Polyspecific Associations

When two separate species cross paths and interact with each other this phenomenon is known as polyspecific association. This is rare and often involves species of similar stature and food preference. The situations where the interactions occur must provide a benefit for at least one of the two species. These polyspecific associations can last from less than an hour to months! Most of the time both species experience higher levels of protection from predators due to their larger numbers. These cooperative survival missions that the allying species go on are reflective of the small habitat area that they must share if they want to occupy.

 

In the main textbook Strier elaborates on polyspecific associations taking place between saddle-back tamarins (Saguinus fuscicollis) and moustached tamarins (Saguinus mystax). These two species live in Brazil, Peru, and other South American rainforests. The smaller saddle-back tamarin has a multicolored saddle on it’s back, which is where it derives its name. The moustached tamarin has fall colors all over it: black, brown, orange as well as a lifestyle defining bright white moustache.

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In the Amazon they have reached a permanent polyspecific association. The moustached tamarin is physically much larger, this plays a role in how the two monkeys interact. By being around each other more often, these groups of tamarins can better foresee predator attacks. The two live in the same niche habitat, and forage together nearly everyday. The saddlebacks live in the understory, 4 meters or less of the ground; while the moustached tamarins frolic in the lower to mid canopy levels- 4 to 15 meters above ground. In this way during foraging parties they can both coexist peacefully without rubbing elbows. The moustached tamarins may be unaware in the ways that they are aiding their cousins below, by dropping insects and foodstuffs that the grateful saddle-backs readily consume. This shows that over time saddle-backs have realized that following their cousins to consume is very advantageous for them. It seems that saddle-backs are behind a number of shortcuts to food through exploiting their primate cousins, the next one I’ll delve into involves brush ins with marmosets.

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In the Primate Ethnographies text book Steve Ferrari divulges the polyspecific associations that occur between saddle-back tamarins and a rare species of marmoset (Mico rondoni). Marmosets are very talented at creating gouge holes in gum trees so that they can consume the sap as food. One day Ferrari saw a group of saddle-backs beeline for a gum tree that they had found to be pockmarked by marmosets earlier, probably the day before. The sap moves slowly, and only creates food sources about once a day, so the food supply is limited but also refills daily. Marmosets have adapted special teeth to gain the ability to create this pathway to the fruit of the gum tree. Somehow the saddle-backs realized this, Ferrari saw them swarming the tree consuming lots of gum very quickly. Then he observed marmosets (much smaller animals than the tamarins) come back towards the pockmarked gum tree, as this happened the tamarins departed. Ferrari said that he heard whimpering sighs coming from the marmosets, as they had been cheated out of the food that they created by the conniving tamarins. The gum was a fall-back food for the tamarins- who must have needed it because of a fruit shortage.

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Ferrari said that he thought of this situation as an undeclared competition war, and that it could potentially affect the wellbeing of the marmosets in that region. This represents a case where the unaware marmosets lost benefits from polyspecific association while the saddle-backs gained. In my understanding the saddle-back tamarins have become very good at utilizing other primates talents, they could be the executives of their niches.

References

Strier, K. B. (2013). Primate ethnographies. Upper Saddle River, N.J.: Prentice Hall. pp 139-149

Strier, Karen B. Primate Behavioral Ecology. Boston: Allyn and Bacon, 2000. Print.

Pictures via: zoochat.com , abher.net , allposters.com

Cognition

The readings and film Ape Genius point toward cognition being difficult to define and even more difficult to test. There are strange ways to study exactly what goes on inside of our primate friends’ heads, most studies aim to understand why they perform certain activities. These studies can be very important to understanding how human cognitive processes work, and why there are differences or divides between us and our primate cousins.

            Strier states that researchers look at three categories when measuring cognition. The first of these categories is learning and imitation. We first encountered learning and imitation in this class when discussing how Japanese macaques began washing their sweet potatoes after watching the one female in their society use that technique. Also imitation is the way that most young primates learn to eat, forage, and live their lives in general. They imitate their mothers during feeding and foraging times. This is considered a low level of cognition but it takes a high level of understanding cause and effect situations.

