Category Archives: primates

Global Warming Negatively Impacts Wild Monkey Diets

Yes, yes, we hear it all the time: More CO2 is good because plants love CO2

That is a rather dumb thing to say for a number of reasons; nature is not simple. You don’t change one variable and expect other variables to respond as though we were turning a garden hose up or down. For example, while plant growth might be enhanced with more CO2 in the atmosphere, there is no reason to think this would be linear, or similar across all plants. You have to dance with the one who brung ya. The plants we have are the plants that have been under Darwinian selection optimizing growth and maintenance physiology for gazillions of plant generations. Changing a fundamental variable may have little effect (and in fact, CO2 increase only enhances growth somewhat, and for only some plants) and may even have negative effects.

A new paper out in Ecology looks at the nutritional value of plants in a Ugandan rainforest and finds that the nutritional value of the leaves eaten by some Colobine monkeys there has declined, because fibre has increased at the expense of usable protein. From the abstract:

Global change is affecting plant and animal populations and many of the changes are likely subtle and difficult to detect. Based on greenhouse experiments, changes in temperature and rainfall, along with elevated CO2, are expected to impact the nutritional quality of leaves. Here, we show a decline in the quality of tree leaves 15 and 30 years after two previous studies in an undisturbed area of tropical forest in Kibale National Park, Uganda. After 30 years in a sample of multiple individuals of ten tree species, the mature leaves of all but one species increased in fiber concentrations, with a mean increase of 10%; tagged individuals of one species increased 13% in fiber. After 15 years, in eight tree species the fiber of young leaves increased 15%, and protein decreased 6%. Like many folivores, Kibale colobus monkeys select leaves with a high protein-to-fiber ratio, so for these folivores declining leaf quality could have a major impact. Comparisons among African and Asian forests show a strong correlation between colobine biomass and the protein-to-fiber ratio of the mature leaves from common tree species. Although this model, predicts a 31% decline in monkey abundance for Kibale, we have not yet seen these declines.

Jessica M. Rothman, Colin A. Chapman, Thomas T. Struhsaker, David Raubenheimer, Dennis Twinomugisha, and Peter G. Waterman, 2014. Long term declines in nutritional quality of tropical leaves. Ecology

Is Curious George an Ape or a Monkey?

Curious George is called a “little monkey” in all of the Curious George literature, TV shows, and movies. But Curious George has no tail, and generally, that means you are an ape. But, there is one monkey with no tail, or at least one that is vestigial and not visible: The Barbary Macaque (Macaca sylvanus). For this reason, some have suggested that George is a monkey, specificaly, a Barbary Macaque or perhaps a close previously undiscovered species.

However, one of the main features distinguishing between monkeys and apes is the intermembral index. This is simply the relative proportion of the forelimbs and hind limbs. Apes have short legs and long arms (unless you are a Man in a Yellow Hat variety of ape) while monkeys have more even length limbs. The image above compares a young Chimpanzee to stand in for the apes, a Barbary Macaque, and Curious George, with the limb lengths marked off with a red line.

This seems to indicate the George is an Ape.

Also, note that the Man in the Yellow Hat originally kidnapped George in a Jungle.

There is another possibility, that Curious George is an undiscovered type of primate that is technically a Monkey but with certain Ape features. We are not certain of the genetic heritage of the mysterious ape Sungudogo, so perhaps George is one of those.

Note that these comparisons are being made among Old World Primates. If New World Primates are included in the mix, there may end up being more questions than answers.

Amazingly cute new primate species in Borneo

The Slow Loris (Genus Nycticebus) is a category of prosimian (primates that are neither monkey or ape) that lives in southeast Asia. Most prosimian species live on the island of Madagascar, but there are several African and Asian forms, all of which are nocturnal. The Slow Loris is special because it is the only primate we know of that has a toxic bite.

ResearchBlogging.orgThe total number of nocturnal primates known has increased considerably over the years and I’d wager there are many more to be found. “Technological advances have improved our knowledge about the diversity of several nocturnal mammals,” said Rachel Munds from the University of Missouri Columbia. “Historically many species went unrecognized as they were falsely lumped together as one species. While the number of recognized primate species has doubled in the past 25 years some nocturnal species remain hidden to science.”

Tomorrow, a paper will be released providing the diagnosis of a new species of slow loris. From the abstract:

The slow lorises … once included only two species, but recent taxonomic studies resulted in the description of three additional species; … The Bornean loris in particular is characterized by pelage and body size variation. In this study, we explored facemask variation in the Bornean loris (N. menagensis). Differing facemask patterns, particularly influenced by the amount of white on the face, significantly clustered together by geographic regions, separated by notable geographic boundaries. Our results support the recognition of four species of Bornean lorises: N. menagensis, N. bancanus, N. borneanus, and N. kayan. Genetic studies are required to support these findings and to refine further our understanding of the marked variability within the Bornean loris populations

Previously, one species of Bornean slow loris, with three subspecies, was recognized. The present study elevates the three subspecies to species status and add the fourth as a new discovery. Obviously, this significantly increases our conception of diversity in the nocturnal Bornean rainforest. One of the biggest threats to these animals is the pet trade. “The pet trade is a serious threat for slow lorises in Indonesia, and recognition of these new species raises issues regarding where to release confiscated Bornean slow lorises, as recognition by non-experts can be difficult,” said co-author Professor Nekaris, from Oxford Brookes University.

