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Observations on Observations

White-browed sparrow weaver nests

 

Camera-trapping has vastly opened up the possibilities of studying animals in the field in a relatively unobtrusive manner. Leaving a bunch of camera-traps clicking away 24/7 over a long period is generally cheaper than employing researchers to stay in the field providing them with accommodation, food and vehicles.
However it has its drawbacks. Good field skills are only learned over time spent in the field and although field researchers cannot operate 24/7 like the camera-traps they are less impartial observers noticing all kinds of fine details surrounding that which they study.
It is these observations that stimulate and inform new scientific questions and drives the understanding of the world around us. I am not suggesting that the results of camera-trap studies can’t also do this but since the days of the first naturalists it is being in the field that nurtures the very interest in studying wildlife in the first place.
The researcher who knows their study area well will be at an advantage to one who has planned from afar after using GIS. I know because I have been both. My first camera-trap project was on a reserve where I had lived for three years and that helped me know intuitively where I should place my camera-traps. On the other hand my latest project involved a very fine time window and I had to set up camera-traps on an unknown farm within two days of arriving. By the end of the 8 week period I was just starting to get a better feel for the place and could have kicked myself for not placing my cameras in the optimum places. When I went back to collect the cameras I found myself wading thigh high through a carpet of small yellow daisy-like flowers that left me coated waist down in a yellow stain. Had I have known the farm better realised this plant grew only in a few areas and could have avoided it entirely and saved myself the turmeric skin wash and a lot of miss-triggers.
My latest trip to Africa reminded me of why living in the field is so rewarding. Whilst the camera-traps are diligently collecting your data it gives you the chance to observe without frantically thinking of your research question, you can take time to take inspiration from the broader environment.
Near my tent was an old dead knob thorn tree that had five white-browed sparrow-weaver nests hanging like straw balls from it. Each night at dusk a pair of sparrow weavers would fly into the tree, call loudly as if claiming the spot and the female would dive into her preferred nest. The male would remain up high above waiting. Just as the last light was fading 3 or 4 small dark shapes would arrive and the sparrow weaver would chase after them squawking disapproval. Having seen them off he would come back and settle himself into the nest of his choice retiring for the night. Watching closely revealed, a few minutes later, the return of the invaders; two pairs of black-faced waxbills. They alighted at the top of the tree and cautiously made their way down towards the remaining nests finally one by one slipping quietly into the unused nests one couple per nest.
The thing about this little drama was that it was played out every night for over two months. None of the birds seemed to alter their routine and none where actively breeding at the time, they just had their bed time ritual. This was the kind of observation that the camera-traps will never quite capture as well as a human. In just the same way, although Snapshot Serengeti would not exist without the cameras it would be nothing without the human, citizen scientists behind the scenes sorting out the images. Even with computer recognition programs on the horizon I believe it would be foolish not to still use humans who’s innate sense of life will always pick up on something that is slightly odd, unusual or different about an image.