The second category is ecological intelligence: this details how primates assess their surrounding environment in terms of spatial memory and tool use. They evaluate their environment by remembering things like where to get food, and even where to get high quality foods versus low quality alternatives. Tool use is how primates utilize materials found within their natural environment for a beneficial action. Gorillas often create nests out of localized branches, twigs, and leaves. Aye-Ayes have adapted their ecological intelligence so that they use their middle fingers as tools to get food from trees. Strier also discusses tool-sets in the reading, these are two separate types of tools that are used in a sequence to complete a goal. Another term she discussed was tool-composites which is two or more tools that have completely different functions being used together to complete an action. Tool use behaviors aren’t simply used for gaining shelter or food though. Strier says that many arboreal monkeys throw branches to threaten or defend themselves, and gorillas have splashed water at one another as a part of social displays. Tool use really depends on what environment the primates live in, as well as their adaptive abilities to that environment. It definitely varies between populations.

            The third way to consider primate cognition is socially, Strier calls it social intelligence. It’s closely related to spatial memory because the primate must recall details about the situation that one finds them self in. In this situation though the details of their surroundings are more transparent and less physical, and require a deeper understanding of their fellow inhabitants. Strier says that because of social intelligence, primates may set a cognitive limit on group size. The most profound idea to me from this section is how primates negotiate their social relationships provides insights into how social interactions have shaped primate cognitive abilities. I think it’s truly amazing that primates distinguish between high and low rank peers, allies, and grooming partners. Also comparing between social organizations and seeing deep-rooted social differences can point towards the importance of setting to separate populations.

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           I found an article online about how Chimps have high-level cognitive abilities and social tolerance of peers. In the video I watched, a Chimp named Ayumu was tested by a memory test using numbers, he would memorize their sequence instantly. At just a glance their memorization skills are far superior to humans. The article also mentioned that chimpanzees are capable of cooperation, and in cooperative activities they possess social tolerance. Bonobos on the contrary don’t possess social tolerance according to this article. Above is a photo of Ayumu playing the memory test, and below is a link to a video of this feat.

http://bcove.me/6wccf8m0

References

Strier, Karen B. Primate Behavioral Ecology. Boston: Allyn and Bacon, 2000. Print.

Williams, Robyn. “ABC Radio National.” Radio National. ABC, n.d. Web. 08 Apr. 2014. <http://www.abc.net.au/radionational/programs/scienceshow/chimps-have-social-tolerance-and-high-level-cognitive-abilities/4534588&gt;.

 

Article Review, Take Two : Captive Gorilla Reproductive Trends

This week I’m reviewing an article from the 1995 Gorilla Gazette entitled Some effects on the reproductive success of captive gorillas. It was written by Angela Meder in Stuttgart Germany, which I find very interesting. The article discusses reproductive strategies that gorillas employ in captivity, as well as why they engage in such activities. The author doesn’t specify what types of zoo gorillas the study is based upon, but I would bet that they are western lowland gorillas as those are the most popular gorillas used in captivity in zoos. The word used most repetitively in this article was dyad as they often described how two gorillas were interacting. The article starts off by saying that out of 700 captive gorilla births there have only been 9 certain and 6 possible births between relatives. Among the certain 4 were between full siblings, 2 between half siblings, 2 between father and daughter, and 1 between mother and son. After reading this harsh introduction to captive gorilla reproductive trends, I knew that much of this article would be concerned about incestuous relationships in captive societies. The article also went into great depth about reproductive differences between mother-raised offspring and zookeeper hand-raised offspring.

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            Meder insinuates that the difference in the reproductive success of differently reared gorillas shows that experiences early in the lifetime of gorillas massively affect their reproductive behavior. Hand reared as well as wild born (also raised by humans) gorillas have offspring much less frequently than those that were raised by their actual mothers. The choice of partners that they have greatly determines whether or not they will breed. Mother reared offspring can reproduce with hand reared counterparts, but the hand reared offspring dyads usually do not produce offspring with each other. Some males copulate with their moms even while older males are present, but Meder insists that the females usually avoid these Oedipus Rex style advances. Copulations with mothers are at about the same frequency as copulations with other females that were already mature adults when the male was born. This suggests that over time the males may view their mother as less of a mother and more of just part of a general age group of their natal group. Regardless, males mate significantly more often with their peers than older females. The largest motivating factor for young males to mate with their peers is that targeting older females would provoke interventions from the dominant male that those females are pledged to sexually. Meder expands that during female estrus dominant males pay less attention to younger prospective female partners, and that allows young males to mate with their peers.

