Archive for the ‘Non-human Primates’ Category

ResearchBlogging.org It creeps in the night.  Where it lives, it is considered the harbinger of death and doom. One of the hypotheses for how it obtained its name is from European travelers seeing it and shrieking loudly. Folk legends say it creeps into the houses of unsuspecting locals and digs its elongated finger into the chest to pierce the heart of the slumbering individual. Its fear of humans is almost non-existent, a curious nature that fuels it to come up to humans and examine them further–but is it for the purpose of causing death?

The aye-aye (Daubentonia madagascariensis) in the wild. (Photo via: World Wildlife Fund)

Not if you’re a human. The aye-aye (Daubentonia madagascariensis) is far from a violent primate–unless you happen to be an off guard grub; the “claws” it has are not sharp enough to pierce through human flesh, at least, not beyond a superficial wound. The aye-aye, at first sight, may not be considered aesthetically pleasing to some. But what it lacks in visual appeal, it makes up for in unique, useful qualities.

The fingers of an aye-aye; notice the elongated middle finger. (Photo by: David Haring)

Much like children at Halloween who knock on doors for treats, the aye-aye uses its aforementioned, elongated middle finger to percussive tap on wood cavities. Then, using its large ears and the touch of the percussive foraging, locates the prey. Next, it uses ever-growing incisors to chew through the wood and relies on its elongated middle finger to pierce and dig out the grub (Lhota et al. 2008).

Because of this foraging method, the aye-aye is culturally regarded as a superstitious creature. The only way to remove the bad luck perceived to come from its presence is to kill it, and potentially, consume it (Simons & Meyers 2001). However, there are also certain regions in southeast Madagascar that perceive the aye-aye very differently–because of its status as an origin for the human race, it is considered as a good luck figure (Sterling & Feistner 2000).

Currently, the aye-aye is considered a Near Threatened species according to the IUCN (2008). While this primate is feared in some cultures, revered in others, it also plays a vital role in its habitat. Much like woodpeckers, aye-ayes serve an ecological niche of preventing insect infestation into wood, keeping it healthy.

Although not a pretty primate, more like the rats that you’d expect to find around a witch’s cauldron, the aye-aye plays a very strong ecological role in maintaining the health of the trees of the forest by consuming potential infestations. Even though it is seen as bad luck to one culture and good luck to another, when the aye-aye comes to “trick-or-treat”–it will never be in a human chest, but in a tree trunk.


Andrainarivo, C., Andriaholinirina, V.N., Feistner, A., Felix, T., Ganzhorn, J., Garbutt, N., Golden, C., Konstant, B., Louis Jr., E., Meyers, D., Mittermeier, R.A., Perieras, A., Princee, F., Rabarivola, J.C., Rakotosamimanana, B., Rasamimanana, H., Ratsimbazafy, J., Raveloarinoro, G., Razafimanantsoa, A., Rumpler, Y., Schwitzer, C., Thalmann, U., Wilmé, L. & Wright, P. 2008. Daubentonia madagascariensis. In: IUCN 2011. IUCN Red List of Threatened Species. Version 2011.1. <www.iucnredlist.org>. Downloaded on 26 October 2011.

Lhota S, Jůnek T, Bartos L, & Kubĕna AA (2008). Specialized use of two fingers in free-ranging aye-ayes (Daubentonia madagascariensis). American journal of primatology, 70 (8), 786-95 PMID: 18473358

Simons, E.L. & Meyers, D.M. (2001). Folklore and beliefs about the aye-aye (Daubentonia madagascariensis). Lemur News, 6: 11-16.

Sterling, E.J. & Feistner, A.T.D. (2000). Aye-aye. In: Reading, R.P., Miller, B. Ed. Endangered animals, a reference guide to conflicting issues.

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The night before I came to the reserve, I was up at 2:30am, looking at the clock in a cockroach-laden hotel thinking to myself: what if I didn’t like the lemurs? I didn’t expect to be empowered. And I definitely wasn’t certain if primatology was for me after all. What was I going to do if this didn’t work out? Aside from being out at least a good chunk of money that could’ve been spent on a large student loan.

