilify them.

But the truth is they are just birds with their own unique ecological niche, one that is absolutely essential to the health of the whole ecosystem.

Lets break it down. That neck, well the fact that the whole head and neck is either bare or only lightly feathered is a marvellous adaptation to keeping clean. Yep, not something people generally associate with vultures but they are in fact pretty clean birds. That beak, well it may look like it could kill quite efficiently but it is actually designed to grip hard and rip. Believe me I have been around rescued vultures and felt the effect, there is a lot of power there. A vulture will use its sizable feet to hold a tricky bit of carcase down when trying to tear off a chunk but the real power comes from the strong neck muscles and the powerful beak.

If you look closely at the different species of vulture you will notice that not only is there a difference in size of individual species but in the beak size. There is a hierarchy in vulture etiquette at a fresh carcase. If the dead animal is large and has a tough hide, say a buffalo, the larger species such as lappet-faced will be needed to ‘break in’. Their huge beaks and added bulk allow them to head straight for the good bits where lesser vultures would have to start with the natural openings such as the eyes, mouth and anus. Once the large vultures have broken in, the rabble takes over and fights it out for the good meat, the white-backed and Ruppell’s. Around the peripheries the hooded vultures will be waiting for the chance to snatch up bits of anatomy that are sent flying by over- zealous cousins or to dart in when the carcase looks almost clean to pick off the last bits of flesh in hard to reach places. It is not uncommon to see this species right inside the empty carcase and its slim lined beak is great at cleaning up.

Vultures search for food from the wing. Research has shown that in the Serengeti it is most often the lappet-faced that arrives first despite the numbers of this species being lower than the others. It seems they are extra vigilant or just have better eyes. The descent of this the largest African vulture draws in the other species who can be clued into the find from over 30kms away. It is quite breath taking to see many vultures on rapid descent with wings held inwards, feathers splayed it can also be noisy.

But other than cleaning up unsightly dead things how do vultures help the ecosystem? Like other organisms that consume dead animal matter vultures are immune to a lot of deadly diseases. Their stomachs are filled with very acidic digestive juices which can destroy diseases such as anthrax, cholera and rabies. Most scavengers would not be immune to these types of disease and what’s more, diseases such as anthrax can lay dormant for decades posing an ongoing risk. Of course vultures alone can’t keep the Serengeti disease free but with their ability to fly over 100km a day they do a darn good job of patrolling the plains and keeping them clean.

But outside of protected areas vultures are in decline. In places like South Africa there has always been a value placed on vultures with Sangoma or witchdoctors prescribing vulture heads for people needing to see into the future to answer big life questions. Of course this has modernised, now people purchase vulture heads to see the winning lottery numbers. Vultures are also targeted by poaching gangs who, in an effort not to have their poaching camps discovered, place poison bait to attract and kill the vultures. India, several years ago nearly lost ALL its Gyps vultures. 95% where thought to have died and the main cause discovered to be adverse effects from a drug called diclofenac that was widely given to domestic stock. The drug has since been banned in India but its use as a veterinary drug in Africa is rising causing major concern amongst conservationists. Loss of habitat is also an issue.

We are lucky that the Serengeti is an ecosystem functioning normally with all its facets. You may be lucky to spot, lappet-faced, white-headed, white-backed, Ruppell’s griffon, hooded and Egyptian vultures in our camera trap images. It is quite remarkable to find this type of balance these days and we thank the vultures for their ongoing services.

Recap on Snapshot

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Snapshot Serengeti camera-trap image: Topi

Whilst stretching the corners of my brain to think about a new topic to write about in the Snapshot Serengeti blogs it astounds me to realise just how long we have been going for; over 7 years now as Snapshot Serengeti and almost 10 if you include the Serengetilive days.

It is also humbling to know how dedicated our followers are and what support we get from them. Our fun would have been over long ago if the community had not backed us. It has occurred to me that Snapshot Serengeti’s followers do so in differing ways. Those who follow our facebook and twitter pages or WordPress fans who follow us through our blogs may have missed what it is we are up to. So at risk of boring those of you who do know I thought it was about time to reiterate what it is we at Snapshot Serengeti do and how it all works.