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            It’s extremely rare for captive gorilla fathers to copulate with their daughters, there were only two examples out of 700 mating pairs backing this stat. Females breed significantly more frequently with males that did not lead their natal group in early infancy, and they prefer their peers, or at least similarly aged males. Females that met their partner when they were 3-6 were much more likely to mate with males that were 3 or more years older than them. This is kind of like how in our society most girls wouldn’t marry a man that is too much older than them, but many will marry those within a decade or fifteen years without thinking much about it. Reasons for daughters not copulating with their fathers are identical to why mothers do not breed with their sons: attraction levels are higher between peers and the dominant adult male often has less sexual interest in young females.

I think that this article puts forth a bunch of interesting information, sometimes it could have been much more specific, like telling exact frequencies of how often certain dyads mate with each other. I’m curious if these trends have continued into recent times since ’95, they seem too natural to have disappeared from behaviors. Also the article didn’t really address differences between gorillas in the wild and captivity, but overall it was a compelling read.

Reference:

Meder, A. (1995). Some effects on the reproductive success of captive gorillas. Gorilla Gazette, 9(1).

Photos from Wikipedia and Vetstreet.com

Proposal: Long Tailed Macaque Behavior and Tool Usage

For my research paper I will be writing a ten page odyssey discovering the behavior and tool using strategies of the Long-tailed Macaque (Macaca fascicularis). Our class was first introduced to this adorable species when we watched a video detailing how they wash off sweet potatoes in salt water before consuming them. I will concentrate my Literature Review paper on their behavior mainly and within their behavior I will explore how these Macaques use tools to consume food. Apparently Macaques are the first old world monkeys to be extensively observed using stone tools, compared to Chimpanzees and Bearded Capuchins which have been studied and investigated quite a bit already in the stone tools realm. These adorable and intelligent little guys use stone tools to consume oysters and other shellfish as well as nuts. The studies I incorporate into this Lit Review about stone tool using Long-tailed Macaques are from Thailand, at Piak Nam Yai Island. I have found reports comparing other species of Macaques’ stone tool usage; by contrasting this data in my paper I will develop a more intimate view of the Long-tailed Macaque. I will also explore other ways that Macaques creatively consume food, like peeling and washing other fruits and veggies in similar ways to the sweet potato.

 

I will also be exploring the general behavior of these highly adaptive and ecologically diverse monkeys. They can live in a large variety of areas, recently with human encroachment they have become known for interactions with human populations; specifically Macaques consume human garbage and crops. There are even reports of aggressive dealings with people, as the Macaques have entered highly populated urban areas.

Long-tailed Macaques often live near large bodies of water, love to eat crabs, and use their nearby water supplies in many aspects of their life. They live in trees more than any of the other species of Macaques; they particularly thrive in tropical swamps and forests. These monkeys live in 30 member groups with mostly females and a patrilineal ranked society. Males depart from their original group to mate in another upon reaching maturity. They avoid intergroup conflict, but will chase/fight individuals from intruding groups. I hope to explore the differences in behavior between juveniles and adults more in depth, and see how that relates to their tool usage. Their hierarchy is based upon fighting skills, age, and their physical make-up. Females are also ranked in their societies because they are the only permanent members of a group; low-ranking females often groom their higher ranked counterparts.

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These Macaques lead such interesting and varying lifestyles, especially this highly adaptive Long-tailed Macaque. They are the only non-human primates to develop learned cultural behavior. Like the video we watched in class with the Long-tailed Macaques washing their sweet potatoes, these Macaques can adapt to their environment. I hope that my continued research points toward some other moments when these Macaques adapted and thrived in a new environment. There may be some cases where over-adapting backfires and they harm themselves. I find them fascinating primates and see many reflections of human recognition and resourcefulness. Every new article I find introduces another adjustment made by these monkeys to survive. They seem to be thriving well, possibly too well in areas close to human populations. They can effectively use stone and environmental tools to wash, obtain, and consume cuisine. From what I’ve read it seems like the Long-tailed Macaques can almost sense local human activity, as they always take advantage of crops and trash that they associate with humans. I’m excited to study more into the personal lives and processes of these resourceful primates. They seem relatively unaggressive except when they’re mentioned with humans, maybe human presence is too much of a culture shock for them.

