Archive | Serengeti Ecosystem RSS for this section

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

 

Advertisements

Celebrating Owls

Sotted eagle-owl

Spotted eagle-owl

 

Although mammals are the target for the Snapshot Serengeti camera-trap project we do on occasion capture other things, humans, vehicles, reptiles and birds. The most common of the birds is probably the larger ground patrolling species like kori bustard, secretary bird, guinea-fowl or the birds that are attracted to mammals like oxpeckers, egrets. It is actually surprising just how many species we have picked up over the years.

One of my favourites though has to be the owls. Always such fascinating creatures they are often loved but often feared too. Their nocturnal, silent flight lends to the mystery but anyone who has been around owls much will know that they can be noisy birds when it comes to calls.

So who might we encounter in the snapshot Serengeti camera-trap images. Well there are 9 species that call the Serengeti home:

  1. Barn owl – Tyto alba
  2. African marsh owl – Asio capensis
  3. Spotted eagle owl – Bubo africanus
  4. Verreaux’s eagle owl –Bubo lacteus
  5. African wood owl – Strix woodfordii
  6. Pear-spotted owlet – Glaucidium perlatum
  7. Southern white-faced scops owl – Ptilopsis granti
  8. African barred owlet – Glaucidium capensis
  9. African scops owl – Otus senegalensis

The barn owl found on every continent except Antarctica is probably familiar to us all. The spotted eagle owl, a medium sized owl is just that, heavily spotted and barred overall greyish. The similar sized wood owl sticks to more densely wooded areas and is a darker chocolate brown. This is a rare bird for the snapshot habitat.

The largest owl we will encounter is the Verreaux’s eagle owl, pale grey the most obvious distinguishing feature is bizarrely its eye lids, they are bright pink. Unmistakeable if you get a good view.

As for the small owls two are actually reasonably active during the day, pearl-spotted and barred owlets. Quite hard to tell apart the pearl-spotted has white spotting on its back where as the barred has, you guessed it, a barred back. However if you are ever lucky enough to hear a pearl-spot in the wild they are unmistakable. It has a slow single note, rising pitch call that builds up to deflating drawn out descending notes. Hard to describe but its other name is the orgasm bird!

We would be lucky to pick up a scops owl, the smallest of all these owls. It remains hidden in trees all day and hunts insects at night.

African scops owl

The African marsh owl is unusual in that it roosts on the ground, tunnelling into long grass. Superficially it resembles a barn owl but the pale facial disc is rounder than the heart shape of a barn owl. They mostly eat rodents.

African marsh owl in flight

The white-faced scops owl has a very striking white face framed by black bands. The rest of its body is pale grey. Size wise it is slightly bigger than the two owlets.

If you want to see more snapshot images of birds follow this link where one of our moderaters has put together some great stuff:

https://talk.snapshotserengeti.org/#/boards/BSG0000008/discussions/DSG0000ek5

 

Dynamic Landscape of Fear

Lions with zebra kill

†

 

The Snapshot team have written another paper using the Snapshot data we all help to classify. The paper A ‘dynamic’ landscape of fear: prey responses to spatiotemporal variations in predation risk across the lunar cycle can be found at http://onlinelibrary.wiley.com/doi/10.1111/ele.12832/full for those of you interested in reading the original.

Lead by Meredith Palmer the paper explores how four ungulate species, buffalo, gazelle, zebra and wildebeest respond to predation risk during differing stages of the lunar cycle. These four make up the bulk of the African lion’s diet in the Serengeti along with warthog. Of course warthog are strictly diurnal so are not affected by the lunar cycle as they are tucked up nice and snug in a burrow.

For the other four night time can be a stressful time. None of these animals sleep all night, they snatch rest here and there, keep grazing and most importantly of all keep a watchful eye or ear out for possible attack.

It has long been thought that prey species territory is shaped by fear and that animals have safe areas (where they rest, give birth, etc) and risky areas where they instinctively know predators may be lurking. These areas trigger a risk versus reward response as they often contain better forage/water etc.

What Meredith and the team argue is that this landscape of fear is very much dynamic changing not only with seasons and night and day but on a very much finer scale as influenced by light availability through the moon.

Lions find it so much easier to hunt during nights where the moon gives of least light. It gives them a great advantage to stalking close to their prey using the dark as a kind of camouflage. The prey species, on the other hand, are at a distinct disadvantage, they can’t see the stalker and even if they sense its presence they are reluctant to flee as this presents a great risk in itself if they can’t see.