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Camera-trap Conundrums

You are probably aware that the 225 camera traps of Snapshot Serengeti are set out in a grid pattern, spaced every 1km over a part of the Serengeti National Park. It sounds relatively simple but actually there is a lot of painstaking scientific pondering as to how exactly to set out your camera traps.
Over the last couple of decades there has been much debate as to the best way to design a camera trap study. The main choice, in terms of placement pattern, is whether to place your camera traps randomly or selectively and what kind of spacing/density to use.
Truly random is to grid your study site and then let a computer randomly choose which grid squares to place the cameras. Alternately you can choose a line or grid and place your camera trap at regular intervals regardless of where that may fall, still a random point. With selective placement each site is carefully chosen for a specific feature.
In reality most projects use a mixture of the above methods and the best method is really determined by what your scientific question is. For instance, if you where trying to acess the number of leopards in a given area it is better to place your camera traps strategically in places you know or guess leopards are most likely to pass rather than using a randomised method. However if you are carrying out a census of an area and wish to know what species are present then a randomised grid is ideal.
As I said a mix of methods is often used. Imagine setting out a grid in the comfort of your office on your computer. It looks good, covers a large area and promises good results. Once out in the field you navigate to your carefully worked out GPS reference point only to discover it is slap bang in the middle of a marsh or in a thick overgrown patch of thorn trees. This is where the scientists allow themselves a little leeway. Often they will take the GPS point as home base but choose an ideal spot within a certain radius of this point where perhaps there is a game trail or some other sign of animals passing, thus allowing them to select a good site within the vicinity.
I have recently had experience of this type of placement and I can say the work done in selecting your study site and then laying out your grid onto a map is laborious but not nearly as much as stomping through the bush keeping your fingers crossed that your next randomly selected site will be perfect. Turning up to emplacement three to find a thick tangle of vegetation is a little soul destroying, mostly you wonder if any animal is likely to bother to pass that way. The reality is that you normally find a spot that is better within 10 meters and with some slight pruning of the vegetation the sites can often turn out remarkably productive.
So that is the placement sorted but there is a long list of other agonising variables to consider, what settings to use on the camera trap itself, how many to use and how long to keep them up. Believe me every scientist designing studies deliberates the pros and cons of these factors and worries incessantly about if they have made the right choice. You don’t want to set up all you camera traps and leave them for a few months only to find your set up was not great, something which happened to me recently when I chose to set the camera trap on high sensitivity to make sure I had every chance of capturing the small, fast critters. The problem was it was so hot, 40°c plus, that the ambient waves of heat set the camera trap off almost permanently between 12pm and 5pm leaving me with 2000 images of nothing. I have had to compromise and reduce the sensitivity to avoid all the miss triggers; hopefully it won’t miss too many small things.
Snapshots camera traps have now been up for over 7 years so most of these teething problems have been ironed out. But as with the best laid plan you cannot control everything, the odd camera still malfunctions as I am sure that our regular classifiers can attest to!

Camera-trap

Snapshot Serengeti – Upcoming Changes

*This weeks blog was written by Jamee Snyder, project coordinator and administrative assistant with the Lion Lab, University of Minnesota. She tells us all about a wider a project that Snapshot Serengeti has evolved into and what we can look forward to in the near future.*

 

Seven years ago, the University of Minnesota Lion Center set out 225 cameras in Tanzania’s Serengeti National Park. These cameras have recorded over 50 species including some of the most threatened species on Earth. With help from over 140,000 citizen scientists from around the world, millions of photographs were reviewed and classified over the past seven years, which provided park managers, conservationists, and researchers with the necessary information to analyze African wildlife population dynamics. This collective effort is a major contribution to ecological research, allowing for the evaluation of long term trends in wildlife populations as well as best practices in conservation management of charismatic african mammals.

hyena

A Snapshot Serengeti Camera-trap image

Snapshot Serengeti was one of the first camera trap surveys to document wildlife populations in a national park and is now one of the longest running camera trap surveys in the world. We have learned a lot over the years, from how to keep our cameras safe from hyena jowls to retrieving data from memory cards that have gone through a wildfire. We are continuously looking for ways to improve this project.

Thanks to years of experience, your participation, and help from several organizations in the U.S. and Africa, we are excited to announce that Snapshot Serengeti is expanding into an international conservation initiative called, “SnapshotSafari.”

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Don’t worry! Snapshot Serengeti isn’t going anywhere. In fact, it will remain essentially the same as we transition into our new platform. The discussion forums and personal image collections will still be available to current and future users. Now, participants will be able to see numerous other parks in addition to the Serengeti. SnapshotSafari will showcase camera trap images from multiple camera trap grids inside dozens of parks and reserves located in six African countries. Intrepid citizen scientists will be able to choose from various exotic habitats, including but not limited to: the Sand Forests of KwaZulu-Natal, the Lowveld of Limpopo, the Fynbos of South Africa’s Cape, and the Karoo desert, in addition to such remarkable ecosystems as Mozambique’s Niassa Reserve, Tanzania’s Ruaha National Park, Swaziland’s Mbuluzi Game Reserve, and Botswana’s Makgadikgadi Pans National Park.

