Monkey sleep, monkey do: how primates choose their trees
December 31, 2014
Primates don’t monkey around when deciding where to spend the night, but primatologists have had a poor grasp on what drives certain monkeys toward specific trees. Now, two extensive studies of Indonesian primates suggest that factors in selecting trees each evening are site-specific and different for each species—and that some overnight spots result in conflicts between monkeys and humans.
“We have to understand what monkeys need [in order] to sleep to know what we have to protect,” said primate scientist Fany Brotcorne of the University of Liège in Belgium, leader of one of the research teams, in an interview with mongabay.com.
When monkeys choose their evening perch, they weigh more than just comfort. The main factors scientists suspect are safety from predators, distance to feeding grounds, human interactions, insect avoidance, and competition with other primates.
“Primates may be spending up to 12 hours at their sleeping sites, and yet we really don’t know much about them,” said Adrian Barnett of the University of Roehampton, in London, U.K., a primatologist not involved in the new work, in an email to mongabay.com.
The two unaffiliated studies occurred on neighboring Indonesian islands. Brotcorne’s team spent 56 nights in the Bali Barat National Park in Bali studying long-tailed macaques (Macaca fascicularis), a thriving primate species. In West Kalimantan on the island of Borneo, primatologist Katie Feilen of the University of California at Davis followed the sleeping behaviors of endangered proboscis monkeys (Nasalis larvatus) for 132 nights.
Both groups noted the sizes and shapes of trees favored by the monkeys. Brotcorne’s group also measured the distance between sleeping sites and human outposts such as temples, tourist areas, or roads.
The proboscis monkeys returned each night to tall, isolated trees near rivers. The monkeys gather in trees that jut above the canopy to avoid predators and insects, believes Feilen. Predators can’t crawl from tree to tree toward the monkeys if the trees’ branches don’t touch. At the same time, the monkeys’ lofty—and windy—perches help them avoid malaria-ridden mosquitoes that tend to remain within the canopy.
“I think insect and disease ecology plays a bigger role in all these questions of primatology than we are all thinking,” said Feilen.
The long-tailed macaques snoozed away in trees near human-modified areas. Brotcorne suspects food availability was the main factor driving the macaques’ bunk choice. The monkeys scooted closer to a Hindu temple and tourist area where fruit, rice, and crackers abounded during the peak tourist season. The timing of their move also coincided with the start of the dry season and a decline in natural fruit production. The two teams reported their findings side-by-side this month in the American Journal of Primatology.
There is not just one evolutionary force influencing sleeping tree preference for primates, pointed out both lead authors.
“Both papers are significant in that they are showing the importance of sleeping sites in primate ecology,” said Barnett. “What is needed is a collation of data that is sufficiently broad to allow general theories to be put up [about sleeping tree selection].”
The distinct sleeping site chosen by the two species also influences the primates’ interactions with humans. Loggers preferentially remove the tall riverside trees favored by the endangered proboscis monkeys, threatening the species’ habitat, said Feilen. The proboscis monkeys she studied had to contend with deforestation by mining and palm oil companies. Also, local hunters knew where to find the predictable primates.
On the other hand, macaques and humans have competed for space and food in human-modified areas for centuries. But their close contact worries Brotcorne because diseases can cross from monkeys to humans and vice versa. Human food is not the healthiest diet for monkeys, she added.
“If you go to the tourist monkey forests, you will see obese monkeys,” said Brotcorne.
Feilen, K., and A. Marshall. 2014. Sleeping site selection by proboscis monkeys (Nasalis larvatus) in West Kalimantan, Indonesia. American Journal of Primatology 76: 1127-1139.
Brotcorne, F., C. Maslarov, N. Wandia, A. Fuentes, R. Beudels-Jamar, and M. Huynen. 2014. The role of anthropic, ecological, and social factors in sleeping site choice by long-tailed Macaques (Macaca fascicularis). American Journal of Primatology 76: 1140-1150.
