CONSERVATION

Bridges for orang-utans

For the first time ever, a wild orang-utan has been photographed crossing one of the specially-designed rope bridges built to re-connect fragmented forest habitats and prevent populations from becoming isolated. The photographer, Ajiran Osman, a member of the local community with an interest in wildlife, said that the ape appeared to be weighing up whether to cross the bridge or not, lingering for about 20 minutes before deciding to take the plunge. ‘It seemed like once he decided to cross, he did so very fast, going over in about three minutes.’ Orang-utans have occasionally been reputed to have crossed man-made bridges, but this is the first official evidence.

In 2003 HUTAN (a French NGO dedicated to orang-utan research and conservation) and the Sabah Wildlife Department installed a number of rope bridges across tributaries of the Kinabatangan River in order to link fragments of the Lower Kinabatangan Wildlife Sanctuary (LKWS). These bridges have become necessary because the large trees that provided natural bridges over wetland and river tributaries have been lost in deforestation, and also because drains built by oil palm producers have further fragmented the forest.

The land in the Kinabatangan flood plain is very wet and, since orang-utans cannot swim, their movement through water is hampered. This means that once the trees spanning the rivers are removed populations become isolated from one another. The rope bridges were a simple solution, but until this year there had been no confirmed recordings of orang-utans using them, even though other endangered primate species, such as macaques, proboscis monkeys and gibbons, have been benefiting from them.

A recent PVA concluded that most of the 20 sub-populations of orang-utans throughout the fragments of the LKWS will be extinct in the foreseeable future unless their forest habitats are reconnected. The World Land Trust is continuing to raise funds for the purchase of critically important wildlife corridors in the area that will permanently connect standing forests and protect them in perpetuity.

Wildlife Extra News (www.wildlifeextra.com), 23 April 2010

Radiated tortoise threatened with extinction

A team of biologists from the Turtle Survival Alliance (TSA) and the Wildlife Conservation Society (WCS) report that Madagascar’s radiated tortoise (Geochelone radiata) – considered one of the most beautiful tortoise species – is rapidly nearing extinction due to rampant hunting for its meat and the illegal pet trade. The team predicts that unless drastic conservation measures take place, the species will be driven to extinction within the next 20 years.

The team recently returned from field surveys in southern Madagascar’s spiny forest, where the once-abundant tortoises occur. They found entire regions devoid of tortoises and spoke with local people who reported that armed bands of poachers had taken away truckloads of tortoises to supply meat markets in towns such as Beloha and Tsihombe. Poaching camps have been discovered with the remains of thousands of radiated tortoises, and truckloads of tortoise meat have been seized recently.

‘Areas where scores of radiated tortoises could be seen just a few years ago have been poached clean,’ says James Deutsch, director of the WCS’s Africa Program. ‘Back then one could hardly fathom that this beautiful tortoise could ever become endangered, but such is the world we live in, and things can – and do – change rapidly.’‘The rate of hunting of radiated tortoises is similar to the hunting pressure on American bison during the early 19th century, when they were nearly hunted to extinction where they once numbered in the tens of millions,’ says Brian D. Horne, turtle conservation coordinator for the WCS’s Species Program.

Tortoise populations near urban centres have crashed, with poachers moving closer and closer to protected areas; it is simply a matter of time before those areas are targeted too, the biologists predict. ‘Radiated tortoises are truly under siege now as never before, and if we can’t draw a line in the sand around protected areas, then we will lose this species,’ says Rick Hudson, president of the TSA. ‘I can’t think of a tortoise species that has undergone a more rapid rate of decline in modern times, or a more drastic contraction in range, than the radiated tortoise. This is a crisis situation of the highest magnitude.’