Meredith and her colleagues took the data from Snapshot Serengeti to quantify nocturnal behaviour of the key species using the presence or absence of relaxed behaviour (defined when we classify a species as resting or eating.) They then overlapped this with data collected through Serengeti Lion Project on lion density and hunting success. This data enabled them to work out what areas where high or low risk to the prey species. Using a clever statistical program, R, the data was analysed to see if lunar cycle had any bearing on animal behaviour, in particular, predator avoidance.

They found that moonlight significantly affected the behaviour of all four species but in a variety of ways. As we mentioned before there is often a good reason to venture into the high risk areas and the trade off in increased risk of predation is a really good feed. Buffalo for instance don’t change their use of space so much but were found to form more herds on dark nights. It seems safety in numbers works well for buffalo. Zebra react similarly in their herding activity but are much more erratic when it comes to space use, moving around a lot more randomly keeping potential predators on their toes.

Each species showed an aversion to using high risk areas at night but, particularly wildebeest and zebra, were found to increase their use of these areas when the moons luminosity was higher and safety increased. It was noted that high risk areas where avoided more frequently in the wet season than the dry. The thought being that there is increased hours of moonlight during the dry season that the animals take advantage of. Perhaps too the drive to find enough good food is a factor.

This paper serves to remind us that although what we do at Snapshot Serengeti is fun it is more than just a way for us classifiers to pass the time. It really has a very significant role in science and that role is ever increasing.

 

Small Cats of the Serengeti

 

Whilst we all love to see lion, cheetah and leopard, the big cats of the Serengeti, their smaller cousins are fairly elusive. I am referring to caracal, serval and wildcat. These three small cats manage to slink around between the large carnivore guild keeping themselves to themselves. Lion cheetah and leopard not to mention hyena will all kill small cats. Despite their diminutive size their larger cousins still see them as competition and threat. All three are solitary cats and to survive in this very competitive world they each have their own niche.

 

Caracal

The largest of the small cats, females weigh in at around 10kg and males up to 19kg. They are found across Africa, Arabia and parts of India preferring drier habitats such as savannahs, steppes and dry woodland. The caracal is a magnificent hunter. It is extremely powerful for its size and is able to take down prey as large as small antelope like duiker and bushbuck. The bulk of their diet is made up of hares, rodents, hyraxes and antelope but they are renowned for their ability to leap into the air to catch flushed birds. Their back legs are longer than their front legs and are endowed with powerful muscles that enable them to burst upwards and snag flying birds.

This cat is uniformly coloured the bulk of its body ranging from a tawny grey to a brick red with some spotting restricted to its pale cream underbelly and chin. Its most distinguishing feature is its black tufted ears and black facial markings as well as a short stubby tail that put one in mind of a lynx. It is in fact not related to the lynx family at all.

 

Serval

Probably the most easily recognised of the three and the most commonly encountered of the cats on Snapshot Serengeti. These exquisite little animals are restricted to the African continent south of the Sahara across savannahs, marshes and forest edges particularly near water courses where tall grassy plants grow.

The serval weighs between 6 and 13 kg with males being larger than females. Proportionate to its size it has the longest legs of any cat species and along with its elongated neck and large pointy ears makes this cat unmistakeable. Its tawny coat is spotted black; these spots may run into bars on its neck, shoulders or legs. Melanistic (all black) morphs are known and we have been lucky enough to capture this rarer variation on Snapshot camera-traps.

Food wise these cats are small mammal specialists stalking prey through long grass locating their prey by sound and then using their long legs to leap into the air and strike prey in a fox like manner. They have very flexible toes and will hook fish and amphibians out of water as well as mammals from burrows. The bulk of their diet consists of small rodents under 200g but they will take reptiles, amphibians, birds and small antelope.

 

Wildcat

These cats are smaller than the other two, heavily resembling a domestic cat it is found throughout Africa, Asia and Europe. They weigh between 2 and 6kg and like the caracal and serval males are heavier than females. Apart from size the appearance of the sexes in all three cats is very similar and show little dimorphism.

Its coat is highly variable in colour and pattern ranging from grey brown to red. Dark spotting tends to appear towards the rump, down the tail and on the legs which often bleed into each other appearing more like dark stripes.

