Camera traps completed one of the most thorough surveys of African rainforest yet



PNS Survey, Author provided

Mattia Bessone, Liverpool John Moores University and Barbara Fruth, Liverpool John Moores University

Tropical rainforests are the world’s richest land habitats for biodiversity, harbouring stunning numbers of plant and animal species. The Amazon and the Congo basins, together with Asian rainforests, represent only 6% of Earth’s land surface, and yet more than 50% of global biodiversity can be found under their shade.

But observing even the most conspicuous species, such as elephants and apes, is still an extraordinarily difficult task. That’s not even mentioning all the secretive species that are protected by thick vegetation or darkness.

Camera traps have led a technological revolution in wildlife research, making it possible to study species without humans needing to be present. They can be left in the depths of a forest for weeks, taking pictures of anything that moves at any time of day or night.

Installing camera traps in Salonga National Park.
Jonas Abana Eriksson/PNS Survey, Author provided

From their advent three decades ago, camera traps have allowed scientists to discover species such as the grey-faced sengi – a new species of giant elephant shrew living in Tanzania – and the Annamite striped rabbit in Vietnam. They revealed that lions still wander the Bateke plateau in Gabon, ending speculation that they were locally extinct. They also photographed the offspring of the elusive Javan rhino, which scientists had thought had stopped breeding. With fewer than 100 individuals left, this gave hope that the species could be saved from extinction.

The grey-faced sengi (Rhynchocyon udzungwensis) was discovered by camera traps in Tanzania.
F Rovero/Wikipedia, CC BY-SA

Spotting stripes

Camera traps are becoming essential for documenting forest species, assessing their distribution and studying their behaviour, as well as counting what’s actually there.

This latter measure, called animal abundance, is perhaps the most important information in wildlife conservation, as it allows researchers to assess the conservation status of a species. But until recently, camera traps could only be used to reliably estimate the abundance of animals with conspicuous markings, such as big cats with spots or stripes peculiar to single individuals.

Big cats, like this African leopard (Panthera pardus), are among the simplest species to document with camera traps.
Haplochromis/Wikipedia, CC BY-SA

Counting animals with camera traps remained impossible for the majority of species that lacked these conspicuous features, as the same individual could be counted twice by different cameras at different times. Methods that account for how animals move in and use their habitat were developed to help overcome the problem of detecting the same individual at different locations.

Another method, called camera trap distance sampling achieves the same result using a different approach. It subdivides the time cameras are active into “snapshots”, taking pictures at, for example, every fifth second in an hour. At a determined moment, an individual can only be spotted at one location, not elsewhere. Double counts are avoided, and researchers get the number of animals within the area surveyed by the cameras at a given snapshot.

We tested this new method in one of the most remote areas of the planet – the southern part of Salonga National Park, a world heritage site in the Democratic Republic of the Congo. Here, rangers only had data on the park’s two flagship species – the forest elephant and the bonobo. Near to nothing was known about the other animals that were more difficult to track.

A flagship species of Salonga National Park, bonobo populations are understudied in 70% of their range.
Christian Ziegler/LKBP, Author provided

What we found

Five field teams walked a forest the size of Wales to deploy 160 camera traps in 743 places. This unprecedented effort produced more than 16,000 video clips, totalling 170 hours of animal footage and revealing 43 different animal species, including bonobos and elephants.

We also captured species rarely detected by human observers, such as the giant ground pangolin, threatened by extinction, the cusimanses, a genus of social mongooses, and the stunning Congo peafowl, a vulnerable species that’s endemic to the country.

Where so far conservation of elusive species such as the African golden cat, the endemic Allen’s swamp monkey and another elephant shrew, the four-toed sengi, had to be based on little to no data, we’re now able to estimate their abundance in the wild.

Nine of 43 species captured by camera traps in Salonga National Park, DRC.
PNS Survey, Author provided

For some species, the news from our findings were good. Our study revealed that the southern part of Salonga National Park alone harboured as many peafowls as were previously thought to be present in the whole country.

