Ecotourism is having a negative effect on primate's behavior

New research shows that the increase in primate ecotourism is having a negative effect on monkey's behaviour.

The study, led by the University of Portsmouth, found that this fast-growing tourism sector where tourists can conveniently reach primates via motor boats is causing stress-related behaviours in monkeys.

The research looked at the impact of a single engine motor boat approaching a community of proboscis monkeys, an endangered species living in a remote riparian area (strips of vegetation that border rivers, streams and lakes) in Sabah, Malaysia. Proboscis monkeys are unusual looking with their very long noses, which adds to making them appealing to tourists.

Many of these boats, carrying multiple tourists, approach the primates quickly and loudly, often reaching the river banks just a few metres away from the wildlife.

The researchers found that frequent visits by such groups, which often involve an unusually high level of noise, caused stress-related behaviours in the primates such as self-scratching, an increased vigilant state, increased levels of aggression and reduced feeding.

Lead author of the study, Dr Marina Davila-Ross, Reader in Comparative Psychology at the University of Portsmouth, said: "Our evidence shows that even a single motor boat moving slowly, with humans behaving calmly, can negatively affect the primate's behaviour and induce stress -- an impact that is likely to be larger with tourist boats.

"The riparian area is an important habitat that has become increasingly popular to primate ecotourism, because it enables tourists to conveniently reach primates via motor boats."

The researchers conducted the experiment by approaching the monkeys in a motor boat with different speeds and travel distances -- fast-close (approaching the monkeys for 10 seconds when 40 metres away at a speed of 14.4 km/hr), slow-close (approaching the monkey for 40 seconds when 40 metres away at a speed of 3.6 km/hr), and slow-far conditions (approaching the monkeys for 20 seconds when 100 metres away, at a speed of 3.6 km/hr). For each condition, they compared stress-related behaviours before the boat approached with after the boat started its approach.

The results showed that the monkeys displayed stress-related behaviours for longer in the fast-close and slow-close conditions and also reduced feeding as a result of the boat approaching in the fast-close condition. They also found that male proboscis monkeys displayed more vigilant behaviour than females.

Once the boat started to approach, the proboscis monkeys gazed at the boat for longer than before the boat approached, showed repeated scratching, and often moved quickly backwards to hide in the trees. This could potentially cause the monkeys to leave their safe sleeping sites and to retreat deep into the forest as it gets dark, where they could face a higher risk of predation.

Dr Davila-Ross said: "Collectively, our findings suggest that the approach of a single motor boat induces stress in proboscis monkeys when approaching them as closely as 60 metres from the other side of the river, regardless of the speed of approach. The findings match those obtained in studies on sea mammals and birds, suggesting that stress is a universal response across animals when a boat approaches -- a large, loud, and artificial object moving toward them is likely to be threatening."

The researchers propose that guidelines for primate tourism in the riparian areas, which are largely unregulated, should include an approach speed of no more than 4 km/hr within 100 metres of the proboscis monkeys. They suggest it is also important to keep a distance, preferably no closer than 60 metres away, from the monkeys.

Read more at Science Daily

Oldest monkey fossils outside of Africa found

 Three fossils found in a lignite mine in southeastern Yunan Province, China, are about 6.4 million years old, indicate monkeys existed in Asia at the same time as apes, and are probably the ancestors of some of the modern monkeys in the area, according to an international team of researchers.

"This is significant because they are some of the very oldest fossils of monkeys outside of Africa," said Nina G. Jablonski, Evan Pugh University Professor of Anthropology, Penn State. "It is close to or actually the ancestor of many of the living monkeys of East Asia. One of the interesting things from the perspective of paleontology is that this monkey occurs at the same place and same time as ancient apes in Asia."

The researchers, who included Jablonski and long-time collaborator Xueping Ji, department of paleoanthropology, Yunnan Institute of Cultural Relics and Archaeology, Kunming, China, studied the fossils unearthed from the Shuitangba lignite mine that has yielded many fossils. They report that "The mandible and proximal femur were found in close proximity and are probably of the same individual," in a recent issue of the Journal of Human Evolution. Also uncovered slightly lower was a left calcaneus -- heel bone -- reported by Dionisios Youlatos, Aristotle University of Thessaloniki, Greece, in another paper online in the journal, that belongs to the same species of monkey, Mesopithecus pentelicus.

"The significance of the calcaneus is that it reveals the monkey was well adapted for moving nimbly and powerfully both on the ground and in the trees," said Jablonski. "This locomotor versatility no doubt contributed to the success of the species in dispersing across woodland corridors from Europe to Asia."

The lower jawbone and upper portion of the leg bone indicate that the individual was female, according to the researchers. They suggest that these monkeys were probably "jacks of all trades" able to navigate in the trees and on land. The teeth indicate they could eat a wide variety of plants, fruits and flowers, while apes eat mostly fruit.

