Sosthene's research project combines behavioral data collected in the field with hormonal data analyzed in the lab. The results of this study will characterize the specific behavioral patterns around the time of ovulation in mountain gorillas; specifically mating behavior, patterns of mating solicitations, and any evidence of coercion (aggression) by the silverbacks directed towards the females.

Sosthene (center) with research assistants. 

Sosthene (center) with research assistants. 

We asked Sosthene a series of questions about his work and here are some of his responses. In a few days we will post another round of Q and A with Sosthene.

Q. How do you identify the gorillas in your group?

A. Some primates, like gorillas can be identified by their faces. In particular, mountain gorillas can be recognized and named individually by looking at their nose-prints! Each of the 480 mountain gorillas found in the Virungas has a different nose print, similar to human fingerprints!

In some cases, experienced trackers help with rapid identification because nose-prints are not always visible. We use additional tips like the gorillas' group; the group/lone individuals' home range; the body size; the status and darkness of hair; the other mountain gorilla individuals found often in proximity (for example: individuals from the same mother, infants or a favorite female around the dominant silverback).

Other ways for identification include abnormal gestures (for example: Gutangara, a female from Pablo's group, is always nudging her left shoulder); and also malformations (for example: Umwana, a female from Inshuti's group has a straightened finger).

blog-gorillas-sosthene.jpg

Q. Are there any former poachers working as Karisoke field assistants now? How does this transition work?

A. Recruiting former poachers was among the initial strategies to get effective information on illegal activities in the National Park of Volcanoes, Rwanda. By recruiting former poachers, they helped us gather a lot of information on the poachers' networks; the types of snares; the other materials used and from where they got those materials; the target animals; the time of entering and getting out from the forest; the tracks used; the most frequented areas; and the time that they spend in the forest.

Karisoke and national authorities use the resulting information to reinforce the anti-poaching patrols and to efficiently sensitize local communities on biodiversity protection. Karisoke recruited one exceptional former poacher, who is now retired. We still have some former poachers working as trackers in with the gorillas' groups monitored by the Rwanda government for tourism. The recruited former poachers are welcomed by gorilla trackers! They are still considered as an asset to their daily work of gorillas' protection.

In addition, they have excellent experience in the forest! Some days, the tracking of gorillas is too hard or even unsuccessful, but the former poachers are consulted to find easy and right tracks! On other side, the resulting collaboration ended the friendships of the former poachers with their former colleagues, as they no longer share trust.

Today, the number of poachers has decreased. Most of them have been integrated in local organizations like traditional dancing troupes, handcrafts small-enterprises, and farming associations. But, some persisting poaching activities are observed; in 2010, Karisoke reported 1,927 snares.

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AuthorBeth Green

Sosthene collecting data

This is the second in a series of posts about Sosthene Habumuremyi’s dissertation research on the hormonal correlations of socio-sexual behaviors in female mountain gorillas. Please see part one here.

By Sosthene Habumuremyi

My study has gathered data on mating behavior, solicitations, and any displays/aggression from adult males towards the females. Sexual swellings, which are extremely small in gorillas, are also noted.

The plan is to monitor at least 6 nulliparous (never having given birth to offspring) females and 10 cycling parous (given birth to offspring at least once) females for 2 cycles each (2-4 months per female) as well as obtain weekly measures from pregnant females. To ensure that the time of ovulation is measured hormonally, urine and or fecal samples must be collected regularly, on a nearly daily basis without gaps of more than 2-3 days.

My research on nulliparous mountain gorillas may answer these questions:

  1. Are cycles ovulatory?
  2. How do hormonal profiles relate to sexual swelling patterns and mating activities?
  3. How do hormonal profiles change with increasing age?
  4. How do hormonal patterns differ in comparison to parous females?

My research on cycling (parous) mountain gorillas may answer these questions:

  1. How does mating behavior relate to ovulation in parous females?
  2. How does mating behavior differ between one-male and multimale groups?
  3. How does mating behavior differ depending on whether the male is dominant or subordinate?
  4. How do patterns of mating solicitations (by the male or female) and potentially coercive behavior (aggression and displays by the males) vary according to reproductive status of the females?
  5. How do female hormone profiles vary in relation to the age of their dependent offspring, age of the female and proximity to conception?