Leigh Cooper is a graduate student in the Science Communication Program at the University of California, Santa Cruz.
This video from India says about itself:
20 December 2014
Kanpur Central Railway Station. Monkey saves friend’s life without any human help.
From the Deccan Herald in India:
Monkey saves ‘dying’ friend at Kanpur Railway station (Video)
New Delhi, Dec 21, 2014, Agencies:
A friend in need is a friend indeed: A hair-raising video that has surfaced on YouTube illustrates this proverb very well. In the video, a monkey could be seen trying to save another monkey lying unconscious on a railway track.
The monkey in the video is surely impressive for its presence of mind and efforts to help its injured friend. One of the monkeys in the video fell unconscious after experiencing electric shock while walking on the high-tension wires in Kanpur’s railway station. The other monkey comes to the rescue.
The conscious monkey licks, bites, hits and puts the unconscious monkey into the stagnant water at the railway track. After 20 minutes of tireless effort, the ‘hero’ monkey brings its friend back to consciousness.
See also here.
These monkeys were rhesus macaques.
This video says about itself:
25 November 2014
Hello! We are from Taiwan. My daughter and I were very lucky to see an upside-down tortoise, but it’s luckier to see his friend trying to help him turn back in Taipei Zoo.
Today (25, November) is the field trip day of my daughter’s school and I also went to Taipei Zoo with her. We were all very lucky to see such kind of scene – one tortoise saves the other one’s life! Also, it’s a great opportunity to give my daughter a lesson – Helping others is the origin of happiness.
From Wildlife Extra:
Five new Amazonian saki monkey species discovered
A 10 year study of the saki monkey has revealed the existence of five new monkeys, bringing the total number of different saki species to 16.
“I began to suspect there might be more species of saki monkeys when I was doing field research in Ecuador,” said lead author Dr Laura K. Marsh, primate ecologist and director of the Global Conservation Institute.
“The more I saw, the more I realised that scientists had been confused in their evaluation of the diversity of sakis for over two centuries.”
Saki monkeys are a secretive group of primates native to the tropical forests of South America. They are often hunted for food, even though their elusive behaviour makes them difficult to find. The five new species are found in Brazil, Peru, and Bolivia – three of them are endemic to Brazil and one to Peru.
This revision increases the number of primates in Brazil to 145; the highest diversity for any single nation.
Primates are major components of tropical rain forest systems, and are of great importance as seed dispersers, predators, and sometimes even as prey.
“Besides being vital for their conservation and survival, the revised scientific description of these sakis is a major step in our understanding of primate diversity in Amazonia and worldwide,” said Dr Anthony B. Rylands, Senior Researcher at Conservation International and Deputy-Chair of the IUCN Species Survival Commission (SSC) Primate Specialist Group, after whom one of the new species, Rylands’ bald-faced saki (Pithecia rylandsi), was named.
The others include Cazuza’s saki (Pithecia cazuzai), Mittermeier’s Tapajós saki (Pithecia mittermeieri), Pissinatti’s bald-faced saki (Pithecia pissinattii) and Isabel’s saki (Pithecia isabela).
“Saki monkeys, like many rain forest primates, are excellent indicators for the health of tropical forest systems,” said Dr. Russell A. Mittermeier, President of Conservation International and Chair of the IUCN SSC Primate Specialist Group.
“This revision of the genus shows clearly how little we still know about the diversity of the natural world that surrounds us and upon which we ourselves depend so much.”
See also here.
The scientific description of these new speciew is here.
This video from North America says about itself:
Black-Capped Chickadee Vocalizations – Did You Know?
19 April 2014
The “Chickadee dee dee” call by Black-capped chickadees is one of the most complex vocalizations in the animal kingdom and is said to be language -like. This call is used in many social interactions such as, contacting members of the flock, or giving information about an individual’s identity, other slight changes in the phrase of this call can relay other specific messages.
