How howler monkeys survive yellow fever


This 2009 video is called Howler Monkeys | National Geographic.

From the University of Utah in the USA:

Mutations may have saved brown howlers from yellow fever virus

Exposure to a past virus may have selected for variations in their immune genes, maybe aided in their survival

August 12, 2020

Summary: From 2007 to 2009, a devastating yellow fever virus outbreak nearly decimated brown and black and gold howler monkey populations at El Parque El Piñalito in northeastern Argentina. An international research team tested if howlers who survived the outbreak had any genetic variations that may have kept them alive. In brown howlers, they found two mutations on immune genes that resulted in amino acid changes in the part of the protein that detects the disease.

At the start of her 2008 field season at El Parque El Piñalito in the Misiones province in northeastern Argentina, Ilaria Agostini knew something was terribly wrong. Agostini has studied Misiones’ two howler monkey species since 2005 — brown (Alouatta guariba clamitans) and black and gold (A. caraya) howlers. Both lived at relatively low densities in the park, but still existed in one of the most continuous, well-preserved remnants of habitat known as the Atlantic Forest. She knows them better than anyone in the world.

But the treetops were silent, void of the booming chorus for which the howler monkeys are named.

“At the beginning, I found one dead monkey. Then in two hours, another one. In all my team and I found 14 dead howlers,” said Agostini, a biologist at the Instituto de Biología Subtropical of Argentina. “That first day, we started to suspect it was yellow fever.”

From 2007 to 2009, a devastating yellow fever virus outbreak nearly decimated El Piñalito’s howler monkey populations. The brown and black and gold howlers are extremely susceptible to the disease that enslavers introduced to the Americas. In the last few years, logging activity has progressively affected the howlers’ habitat and brought humans closer to wildlife, increasing the risk of virus transmission from the loggers to the howlers. When laboratory analyses confirmed that the monkey’s died from yellow fever, health authorities vaccinated human populations to prevent further transmission. By then, the damage was done.

“Our howler groups just disappeared from the park. We found almost no signs of a presence until 2014 — six years after the outbreak,” Agostini said.

A recent United Nations report predicts that more diseases that spread from animals to humans, such as COVID-19, will emerge due to habitat destruction. The flip-side — human disease spreading to animals — is also true. How will increased virus transmission affect wild animal populations? The yellow virus outbreak in El Parque El Piñalito provided a natural laboratory to investigate.

In a study led by the University of Utah, an international research team tested whether howler monkeys who survived the yellow virus outbreak had any genetic variations that may have kept them alive. The article was published online on June 25, 2020 in the American Journal of Physical Anthropology.

In 2017, Nicole Torosi, postdoctoral researcher at Rutgers University and then a doctoral student at the University of Utah, joined Agostini in El Piñalito to search for any living brown or black and gold howlers. They eventually counted nine brown howlers and two black and gold howlers. Torosin sequenced the genomes of liver samples that Agostini’s team had collected from monkeys who died before the outbreak, right after the outbreak, and she extracted DNA from the poop of those who had survived.

“We saw many more dead black and gold howler monkeys than brown howlers after the outbreak,” said Torosin, postdoctoral researcher at Rutgers University. “We wondered if there were genetic differences that may have helped the brown howlers survive somehow.”

The scientists focused on two immune genes that detect the type of single-stranded RNA viruses to which yellow fever virus belongs. The genes, toll-like receptor (TLR) 7 and TLR 8, recognize and destroy the invading viruses in both humans and non-human primates.

The team found no genetic variants present at higher rates in the surviving monkeys than in the deceased ones. However, in comparing the two species, they found three mutations in the DNA sequence of the brown howler individuals. Two of these mutations result in amino acid changes in the part of the protein that detects the disease. In a companion study published in Molecular Phylogenetics and Evolution, Torosin found that the changes were positively selected in the brown howler population.

“If the amino acid sequence is different, then the protein is different, and that could affect the entire downstream response to dealing with the virus,” said Torosin. “Maybe that’s why more brown howlers survived.”

The researchers hypothesize that the brown howlers were exposed to a different virus in the past that selected for the mutations and may have helped them deal with yellow fever virus. Torosin’s next steps are to do an immune test for the two species by exposing cells to the virus to see what the responses are in a controlled environment

“With COVID-19, we’ve seen how a virus that originated in China can spread across the world. Here, humans brought a virus to primates that have evolved without exposure to it for tens of millions of years and it nearly wiped them out,” said co-author Timothy Webster, anthropologist at the U. “We’re interacting with species in new ways that are creating new immune challenges, both for humans and for other species.”