References

Bonadio, C. 2000. “Macaca fascicularis” (On-line), Animal Diversity Web. Accessed March 27, 2014 at http://animaldiversity.ummz.umich.edu/accounts/Macaca_fascicularis/

Cheewapap, C. and Hamada, Y. (2007), Stone-tool usage by Thai long-tailed macaques (Macaca fascicularis). Am. J. Primatol. 69, (227–233).

Malaivijitnond, S., Lekprayoon, C., Tandavanittj, N., Panha, S., Cheewatham Wheatley, Bruce P. (1988). Cultural behavior and extractive foraging in macaca fascicularis. Current Anthropology, 29, (516-519)

Nahallage, CAD. , Huffman, Michael. (2008). Comparison of stone handling behavior in two macaque species: implications for the role of phylogeny and environment in primate cultural variation. American Journal of Primatology. 70., (1124- 1132).

 

Zoo Impressions

I had a glorious time at the zoo! I had the opportunity to make a lot of new friends, including hamadryas baboons and Dr. Kulstad. On the return trip home I ate at a walk-in cookout, the first such experience that I’ve ever had. The zoo experience was overall very positive, though it started off on the wrong foot when the temperature was too cold for the gorillas to socialize in their enclosure. Getting from North America to Africa in the zoo also took a very long time, which should be expected as in the real world they are oceans apart. There were many positive experiences that stemmed from waiting for the gorillas to come into their enclosure though; I had the opportunity to closely examine hamadryas baboons as well as chimpanzees. The baboons were very fascinating to me, they constantly annoyed each other and caused conflict. It was easy to see hierarchy between the adult males, and even the juveniles as they fought and chased one another.

Once it became warm enough for the gorillas to come out into the enclosure I thoroughly enjoyed watching them and learning how to study them using sampling strategies. It was fun getting to know the personalities of our five gorilla friends, my personal favorites were Apollo and Bomassa. I thought it was adorable when their mothers Olympia and Jamani would carry them about the enclosure on their backs. It was sometimes difficult to distinguish between what focal activities the gorillas were performing as many times they could be performing multiple activities at once. Apollo was the most active of the gorillas, several times in my notes I had him socializing, moving, and feeding all at the same time. Apollo and Bomassa both enjoyed playing with burlap sacks and wrestling with the adult females in the group. At one instance I saw Apollo stand on his hind legs and beat his chest challenging Bomassa into wrestling him, that was epic. Acacia really looked down in the dumps due to her recent loss of a baby .

The gorillas behavior and appearance truly reminded me of humans, and looking at their eyes I was spooked out by the likeness to my own. When Olympia and Jamani cuddled with their young sons I felt that I got a first hand look into how our nurturing and affection processes are similar. I felt that their cognition processes seemed similar, and they had a certain way of dealing with each other that was certainly similar to humans. When Jamani would scold Apollo you could get the sense that she was scolding a friends kid that did something wrong, and it would have been different with her son Bomassa.

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Other animals that I got to view were two fast running zebras that would be the stars of any racing stripe remake, as well as the most awkward Ostriches that I have ever come into contact with- they were the staring type. Overall I thoroughly enjoyed my zoo trip, even though it was chilly it was still an excellent way to spend an early spring Saturday. I think that studying gorillas in the wild would be much more revealing because it would showcase them in their absolute most natural state. The gorillas we studied were sheltered, fed, and protected from harm whereas a wild gorilla wouldn’t have those advantages and would subsequently have more naturalized behavior. It was still wonderful to study these extremely human like primates in person and the next time I go to a zoo I feel that I will understand much more about gorilla behavior.