The study used 25 photographs and 27 museum specimens including the type specimens for two of the previously designated subspecies. A large number of features were examined and measured, of which eight showed variation across the sample, thus showing promise to use as in classification. Here is an example of one of the traits, called “Crown”:

Various fancy statistical analysis were done to produce two “functions” (combinations of variables) that separate the samples as indicated in this graph:

These traits clearly sort out the groups, and these groups have geographical distinctions as well.

Group 1 is on the island of Bangka and in the southwestern portion of Borneo south of the Kapuas River and east to the Barito River; this group’s boundaries appear not to extend all the way east to Barito River. Group 2 is found in central Borneo, north of the Kapuas and Mahakam Rivers. It is often found in higher ele- vations, but is not restricted to them. The boundary of Group 3 overlaps in part with Group 1, as it is found north of the Kapuas River, but its range ex- tends as far east as the Barito River. Finally, Group 4 inhabits the southern Philippines and northern and eastern Borneo, primarily in coastal and low- land areas. It does not range south of the Mahakam River.

So there are now four species: N menagensis, N. bancanus, N. borneanus and N. kayan. That last one is the new designation, and is named for a river flowing through the region in which it lives..

The conservation and research project responsible for this work has a web page with cute pictures, interesting videos, and more information on conservation related matters: Prof Anna Nekaris’ Little Fireface Project

Munds, Rachel, Nekaris, K.A., & Ford, Susan (2012). Taxonomy of the Bornean Slow Loris, with new species Nycticebus kayan (Primates, Lorisidae) American Journal of Primatology, 75, 46-56 : 10.1002/ajp.22071

Wild angry baboons on the high cliff

We three had somehow wound our way down into the canyon without experiencing any really steep slopes, but having walked for several miles in the sandy dry riverbed, Trusted Companion, Young One, and I were now looking rather hopelessly at unsafe-to-climb cliffs on both sides, covered with imposing vegetation of the kind that sports a thorn every few inches. The sun was low enough that the canyon floor was in a dark shadow, and the air was beginning to chill down. We were far enough from the vehicle, lost enough, and sufficiently plan-free that it would be perfectly reasonable to worry that we might not make it across the remote African Savanna before the leopards and hyenas came out to hunt. It was even possible that we’d have to spend the night huddled in some spot we could convince ourselves was protected from the elements and the wild animals. All this dark and scary truth had dawned on me over the last hour as we continued heading up a seemingly endless side canyon in search of a place to climb out of this river valley known among international extreme outdoors people as one of the most treacherous in the world, and known among the more traditional local folk for its dragon-like 50-meter long human-eating snake that was supposedly mythical.
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On the Move

On the Move: How and Why Animals Travel in Groups, edited by Sue Boinski and Paul Garber is a compendium of academic research on … well, on how and why animals travel in groups. Notice of this book is a fitting start to a series of reviews of migration-related books that is part of Migration Week on GLB. (For an overview of the Bigness and Vastness of bird migration in particular, see A Question of Migration.)
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Isabel Behncke: Evolution’s gift of play, from bonobo apes to humans

With never-before-seen video, primatologist Isabel Behncke Izquierdo (a TED Fellow) shows how bonobo ape society learns from constantly playing — solo, with friends, even as a prelude to sex. Indeed, play appears to be the bonobos’ key to problem-solving and avoiding conflict. If it works for our close cousins, why not for us?

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What I know about Marc Hauser, the recently ‘investigated’ Harvard primatologist

I know Marc Hauser, and I trust him. I worked with him for a few years as a colleague on the faculty in the Anthropology department on various administrative matters (such as graduate admission and undergraduate program development) and we taught together. We are very different kinds of people, and did not always see eye to eye (well, we disagreed on one thing, once), but the same can be said of almost any two people from those days and that department, to some degree.
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New Primate Fossil Informs Us of the Ape-Monkey Split During the Oligocene

ResearchBlogging.orgThe newly reported Saadanius hijazensis may or may not be a “missing link” but in order for this monkey to climb onto the primate family tree, a new branch had to be sprouted. So, not only is Saadanius hijazensis a new species, but it is a member of a new taxonomic Family, Saadaniidae, which in turn is a member of a new Superfamily, Saadanioidea. Why is this important? It’s complicated. But not too complicated.

The fossil was found while University of Michigan paleontologist Iyad Zalmout was busy looking for dinosaur fossils in western Saudi Arabia. He found the monkey, from a much later time period, instead. Ooops.
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Keep an eye on the prey: You’ll find the predator

In Robert Gardner’s documentary film Dead Birds, the men of a highland New Guinea village guard the perimeter of the territory, watchful for men of the neighboring group who may be intent on sneaking into the gardens to capture and kill an unwitting child or woman in order to avenge a prior death. But they don’t see the men sneaking through the dense riparian forest. They don’t even look for them. Rather, they see the birds fly from their preferred habitat where they are foraging or resting, startled into the open by … something. The birds belie the predator.
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