But I do, I am, and I have never been so certain of anything in my life. Much like how I stumbled into primatology by taking an introductory anthropology course to satisfy a general education requirement, I fell face first into my new favorite species. When I came, I wasn’t sure about lemurs all that much; my prior education had been composed of mostly new world monkeys and a brief research stint with some rhesus macaques.

At first, I thought the mongoose lemurs were incredible. My first experience with them was in the form of the female leaping onto my shoulders and crawling about as if I were a walking island for her convenience. Over time, it’s not that I didn’t love them–I do, but my heart was more violently gripped by another species, the ones I was the least sure of–the ring-tailed lemurs.

Ansell and Harp, two ring-tailed lemurs (Lemur catta).

Their personalities were so pronounced; there was the dominant mother, Ansell who wasn’t afraid to cuff her subordinate males, Sam and Adam. Sam, who was initially described as “pathetic,” quickly rose to one of my favorites. Whenever I’d watch Sam, I’d always catch his eyes watching me–perhaps I’m anthropomorphizing, but one of the girls suggested he was the most cognizant of the lemurs, and I’d have to agree. Whenever I’d be following him as my focal, he wouldn’t venture too far forward without stopping and waiting for me to catch off before darting forward a little bit or foraging. Then, there was Molson, one of the sweetest lemurs I’d ever seen in the other forest. Initially, Stella, the lady-like lemur (who always had her legs crossed while eating and her tail covering her ladybits) bored me.

And then a rattlesnake made itself present in front of me and my colleague. While I was following Stella, curious as to why she was walking so slowly and grunting repeatedly before standing on her hind legs, the infamous rattle was heard and obeyed. We quickly backed off–but not Stella. No, Stella was not having a snake in HER forest that day. Instead, she stood up to the snake with her hands out and growled right back at the hissing as Molson looked on at her.

Moments like that with the lemurs made me come to love them and even more upset to be having to leave them. I have three days left and I intend to make the best of it. I have plenty of pictures to remind myself of all of them–even the pesky red ruffed lemurs who were not afraid to crawl right up to me and sniff my feet. Nor the Sanford’s lemurs who had completely ignored the rattlesnake, but lost it at the sight of a raccoon.

I’ve heard many a time about how you can recognize yourself through an ape’s eyes and all of the tropes along with it, but for me, I’ve never felt more connected to my primate self than working with these lemurs and getting to know prosimians. I’m not knocking the appeal of apes or any other primate, but truly–this experience with lemurs has been the most personally rewarding primatology experience I’ve had this far and reinvigorated my passion for primatology tenfold.

I’m not sure what the future holds for me in terms of graduate school, but I think I would like to one day work with lemurs again.  When I leave, I know I’ll be empowered thanks to my time here with the lemurs–I can identify a lemur by sight, even some of the red ruffeds without the collar. I can handle being out in a field for hours at a time and I can do this. And for that, I have lemurs to thank.

Veloma, my lemur friends–but not for good.

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A red ruffed lemur (Varecia rubra) lazing about. (Photo by: CCH)

It wasn’t my intention not to update, but over the past two weeks I’ve been busy in training and preparing to start data collection. I’ve passed all the inter-observer reliability tests and safety training, so I’m ready to go! Because neither of those are particularly interesting, I figured I would hold off on updating until I could get to the more exciting things. I swear I haven’t been entirely like the red ruffed as seen above. Lazy lemur.

Since I’ve been here, I’ve learned an important lesson in “killing your darlings,” and truth be told, it’s worth it. From the ethogram I originally designed to the actual project itself, I’ve cut out a lot of things since coming up with the plan and it’s been for the better. If there is anything I wish for people, it’s that they have someone who’s good at cutting the excess from projects, proposals, and other things like I’ve been lucky enough to have. Originally, I had a two page ethogram–which was cut down to essentially food-related behaviors and then five others. In doing so, it maximizes the time in which I’m able to collect data.