By incorporating multiple sites, we can ask more complex questions regarding African wildlife populations and the factors that contribute to ecosystem stability. For example, researchers can compare population dynamics of reserves that are fenced versus those that are unfenced, or theycan evaluate the environments that successfully host multiple predator species without depleting prey populations. Researchers at the Lion Center will use this dynamic platform to investigate the cascading effects of large mammal reintroductions and ways to limit direct human interventions while still maintaining stable ecosystems within fenced reserves. SnapshotSafari provides an opportunity for participating reserves to collaborate and subsequently develop the most effective conservation strategies for protecting biodiversity.

We are working hard to get SnapshotSafari ready to launch in January. We just completed beta-testing, and the feedback has been very positive. To all of the citizen scientists who participated and to those who continue to be involved with Snapshot Serengeti, we are extremely grateful!

Now, we need your help to finish classifying the final series of images on our original platform, Season 10, at http://www.snapshotserengeti.org before we initiate SnapshotSafari, which will host Season 11. We are very close to finishing classification of these images, so don’t hesitate to invite your friends and family to take a trip to the Serengeti through the lens of one of our camera traps and classify wildlife. Let’s push this meter to the end!

Stay tuned for an official count down, so you can be one of the first to participate in SnapshotSafari and contribute to our collective knowledge and ability to successfully conserve African wildlife.

 

Back in Africa

The Waterberg Plateau

You know you are in Africa when you wake up at the airport lodge on the edge of a capital city and stepping out from your room you come face to face with a bird that towers above you. Ostrich aside the dry heat of the Kalahari leaves you in no doubt you are in Africa.

I am in Namibia where I will be for the next two months. I am working on a cattle farm in the Waterberg plateau that is part of a greater nature conservancy. I have already got my camera-traps out, hopefully snapping away as I write. The idea is to look at how camera-trap spacing affects the chances of recording smaller mammals. There are plenty of those here, bat-eared fox, jackal, caracal, mongoose, pangolin, hare and aardwolf to name but a few.

The great thing about using camera-traps is that now they are up I have some weeks to wait before moving them so I have plenty of time to immerse myself in the African bush. I have already clocked up over 100 bird species in less than a week, its taking a while to get my ear back in gear, I keep hearing tantalisingly familiar calls but can’t quite remember who they belong to. It is the start of the rainy season and subsequently the breeding season so there is an awful lot of activity. The binoculars are back living on my shoulder and in use every few minutes.

The bush here consists of a lot of small bushes and trees interspersed with small open grass patches. Plenty of sickle bush, raisin bush and buffalo thorn. I forgot how hard it is to walk through, constantly getting hooked up on vicious thorns that grab at you as you pass.

The best bit of the trip is living in a tent, ok afternoon naps are impossible in the heat but you get to wake up early to the birds calling. The francolins and spurfowl are calling before the sun even rises. There are white browed sparrow weavers building nests in a tree near the tent that have the loveliest melodies. Then there is the night shift. It is pretty hard to fall asleep sometimes when the noises just make you want to get up and investigate. So far I have come face to face with a honey badger sniffing around our fire and several genets. The jackal’s shrill call is omnipresent but the one I listen out for is the rasping call of the leopard. I haven’t been disappointed, every other night that sound rumbles through me.

My internet connection is not so great but I should still be making regular posts for Snapshot Serengeti and there are still plenty of images to classify. We would like to run season 11 in the New Year if we can get season 10 completed. I may even have the odd camera-trap image from my Namibia project to share. Watch this space.

Identifying Small Carnivores

 

One of the groups of animals that seem to prove quite tricky to tell apart on Snapshot Serengeti are the small carnivores that belong to the canid and hyenid family. That is to say the jackals, black-backed and side-striped, the bat-eared fox and the aardwolf.

There are good reasons for this. Firstly they are predominantly nocturnal, though the jackals can often be seen in day light hours. Secondly they are small and constantly on the watch for larger predators. Studies have even shown that similar species such as coyotes are rather camera-trap shy so it could be possible these African cousins are avoiding the cameras. I noticed when looking for bat-eared fox images particularly that there are very few close up images, the foxes always seem to be in the distance. Something to maybe study?

So back to classifying, what’s the best way to tell these species apart?

Let’s start with the jackals, the most dog–like of the Serengeti’s small carnivores.

The first thing to note is there are actually three possible jackals to be found in the Serengeti but I will stick here to the side-striped and black-backed as the most common, the golden jackal doesn’t come up so often on our cameras but looks broadly the same as the other two with slightly more uniform colouring.