For other species, the results confirmed the need for greater protection. The 17,000 km² large and intact primary rain forest contains fewer than 1,000 giant pangolins. An alarming figure given the current illegal trade of pangolin scales.

As the technology and methods of camera trap surveys improve, they’re becoming capable of monitoring a diverse range of wildlife, from the tiny elephant shrew to the mighty forest elephant. This gives an insight into the complex and delicate equilibrium of the rainforest community and the threats to its survival.The Conversation

Mattia Bessone, PhD Researcher in Conservation Biology, Liverpool John Moores University and Barbara Fruth, Associate Professor, Liverpool John Moores University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

From Australia to Africa, fences are stopping Earth’s great animal migrations



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Wildebeest crossing the Mara River in Tanzania during their annual mass migration.
Jane Rix/Shutterstock

Bill Laurance, James Cook University and Penny van Oosterzee, James Cook University

For time immemorial, many wildlife species have survived by undertaking heroic long-distance migrations. But many of these great migrations are collapsing right before our eyes.

Perhaps the biggest peril to migrations is so common that we often fail to notice them: fences. Australia has the longest fences on Earth. The 5,600-kilometre “Dingo Fence” separates southeastern Australia from the rest of the country, whereas the “Rabbit-Proof Fence” stretches for almost 3,300 kilometres across Western Australia.

Emus attempting to cross the Rabbit-Proof Fence in Western Australia.
Western Australia Department of Agriculture & Food

Both of these enormous fences were intended to repel rabbits and other “vermin” such emus, kangaroos and dingoes that were considered threats to crops or livestock. Built over a century ago, their environmental impacts were poorly understood or disregarded at the time.

Since construction these fences have caused recurring ecosystem catastrophes, such as mass die-offs of emus and other species trying to find food and water in a land notorious for the unpredictability of its rainfall, vegetation growth and fruit production.

Fatal fences

The same thing is happening across much of the planet. While a nemesis for larger wildlife, nobody knows how many fences exist today or where they’re located. A study that mapped all the fences in southern Alberta, Canada, found there were 16 times more fences than paved roads.

Scientists are waking up to the peril of fences, realising that from an environmental perspective they’re grossly understudied — “largely overlooked and essentially invisible,” according to a recent global review.

A zebra noses a fence in Kenya.
Duncan Kimuyu

In Africa, home to some of the most spectacular wildlife migrations, scientists found that of 14 large-mammal species known to migrate en masse, five migrations were already extinct. Proliferating fences, along with habitat loss and wildlife poaching, has sent ecosystems such as the Greater Mara in Kenya crashing into ecological turmoil.

And a 2009 audit of Earth’s greatest terrestrial-mammal movements showed that of 24 large species that once migrated in their hundreds to thousands, six migrations have vanished entirely.

Many remaining migrations are mere shards of their former glory. For instance, Indochina once had mass migrations of elephants and other large mammals, big cats, monkeys and birds — often called the “Serengeti of Southeast Asia”.

Elephants and Banteng graze in Kuri Buri National Park in Thailand, vestiges of a once-massive fauna that migrated annually across Indochina.
Pattarapong/iStock

The thundering herds of American bison – some numbering up to 4 million animals – which once dominated the plains of North America have all but vanished today.

How to save mass migration

There are two main ways to destroy mass migrations: killing the animals outright by hunting and over-harvesting, or stopping the animals from accessing food or water, typically by fencing them out or clearing and fragmenting their habitat.

As the human footprint rapidly expands, scary things for wildlife are happening all over. Research that one of us (Bill Laurance) led revealed that 33 African “development corridors” would, if completed, exceed 50,000 kilometres in length and crisscross the continent, chopping its ecosystems into scores of smaller pieces.

Cost-benefit assessment for 33 massive ‘development corridors’ that are proposed or under construction in Sub-Saharan Africa.
William Laurance

Beyond this, over 2,000 parks and protected areas in Africa would be degraded or cut apart by the massive developments.