I’ve been learning a lot about lemurs too. For example: red ruffed lemurs possess a sufficient amount of knowledge to distract a researcher and attempt to steal things. They tend to work in teams when they do this. Mongoose lemurs are also particularly good at catching you off-guard as well and will exploit this in order to have a free ride from one tree to the next, with a “human island” in between. For anyone that suggests lemurs are not intelligent, they clearly have never worked with a lemur before. I’m also surprised about how much I’ve come to really like ring-tailed lemurs, as well. It’s not that I thought I would dislike them, but I expected to be more ambivalent. Instead, they have quickly become my favorites and the ones I’m most excited to watch. The ones here are very diverse in personality; there are three that are particularly aggressive and there are also a few you will have to find yourself tracking in between scans just to ensure a healthy distance, lest you desire a small lemur paw touching your tripod chair. (And of course, we don’t want that because it manipulates behavior and data you’re trying to collect.)

The differences between here and La Suerte are particularly notable. Aside from the obvious of living in America still versus Costa Rica and the privileges and drawbacks of both, and that the primates here are still captive (even if semi-free-ranging) compared to wild, there’s a large difference in just walking around the field. For example, in La Suerte, I was most concerned about eating enough to sustain the forest walks, being able to breathe in a smaller forest due to allergies, and just being able to see the primates. Whereas, here, I’m more concerned about faceplanting into a massive spider’s web and attempting to avoid getting destroyed by mosquitoes (I found it more tolerable in Costa Rica, however, I invested in 100% DEET lotion versus the 35% DEET bug spray I use here), ticks, and fire ants. When I worry about potential diseases, I was never worried about malaria (the area in which La Suerte is located has not had a case of malaria in some time, to my knowledge), though I was terrified of having rabies (due to an incident of waking up with a dead bat in my bed). Here, I’m anxious about West Nile virus, encephalitis, and lyme disease.

But there are a lot of similarities too: attempting to avoid stepping on or nearby snakes or other wildlife, humidity and hydration are two major issues every researcher endures, and in the mornings, the red ruffed and mongoose lemurs can be particularly difficult to identify while 15m+ (or ~49+ ft.) in the air.

I don’t think I’d trade anything else in the world for this, though. If anything, this experience has really emboldened me and convinced me this is the field I was meant to be in and makes me voracious to learn more about primates–be it lemurs or any other species. As such, I’ve been doing a lot of work researching graduate schools in my down time. I’ve been contacting professors left and right (so far, I’ve had either positive responses or none at all–a good sign, perhaps?) and I’m doing some of my statements of purpose now so I can get more revisions in and make them better before applying. My goal is to have five programs picked out by the end of the next two weeks so I can contact letter of recommendation writers. So far, I have 3/5 and I’m looking into a few more to close that gap and get moving on.

Field work is different depending on where you go and what you intend to study, but there are some consistencies that are particularly rewarding. In what other career path could I say I watched lemurs run and tackle each other for twenty minutes?

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I didn’t understand the value of hunting until I was 10 years old. I never had an opinion on it either way, but I could never understand why someone would just want to go out and kill an animal. It wasn’t until I was watching my dad, uncle, and cousins sit on their porch and spy a white-tailed deer in the backyard. Where we live, these deer are common. Not exactly habituated, but it’s common practice in more rural areas to provision them with salt licks and feed; if nothing else, to get a good look at them while you’re looking outside and basking in the northern Midwestern landscape.

On this particular night in late-autumn, celebrating my birthday with my cousin, they had spotted a deer eating from the salt-lick. It was a male and he had a gorgeous set of antlers–I can’t recall how many points, but enough to make my uncle and cousin jump from their seats and slowly creep towards where they had a small gun stowed. Carefully, my uncle opened the door and a loud pop! sound later, the deer ran off. He had missed, but afterwords, I looked at my dad and asked, “Why’d he shoot the deer? It wasn’t eating his garden or anything.”

“The deer population this year is high; if we don’t hunt, they’ll cause a lot of trouble for us and themselves.” He stated, matter-of-factually. I didn’t understand what it meant at the time, as I dropped the subject in lieu of birthday cake, but as I grew older–I understood. Without hunting, the populations would rise to unsustainable levels; more deer would mean less available food when resources were already scarce in the winter months and potentially lead to more dangerous accidents for drivers, as my aunt and grandmother both experienced first-hand years later. But, at the time, I understood more why it would be dangerous for us–which later gave me enough curiosity to understand why it would be bad for “them.”