 

Jackals have dog like proportions with the shoulders and hind end approximately the same height. They have very pointed muzzles and large pointed ears. The black-backed can be distinguished by its black saddle running from the back of the neck through the shoulders up to a point at the top of the tail. It is flecked with white hairs giving a grizzled appearance. The rest of the body is a sandy colour. The side-striped is more uniform grey brown with a flash down its side both light and dark but lacking the saddle. The tip of the tail is often white. Their ears are smaller than black-backed jackal.

 

The bat-eared fox meanwhile is a strange looking creature. All three of these carnivores have large ears to help them locate prey but the bat-eared fox wins the prize. Its ears dwarf its little face which is very small. They need these huge ears to locate their insect prey. Over all bat-eared foxes are the smallest of the three and have a rather plain silver/grey coat with dark legs, ears and upper parts of its thick bushy tail. If you are not sure look at the over all posture. The jackals hold their head high on a strong neck but the little bat-eared fox often has his head down and appears to have no neck.

Aardwolf, although not canids, are included here because in size and shape they are very similar to the other two. Fortunately these guys have distinctive striped coats which help separate them from all but the much larger and very rare (in Snapshot Serengeti) striped hyena. The aardwolf seems to have a rather thick long neck and a much more hyena shaped heavy muzzle.

So the tip here is to look closely at body form as well as colour, hopefully seeing these images of the three together will be helpful next time you get stuck classifying.

 

 

 

 

 

 

 

 

 

Happy Birthday To Us

Camera-trap

 

Snapshot Serengeti has around 225 camera-traps laid out in a grid in the heart of the Serengeti National Park. They have been there for around 7 years and make up one of the longest running camera-trap monitoring projects in the world. Snapshot was launched on the Zooniverse portal in December 2012 and has inspired many more similar camera-trap projects from around the world. So Happy 5th Birthday to us, may there be many more to come.

There is no doubt that camera-trapping has gripped the hearts and imagination of both scientists and the public. Eight years ago when I first used camera-traps I had to explain them very carefully to friends and family as they had never encountered them, these days references to camera-traps appear in popular press articles and  wildlife documentaries and most people have a basic idea of their use in conservation.

It was K. Ullas Karanth, an Indian wildlife zoologist, who is credited with pioneering the use of camera-traps as scientific tools in his study of tigers in the 1990’s. In the last two decades the technique has advanced at a hugely fast pace and has revolutionised the study of elusive and seemingly well known species alike. It is a scientists dream to observe animals without being present yourself to influence their behaviour.

But looking at the history of the discipline I can across many references to much earlier work using camera-traps. Back in 1927 National Geographic published an article by Frank M Chapman titled delightfully “Who Treads Our Trails”. The piece opens with this amazing paragraph

“If there be any sport in which the joys of anticipation are more prolonged, the pleasures of realisation more enduring, than that of camera trapping in the Tropics I have yet to find it!”

This guy would have loved Snapshot Serengeti. This is most likely the very first scientific paper to report on using camera-traps all be it very different cameras. His rig involved a tripwire the animal steps on rigged up to the camera shutter and bowls of magnesium that will explode and create the flash needed to illuminate the animal at night time. It seems incredible now that this would be allowed considering today’s ethically minded ethos but the author himself points out that the alternatives to studying animals could include using dogs or trappers to catch an animal or even poison bait. He decides he wants a census of the living not a record of the dead and so the idea of camera-traps for scientific study are born. He drew heavily from the work of George Shiras who published the first pictures taken by remote camera back in 1906 (also in National Geographic). George Shiras took the pictures for the pictures sake only later becoming involved with conservation but Frank Chapman was a true scientist.

Obviously the technology has changed a lot and the loud noisy explosions that accompanied Franks work have been replaced by covert black IR where even the glow of the infra-red flash is almost invisible. He would marvel at the amount of pictures that can be stored on an average SD card and that camera-traps are being used from the tropics to the snowfields of Antarctica.