It is perhaps more of a generalist than the other two small cats and takes a wide variety of small prey with rodents making up the bulk of its diet. Birds are less frequently taken but insects have been identified as an important part of the diet. Its method for hunting is more familiar to us than the stalk and pounce of the caracal and serval. It will locate prey by sight or sound and then silently creep towards it by slinking belly to the ground before pouncing at the last minute. We have probably all witnessed a domestic cat stalking like this.

 

Of course once you are familiar with these three cats it is easy to tell them apart, that is if you are lucky enough to get a good daytime or colour image. Although serval are seen out in the day caracal and wildcat are less frequently active during daylight and all three mostly hunt at night. It can be harder to tell one from the other in a black and white night image but the trick is to concentrate on the shape. Does it have outsized ears, long legs and obvious spots (serval) or a rounded head on powerful shoulders and ears with tufts (caracal) or does it really remind you of the proportions of a domestic cat (wildcat). Like always make your best guess and perhaps post on the descussions page for more help.

How Termites Shape the Serengeti

ser haartebeest.JPG

 

The Serengeti is one of the best examples of a fully functioning grazing ecosystem. It is home to the world’s largest body of free roaming herbivores. If you have helped classify snapshot Serengeti’s millions of camera-trap images you will know that wildebeest, zebra, topi, hartebeest, and gazelle to name a few are far more common than lion, cheetah and leopard.

Most people are aware of the millions of antelope that, along with the grasses themselves, shape this environment but they are not the only herbivores out there. There is a micro world down at ground level that is often forgotten about but which plays an enormous role in the functioning ecosystem; herbivorous insects such as grasshoppers, beetles ants and termites.

I want to take a look at termites. When most people imagine an African savannah they think of an endless vista of gently swaying grasses interspersed with the odd umbrella shaped tree and termite mounds. Termites are an integral part of the ecosystem here and it is thought that in terms of biomass they exceed the combined weight of the Serengeti’s mammals. They consume dead plant matter above ground (often during the night) then retreat underground where anaerobic bacteria in their stomach gets to work on breaking it down into a useable form, this is very similar to the process in ruminant herbivores.

Why are termites so important to savannah ecosystems? Well they serve multiple functions such as nutrient cycler’s, habitat architects and as food for other animals.

The daily activity of millions of tiny termites who bring dead vegetation into their underground homes helps to circulate nutrients with in the soil layer as well as aerating the soils themselves. If you ever get to look at a termite mound you will see that the grasses on them are often cropped short were as the surrounding area is full of long grass. This is because the grasses growing on the termite mound are particularly nutrient rich, thanks to the termites having created a nutrient hotspot and wildebeest, topi and zebras all know this and preferentially munch this grass.

Termite mounds shape the plains around them giving a relief to the flatness. Other animals such as topi, hartebeest and cheetah will use these small hills to climb onto to get a better view of their surroundings. In this flatness even a few inches of elevation could give an advantage. Many animals use termite mounds to create their own burrows.  Hyena, warthog and jackal will use them as dens but the master creator is the aardvark who does most of the excavating. Snakes, lizards and mongoose readily take to old mounds too.

Termites are nutritious critters themselves and almost any omnivorous animal will make a meal of them when the chance is offered. I remember seeing about twenty large raptors walking around on a dirt road in the Kruger Park looking like a flock of chickens gobbling up termites after an eruption.

Then there are the termite specialists, aardwolf can consume around a kilogram of termites in a night. Another predator is the ant, whispering ants will raid termite mounds grabbing worker termites, carrying two or three each at a time back to their own nests.

All in all termites are a hugely important part of the Serengeti ecosystem playing a vital role in so many lives be it nutrient provider, habitat provider or as food themselves. You will probably never classify a termite on snapshot Serengeti but it’s worth remembering just how important they are.

The Serengeti Plains

50c214218a607540b90367f2_0

 

Here on the Snapshot blogs we seem to concentrate on talking about the animals that populate the Serengeti. Of course these are the subjects of our many camera-trap images (oh, apart from those annoying over grown vegetation ones) and they are loved by us all but for once I thought I would talk about the Serengeti itself. Monitoring the animals that live in the Serengeti is a valuable way to assess the health of the landscape but to get a true idea of the state of play the whole ecosystem needs to be looked at. More and more scientists are realising that a holistic approach is needed to truly understand what makes an ecosystem tick and how to preserve it. Studying lion without looking at their connection to wildebeest and grass is like studying maths by looking at the numbers without the plus or minus signs.