Yesterday, Dr. John C. Mitani of the University of Michigan wrote an opinion article on the endangerment and potential extinction of both lesser and great apes. In it, he brings up a multitude of reasons for saving great apes from behavioral quirks, the primate heritage, and drawing connections between human primates and non-human primates. He even points out that politicians in Congress have put aside party differences in being able to provide conservation aide for apes. It was well-written and provided a bevy of reasons in which people should consider taking action to provide great apes with the aide they require in order to maintain populations and mitigating anthropogenic effects.

While there is nothing I would contest against what Dr. Mitani says, it’s what he doesn’t say that’s most interesting to me (which, could also have been removed due to editing or other reasons–I’ve had my share of time in journalism and I understand that not everything written goes to print). And this is something I’ve noticed before when people talk about conservation and taking action.

A critically endangered Sumatran orangutan (Pongo abelii) and a caretaker at Bukit Lawang (Photo from: WikiMedia Commons)

For me, before I had been given an education in conservation, to understand the importance of doing so was best expressed in a practical, utilitarian format–how conservation tactics (like hunting) provided benefits to both humans (in terms of safety) and wildlife populations (in terms of sustainability).

I believe it’s possible to foment interest in conservation by using the anthropogenic hook and then using primates as further bait to take action. Harcourt et al. (1986) discovered that knowledge about wildlife species was a critical factor in attitudes about wildlife. Furthermore, negative perceptions of conservation are driven through a lack of education in how it can affect both wildlife and humans (Fiallo and Jacobsen 1995). In knowing that we are also great apes and share a heritage, why are we apt to leave ourselves out of this equation? Particularly when helping ourselves is one of the best things we can do for our evolutionary lineage. Kofi Annon, Secretary General of the United Nations once wrote:

Saving great apes is about saving people. By conserving the great apes, we can protect the livelihoods of many people who rely on forests for food, clean water, and much else. Indeed, the fate of the great apes has both practical and symbolic implications for the ability of human beings to move towards a more sustainable future.

In addition to the effects helping humans can have on non-human primates, in turn, non-human primates have an effect on us. Recently, it was discovered seeds ingested and passed through orangutan (Pongo pygmaeus wurmbii) guts in addition to being spat out can remain viable and germinate (Nielsen et al. 2011). Given that orangutans can consume around 118 species of fruiting plant and a large day range, orangutans can disperse seeds throughout a great range in the Sumatran rain forest, potentially providing more future fruit trees for both human and wildlife consumption (Nielsen et al. 2011).

When written like that, the purpose for conservation changes: not only does conserving apes help the environment, but it helps others–including us. Humans nor great apes exist in a vacuum; we frequently co-exist and affect each other. But maybe that’s where the discomfort and hesitance in using a more utilitarian approach lies.

I understand the utilitarian format is not without potential problems: in approaching ape conservation from a “What can it do for us?” perspective, we can run the risk of focusing only on anthropogenic needs rather than the needs of both.

I also realize thinking about just ourselves is part of the issue. I’m not sure if I believe the trope that humans are inherently selfish and the like; and definitely, there is a sense of greed that needs to be addressed. But if we need to be taking action immediately, why aren’t we willing to combine the two more frequently when we talk about conservation if it means it will change perceptions and get people to act?

Regardless of thoughts on human influence, we are a part of ecosystems all over the world, for better or worse. I welcome any readers to share their thoughts on this subject.


Fiallo, E.A. & Jacobsen, S.K. (1995). Local communities and protected areas: attitudes of rural residents towards conservation and Machalilla National Park, Ecuador. Env Conserv, 22: 241-249.

Harcourt, A.H., Pennington, H., & Weber, A.W. (1986). Public attitudes to wildlife and conservation in the Third World. Oryx, 20: 152-154.

Nielsen, N.H., Jacobsen, M.W., Graham, L.L.L.B., Morrogh-Bernard, H.C., D’Arcy, L.J., & Harrison, M.E. (2011). Successful germination of seeds following through orangutan guts. J Trop Ecol, 27: 433-435.