You can look for the original article with this reference:

Chapman, F.M., September 1927. “Who Treads Our Trails?“, National Geographic, 52(3), 331-345

Or visit this site to see some of Frank Chapman’s images: http://www.naturespy.org/2014/03/camera-traps-science/

Unusual Critters

There is a small mammal that is found in the Serengeti which I am not sure we have ever captured on camera-trap or if we have most of you won’t have got the chance to classify them as the capture rate will be very low.

It is not because they are rare or even that elusive, visit the Serengeti or any number of suitable reserves across Africa and you will bump into these odd little creatures. It is just that they are very restricted by their habitat which is rocky outcrops.

The mammal I am talking about is a relative of the elephant, yes that’s right, the largest land mammal is cousin to this rabbit sized African curiosity, the hyrax otherwise known as rock rabbits or dassies. It seems that the two species split some 70 odd million years ago so plenty of time to both specialise in their own way. However one odd trait the hyrax retained was a long gestation period (7 months) more similar to larger mammals. Compare this to scrub hares that have a gestation period of around 42 days. New born hyraxes are extremely well developed and commence eating grass within a few days of birth. Unusually for a small mammal life expectancy is long, up to 12 years.

 

Rock Hyrax  Procavia Capensis

Rock Hyrax

 

Photo Credit: Max Pixel; creative commons zero- cco

 

There are two species of hyrax we could encounter in the Serengeti, the rock hyrax (Procavia sp) and the bush hyrax (Heterohyrax brucei). In fact they can even be seen side by side sunning themselves on rocks. Although they both make their homes in rocky outcrops the two have decidedly different life styles. The rock hyrax eats predominantly grasses and rarely strays far from rocky out crops, conversely the bush hyrax eats mainly leaves, twigs and bark which it climbs trees to eat. The two species however live in colonies in rocks and in the Serengeti at least these colonies can be a mix of both species. The rocky retreats act not only as safety from the many predators that eat hyrax but also offer a way to thermo-regulate.

It’s a wonder that these closely related species don’t hybridise but it seems they have extremely different genital structures as well as the differing dental work needed to cope with the different diets. All species have long sharp upper incisors that are often used in dominance scuffles, hyrax can be very bad tempered and those incisors can inflict serious damage.

 

Bush Hyrax showing incisors

 

Photo Credit: Peter Steward, Flickr CC-BY-NC2.0

 

Living in a relatively small area and in colonies has lead to some interesting behaviour amongst hyrax. They use latrines which are thought to be centuries old. In fact you can often spot the white stains on the rocks of an active colony.

All in all a fascinating little creature, if you are ever faced with a snapshot image with rocks in, take a good look to see if you can’t see a hyrax sitting there.

Wonderful Wildebeests

Wildebeest

 

I thought I would write about wildebeest this week, it seems we take them for granted a bit. Certainly on Snapshot Serengeti they generate about the most images and it has been commented in the past “No, not another wildebeest”. The Serengeti is after all world famous for its wildebeest.

But what do you know about them, other than the roam around in large herds and get eaten by lions, leopards, hyenas and crocs?

Well ecologically they have evolved in a fascinating way. They are heavily dependent on water, never straying more than 20km or so from it. However, their square looking lips are designed for nibbling at short grass swards that are found in drier, fire maintained grasslands like that of the Serengeti and they are unsuited to wetter areas of equatorial Africa where grasses become tall and rank. They are bulk grazers that operate in large herds. Wildebeest are not especially fast runners having a body shape that favours their digestive tract, instead they rely on the size of the herd for protection. Unlike their close cousins, the hartebeest who are designed to outpace predators, wildebeest have proportionately shorter legs and males develop sturdy thick necks.

We have all seen footage of the migration with nervous looking wildebeest stampeding along, hell bent on reaching their destination. What you may not know is that this mass getting together stimulates the rutting state in both sexes. In amongst the moving herds males try desperately to mark out and keep a small territory from which he cavorts around noisily evicting other males and trying to impress a few females to mate with. The problem is he has to keep moving with the herd so these territories are very temperal and really only exist in his mind and he has to move on every day or so in order to keep up with the ladies. There are always a few males left in the wake of the procession that get caught up with fighting each other and trying to hold territories without realising the females have all gone. Once the migration has reached its destination everything calms down a bit and things get back to normal, breaking up into smaller groups until it’s time to do it all again.