From daily The Morning Star in Britain:
Animal noises ‘more closely linked’ with human speech
Tuesday 19th August 2014
ANIMAL vocalisations have more in common with human speech than previously thought, scientists claimed today.
Research published by the Royal Society in its Proceedings B biological science journal suggests there may be a missing link between sounds animals use to communicate and the more complex linguistic abilities of humans.
“Language is the biggest difference that separates humans from animals evolutionarily, but multiple studies are finding more and more stepping stones that seem to bridge the gap,” said lead scientist Dr Arik Kershenbaum of the National Institute for Mathematical and Biological Synthesis in Tennessee, US.
“Uncovering the process underlying vocal sequence generation in animals may be critical to our understanding of the origin of language.”
It has long been recognised that some species of animals possess distinct vocabularies.
Some monkeys have a range of cries distinguishing between threats, which is useful since the evasive action appropriate for a snake attack is different from that for a bird of prey.
But linguists have so far held that animals lack the ability to use grammar to change or extend the meanings of individual sounds by reordering them.
Their vocalisations were believed to follow a structural system known as the Markov process, where sound sequences could easily be predicted by listening to a finite number of preceding elements.
The sounds produced fitted statistical models for human language instead, the scientists concluded.
28 July 2014
Monkeys use researchers as human shields
A team of researchers in South Africa believes monkeys may be using their presence to guard against predators, according to a paper published online earlier this month in Behavioral Ecology.
From daily The Independent in Britain:
The samango monkeys of South Africa usually have a good reason not to stray too far from the forest. Although they spend much of their time loping through the trees they know to keep within a certain range: climb too high and they’re targets for eagles, too low and they could be a big cat‘s lunch.
However, it seems there is an exception to this behaviour – and that’s when people are around. A new study from the journal of Behavioural Ecology reports that samango monkeys under observation by scientists use the researchers as “human shields”, counting on their presence to avoid being picked off by a leopard.
23 March 2014 in Costa Rica.
A mantled howler monkey family with a youngster in the trees, early in the morning.
Four black-necked stilts near the lakelet. They drink.
Two least grebes swim.
A flock of black vultures.
Near the next lakelet, a green heron on a tree.
Two great kiskadees, busy with nesting material in their bills.
A black-headed trogon in a tree.
A solitary sandpiper on a lake bank.
A blue-black grassquit in a tree.
This video from South Africa is called International Primate Rescue (1 of 4): Playing with Marmosets.
By Joana Ramiro in Britain:
Halt ‘disturbing’ medical tests on monkeys, campaigners urge
Monday 7th April 2014
Cure Parkinson’s Trust sponsors experiments pumping primate brains full of harmful drugs
Animal welfare activists have begged a British charity to stop “profoundly disturbing” experiments on monkeys’ brains for medical research into Parkinson’s disease.
Campaign organisation Animal Aid issued a statement today denouncing the Cure Parkinson’s Trust for sponsoring Canadian scientists to inject monkeys with brain-damaging drugs.
“The vast majority of the British public do not want their money being used to fund profoundly disturbing experiments on animals,” said Animal Aid director Andrew Tyler.
In papers published in the Journal of Neuroscience and Public Library of Science ONE between 2011 and 2012, the testing was described as injecting marmoset monkeys with the chemical MPTP, which mimics Parkinson’s by killing brain cells.
The animals were then given differing doses of L-Dopa — a Parkinson’s treatment drug — to monitor its side effects.
Cure Parkinson’s Trust was named in the media as a supporter of the tests.
“We are calling on charities like the Cure Parkinson’s Trust to focus solely on productive non-animal research,” added Mr Tyler.
Animal Aid argues that the recurrent use of the same animals was equally disgraceful, given that — according to the Home Office’s measurement of animal tests — the suffering induced to the marmoset monkeys was “severe.”
Mr Tyler claimed that the British public’s money was ultimately being used to torture the animals.
In Britain, as in Europe, it is illegal to re-use animals for experiments on the “severe” threshold of pain, distress or lasting harm.