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This post was chosen as an Editor's Selection for ResearchBlogging.org By now, I know of few people who haven’t seen the movie, Mean Girls. But in case you haven’t, here’s what you should know about it: the story is essentially an explanation of social cliques and aggressive teenage girl behavior. As a study recently published in Behavioral Ecology suggests, this agonistic behavior between females in cliques is not exclusive to human primates, but is found in our non-human primate kin as well.

Over 18 months and 1027 interactions, Huchard and Cowlishaw (2011) discovered a correlation between sexually receptive female baboons and female-female aggression in groups. In female baboons, sexual receptiveness is typically a period in which individuals are estrous, or “in heat.” A way in which a female can display this information is through sexual swellings, or a swelling of the perineal skin, which indicates ovulation. Additionally, females with wider sexual swellings are perceived as “sexy,” as they attained sexual maturity earlier and generally have more offspring that survive (Domb and Pagel 2001).

A female baboon in estrus--the baboon version of Regina George? (Photo from: WikiMedia Commons)

With that in mind, enter female-female competition. Female-female competition is thought to occur more often under circumstances where resources for success in reproductive factors might be limited: for example, yielded access to food resources inhibits successful gestation or production of milk or helpful mates that provide more access to resources through social rank.

In the study performed by Huchard and Cowlishaw, sexual receptiveness was perceived to be the driver of aggressive behaviors as sexually receptive females received the most aggression, while lactating mothers received the least. It is thought this might be a tactic to delay conception; thus, females who have already conceived or have offspring would be more likely to receive access to resources and thereof prevents competition. Females who eat less (or would have limited access to food resources) also tend to have less reproductive success (Altmann and Alberts 2003). In addition, it is also possible by inflicting the cost of aggression onto sexually receptive females, the stress may make it more difficult to conceive or support a pregnancy (Beehner et al. 2006). Therefore, by being aggressive to these sexually receptive females, pregnant females or females who have offspring are conserving their resources and limiting the competition.

While no reports of any baboons getting thrown in front of buses have been reported yet, if it does happen—be sure to check the sexual swelling for the baboon version of Regina George.


Altmann, J. & Alberts, S.C. (2003). Intraspecific variability in fertility and offpsring survival in a non-human primate: behavioral control of ecological and social sources. In: Wachter KW, Bulatao RA, editors. Offspring: human fertility behavior in a biodemographic perspective. Washington (DC): National Academy Press; p. 140-169.

Beehner, J.C., Nguyen, N., Wango, E.O., Alberts, S.C., & Altmann, J. (2006). The endocrinology of pregnancy and fetal loss in wild baboons. Hormones and Behav, 49: 688-699.

Domb, L.G. & Pagel, M. (2001). Sexual swellings advertise female quality in wild baboons. Nature, 410: 204-206.

Huchard, E., & Cowlishaw, G. (2011). Female-female aggression around mating: an extra cost of sociality in a multimale primate society Behavioral Ecology DOI: 10.1093/beheco/arr083

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Yesterday morning, I woke up at 5am to winds at a high speed. About thirty seconds later, there was a torrential downpour. A minute after that, tornado sirens rang. In the course of three minutes after the alarms, my significant other and I had gotten up, put on suitable clothes and shoes, corralled the cats into their carrier, and booked it downstairs to the first floor of our apartment.  Fortunately, not much came of it and both of us came up within fifteen minutes. While nothing happened, my general instinct was to go to the area in which we would be the safest.

This is an instinct we share with multiple animals, but particularly so with our evolutionary ancestors.

A few weeks back, a chemical explosion occurred in a chemical plant near the New Iberia Research Center, a primate research institute which contains 360 chimpanzees and 6,500 new and old world monkeys.  While the wind blew the smoke north, rather than west closer to the primate research center, individuals outside the facility could feel the strong heat.

The researchers also noticed an interesting reaction from the primates as the incident occurred; the rhesus macaques housed outside were quick to drop from their perches for enrichment and get as close to the ground as possible to avoid overheating.   According to the director of the facility, Thomas Rowell, “The animals nearest the incident were down at the bottom of the cages, eating and milling about. The intensity of the heat, if you were standing … was overwhelming. At ground level, there was little, if any heat. They were smart enough to squat on the ground and not expose themselves to the intense heat.”