Help Sosthene Habumuremyi become the first Rwandan to receive a PhD in Primatology

» learn more

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AuthorSosthene

189 gorilla pregnancy tests

By Sosthene Habumuremyi

The overall goal of this study is to investigate the hormonal correlates of socio-sexual behaviors in female mountain gorillas. Specifically, we want to understand the variation observed in mating strategies and fertility parameters among female mountain gorillas. By using hormonal data, we want to know if this variation is governed by internal stimuli. For a detailed analysis, we formulated multiple research questions, centered around different reproductive status of females. We selected our target individuals from nine gorillas groups monitored by Karisoke Research Center. In the field, we have been simultaneously collecting behavioral data as well as urine and feces samples.

Following the end of the field work, we’ll carry out the endocrinological measurements in the laboratory at the Max Planck. The results of this study will characterize the specific behavioral patterns around the time of ovulation in mountain gorillas, specifically mating behavior, patterns of mating solicitations, and any evidence of coercion (aggression) by the silverbacks directed towards the females. Furthermore, we will search for evidence of pregnancy losses. Also, we will provide additional information on adolescent sterility and sexual swellings in female mountain gorillas. The results of this study contribute to our understanding of fertility in gorillas, which is useful information for understanding the potential for the population to increase. Moreover, we hope that this research will help to provide useful information on the evolutionary profile of reproductive behaviors in primates.

Help Sosthene Habumuremyi become the first Rwandan to receive a PhD in Primatology

» learn more

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AuthorSosthene
Rodrigo Lacruz

Rodrigo Lacruz

In this episode of Dig Deeper, we ask Rodrigo Lacruz seven questions about his area of research. Rodrigo is a Research Associate at the Center of Craniofacial Molecular Biology in the School of Dentistry at University of Southern California, Los Angeles.

His area of expertise involves the dental development of early hominids. Rodrigo discusses how teeth are not unlike trees - giving away our age with microscopic lines much like arboreal growth rings. He also talks about the heartbreak of research equipment failures and a certain magic the number 6 holds for him.

Dig Deeper - a podcast produced by The Leakey Foundation

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AuthorBeth Green

In November, Stanford University and UC Berkeley were home to the 12th Annual Bay Area Festival of Science, aptly named Wonderfest. Two Leakey Foundation Grantees, Henry Gilbert, Assistant Professor of Anthropology at CSU East Bay and David DeGusta, former Assistant Professor of Anthropology at Stanford, were featured speakers. They jointly discussed how evolution has shaped our behavior today.

 

You can view the full program, separated into its individual chapters, at fora.tv

Through public discourse about provocative scientific questions, Wonderfest aspires to stimulate curiosity, promote careful reasoning, challenge unexamined beliefs, and encourage life-long learning. Wonderfest achieves these ends by presenting series of scientific events to the general public. At most of these events, pairs of articulate and accomplished researchers discuss and debate compelling questions at the edge of scientific understanding. For more information, visit Wonderfest.

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AuthorBeth Green
CategoriesIn the News

 

First Out of Africa

David Lordkipanidze

The site of Dmanisi, Georgia has produced surprising evidence for the early dispersal of hominids out of Africa. The remains are the first discovered outside of Africa and they represent a missing link between Africa, Asia and Europe.

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AuthorBeth Green

Jeffrey Laitman (Mt. Sinai School of Medicine) will be speaking at The Field Museum in Chicago, on October 9th, as a part of The Leakey Foundation's Speaker Series on Human Origins. Below is an article, written by Dr. Laitman, describing the moment he realized his interest in studying primates.

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The Magic of the Monkey House: New Insights Into the Anatomy that Makes Primates Primates Jeffrey T. Laitman Associate Editor,† | Article first published online: 16 MAR 2010 | DOI: 10.1002/ar.21131 | © 2010 Wiley-Liss, Inc.

De Brazza's Monkey at the Bronx Zoo Monkey House

The year 1958 began as a really horrible one for me. Two events made this so. The first occurred in the early spring when I realized that the Brooklyn Dodgers—our baseball team and the soul of Brooklyn—had abandoned us and fled to some bizarre place where people ate tacos instead of Nathan's franks and where it never snowed. Even their perennial nemesis—the New York Giants—left town for another unfathomable hamlet that was always having earthquakes. My almost 7-year-old mind could not fathom all this; the heroes I worshipped (Jackie Robinson often patted my little crew-cut head) were gone forever. I even became a Yankees fan.