"The thing that is fascinating about this monkey, that we know from molecular anthropology, is that, like other colobines (Old World monkeys), it had the ability to ferment cellulose," said Jablonski. "It had a gut similar to that of a cow."

These monkeys are successful because they can eat low-quality food high in cellulose and obtain sufficient energy by fermenting the food and using the subsequent fatty acids then available from the bacteria. A similar pathway is used by ruminant animals like cows, deer and goats.

"Monkeys and apes would have been eating fundamentally different things," said Jablonski. "Apes eat fruits, flowers, things easy to digest, while monkeys eat leaves, seeds and even more mature leaves if they have to. Because of this different digestion, they don't need to drink free water, getting all their water from vegetation."

These monkeys do not have to live near bodies of water and can survive periods of dramatic climatic change.

"These monkeys are the same as those found in Greece during the same time period," said Jablonski. "Suggesting they spread out from a center somewhere in central Europe and they did it fairly quickly. That is impressive when you think of how long it takes for an animal to disperse tens of thousands of kilometers through forest and woodlands."

While there is evidence that the species began in Eastern Europe and moved out from there, the researchers say the exact patterns are unknown, but they do know the dispersal was rapid, in evolutionary terms. During the end of the Miocene when these monkeys were moving out of Eastern Europe, apes were becoming extinct or nearly so, everywhere except in Africa and parts of Southeast Asia.

Read more at Science Daily

'Little brain' or cerebellum not so little after all

When we say someone has a quick mind, it may be in part thanks to our expanded cerebellum that distinguishes human brains from those of macaque monkeys, for example.

Sometimes referred to by its Latin translation as the '"little brain"', the cerebellum is located close to the brainstem and sits under the cortex in the hindbrain. New research at San Diego State University, however, calls the "little" terminology into question.

The cerebellum plays a versatile role, contributing to our five senses as well as pain, movements, thought, and emotion.

It's essentially a flat sheet with the thickness of a crepe, crinkled into hundreds of folds to make it fit into a compact volume about one-eighth the volume of the cerebral cortex. For this reason, the surface area of the cerebellum was thought to be considerably smaller than that of the cerebral cortex.

By using an ultra-high-field 9.4 Tesla MRI machine to scan the brain and custom software to process the resulting images, an SDSU neuroimaging expert discovered the tightly packed folds actually contain a surface area equal to 80% of the cerebral cortex's surface area. In comparison, the macaque's cerebellum is about 30% the size of its cortex.

"The fact that it has such a large surface area speaks to the evolution of distinctively human behaviors and cognition," said Martin Sereno, psychology professor, cognitive neuroscientist and director of the SDSU MRI Imaging Center. "It has expanded so much that the folding patterns are very complex."

Unprecedented insights

Collaborating with imaging and cerebellum experts from the United Kingdom, Netherlands and Canada, Sereno used customized open source FreeSurfer software that he originally developed with colleagues while at the University of California San Diego to computationally reconstruct the folded surface of the cerebellum. The software also unfolds and flattens the cerebellar cortex so as to visualize it to the level of each individual folia -- or thin leaf like fold.

A pioneer in brain imaging who has leveraged functional MRI to uncover visual maps in the brain, Sereno found that when the cerebellum is completely unfolded, it forms a strange "crepe" four inches wide by three feet long. The findings were published this week in a study in PNAS (Proceedings of the National Academy of Sciences).

"Until now we only had crude models of what it looked like," Sereno said. "We now have a complete map or surface representation of the cerebellum, much like cities, counties, and states."

Puzzle pieces

Previous research discovered that while there were many similarities between the cortex and the cerebellum, there was one key difference. In the cerebral cortex, regions representing different parts of the body are arranged roughly like they are in the actual body: juxtaposed and orderly. But in the cerebellum, they were placed more randomly.

"You get a little chunk of the lip, next to a chunk of the shoulder or face, like jumbled puzzle pieces," Sereno explained.

Those parts of the cerebellum are therefore set up to pull in and coordinate information from disparate parts of the body.

It is intriguing to think that there might be analogs of '"fractured somatotopy"' in the cognitive parts of the cerebellum that could help support highly complex, sophisticated cognitive functions, such as language or abstract reasoning, Sereno said.

"When you think of the cognition required to write a scientific paper or explain a concept, you have to pull in information from many different sources. And that's just how the cerebellum is set up."

Until now, the cerebellum was thought to be involved mainly in basic functions like movement, but its expansion over time and its new inputs from cortical areas involved in cognition suggest that it can also process advanced concepts like mathematical equations.

"Now that we have the first high resolution base map of the human cerebellum, there are many possibilities for researchers to start filling in what is certain to be a complex quilt of inputs, from many different parts of the cerebral cortex in more detail than ever before," Sereno said.