Rebuilding the chorus

There are still howler monkeys in the park, but they need time to recover and reorganize into groups — if they’re not wiped by another outbreak, which is a real possibility, Agostini said. In order to document their progress, Agostini and her team of Proyecto Carayá Rojo, together with the NGO Asociación Civil Centro de Investigaciones del Bosque Atlántico (CeIBA), came up with a new way of tracking — by recording their calls using wildlife acoustic recorders.

“Just looking for them in the forest isn’t efficient. They’re so elusive, and live at such low densities, you can go days without finding them,” she said. “Recording their vocalizations could be very useful for howlers. They give these very loud calls.”

Drill monkeys of African Bioko island


This 17 July 2020 video from Equatorial Guinea says about itself:

Roughly 20 miles off the coast of West Africa, the island of Bioko sits alone in the Atlantic Ocean. This rainforest-dominated terrain is home to one of the rarest primates in the world: the drill.

Monkey grammar, similar to humans?


This 2014 video says about itself:

How to speak monkey: The language of cotton-top tamarins – Anne Savage

The cotton-top tamarin is a very vocal monkey — the species communicates using a sophisticated language of 38 distinct and grammatically structured calls! Anne Savage teaches a few of these chirps and whistles, taking us through a day in the life of Shakira the tamarin (using sounds pulled from the wild) as Shakira signals to her family, talks to her food and warns against potential predators.

Lesson by Anne Savage, animation by Avi Ofer.

By Bruce Bower, June 26, 2020, at 2:00 pm:

Monkeys may share a key grammar-related skill with humans

A capacity for recursion evolved early in primate evolution, a contested study suggests

An aptitude for mentally stringing together related items, often cited as a hallmark of human language, may have deep roots in primate evolution, a new study suggests.

In lab experiments, monkeys demonstrated an ability akin to embedding phrases within other phrases, scientists report June 26 in Science Advances. Many linguists regard this skill, known as recursion, as fundamental to grammar (SN: 12/4/05) and thus peculiar to people.

But “this work shows that the capacity to represent recursive sequences is present in an animal that will never learn language,” says Stephen Ferrigno, a Harvard University psychologist.

Recursion allows one to elaborate a sentence such as “This pandemic is awful” into “This pandemic, which has put so many people out of work, is awful, not to mention a health risk.”

Ferrigno and colleagues tested recursion in both monkeys and humans. Ten U.S. adults recognized recursive symbol sequences on a nonverbal task and quickly applied that knowledge to novel sequences of items. To a lesser but still substantial extent, so did 50 U.S. preschoolers and 37 adult Tsimane’ villagers from Bolivia, who had no schooling in math or reading.

Those results imply that an ability to grasp recursion must emerge early in life and doesn’t require formal education.

Three rhesus monkeys lacked humans’ ease on the task. But after receiving extra training, two of those monkeys displayed recursive learning, Ferrigno’s group says. One of the two animals ended up, on average, more likely to form novel recursive sequences than about three-quarters of the preschoolers and roughly half of the Bolivian villagers.

How living monkeys react to robot monkeys


This 2017 video says about itself:

Langur monkeys grieve over fake monkey | Spy in the Wild – BBC

Langur monkeys mistake the motionless robotic spy monkey that was accidentally dropped as a lifeless baby langur and begin to grieve.

Documentary in which animatronic spy creatures infiltrate the animal world to explore their complex emotions.

From the Society for Neuroscience:

Monkeys appreciate lifelike animation

Monkeys experience the uncanny valley effect, just like humans, but a new realistic avatar can overcome it

June 8, 2020

Monkeys can overcome their aversion to animated monkeys through a more realistic avatar, according to research recently published in eNeuro.

Humans feel more comfortable toward life-like humanoid robots, but if a robot gets too life-like, it can become creepy. This “uncanny valley” effect plagues monkeys, too, which becomes a problem when scientists use animated monkey faces to study social behavior. However, monkeys overcome the uncanny valley when presented with a sufficiently realistic monkey avatar created using movie industry animation technology.

Siebert et al. compared how Rhesus monkeys reacted toward five types of monkey faces: video footage from real monkeys, a natural-looking avatar with fur and facial details, a furless avatar, a greyscale avatar, and a wireframe face. The monkeys looked at the wireframe face but avoided looking at the furless and greyscale avatars, showing the uncanny valley effect at work. However, the natural-looking avatar with fur overcame this effect. The monkeys looked at the model and made social facial expressions, comparable to how they would act around real monkeys. Using this type of avatar will make social cognition studies more standardized and replicable.