My second crisis occurred before school ended in late spring. Our class had trip to the great American Museum of Natural History in Manhattan. I loved museum trips as I got to see dinosaurs, my second passion after the Dodgers. Tyrannosaurs, triceratops, hadrosaurs, I loved them all, but none more than the brontosaurus. I adored the big beasts with little heads, so much so, that I could not help but go under the ropes to climb on one's tail to get “up close and personal.” Caught in this act of defilement by a Goliath-sized museum guard, I was hauled off by the scruff of the neck (those were the days before “spare the rod” philosophy was in effect) and ejected from the Museum. My teacher banned me from future trips.

Ejected and branded (all but a scarlet letter emblazoned on my forehead) in my seventh year. To make matters worse, I had no project to write up for my school report; no postcards of dinos or stuffed grizzlies or meteorites to glue into a folder. I was sure the dreaded—and oft threatened—“summer school” would be my fate. And worst of all—what would I tell my mother? Oy!

As I sat on the front steps of our Brooklyn home, watching the other kids play stickball or marbles, I pondered the enormity of my failure. Lost in my melancholy, I didn't notice my father come home. I was glad he saw me before my mother as she was the disciplinarian and he a gentle Parisian who would say something I didn't understand in French and not get too angry. When I explained what happened, he just said he had an idea, and I should get up early on Sunday.

When Sunday arrived, my dad bundled me into our old Chevy and set off…to the Bronx Zoo. “Forget the dead animals,” dad said, “let's look at live ones.” This was my first time at the Bronx zoo and I was riveted to all the sights and sounds, but, truthfully, nothing set my heart to flutter. The elephants were big, but smelled foul; the seals and sea lions looked and sounded like dogs; the rhinos reminded me of garbage trucks; I was scared of cats the size of small cars. And then I saw a sight that would forever change my world: The Monkey House.

I sat and stared at the assortment of baboons and macaques and squirrel monkeys for most of the day. While I had seen some stuffed ones in the Museum, I never realized that these animals looked and acted so much like my family and friends. I even started to name them in my mind after relatives: there was Aunt Flo, big and bossy; Uncle Joe, snoozing away; Cousin Richie, climbing all over his brother Irwin, on and on. They had hands and fingers and toes that seemed to do all that I could do, and I envisioned them talking together and planning their day. And then it happened: as I pondered my new hairy family, a wad of poop landed smack on my crew-cut head, thrown by some impish baboon. “Wow!” my shocked little mind took a moment to cogitate, “Poop! They hit me with poop! These guys got attitude; they are definitely cool. They could make it in Brooklyn.”

A bond was forged that day between those poop-throwing cousins and me, one that has led me on my own career path: to understand our place among those remarkable relatives. Like most of us who spend our days trying to figure out why we pay taxes and these relatives don't, or how their historical trajectory landed them in the zoo and we were able to enjoy (albeit momentarily for some) the excitement of pondering dinosaurs at a museum, I'm always torn between my scientist's focused curiosity to discover the nuances of our collective anatomical similarities and a profound adoration for these kin. I know it might sound a tad odd to those whose science keeps them at some emotional distance from their object of study (I know you can't get too emotional over a zebrafish, drosophila, or an endoplasmic reticulum), but one of the traits I've found shared by primate biologists—anatomists, paleontologists, anthropologists, lab and fieldworker alike—is our emotional ties to the animals we study. There is undisputable joy in our science, but it is also inseparably coupled with an overriding knowledge that we are studying ourselves.

That fusion of scientific exuberance and “looking-in-the mirror” curiosity has been captured in this month's special issue of The Anatomical Record, “From head to tail: New models and approaches in primate functional anatomy and biomechanics,” guest edited by Jason Organ, Valerie DeLeon, Timothy Smith, and Qian Wang (Organ et al.,2010). This quartet of energetic primates collectively brings to our intellectual forest a robust array of knowledge and insights into cutting edge research on our closest relatives, empowering this issue to cover advances literally from top to bottom. Knowing these, now mature scientists from their intellectual pubescence as graduate students, I've watched their own fine work on tails and skulls, noses and teeth, help redefine our understanding of primate functional anatomy. These guest editors have traveled their own interesting, individual paths to find their love for our cousins: Jason planned on putting his Hebrew school training to good use as a biblical archeologist (his parents were probably so proud!); Valerie, ever the erudite scholar, enraptured by unraveling the intricacies of medieval European history, chartered a career as a field archeologist (and even managed to squeeze in a Law Degree and a stint as a tax attorney in the middle of all that; think of all the money she could have had!); Tim, a true heir of Da Vinci, had an art school background that sharpened his mind to see anatomy in extraordinary ways (not to mention producing outstanding artwork on primates in the process; see, e.g., Burrows and Smith (2003), and the beautiful covers of that issue and this special issue as well); and Qian, whose eight-year old mind was set afire with wonderful and wondrous visions through reading a lay book on primates by the great Chinese anatomist and paleontologist Ju-kang Woo (who, I was fortunate to know and communicate with often throughout my own career.) No matter what their original plans may have been, they all heard the “call of the wild,” so to speak, and were inextricably drawn to search for the Holy Grail of understanding primates.