Formerly occupying a vast swathe of the southern portion of Madagascar, the radiated tortoise was once considered one of the world’s most abundant tortoise species, with an estimated population in the millions. It is now ranked as Critically Endangered by the IUCN Red List. One of the most troubling trends is that poachers are now entering protected areas to collect tortoises and the staff there are poorly equipped to patrol and protect populations. The situation is exacerbated by several factors: years of extreme drought have led to diminished agricultural production and increased poverty, which leads people to tortoise hunting for survival; enforcement action is often days away, so that local officials do not have the capacity to stop poachers; severe habitat degradation has made the spiny forest the most endangered forest type in Madagascar – after burning and clearing for agriculture, invasive plant species take over and today thick stands of opuntia (prickly pear) and sisal (agave) dominate the landscape; current political instability has resulted in increased open access to natural resources and illegal pet trade. The radiated tortoise is still able to ‘make a living’ and survive in this degraded habitat. However, the tortoise cannot survive the current threat of wholesale collection for food markets. Community mobilization linked to sustainable habitat protection is needed to save this unique critically endangered species.The Wildlife Conservation Society’s Bronx Zoo owns many radiated tortoises, with about a dozen held at the zoo and others at the Behler Chelonian Conservation Center (Ojai, California) and other U.S. zoos. Many of these are SSP-recommended animals for breeding. These animals form a significant percentage of the animals in the U.S.

Wildlife Extra News (www.wildlifeextra.com), 7 April 2010

Ol Pejeta rhino project update

The project to transfer four (2.2) northern white rhinos from Dvur Králové Zoo, Czech Republic, to the Ol Pejeta Conservancy in Kenya [see IZN 56 (7), 432–434] was logistically challenging. The animals were trucked in specially-designed crates from the zoo to Prague, then flown to Nairobi and driven to the conservancy, a trip of nearly 24 hours going from European winter to African heat. Though all the rhinos were in good condition, there was some uncertainty over how they would handle the move.

Fortunately the operation went smoothly. After initially being kept in small enclosures, or bomas, the rhinos are now spending most of their time grazing in larger paddocks. This is the first critical step to their introduction into two 600-acre [24-ha] breeding areas. It is still early days, but all signs at the moment are good.

Ol Pejeta is an ideal safe haven as it has excellent anti-poaching teams, good habitat and a growing southern white rhino population. These four rhinos carry valuable genetic diversity, such as resistance to disease, and it is hoped that once back in natural conditions, they will breed again and re-establish a wild population.

‘It is gratifying to see how well the rhinos have adapted to their new surroundings and a wild diet,’ says Dr Rob Brett, FFI Africa Regional Director and member of the IUCN African Rhino Specialist Group. ‘The stimulus of living with other white rhinos over the next few months will give them the best chances of getting into the right condition to breed naturally.’

Abridged from FFI Update (the newsletter of Fauna & Flora International) No. 15 (Spring 2010)

First wild-born cheetahs for 40 years in Arabia

The last known Arabian cheetah was shot in Saudi Arabia in 1950, though they may have hung on in Oman until around 1970. Now four cubs have been born in the wild in the Arabian Wildlife Park, a nature reserve on Sir Bani Yas Island off the coast of the United Arab Emirates. This is believed to be the first time that cheetahs have been successfully reintroduced into the wild anywhere in the world.

The mother and father of the cubs, Safira and Gabriel, were raised in Dubai’s Wildlife Centre and the Sharjah Breeding Centre for Endangered Arabian Wildlife [see IZN 56 (4), 218–222]. The cheetahs were brought to the island as part of conservation efforts which include breeding, re-wilding, and releasing into the park to become an integral part of the natural population control for hoofed species on the island.

The Sir Bani Yas Island conservation team spends a great deal of time and effort putting captive-bred animals who are brought to the island through a ‘re-wilding’ programme and ensuring that the animals are trained to hunt and be self-sufficient before they are released into the park. Once they are released, the team is removed completely from the animals’ day-to-day activities. Safira and Gabriel are a telling example of what can be achieved through re-wilding, as they hunt and fend for themselves without human interference.

Survival rates for cheetah cubs are very low both in the wild and in captivity, but Safira is doing an impressive job of taking care of her cubs, even though she was raised by humans. She has not yet moved the cubs from their original birthplace in a small cave in the mountains. She is fitted with a radio collar and can be tracked and monitored by the conservation team on the island.

The flagship species on Sir Bani Yas is the Arabian oryx, which was introduced in 1971. Now, there are around 400 oryx on the island, roaming freely in the park.