So we have all heard of the Serengeti but what do we really know. It surprises me how many friends don’t actually know what country it is in. The Serengeti National park, where our 225 camera-traps are located is in Northern Tanzania bordering Kenya’s Maasai Mara National park. The two together with the Ngorongoro Conservation Area and other private game reserves make up the Greater Serengeti Ecosystem which protects the area of the great migration. It is easy to see where the confusion comes from.

Everyone has heard of the wildebeest migration but did you know that it is one of the largest animal migrations in the world that has not been drastically altered by humans, there are no barriers to impede the movement of the millions of animals that seek fresh grazing and water. The 1000km circular migration route sees around 500 000 zebra, over 1 million wildebeest followed by hundreds of thousands of other ungulates annually. All this is still able to happen thanks to the protected status of the entire ecosystem.

The Serengeti National Park itself is made up of around 1.5 million hectares of savannah. Flat or undulating plains covered in grasses which are nourished with ashy soils derived from nearby volcanoes dominate the landscape. Rocky out crops known as kopjes punctuate the flatness with infrequent river courses and their riverine habitat easing the monotypic view.

So what triggers the massive ungulate migration and all the inherent predator action? At the onset of the dry season grasses begin to dry out and water becomes scarce, ungulates are forced to follow their nose to find food and water. Luckily nature is well designed and there is a well defined gradient across the migratory path that sees differences in place and time for abiotic factors such as rainfall, temperature and soil type. It is these factors that govern what vegetation grows where and how available water is and of course where the millions of hungry herbivores can move to next to satisfy their needs. Once settled across the Mara River they can last out the dry season in the mixed savannah woodlands where food is not so scarce. But the pull of the plains is always there and with the onset of the rains back they go thundering towards the Serengeti once more in a tradition that has possibly been around for over a million years.

The area is the last remaining example of a large mammal dominated ecosystem that existed across much of Africa during the last 1.8 million years. With its relatively intact biodiversity and sheer size it is easy to see why scientists flock to study both the individual species that occur here and functioning of the ecosystem as a whole. Sadly there are not many places like it left on Earth.

 

Topi versus Hartebeest

Here is another pair of antelope that are often muddled up on Snapshot Serengeti; topi and hartebeest. These two share a similar size and body shape and for those of you not familiar with them they can prove a bit tricky.

Topi and hartebeest belong to the same tribe, Alcelaphini, which also includes wildebeest. These antelope typically have an elongated face, long legs, short necks and stocky bodies. Although these antelope have reasonably large bodies their long legs mean they have retained the ability to run fast, a good adaptation for life on the open plains. It is believed that the long face developed in place of a long neck in order to reach the grasses they consume.

There are several species of both topi and hartebeest in Africa, two are found in the Serengeti. Coke’s hartebeest or kongoni (Alcelaphus cokii) are selective grazers with browse making up less than 4% of their diet. Serengeti topi (Damaliscus jimela) are 100% grazers

In both species males are territorial but topi also form leks from which to display to passing females. Males holding territory close to the lek are more desirable to females. Dominant females will actively prevent subordinate females from mating with these males.

 

Topi                                                         Hartebeest

So side by side we can see that the topi is much darker coloured than the hartebeest with distinct sandy socks up to its knees and conspicuous black patches on the thighs and shoulders. In contrast the hartebeest has pale legs and underbelly with a darker upper body. The paleness forms a patch on the top of the thigh.

 

Topi                                                                        Hartebeest

From behind the contrast between leg colour and backside is very obvious with topi sporting dark legs with pale rump and back and hartebeest pale legs and rump with dark back.

Horn shape is also different. A topi’s horns sweep up and back whereas a heartebeest’s sweep out to the side before kinking back. They also sit on a prominent bony ridge on the top of the head.

Hopefully this will help you tackle all the images waiting on season 10.

Meet the People #2

kopelion_maasai_fieldwork

Ingela showing camera-trap images to local Maasai

Photo: KopeLion

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.

http://kopelion.org/

 

kopelion_imobilization_lion_puyol_naibardad_-nca-2

The KopeLion team immobilizing a lion

 

Photo: KopeLion

Meet the People

 

Over the next few months I would like to bring you a few blogs about the many people that work to make Snapshot Serengeti possible. Without them there would be no data for us to pour over but what exactly do they do and who are they?