For those among us that don't cohabitate a primatologists tree, a few words should be said about who primates are and why some of us go gaga over every third molar, tail bone, or nasal concha they possess. While some will argue incessantly that whales are brilliant, felines have consciousness, bees have grammar, or cockroaches will outlive us all (particularly the New York ones; I think I saw one last week with biceps), lets face facts, there's only one sheriff in town, and it's us. This was unambiguously recognized by Linnaeus (1758) who crowned us as “the first” or the “Primates” (spelled with a capital “P” and pronounced “pri-MAY-tees” only when used as the proper noun). To be fair, it is not always clear who has the primate credit-card and who doesn't, and this little point of contention has produced some pretty good arguments over the years (see classic reviews in Szalay and Delson,1979; Martin,1990; Fleagle,1999) Generally speaking, however, our Order consists of: the great (chimps, gorillas, orangs) and lesser (gibbons and siamangs) apes (rumor has it that gibbons at the Bronx zoo are protesting this condescending term; they have received support from “pygmy” chimpanzees and the “killer” whale lobby); monkeys (both Old World ones from Africa and Asia, and New World ones from the Americas); and a generally less well-known group, the prosimians, that include an assortment of lemurs from Madagascar, tarsiers, lorises, galagos, and the little tree shrews. This latter collection has sometimes been derogatively called “lower” primates due to their retention of somewhat more “primitive” features and the public's general lack of familiarity with them (although the “Madagascar” movies have made megastars out of species previously unrecognized outside of zoos.)

In addition to all the living primates listed above are all of our collective parents, grandparents, and relatives going back to the days when we all scrambled around as quasi-bipeds on the savannas of eastern and southern Africa. Indeed, for many of our ilk, the hunt to define a primate is inextricably tied to trying to figure out exactly who Homo sapiens is, and how our particular clan came to be. While arguments have existed aplenty as to who can claim inheritance to the primate lineage, they pale in comparison to the cataclysmic wars that have ensued regarding who is invited to sit at the “grownups” table of our own species. I have seen Distinguished Professors and members of national academies almost come to blow at anthropological or paleontological forums when the preeminence of their cherished fossils (or sacred ideas) have been challenged [to get an idea of the extent of the anger and combativeness that can surround studies on human origins, see the chapter on “Johanson versus the Leakeys” in Hellman (2007)]. To put things in perspective, disagreeing about the importance of someone's fossil is the equivalent to calling their baby “ugly”; go there at your own peril. In the paleoanthropological world, no one gets stars for having the second most important fossil; “close” only counts in horseshoe throwing, not in hominid phylogenetics. At its core, every study of primates, somewhere, somehow, addresses an issue of our own species trajectory.

Pooling their collective energies and interests, our editorial quartet have put together an excellent array of hypothesis-driven science that presents the latest in techniques and approaches searching for those elusive elements that make primates, well, primates. In true comparative mode, the work herein spans the spectrum from modeling studies using nonprimate mammals to examination of humans, with members of our brethren from little bushbabies, to South American monkeys, to baboons, to apes, all making appearances. And the nooks and crannies that are investigated would warm any comparative primate anatomist's heart. Studies take us from prosimian shoulder morphology to the inside of galago noses, from how South American monkeys got their tails to how our weight bearing long bones came to carry their weight. For those among us who are cranial cognoscenti, there are many studies to warm our bones, assessing various aspects of teeth, mandibles, and assorted crevices of the face and vault.

As noted above, the quest for insight into the nature of human origins and human anatomy weaves its way through many studies. Some directly tackle the issue by investigating adaptations and biomechanics among groups of ancestral hominids such as Plio-Pleistocene Australopithecus or enigmatic near-relatives such as the ever-pesky Neanderthals. Many other studies integrate their findings on specific topics with aspects that humans share with other species, or how humans may display autapomorphic features (uniquely derived traits) in these regards. Observations are often tantalizing, and readers will have much to chew on.