Wildlife Extra News (www.wildlifeextra.com), 15 April 2010

Frogs threatened by New Zealand Government proposal

In the 1990s areas of New Zealand that were considered to be of ‘high conservation value’ (including many national parks) were placed on Schedule 4, which recognised their conservation significance and proclaimed them as ‘no go areas’ for all other activities. The Government is now asking for public submissions about their proposal to remove some of this land from Schedule 4 to open it up for mining (coal, gold, iron ore and rare minerals). The areas to be mined include several sites where the frog populations have been continually monitored for over 40 years – this represents the best data on frog populations anywhere in the world. In addition, one proposed mining area includes the ‘type’ localities of Archey’s frog (Leiopelma archeyi) and Hochstetter’s frog (L. hochstetteri). These endangered species (Archey’s are Critically Endangered, having lost 88% of their population since 1996) are just hanging in there and without help they will disappear. ‘Save our frogs – stop the mining’ is currently the biggest issue in New Zealand conservation. More information on how the frogs will be affected (including maps of distribution and proposed areas to be mined) is available at www.nzfrogs.org.

Abridged from an Amphibian Ark press release (www.amphibianark.org)

Climate change might threaten African leaf-eating primates

Primate species will become ‘increasingly at risk of extinction’ because of global warming, according to new research. It reveals that populations of monkeys and apes in Africa that depend largely on a diet of leaves could be wiped out by a rise in annual temperatures of two degrees Celsius. The study by researchers from Bournemouth University, Roehampton University and the University of Oxford suggests that the species most at risk are the already endangered gorillas and colobine monkeys.

The study, published online in December by Animal Behaviour, pinpoints which species are most threatened by climate change in a series of new global maps. They show current and predicted distribution patterns of primates, comparing the populations according to their diet and the amount of enforced rest they are predicted to need.

They warn that Old World monkey populations in Africa will be hardest hit even by a very modest two degrees Celsius increase in global mean temperature, especially those whose diets are mainly leaf-based such as the beautiful colobine monkeys. In contrast, New World monkeys will be virtually unaffected by a rise of two degrees in mean temperatures. However, even the South American species will begin to suffer if temperatures rise as much as four degrees Celsius (the currently predicted most extreme value), because suitable habitats will then become increasingly fragmented and small fragmented populations are more liable to chance risks of extinction.

These predictions are based on analyses of the ecological constraints that determine how much time animals are forced to rest. Animals that have forced rest have less time to forage for food or engage in other biologically essential activities, such as forming friendships. Although most primates have adaptations that help them cope with the heat, they head for shelter and rest when the sun gets too hot.

The researchers show that resting time is influenced by three main factors: the percentage of leaves in the animals’ diet, temperature variation and mean annual temperature. When these three effects come together, susceptible species will be unable to cope and populations will go extinct.

The researchers used climate models coupled with an analysis of quantitative data on the behaviour, diet and group size of different primate species across the world. African monkeys and apes that have a high percentage of leaves in their diet are geographically more restricted even now, being confined to a relatively narrow region around the equator. However, fruit-eating species like the baboons and guenon monkeys of Africa typically have a much wider latitudinal range and can cope with a wider range of climatic conditions. This ecological separation between fruit- and leaf-eating species is much less obvious in the Americas, and so these species will be much less badly affected by climate warming. The contrast between the continents may be due to the fact that African fruit-eating species may have developed a particular ecological adaptation to more challenging habitats than those encountered by species in South America.

Lead author Dr Amanda Korstjens, from Bournemouth University, says: ‘The possibility that enforced resting time might have so strong an effect on where on the map a major mammal group is likely to survive has not previously been appreciated. This study suggests that the amount of time available for monkeys and apes to gather food and socialise may be a key factor when looking at possible effects of climate change on animal distribution patterns in the past and in the future.’

‘We often worry about deforestation and hunting as the two main factors threatening the extinction of primate populations,’ says Professor Robin Dunbar, from the Institute of Cognitive and Evolutionary Anthropology at the University of Oxford, ‘but these results suggest that even if we find ways to solve those problems, it may not save some species of monkeys and apes from extinction. Instead, we perhaps should worry about ensuring that we provide these species with habitats that are more in tune with their capacities to cope with climate change.’‘At overall temperature increases of two and four degrees Celsius, the distribution of habitat suitable for species that eat a lot of leaves