Our largest group of followers do so at www.snapshotserengeti.org helping us classify the millions of camera-trap images that are produced by around 225 camera-traps placed in a permanent grid pattern in our study zone in the Serengeti National Park. For continuity’s sake these sites, after an initial bit of trial and error have remained in their fixed spots since they were first chosen by the projects designer, Dr Ali Swanson back in 2010.

Originally the camera-trap grid was set up to answer questions on carnivore interactions specifically if carnivores were avoiding one another spatially and temporally, it soon became apparent that it could be used to pose many more scientific questions amongst them herbivore coexistence and predator prey relationships. The wisdom to leave this permanent window of observance into the lives of the Serengeti animals should lead to many future studies and has spawned many new similar camera-trap projects around the world.

It’s not all about the animals, in fact since teaming with Zooniverse the project has been as much about the advancement of citizen science as anything else. Back in the Serengetilive days there were so few of us taking part that we used to have our names up in a sort of league table of who had classified the most images. Each classified image was labelled by the classifiers name. Now of course there are far too many participants to bother with that kind of thing, besides with multiple people having to agree on each classification it might get messy. The work on developing a robust algorithm that dealt with the uncertainties in each individual classification was so involved it also paved the way for many more projects and several scientific papers.

So what do we ask classifiers to do? Well first you are presented with either a run of 3 images (day time) or 1 image (night time). You are then asked to decide and record what animals are present, numbers of each species, behaviour and whether there are young present or not. It’s pretty straight forward with prompts along the way. If you don’t know what the animal is you simply guess. Yes you read that right, you guess. One thing the developers worked out is that the whole project works better if you cannot skip images. For one thing it avoids all the hard or boring images being left till the end. As each image has to be agreed upon by several classifiers before it is retired this tends to smooth out any miss classifications and research has shown we are around 97% accurate.

If you find something good or something you cannot id and are curious you can add the image to Talk which is the discussion forum. There we have some very dedicated moderators who will help you with your queries.

All in all Snapshot Serengeti is about learning and sharing both for the researchers and for the community of classifiers so if you have been enjoying the facebook posts or reading the blogs but have never had a go classifying get yourself over there to www.snapshotserengeti.org and have a go.

The Other Great Migration

White Stork

 

I am sitting at home in France in a sweltering 40oc listening to golden orioles calling from the tall riverine trees. I could definitely be in Africa, though if I was I would probably be somewhat reluctant to jump in the river to cool off, something I am about to do, what with all the hippo and crocs that the Serengeti is so famous for.

It has got me thinking though about all our shared birds between Africa and Europe. Hearing the orioles today has made me realise that they will be setting off very soon, in the next couple of weeks probably, for their return trip to their wintering grounds in Africa.

Now the Serengeti is justly known for its rather famous herbivore migration but to me it is utterly fascinating that birds, particularly the tiny ones are also taking part in seasonal movements that cover 1000’s of kilometres.

It’s a dangerous journey, they risk predation, starvation and severe weather and if that’s not enough they have to pass over several places where humans think blasting as many of them out of the sky as possible is sport. For the birds migrating from Europe to Africa they have to fly over open sea and a lot have to negotiate the Sahara Desert, an area around the size of the United States. It is estimated that 500 million birds have to cross this unforgiving wilderness and some do it in a long nonstop flight. Just imagine how exhausted they are the when they reach the safety of the green belts that fringe it. My husband used to work in the Sahara and can attest to finding dozens of swallows just lying panting on the ground, being able to pick them up and give them water before launching them onwards.

So why do they do it, well much the same reason as wildebeest and zebra do, resources. Birds have the very special ability to travel very efficiently, it has been said that a small bird can fly the same distance in hours that an elephant would cover in three days. With this ability birds are able to switch geographical areas in order to take advantage of seasonal food supplies and so they enjoy the best of both worlds in terms of food abundance despite the risk involved with moving the great distance between the two. Risk versus reward.