Of particular interest to those of us primates whose age is starting to show in our temporal regions, is the potency and diversity of the methods employed in these studies. Our field—and here I refer to primate comparative anatomy and its subsets in aspects of physical anthropology—has come a long, long way from simple calipers measuring a few craniometric points. Don't get me wrong, lumps and bumps have been my bread and butter, and I love my calipers dearly (I also loved my slide-rule—any of you remember these?), yet, we have come a long way from relying solely upon gross dissection or linear measurements. The potency of new technologies, sometimes alone sometimes melded with the strength of the old, can be seen throughout this issue. Indeed, the power of experimental approaches to anatomy, new microanatomical techniques, kinematic and kinetic biomechanical approaches, high-resolution computed tomography (CT), or assessment via Finite Element Modeling and analysis are some of the arrows in the quivers of the cutting-edge papers offered in this special issue. The power of the future is clearly put forward.

“Get off the fence kid,” bellowed the Bronx Zoo guard, “no leaning on the rail.” “I wasn't hurting anything, Mister, just trying to get a closer look at the monkeys,” I tried to explain. “Didn't ya hear me, kid!?” Goliath roared, “I said get your butt…” At this exact moment—forever given a hallowed place in my mind's eye—a wad of poop landed smack in the middle of his bulbous Bronx nose. The zoo guard ignominiously retreated, spewing forth a cacophony of words I was told never to use. It was the perfect ending to the perfect day.

Oh, by the way, I never told my mother what happened at the museum. There was no need to, as I got the highest grade in the class for my report: The Magic of The Monkey House.

Literature Cited

Burrows AM,Smith TD. 2003. Muscles of facial expression in Otolemur, with a comparison to Lemuroidea. Anat Rec 274A:827–836. Direct Link:  Abstract |  Full Article (HTML) |  PDF(578K) |  References

Fleagle JG. 1999. Primate adaptation and evolution. 2nd ed. San Diego, CA: Academic Press.

Hellman H. 2007. Great feuds in science: ten disputes that shaped the world. New York: Barnes & Noble.

Linnaeus C. 1758. Systema naturae per regna tria naturae, secundum classes, ordines genera, species cum characteribus, differentris, synonymis, locis. Editis decimia, reformata. Stockholm: Laurentii Salvii.

Martin RD. 1990. Primate origins and evolution. A phylogenetic reconstruction. Princeton: Princeton University Press.

Organ JM,DeLeon VB,Wang Q,Smith TD. 2010. From head to tail: new models and approaches in primate functional anatomy and biomechanics. Anat Rec 293: 544–548. Direct Link: Abstract |  Full Article (HTML) |  PDF(63K) |  References

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This article first appeared in The Anatomical Record: Advances in Integrative Anatomy and Evolutionary Biology Special Issue: From Head to Tail: New Models and Approaches in Primate Functional Anatomy and Biomechanics Volume 293, Issue 4, pages 541–543, April 2010 The Magic of the Monkey House: New Insights Into the Anatomy that Makes Primates Primates Jeffrey T. Laitman Associate Editor, Article first published online: 16 MAR 2010 DOI: 10.1002/ar.21131 Copyright © 2010 Wiley-Liss, Inc.

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AuthorBeth Green
Nate Dominy, Dartmouth

Nate Dominy

In this episode of Dig Deeper, we ask Nate Dominy seven questions about his area of research. Dominy, who is a Leakey Foundation Grantee, recently accepted the position as Associate Professor in the Department of Anthropology at Dartmouth, where he will focus on evolutionary and behavioral ecology of humans and non-human primates. Before his new position at Dartmouth, he ran The Dominy Lab at University of California, Santa Cruz, which included a specific emphasis on sensory and foraging ecology.

Some of his recent projects include:

Dig Deeper - a podcast produced by The Leakey Foundation

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AuthorBeth Green

In partnership with The Department of Expansion, The Leakey Foundaiton has launched a series of four short films.

Today, on scientificamerican.com, Leakey Foundation friend Frans de Waal wrote an article for the Guest Blog, with accompanying short film "The Bi-Polar Ape." This film is part of a four part series on human behavior and evolution.

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AuthorBeth Green