7: Food and Social Organization

As a semi-active growing boy I would say that my next meal is usually in the back of my mind. Luckily for me I don’t have to compete with any of my fellow students for food, as it is readily available in an abundance of locations on campus. However, if there were only a few locations with a scarce amount of food that would feed around 1/2 of who needed to be fed what they want and the other half fed bad foods I bet that within hours it would become a competition for food. This describes aspects of the daily feeding schedule for all wild species of primates. It’s easy to see how food would correlate with social organization for primates, because most of them use half of their day just foraging for it. Strier points out that many of the anatomical distinctions between primates have been brought on through dietary niches over an evolutionary timescale. These dietary niches evolved from the correlation between distribution of foods and the primates location.

Feeding patterns change from season to season for primates, as seasonal differences affect the types and amounts of food that they can forage. Spatial distribution coincides with seasonal availability to give primates either a narrow or large food selection. In almost all primate species that Strier could think of she said that females always have a higher quality diet than males. The reason for this is clear; females need better food and more of it for gestation and lactation. Strier notes that access to food is just as necessary to female reproductive success as access to fertile females is to reproducing males. This means that access to food comprises the fertility of female primates. The end of pregnancy is critical for consumption of food in females, they have to eat enough to nourish themselves, their fetus, and to maintain body fat so that they can nurse post pregnancy. On top of lactating, many mothers must also carry their young until they are able to forage themselves, which also requires more energy. For these reasons it’s good for females to reproduce during periods where they have a large selection of high-quality nutritious foods. These high quality foods contain proteins and nutrients and usually are fruits, insects, or seeds.

            Primates are experts in saving energy while foraging and feeding. Spatial distribution of foods plays a large part in their foraging exploits. Normally there is a greater abundance of less nutritious leaves than there are clusters of fruits in Primate habitats. This means that lower quality foods are more accessible on a regular basis, and primates require toward energy saving techniques. They will travel longer distances to obtain high-quality foods, and shorter distances to obtain lower quality sources of nutrition. In this way they keep their energy levels relative. The species size is also relative to what kind of food they consume; smaller primates like the dwarf lemur ingest insects and tree sap, while the larger chimpanzee may consume vertebrates as well as vegetation.

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To conserve food dwarf lemurs will torpor from weeks to months: hibernating as a way to reduce body temperatures, metabolic rates, and exposure to predators. Considering that their main foods are tree sap and insects, they have to fatten up on some very scarce resources that would require a high amount of foraging energy up front. Folivorous primates like Gorillas consume more high-quality fruits when they’re readily and easily available. I would equate this to eating pancakes for breakfast when available compared to constantly eating lots of oatmeal every morning. I can only imagine the excitement that Gorillas would feel when eating fruit compared to constant leaves.

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 Source Consulted:: Strier, K.B. (2011) Primate Behavioral Ecology, 4th Edition, Pearson/Prentice-Hall.

Pictures: northrup.org- gorilla & dharing.zenfolio.com – dwarf lemur

 

Female Bonobo Sexuality

Growing up as a boy interested in primates I had always heard a great deal about Chimpanzees. Movies like MVP: Most Valuable Primate and its sequel Most Vertical Primate helped spark my interests in seeing how similar our two species were. In Most Valuable Primate the Chimp is an expert Hockey player while in Most Vertical he’s a gnarly skateboarder. I had thought that these Chimpanzees were the closest genetic match to us homo sapiens, but it turns out that Bonobos are just as similar to humans as Chimpanzees. This means that all that I had heard about a single potential final evolutionary link between us humans and Chimpanzees is now false and there are two links: including our genetic cousin the Bonobo. This secondary link into our past can help us reveal truths about our roots in social behavior and anatomy. We can do this by comparing and contrasting differences between Bonobos and Chimps, and between either of them and ourselves to understand deeper connections.