While there have been no signs of stress or illness, staff will be monitoring the primates to ensure individuals weren’t exposed to chemicals from the plant.

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ResearchBlogging.org With great sadness, I write about the passing away of Japanese primatologist, Professor Toshisada Nishida. Nishida studied chimpanzees (Pan troglodytes schweinfurthii) and was considered the leading scholar on the Tanzanian chimpanzees in the Mahale mountains. While he was known for his work on chimpanzees, he was also known for his work on studying Japanese macaques, red colobus monkeys, and bonobos.

Nishida was one of the trailblazers of Japanese primatology. In addition to having the second longest running field site at Mahale, he was known for being the first Japanese primatologist to be published in a western journal (Nishida 1973), and authoring the first Japanese primatological research report in a non-Japanese primatology journal (Nishida 1976). Furthermore, he is credited with training an entire generation of Japanese primatologists (Mitani, McGrew, & Wrangham 2006).

In tribute to Nishida’s lifelong pioneering work, John Mitani, William McGrew, and Richard Wrangham (2006) wrote a beautiful article detailing Nishida’s contributions to primatology. In it, they mention the importance of his work for establishing quantitative analysis for primatology, clarifying social structures of chimpanzees, and during a period of time when it was believed that chimpanzees were largely nomadic with a lack of boundaries defined by communities, he provided data and support to constitute that chimpanzees lived in very specific social groups with variations in party size and composition, and with female members transferring between these groups. All of these findings have helped not only determine behavioral ecology of chimpanzees, but also provide a potential framework for early human ancestors.

Toshisada Nishida and the chimpanzees of Mahale (Photo by: International Primatological Society)

Through Nishida’s research, we have learned a significant amount of information about chimpanzee social behavior and characteristics which may explain some human behaviors. For example, in an anecdotal report, an adult male chimpanzee with morbidity symptoms similar to influenza was found using a stick to encourage sneezing and clear his blocked nasal passage (Nishida and Nakamura 1993). Even though anecdotal, Nishida & Nakamura were able to contribute to the addition of further evidence corroborating the advanced cognitive abilities of wild chimpanzees.

In another example, “leaf-clipping displays,” as Nishida wrote, were usually communication signals given by adult males to estrous females in a possessive manner, adolescent males to estrous females as a courtship behavior (or, conversely, estrous females might offer these leaf-clippings to adolescent males for copulations), or even to human observers for sharing food (Nishida 1980). To most, this probably means nothing–however, I would argue, don’t humans have behaviors like this? For example, it’s common on first dates for individuals to give flowers as a form of courtship, no? While I wouldn’t argue that example is an evolutionary behavioral characteristic, it is something shared between chimpanzees and humans and gives further reason to give empathy towards our evolutionary ancestors.

After all, a large part of Nishida’s ambition was dedicated to his desire to teach others about the value and wonders of nature. Given the nature of his work and the impact of his contributions to primatology, I believe his work and his proteges will continue to contribute to teaching others of the appreciation of nature and wildlife and the inherent value both possess. While I was never able to meet him in person, I find his work to be inspiring and him as one of the greatest figures of international primatology.

Mitani JC, McGrew WC, & Wrangham R (2006). Toshisada Nishida’s contributions to primatology. Primates; journal of primatology, 47 (1), 2-5 PMID: 16132169

NISHIDA, T. (1973). The ant-gathering behaviour by the use of tools among wild chimpanzees of the Mahali Mountains Journal of Human Evolution, 2 (5), 357-370 DOI: 10.1016/0047-2484(73)90016-X

Nishida, T. (1976). The Bark-Eating Habits in Primates, with Special Reference to Their Status in the Diet of Wild Chimpanzees Folia Primatologica, 25 (4), 277-287 DOI: 10.1159/000155720

Nishida, T. (1980). The leaf-clipping display: A newly-discovered expressive gesture in wild chimpanzees. Journal of Human Evolution, 9(2): 117-128.

Nishida, T. & Nakamura, M. (1993). Chimpanzee tool use to clear a blocked nasal passage. Folia primatologica, 61(4): 218-220.

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