Migrations are vulnerable even in the seas. Recent research shows that growing shipping traffic is an increasing danger to migratory great whales, basking sharks, and giant whale-sharks – all highly vulnerable to collisions with fast-moving ships, as well as disruption of their sensitive hearing and vocal communications by shipping noise and sonar, and pollutants from vessels.

But the inspiring news is that, if you remove barriers such as fences, animal migrations can spontaneously resume – like a phoenix rising from the ashes.

A Red-Billed Oxpecker, which feeds on skin parasites of African mammals.
Fernando Quevedo de Oliveira/Alamy Stock Photo

In 2004, a fence that had blocked a former zebra migration in Botswana was removed. By 2007 it was one of the longest animal-migration routes in the world.

And a few places on Earth are still free from fencing and fragmentation. The world-famous Seregeti ecosystem of Tanzania is an iconic example. In war-torn South Sudan, a spectacular mass migration of a million antelope — known as white-eared kob — is still intact because there are no fences.

And caribou still migrate in great herds across large expanses of northern Canada and Alaska.

Alarming news for Botswana

Collapsing migrations are a global concern, but right now conservationists are most worried about Botswana.

This mega-diverse nation in southern Africa is considering profoundly changing its wildlife management by expanding fences and cutting off wildlife migrations not considered beneficial to the country’s current priorities.

This would be a shocking decision, because Botswana’s wildlife conservation is almost entirely dependent on its mass migrations.

For wildebeest, zebra, eland, impala, kob, hartebeest, springbok and many other large migrants, isolation is a killer – destroying their capacity to track the shifting patterns of greening vegetation and water availability they need to survive.

And it’s not just grazing and browsing animals that are affected: entire suites of large and small predators, scavengers, commensal and migratory bird species, grazing-adapted plants and other species are integrally tied to these great migrations.

Lions attacking an Angolan Giraffe, one facet of Botswana’s complex migratory ecosystems.
Michael Cohen

Botswana is already sliced into 17 giant “islands” by fences, erected in colonial times to protect the livestock of European farmers from foot-and-mouth disease.

But foot-and-mouth disease is far more likely to be spread by cattle, not wildlife. Fence-free strategies for managing disease risk also have have great potential.

And nature tourism in Botswana is a large, vibrant, and growing part of the national economy. Ecotourists will continue to favour the nation so long as it maintains untrammelled areas and spectacular animal migrations.

Botswana is expected to have over 40,000 tourism-related jobs by 2028, showing their key importance to the national economy.
Travel & Tourism Economic Impact: Botswana 2018

But you can kiss a lot of those tourism revenues goodbye if Botswana shatters its great migrations – killing off the spectacular living panoramas that are a magnet for the world’s nature lovers.

If we can avoid fencing and bulldozing critical parts of the Earth, we could hugely increase the chances that our most vibrant wildlife and ecosystems have a fighting chance to survive.The Conversation

Bill Laurance, Distinguished Research Professor and Australian Laureate, James Cook University and Penny van Oosterzee, Adjunct Associate Professor James Cook University and University Fellow Charles Darwin University, James Cook University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Why cheetahs in the Maasai Mara need better protection from tourists



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In parts of the Maasai Mara its not uncommon to see more than 30 tourist vehicles at a sighting.
Femke Broekhuis

Femke Broekhuis, University of Oxford

The global cheetah population is continuing to decline with only about 7000 individuals left in Africa. This is thought to be about half the population that existed 40 years ago. The decline has been caused by the loss and fragmentation of their natural habitats, a decline in their prey base, the illegal trade in wildlife as well as conflict with humans for space.

Cheetahs have disappeared from 91% of their historic range. This is hugely problematic as cheetahs are a wide-ranging species. To be viable a cheetah population needs a contiguous, suitable habitat which covers about 4,000–8,000 km2. But few protected areas in Africa are larger than 4,000 km2.

As a result, most of the cheetahs in the world – 77% – are believed to range outside protected areas. But this isn’t ideal for the animals as, from previous research we conducted using data from GPS satellite collars fitted on cheetahs in the Maasai Mara, we found that cheetahs avoid areas of high human disturbance and prefer protected, wildlife areas.