Unlike the Serengeti herbivore migration birds have many different strategies when it comes to undertaking their colossal movements often depending on the species unique design. Many small passerines will migrate in small groups, travelling at night and will try for the shortest, most direct route. A kind of fast and furious approach that relies on having fed up well and being able to feed quickly at the few places they do stop to refuel. Other birds, particularly waders will take a more leisurely approach flying down waterways and coasts, stopping for days or weeks at a time to feed up before moving on. Many raptors and storks cross the Mediterranean Sea over Gibraltar and Tarifa in Spain. It is roughly a 14 kilometre crossing. It is an amazing spectacle to see. Thousands of birds can be seen soaring around in the late morning over land waiting for the thermals to build up which they will use to ride across the sea to Africa. It’s kind of like surfing only on hot air.

Once they get to Africa of course they have a huge choice of where to go and they spread out accordingly, many making it all the way to South Africa. In fact we still don’t know where a lot of them go, something that is vital to understanding the threats facing them today.

So who are the feathered migrants that we may see in the Serengeti? Well across Tanzania there are thought to be around 160 species of Palaearctic/African migrants. The Palaearctic is a large region covering Europe, Russia, North Africa, Arabia and parts of Asia so that’s a lot of movement.

Some of Europe’s smallest birds can be found in the Serengeti amongst them willow warblers, wood warblers and blackcaps. Spotted flycatchers and several shrikes can be easily seen. The common cuckoo is trickier as it is, like many migrants, silent outside of its breeding ground. European bee-eaters and rollers meet up with their African cousins as do barn swallows and common house martins.

Even raptors make it to the famous park; lesser spotted, steppe and imperial eagles all breed in the Palaearctic. Eurasian marsh harrier, black kite and common buzzard all enjoy the warm African conditions before heading back north to breed.

For Snapshot Serengeti followers the most commonly seen migrants on our camera-traps are probably storks, white storks and black storks all take the long journey north for breeding. More surprisingly given it is not noted for its water even European ducks have been spotted in the Serengeti, wigeon, Eurasian teal and garganey amongst them.

This is not an exhaustive list but gives you an idea of the level in which the two continents are connected through their shared avian fauna and reminds us of what a truly global planet we live on.

Snapshot of a Crossroads

When we think of Snapshot Serengeti we think about the massive array of 225 camera-traps that are spread over 1125 km2 in the Serengeti National Park permanently clicking away. Partly this is fostered by the fact that when citizen scientists help out classifying images for the project they are randomly assigned images from a mixture of the 225 camera-traps rather than a sequential set from one camera. This is done so that each member of the community gets the chance to see a good range of different animals rather than, say, getting a camera-trap that was triggered 1000’s of times by grass.

For the most part anyway, people are concentrating so hard on the animals in the image that the scenery in the back ground is almost incidental. Regular contributors though will be aware that there are one or two camera-traps that are in very recognisable locations for example one trained on a group of boulders and one on a log. For some reason these spots seem to produce some really memorable images; the log was the scene of our melanistic serval as well as lion cubs, the boulder gave us some stunning images of spotted eagle-owl.

Recently the most epic capture event ever on Snapshot Serengeti surfaced of a pride of lions hunting a buffalo (if you missed it look here, https://www.facebook.com/SnapshotSerengeti/). That sequence was captured at a special little spot in the Serengeti, Dik-Dik Corner. The view is basically of a lone tree standing at a three-way cross road in animal tracks. There seems to be a pair of dik dik who hold this area central to their territory and they appear regularly, hence the name, but they are certainly not the only ones.

Here is a slide show of the passing wildlife at Dik Dik corner.

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Of course these are not the only critters to have passed this way but this selection really shows how the animals follow the trails, something camera-trap researchers have used to their advantage over the years.

Zorilla

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Zorilla – a rare find!