Read more at Science Daily

Humans and monkeys show similar thinking patterns

Rhesus macaque

Humans and monkeys may not speak the same lingo, but our ways of thinking are a lot more similar than previously thought, according to new research from UC Berkeley, Harvard University and Carnegie Mellon University.

In experiments on 100 study participants across age groups, cultures and species, researchers found that indigenous Tsimane' people in Bolivia's Amazon rainforest, American adults and preschoolers and macaque monkeys all show, to varying degrees, a knack for "recursion," a cognitive process of arranging words, phrases or symbols in a way that helps convey complex commands, sentiments and ideas.

The findings, published today (Friday, June 26) in the journal Science Advances, shed new light on our understanding of the evolution of language, researchers said.

"For the first time, we have strong empirical evidence about patterns of thinking that come naturally to probably all humans and, to a lesser extent, non-human primates," said study co-author Steven Piantadosi, a UC Berkeley assistant professor of psychology.

Indeed, the monkeys were found to perform far better in the tests than the researchers had predicted.

"Our data suggest that, with sufficient training, monkeys can learn to represent a recursive process, meaning that this ability may not be as unique to humans as is commonly thought," said Sam Cheyette, a Ph.D. student in Piantadosi's lab and co-author of the study.

Known in linguistics as "nested structures," recursive phrases within phrases are crucial to syntax and semantics in human language. A simple example is a British nursery rhyme that talks about "the dog that worried the cat that killed the rat that ate the malt that lay in the house that Jack built."

Researchers tested the recursive skills of 10 U.S. adults, 50 preschoolers and kindergarteners, 37 members of the Tsimane' and three male macaque monkeys.

First, all participants were trained to memorize different sequences of symbols in a particular order. Specifically, they learned sequences such as { ( ) } or { [ ] }, which are analogous to some linguistic nested structures.

Participants from the U.S. and monkeys used a large touchscreen monitor to memorize the sequences. They heard a ding if they got a symbol in the right place, a buzzer if they got it wrong and a chime if the whole sequence was correct. The monkeys received snacks or juice as positive feedback.

Meanwhile, the Tsimane' participants, who are less accustomed to interacting with computers, were tested with paper index cards and given verbal feedback.

Next, all participants were asked to place, in the right order, four images from different groupings shown in random order on the screen.

To varying degrees, the participants all arranged their new lists in recursive structures, which is remarkable given that "Tsimane' adults, preschool children and monkeys, who lack formal mathematics and reading training, had never been exposed to such stimuli before testing," the study noted.

"These results are convergent with recent findings that monkeys can learn other kinds of structures found in human grammar," Piantadosi said.

Read more at  Science Daily

Ancient teeth from Peru hint now-extinct monkeys crossed Atlantic from Africa

Marmoset. Ucayalipithecus perdita would have been very small, similar in size to a modern-day marmoset.

Four fossilized monkey teeth discovered deep in the Peruvian Amazon provide new evidence that more than one group of ancient primates journeyed across the Atlantic Ocean from Africa, according to new USC research just published in the journal Science.

The teeth are from a newly discovered species belonging to an extinct family of African primates known as parapithecids. Fossils discovered at the same site in Peru had earlier offered the first proof that South American monkeys evolved from African primates.

The monkeys are believed to have made the more than 900-mile trip on floating rafts of vegetation that broke off from coastlines, possibly during a storm.

"This is a completely unique discovery," said Erik Seiffert, the study's lead author and Professor of Clinical Integrative Anatomical Sciences at Keck School of Medicine of USC. "It shows that in addition to the New World monkeys and a group of rodents known as caviomorphs -- there is this third lineage of mammals that somehow made this very improbable transatlantic journey to get from Africa to South America."

Researchers have named the extinct monkey Ucayalipithecus perdita. The name comes from Ucayali, the area of the Peruvian Amazon where the teeth were found, pithikos, the Greek word for monkey and perdita, the Latin word for lost.

Ucayalipithecus perdita would have been very small, similar in size to a modern-day marmoset.

Dating the migration

Researchers believe the site in Ucayali where the teeth were found is from a geological epoch known as the Oligocene, which extended from about 34 million to 23 million years ago.

Based on the age of the site and the closeness of Ucayalipithecus to its fossil relatives from Egypt, researchers estimate the migration might have occurred around 34 million years ago.

"We're suggesting that this group might have made it over to South America right around what we call the Eocene-Oligocene Boundary, a time period between two geological epochs, when the Antarctic ice sheet started to build up and the sea level fell," said Seiffert. "That might have played a role in making it a bit easier for these primates to actually get across the Atlantic Ocean."

An improbable discovery

Two of the Ucayalipithecus perdita teeth were identified by Argentinean co-authors of the study in 2015 showing that New World monkeys had African forebears. When Seiffert was asked to help describe these specimens in 2016, he noticed the similarity of the two broken upper molars to an extinct 32 million-year-old parapithecid monkey species from Egypt he had studied previously.