Dr Michael Anderson is currently in the Serengeti collecting data and checking up on how the various projects that make up Snapshot Serengeti are getting along. As part of the projects commitment to engaging with the local community Michael has begun a National Geographic funded intern program. Its aim is to give young locals valuable training and research experience in the fields of ecology and conservation.

The first student to be taken up on the program is Roimen Lelya Olekisay. He is a Maasai from the Ngorongoro Conservation Area. His story highlights why the intern program is a vital part of both the scientific and conservation work we do. Many local people see wild animals as a threat to their own domestic stock as well as themselves and retaliatory killings are common. Living alongside wildlife is not easy. Without the good will of the local people it is very hard to change their attitudes to the work we do and the animals themselves.

Roimen grew up on the Western slope of the Ngorongoro crater, his family, like many Maasai are herders. As a young boy he roamed all over the Ngorongoro protected area (NPA) with the family livestock. The Maasai are permitted to live in the NPA where they can graze livestock but are not allowed to cultivate the land. Roimen spent two years away at secondary school before returning to the family to continue herding. This is a familiar story for many Maasai. The importance of livestock is paramount and many boys do not complete schooling.

As a young warrior, like many his age, Roimen speared and killed at least three lion. Tradition dictates that young Maasai warriors must kill a lion to become a man. He would have maybe carried on killing lions whenever he perceived a threat to his family’s livestock but he met up with Ingela Jannsen’s group Kope Lion Project in 2013 who work in the area trying to mitigate lion/human conflict. He helped fit a radio collar to a lion and this interaction with the king of beasts up close transformed him from a lion hunter to a lion protector. He became one of Ingela’s lion scouts (more about Ingela and the Kope Lion Project in next week’s blog) recording predator-livestock attacks in the conservation area and working to prevent lion conflicts and hunts. His enormous enthusiasm for lions and their research makes him a perfect candidate to further his scientific skills. This is someone with a natural ease and interest in the wildlife around him and its preservation.

In his new role as the first intern for the National Geographic-Serengeti National park program Roimen will be tracking lions and setting up a camera-trap network that hopes to dissuade human-lion conflicts and generally learning all the scientific skills associated with this work. He has just started and will be with us for six months, hopefully we can catch up with his progress in a few months.

 

Photo’s curtsey of Ingela Jannsen and KopeLion project

 

 

Why we do it

Congratulations, your time classifying images on Snapshot Serengeti has resulted in yet another scientific paper. Over 70,000 of you have contributed to analysing the millions of images produced by the 225 Snapshot Serengeti cameras over the last few years. Thanks to all your effort the cameras are still rolling, creating one of the longest running cameratrap studies going.  This data set is so important to scientists because of the size of the area it covers as well as the length of time it has been recording for. It allows them to ask many and varied questions about a naturally functioning healthy ecosystem and in today’s changing world it has never been so important to figure out what makes this planet tick.

The paper ‘The spatial distribution of African Savannah herbivores: species associations and habitat occupancy in a landscape context’ was published last year in Philosophical Transactions B. Visit here to read the article.

http://rstb.royalsocietypublishing.org/content/371/1703/20150314

The Snapshot Serengeti team argue that if we want to predict the impact of changes/ losses of large mammals in the future we need to have a quantitative understanding of a currently functioning ecosystem. It just so happens that the Snapshot data set is perfect for this. The Serengeti National Park is representative of the grass dominated Savannahs of East Africa which are home to the world’s greatest diversity of ungulate (hoofed animals) grazers.

The team present a neat graphic that shows how the various elements interact to affect herbivore habitat occupancy.

f1-large

Predators, herbivores, termites, fire, grasses and trees all play a role in determining where different herbivores choose to roam.

It seems that herbivore body size is also important to habitat selection. For example large herbivores survive by bulk grazing whereas small herbivores concentrate on grazing quality over quantity. Recently burned ground results in new vegetation growth. This growth is relatively high in nutrients compared with unburned patches and the same can be found on and around termite mounds. Small herbivores were found to occupy these areas but the sparse coverage does not favour large herbivores that must eat more volume.

The paper highlights the complex relationship between predators, herbivores, vegetation and disturbance and is well worth a read. Next time you are classifying images see if you agree. Do you see many herds of zebra or wildebeest on burnt areas or is it mostly Thompson’s gazelle? It’s another way to look at the images you classify.