Mantled howler monkeys in Panama


This 7 June 2020 video says about itself:

The Mantled Howler Monkey is the loudest animal of the rainforest

The Mantled Howler Monkey (Alouatta palliata) is one of the most prominent species of monkeys in the beautiful country of Panama. It thrives in deep lush jungles along the Canal of Panama and spends most of the day in the canopy of large mature tropical trees. Its home is typically the hostile and busy rain forests of most of Central and South America.

Like most of its cousins, the Mantled Howler will likely eat anything smaller than its own size. On the other hand, its natural predators are mainly feline like the jaguar and puma among other big predatory cats. The infamous loud and threatening sounding call of the Mantled Howler Monkey resonates over the thick dramatic and stunning vegetation of the Gamboa region and can be heard far in the distance through the jungle.

Among 5 other relatives of monkey species present in Panama, the Mantled Howler also shares its beautiful natural habitat with dozens of other mammal species and hundreds of bird species. Footage in this two-hour continuous uninterrupted calm and relaxing compilation was filmed in 4K Ultra High Definition in the evergreen humid rain forest of the lush Pipeline Road hiking trail in Gamboa, Panama.

Olive baboons in Africa, video


This 26 May 2020 video says about itself:

This week in Candid Animal Cam, we’re headed to Africa to meet and learn about the olive baboon. This primate species has a symbiotic relationship with elephants. But you’ll have to watch the video to find out what it is!

And shout out to our writer and biologist Romi Castagnino, who hosted, produced and shot this video!

Mandrill monkeys family relationships, new research


This 3 July 2016 video is called Wild Mandrill Monkeys Encounter in Lekedi, Gabon.

From the Deutsches Primatenzentrum (DPZ)/German Primate Center:

AI reveals mechanism for kin selection in a wild primate

May 27, 2020

More like mom or dad? Human babies always get this curious look in their face combined with the question whom the child resembles most. The answers vary depending on the degree of kinship, gender and the time of assessment. Mandrills, monkeys living in Equatorial Africa, may recognize facial features coding relatedness better than humans. Scientists at the German Primate Center — Leibniz Institute for Primate Research in Göttingen, together with colleagues from the Institut des Sciences de l’Evolution de Montpellier (ISEM), showed by using up-to-date artificial intelligence (AI) that half-sisters, who have the same father look more alike than half-sisters who share the same mother. The paternal half-sisters also have closer social relationships with each other than unrelated mandrills. This result provided the first evidence suggesting that interindividual resemblance has been selected to signal paternal kinship (Science Advances).

Throughout the animal kingdom, related conspecifics show similar features. Some are the spitting image of each other. However, whether resemblance between kin merely reflects their genetic resemblance or results from selection to facilitate their recognition is still unknown. A team of scientists led by Marie Charpentier of the ISEM in Montpellier, including Clémence Poirotte and Peter Kappeler of the German Primate Center in Göttingen, used for the first time artificial intelligence (deep learning) to examine the hypothesis that the similarity of the facial features of free-living mandrills is the result of selection. The database consisted of 16,000 portraits of mandrills, taken since 2012 as part of the Project Mandrillus in Gabon. This natural population of mandrills is the only one habituated to the presence of humans. Using a trained algorithm of deep learning, the individuals were first identified and then quantified in terms of facial resemblance. The results were subsequently related to relatedness data of the study animals.

Mandrills live in groups consisting of more than 100 individuals and are characterized by the fact that the females are maternal relatives. They are familiar with each other and remain in the same family throughout their lives. Since reproduction in mandrill groups is mainly monopolized by the alpha male, young mandrills of similar age often have the same father. However, as members of different family groups within the large groups, they should hardly know each other. Nevertheless, half-sisters on the paternal side, as well as half-sisters on the maternal side, interact with each other more often than unrelated animals. “This observation suggests that paternal half-sisters recognize each other as relatives by their facial features. Although maternal and paternal half-sisters share the same degree of genetic relatedness, the facial resemblance is stronger among paternally related females. We suspect that the similarity of facial features between paternal relatives has evolved to facilitate social discrimination and nepotism between kin,” says Clémence Poirotte.

Golden-headed lion tamarin monkeys, video


This 1 May 2020 video says about itself:

Parenthood Is Tough For A Squirrel-Sized Monkey! | Primates | BBC Earth

There are plenty of bite-sized morsels for these [golden-headed] lion tamarins to eat. But being bite-sized themselves means it’s dangerous to stay in one place for too long.

Geoffroy’s spider monkeys, video


This 21 April 2020 video says about itself:

What is a Geoffroy’s spider monkey? Candid Animal Cam takes you in the trees this week

This week, we’re talking about an animal that has three arms (kind of)! That’s the Geoffroy’s spider monkey, which uses its tail to get around in the trees. This animal is found in South America, and travels in large groups.