Wildebeest no longer exist in their historic numbers. They are particularly affected by land use changes, susceptible to domestic live stock diseases and are targeted by poachers. Their dependence on water, quality short grasslands and large herd size means they don’t fare well on marginal land. However it’s not all bad news. Wildebeest are well represented in national parks across their range in Africa.

 

Leopards; Most catty of cats?

This week I posted a great image of an elusive leopard on the Snapshot Serengeti facebook page. I have a real soft spot for these large cats that stems from my first foray into the world of camera-trap studies. Back then I lived on a small nature reserve in South Africa where leopards were the top predator. Without lion present and an abundance of prey the leopards thrived there and our study looked at the population density on the reserve. The interesting thing with the study was that we almost never physically saw a leopard on the reserve yet we were able to get heaps of camera-trap photos. It was although these leopards had learned that yes this was a great place to live, just keep your head down when one of those humans comes by.

I have been thinking about what draws me to leopards more than the other big cats of Africa and decided it’s the catty-ness of them. Now don’t get me wrong, lion and cheetah are definitely cat like too but somehow they are out done by the leopard.

Let’s take the lion. King of beasts they may be but really, hanging out in prides, what’s that all about. That’s what dogs do right? And cheetah, well with those only semi retractable claws and that speed over the plains, well, it could almost be a greyhound.

Now back to the catty-ness of leopards. Well they slink about, pounce on anything they can get away with, shoot up trees at the drop of a hat and generally act aloof just like you average house moggy. One more thing they share with their diminutive house cousins, they love to sit in boxes. Ok maybe not boxes but I have seen leopard tucked up all cosy in various natural alternatives. The picture below I took in the Kgalagadi where this leopard was sound asleep on top of a giant sociable weaver nest.

 

Leopard in weaver nest

 

 

The beautiful cryptic pattern of the leopard is one of its best adaptations that allow it to thrive in all kinds of habitats across Africa and Asia. Their coat pattern helps to break down their overall shape and they use broken terrain and vegetation to conceal their presence as they stalk close to prey and then ambush. More than capable of taking large prey leopards will happily snack on rodents, insects and small mammals if the opportunity presents itself. This camera-trap image shows a leopard with a zebra kill. The actual event was witnessed by a colleague who confirms that the leopard came out of nowhere and caught the zebra totally by surprise.

 

Leopard with zebra kill

 

Despite this seemingly remarkable ability to blend into the background leopard do not go unnoticed by man and recent studies have highlighted that leopard numbers too have plummeted as they are targeted for their skins, as trophies and just killed as pests. They seem to be declining in the same way they thrived, quietly and out of sight.

Wildlife Photographer of the Year

Well it is that time of year again when the winners of the prestigious wildlife photographer of the year awards are announced.

Having a browse through this year’s winners I notice with a touch of sadness but a good dose of hope just how many of the photos touch on the demise of wildlife and have a conservation message. Brent Stirton’s moving image of a poached black rhino although tragic is a strong weapon in itself in the fight to change the hearts and minds of those people that covet rhino horn.

One of my favourite images is in the bird behaviour category. The much maligned marabou stork is the subject and the shot was taken in the one spot on this planet that Snapshot Serengeti fans know so well, yes the Serengeti.

But the story doesn’t end there. The photographer who was awarded finalist in the bird behaviour category is well known to us. Daniel Rosengren worked for the Serengeti Lion project for 5 years in the field with the most enviable job going. He spent every day following the study lions getting to know them intimately and generally building up the rich source of study data that this 30 year+ project has gained.

Of course when Dr Ali Swanson came up with her wonderful idea of seeding the area with 200 odd camera traps and the Snapshot Serengeti project was born it was Daniel who looked after our precious cameras for several years. So we have a lot to thank him for.

Daniel moved on from the project in 2015 to pursue a career as a professional wildlife photographer and we congratulate him on his achievement this year in the wildlife photographer of the year award. Well done!

If you want to learn more about the story behind his image or just want to see some stunning wildlife images visit his website here http://danielrosengren.se/wpy-awardee/

And to see all the other winners from this year’s wpy 2017 visit

http://www.nhm.ac.uk/visit/wpy.html