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(this smiley Bonobo comes from scienceblogs.com)

Both of these primates are in the Pan genus, Chimpanzees are known as Pan Troglodytes and the Bonobo Pan Paniscus. Female Bonobos seem absolutely dominant of sexual and social situations to me after reading Parish and De Waal’s paper, but I find it very strange that many researchers ignore this obvious fact. Parish and De Waal mention female Bonobos attacking a male that interrupted her mating with a lesser male, attacking her mate when he was interrupted by a higher ranking male, and even attacking males that reject their sexual advances. In the last situation the female chased the rejecting male up a tree screaming at him, and was aided in her pursuit by other dominant females. Female to male disputes involve chasing, eating, and biting while male to male disputes are often described as more civil. Female Bonobos often engage in same sex sexual activities, and prefer to associate with each other over males, often forming alliances to attack males and exert dominance. They view other females as lesser if they lack offspring, giving females a very interesting social construct when relating to each other.Image

(two female Bonobos rubbing genitals courtesy of blogspot.com)

Female Bonobos also hunt, claim, and distribute meat making them the head breadwinners in this Bonobo society. And though males can forage for fruit and lesser foods the females will indubitably take control of that food in terms of ownership and distribution. This works in sharp contrast to the male dominated Chimp society. Bonobos relate to humans and dolphins in that sex for them is more socially structured than ecologically. These animals have sex for fun, reconciliation, as an expression of affection, and even to relieve stress; this all sounds very similar to humans. Female Bonobos in captivity and the wild engage in genital rubbing, this comes as a sharp contrast to Chimps that would never indulge in such behavior. Behavior like this reveals a darker side of human thinking that most of society ignores, but there is proof in these Bonobos that this behavior is ingrained into our genes. When I look at the contrasting social landscapes of Chimpanzees and Bonobos and try to combine them into how our own society should function I find that human females and males both have the ability to be dominant. In most cases in today’s society this is true, but unfortunately there are still biases that forced human researchers to see female Bonobos as less dominant than they truly were. I’d like to see other populations of species that female dominance applies to: a common example in my mind would be the Black Widow spider. I’m very impressed by the female Bonobos way of organizing their society, in a lot of ways I think that their behavior relates to more complex human social expressions like sexuality and societal roles. 

Mandrill Horde Journal Analysis

For this weeks e-portfolio entry I will be reviewing an article about Mandrills from the American Journal of Primatology. The article was published at a time when I was 4 years old, Michael Jordan was dominating the NBA, and the United States hosted the Olympics in Atlanta: 1996. The study followed a rather large horde of Mandrills in the Lopé Reserve of the West African nation of Gabon. The reserve is in the core central region of the country just below the equator line, about where Kansas would be in the United States. Gabon lies on the west coast of Africa, west of Congo and South of Cameroon. This study of 600+ Mandrills was conducted by six researchers, led at the helm by M. Elizabeth Rogers. It was conducted in ten days in the dry season of 1995, so probably sometime between July and August.Image(a fatted colorful male courtesy of tumblr.com)

The alpha males of the horde were fully colored and described as “fatted” by the authors, they were dispersed through the horde at a ratio of 1:21. Non-fatted paler adult males as well as subadult juveniles were also dispersed throughout the horde. Rafiki from the Lion King would be an example of a fatted fully colored male, he would have had dominance over less colored cartoon mandrills in the original film. This article discusses the Mandrill hordes ranging environment, their diet, and how those are related.

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(zoom of a horde of Mandrills courtesy of corbisimages.com)

The journal entry describes this Lopé Reserve environment as a forest-savannah mosaic, which I interpreted as an undefined mixture of the two terms. From reading this article I would contest that Mandrills exist in social structures similar to Anubis Baboons, large groups without One-Male-Units. These Mandrills thrive in this Savannah Forest Mosaic because it offers them fruits, veggies, and small animals to eat all in one environment. To study their food intake, the researchers looked at before and after effects of fruit populations of trees where Mandrills were interacting with their environment, also they studied the fecal remains of these beautifully colored primates. The study revealed that these Mandrills ate insects, animals, local leaf fragments, fruit, and seeds from the local environment. There were thirty species of trees that the Mandrills could have picked fruit from, and about 50% were actually harvested from. When researchers followed the horde’s path through this savannah forest mosaic they found that these Mandrill had consumed many arthropods (insects). The types of arthropods were largely varied and contained spiders, mites, scorpions, beetles, and millipedes among others. The article suggested that the Mandrills would live and consume food in different areas depending on what time of the year it is in Africa, so their diet and landscape constantly change throughout the year. They don’t seem to be very picky in my understanding of this article, and probably possess the ability to consume many types of animal and plant remains without frustration. I think that this article addressed well several components of mandrill life, mainly their habitat and their diet and how those two components work together. I think that if there were a smaller population than the 600+ that the researchers studied then more assumptions about their social structure could have been made. There was just too much going on for them to pay attention to social details. That being said the methods these primatologists used to collect information about diet and selection was very interesting, thorough, and effective. I learned an extensive amount of information about an exquisite and fascinating species from this article, I now respect Rafiki much more than I had previously. 