An expedition to the Peruvian fossil site in 2016 led to the discovery of two more teeth belonging to this new species. The resemblance of these additional lower teeth to those of the Egyptian monkey teeth confirmed to Seiffert that Ucayalipithecus was descended from African ancestors.

"The thing that strikes me about this study more than any other I've been involved in is just how improbable all of it is," said Seiffert. "The fact that it's this remote site in the middle of nowhere, that the chances of finding these pieces is extremely small, to the fact that we're revealing this very improbable journey that was made by these early monkeys, it's all quite remarkable."

About this study

In addition to Seiffert, the study's other authors are Marcelo Tejedor and Nelson Novo from the Instituto Patagónico de Geología y Paleontología (CCT CONICET -- CENPAT); John G. Fleagle from the Department of Anatomical Sciences, Renaissance School of Medicine, Stony Brook University; Fanny Cornejo and Dorien de Vries from the Interdepartmental Doctoral Program in Anthropological Sciences, Stony Brook University; Mariano Bond from CONICET, División Paleontología Vertebrados, Museo de Ciencias Naturales de La Plata and Kenneth E. Campbell Jr. from the Department of Vertebrate Zoology, Natural History Museum of Los Angeles County.

Read more at Science Daily

A monkey's balancing act

The study, which looks specifically at the behaviour of an endangered monkey species, reveals that even in national parks where human presence is reduced and regulated, the animals carry out careful calculations and modify their natural behaviour to balance the pros and cons of living in close proximity to humans.

It reveals the negative impact that consuming human foods can have on the physical health of the monkeys, and highlights the need for new and sustainable conservation programmes to save the growing number of endangered species in their natural habitats.

Barbary macaques are an endangered species of monkeys restricted to the forests of Morocco and Algeria, with an introduced population also living on the Rock of Gibraltar. The wild population in North Africa has dramatically declined in the last decades.

The new study, led by Dr Bonaventura Majolo from the University of Lincoln, UK, involved a detailed examination of the effects of human activity on wild Barbary macaques in Ifrane National Park in Morocco.

Dr Majolo said: "When we observe animals in the wild we often talk about a 'landscape of fear'. This term refers to the decisions that animals make when they choose whether or not to avoid an area where the risk of predation is highest; weighing up the risk of attack against the possible rewards to be found there.

"Our study shows that macaques make many behavioural adjustments in response to varying levels of risk and reward, and that the way the macaques respond to human activity is very similar to the way in which they respond to predation risk. We see evidence here that the macaques are capable of great behavioural flexibility as they navigate the problems and the opportunities that sharing space with humans presents."

The researchers followed five groups of Barbary macaques and observed their behaviour and habitat selection over the course of a year. Their findings reveal the true extent of human activity on the monkeys' habitats and choices.

The researchers observed the macaques making significant adjustments to their behaviour and navigating their environment strategically in relation to human activity. They appear to balance food acquisition and risk avoidance -- for example they minimise risk by avoiding areas used by local shepherds and their dogs (which are now among the monkeys' most dangerous predators), and exploit opportunities to receive high-calorie human food by spending time close to roads.

Although being fed by humans may appear to be beneficial for the monkeys, food provisioning in fact has negative impacts on the macaques -- increasing their stress levels, heightening the probability of road injury and death, and having a detrimental impact on their health.

The monkeys' behaviour also shows seasonal trends in correlation with human activities. The macaques avoid herding routes during summer months, when herding activity by the local shepherds is at its peak, and they are more likely to use areas close to roads in the autumn and winter months, when natural food sources are low and the benefits of receiving high calorie human food may exceed the risk of being injured or even killed by road traffic.

The study reveals that the 'home range' of each observed macaque group (the area where a group of monkeys spend most of their time) included some kind of human structure, from roads and paths to picnic areas and farms. They also found that all of the study group's home ranges overlapped with at least one other, which the researchers conclude could be a result of declining availability of suitable habitats and food sources, or of direct competition over profitable areas close to roads and safe sleeping sites.

Their findings are published in the scientific journal Animal Conservation.

James Waterman, first author of the paper and a PhD student at Liverpool John Moores University, said: "Even in a national park, the effect of human disturbance on animal life can be considerable, and as our landscapes become increasingly human dominated, many wildlife species must cope with new ecological pressures. The impact of habitat loss and fragmentation, climate change, expanding human infrastructure, hunting and poaching quickly and dramatically alters habitats, forcing wildlife to adjust, move to more suitable areas (if these are available), or ultimately face the threat of extinction.

"This study highlights that it is more important than ever to develop conservation programs that take into account the requirements of all involved, including, but not limited to the wildlife that is ultimately at risk. Programs that fail to do so rarely produce lasting, positive change."

Read more at Science Daily