These results show the importance of wildlife areas for cheetahs, but my most recent research shows that these protected spaces have challenges of their own. We found that the number of cubs a cheetah is able to rear is lower in areas that receive lots of tourists compared with areas that are visited less. This suggests that cheetahs aren’t getting the protection they need, particularly from the impact of growing numbers of tourists.

Maasai Mara

Kenya’s Maasai Mara has one of the highest cheetah densities in the world, but it’s a landscape that is under increasing human pressure.

Famous for its spectacular wildebeest migration, the Maasai Mara is a popular tourist destination. The wildlife areas of the Maasai Mara include the Maasai Mara National Reserve, which is managed by the Narok County Government, and numerous wildlife conservancies, each run by different management companies.

The conservancies are formed through a partnership between Maasai landowners and tourism companies, whereby landowners receive a fixed, monthly payment for leasing their land for wildlife based activities on the condition that they do not live on the land, cultivate or develop it. Combined, the wildlife areas, which are predominantly used for photographic tourism, cover an area of about 2,600 km2 – one-tenth the size of Wales or Belgium.

During the high season about 2,700 people visit the Maasai Mara National Reserve daily. But they are often not adequately managed.

The Mara Reserve – with the exception of a conservancy called the Mara Triangle – doesn’t limit the number of tourists that enter the park per day, and there are no restrictions on the number of tourist vehicles at a predator sighting. It’s therefore not uncommon to see more than 30 tourist vehicles at a sighting.

Ideally, the Mara Reserve should restrict the number of tourists, especially during the peak tourist seasons.

Tourists also affect the landscape of wildlife areas. For example, tourist accommodation is continuing to increase in the Mara Reserve and these facilities are usually built on river banks which are prime habitats for species such as elephants, leopards and breeding raptors.

The research

One crucial element for a healthy cheetah population is cub recruitment, defined as offspring survival to independence.

Cheetahs have relatively big litters, ranging between one to six cubs. But cheetah cubs can succumb to various factors including abandonment, poor health, and fires so the number of cubs that reach independence can be very low, ranging from 5% to 28.9%.

I was interested in finding out if tourism is playing a role in this.

By analysing four years of data on female cheetahs with cubs it became apparent that high numbers of tourists are having a negative effect on the number of cubs that reach independence. More specifically, females in areas with a lot of tourists on average raised one cub (or none survive) per litter to independence compared to more than two cubs in low tourist areas.

There was no hard evidence of direct mortality caused by tourists. But my conclusion from my findings is that tourists are likely to have an indirect effect on cub survival. This could be because they lead to cheetahs changing their behaviour and increase their stress levels by getting too close, overcrowding with too many vehicles, staying at sightings for prolonged periods of time and by making excessive noise.

What can be done?

My study highlights the importance of implementing and enforcing strict wildlife viewing guidelines, especially in areas where tourist numbers are high. The Maasai Mara’s wildlife conservancies are largely getting this right. Tourist numbers are limited to the number of beds per conservancy and only five vehicles are allowed at a sighting at any given time.

Actions that could be taken include:

  • allowing no more than five vehicles at a cheetah sighting;

  • ensuring that no tourist vehicles are allowed near a cheetah lair (den);

  • ensuring that vehicles keep a minimum distance of 30m at a cheetah sighting;

  • ensuring that noise levels and general disturbance at sightings are kept to a minimum;

  • ensuring that vehicles do not separate mothers and cubs; and that

  • cheetahs on a kill are not enclosed by vehicles so that they can’t detect approaching danger.

If tourism is controlled and managed properly, it can play a very positive role in conservation. Money from tourism goes towards the creation and maintenance of protected areas – like the wildlife conservancies – and can help alleviate poverty. It also shows local communities the benefits that predators can bring and can positively influence attitudes.

The ConversationHowever if human pressures, like tourism, remain unchecked it risks having a negative impact on wildlife and could mean the loss of some of the biggest attractions – like cheetahs.

Femke Broekhuis, Senior research associate, University of Oxford

This article was originally published on The Conversation. Read the original article.