 

A few years back the Snapshot Serengeti community classified its first ever zorilla (Ictonyx striatus). It’s not an animal that most people are familiar with and you would probably not expect to even see one on a safari in Africa. It is certainly not on the big five list or even on the little five list but just like its bigger cousin the honey badger it’s a gutsy little creature.

The zorilla, or African striped polecat belongs to the Mustelidae family that includes the well known honey badger, otters and weasels. Although superficially similar looking to skunks they are unrelated.

So how would you recognise one? First of all they are small, only 28 – 38 cm long with a bushy tail of around 25cm. The most striking feature is the black and white stripy coat. The body is overall black with four white stripes running from the head to the tail which is mostly white. There are white patches on the face and head and the small ears are often white rimmed. The fur is quite long lending the zorilla a slightly scruffy appearance.

Zorillas share more than their looks with skunks; they are also able to squirt noxious smelling liquid from their anal glands as a defence mechanism against predators. So if you do ever encounter one, give this little guy the respect it demands and stay well back.

These tough little creatures will eat a wide range of items, invertebrates, reptiles, rodents and birds but they seem to favour rodents and insects. They are known to tackle venomous snakes and large rats by pinning them to the ground and repeatedly biting at the back of the neck to make the kill. Nocturnal, they find most prey by smell and won’t hesitate to follow prey down into burrows or use their strong claws to un-earth something. Its small elongated size is perfectly adapted for this task.

Zorillas are found across sub Saharan Africa in a wide variety of habitats but seem to avoid the wetter rainforest belt through west and central Africa. They are mainly terrestrial but are known to be good climbers and happy to swim if needed. Due to their widespread presence in Africa their conservation status is classed as Least Concern by the IUCN red list.

So why don’t we see more on our camera-traps? Well not much is known about zorillas, their small size and nocturnal habits make them hard to study and in a place like the Serengeti they are just not a high priority species. However we do know they are present because they do show up on the camera-traps from time to time. I suspect that the main reason they are not picked up more frequently is their small size coupled with their fast paced frenetic life. The weasel family is notoriously hard to capture on camera-trap as they tend to shoot through the trigger zone before the camera has got its-self together to trigger. Perhaps we will see more zorillas in the future when the camera trigger speeds increase.

 

Lions

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This is a great sequence from one of our 225 camera-traps that are tirelessly snapping away in the heart of the Serengeti National Park. One of the largest and longest running camera-trap projects, Snapshot Serengeti has been running for over 8 years with out a break.

The millions of images generated by so many cameras are processed by the amazing online community of citizen scientists without whom the team of scientists would probably still be working their way through season 2 rather than ploughing their way through season 10 (that’s were we are at currently, November 2015 to September 2016).

Those of you who have helped out on Snapshot Serengeti will realise that there is a great variety of images that come up, they are randomly assigned to each classifier and currently have to have at least 10 matched classifications before being retired. A great many are of grass or the tail end of animals as they pass by. Its the frustration of camera-trapping, when you look at the results you just wish you could nudge the camera to the left a bit to get a better image but of course its way to late for that once you have the image safely in hand.

But every once in a while we get a stunning image worthy of a professional photographer or one that shows really interesting behaviour and those are the images that get people hooked on returning day after day to help out on Snapshot Serengeti. A little fix of wildlife in its environment enjoyed from your home.

This sequence of a lion pride is great. In all likely hood the four individuals we can see here are not the only members, others could be out of frame. It looks as though the female has a pink tone to her muzzle, now it could be a trick of the light but its also possible that the pride have recently fed. The full looking belly and the relaxed nature of the other members would lend weight to this possibility but we will never know for sure (unless more images from that camera-trap reveal more proof!)

It is most definitely one of those moments when you wish you could pan the camera around to see what else is going on, did we almost get a kill on camera? are there a bunch of cubs laying under a bush to the right? are there a pair of resplendent pride males slumbering to the left?

If you do discover more from this series do let us know but for the time being we shall have to let our imagination ramble.