Sources Consulted

Rogers, M. E., Kate A. Abernethy, Benoit Fontaine, E. J. Wickings, Lee JT White, and Caroline Tutin. “Ten Days in the Life of a Mandrill Horde in the Lope Reserve, Gabon.” American Journal of Primatology 40.4 (1996): n. pag. Web. <http://onlinelibrary.wiley.com/doi/10.1002/(SICI)1098-2345(1996)40:43.0.CO;2-T/abstract&gt;.

Week 4: Primate Hybridization

 

Oftentimes when hearing the word hybrid you think of a product that had to sacrifice looks in order to be more efficient in some type of task, but this is not the case in primate hybridization! In our textbook Strier defines a hybrid as a genetically unique animal that derives from the fertile mating between two separate species. In some cases these hybrids can interbreed with members of one of their parental species, but in other cases the hybrids have become sterile. The first several hybrid animals that I had heard of in my youth were the Liger that derives from a Lion and a Tiger, and the Wolf Dog or early form of Husky that often results from a Wolf and a Dog mating.

Image(Liger Picture from Envirocivil.com)

These animals are biologically similar and it makes sense that they possess the ability to mate. In our textbook Strier explains that the finest examples of primate hybridization come from the Hamadryas and Anubis (Olive) Baboons. These two species of Baboons live in eastern Africa and have overlapping habitats. Strier states that hybrids occur naturally and need only to geographically overlap, recognize eachother as potential mates, and to have the ability to produce offspring. In Awash National Park of Ethiopia the Anubis and Hamadryas have juxtaposed habitats, and often interbreed to create hybrid Baboon offspring. To avoid taxonomic confusion with these hybrids, the Anubis Baboons are now classified as Papio Hamadryas Anubis instead of simply Papio Hamadryas. These hybrid offspring are capable and apparently actively engaged in reproducing successfully.

These two different species have differing social orders. The Anubis lives in a unified, multi-male and female matrilineal society a lot like that of many other Baboon species. In sharp contrast the Hamadryas has small societal one-male units that dominate their hunting and breeding. In these one-male units a prominent Hamadryas male collects several females into his unit that groom him and help him forage for food. The males are only replaced by younger more rigorous versions of themselves to take these female companions to be theirs. To herd the females into their OMU the Hamadryas nip their females on their necks. These individual OMUs forage and hang out with other OMUs of lesser males to form a band. And when the lesser males are ready to overtake their greater counterparts, they take on the females from that OMU. Hamadryas in Ethiopia are often called cross migrants, as they go looking for females in Anubis societies within the Awash National Park. It’s difficult for Hamadryas males to pick up the Anubis females though, as the female Anubis Baboons are less interested in Hamadryas males when they’re not on their estrous cycles. These produced offspring behave differently from either of their parents though, and both males and females of each species mate with each other due to their overlapping landscapes. In the Awash National Park hybrid sons look more like Hamadryas and hybrid daughters appear more in the form of Anubis Baboons. Strier stresses that this is not the first successful case of Baboons interbreeding fertile offspring successfully. These Hamadryas Anubis hybrids sure are adorable, who knew Ethiopia would hold such a primate treasure.Check out this hybrid Fifi!Image( from theprancingpapio.blogspot.com)

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Primate Diversity: White Faced Capuchin Monkey

The subject of my primate diversity entry is making an encore appearance to my blog, the adorable and highly intelligent capuchin monkey! There are eight different types of capuchin monkeys within their genus, Cebus. All eight live within tropical and subtropical areas of Central and South America. The eight species all vary slightly in color and size, but look quite related when juxtaposed beside one another. The species by name are the white fronted capuchin, brown capuchin, kaapori capuchin, black-striped capuchin, black capuchin, weeping capuchin, golden bellied capuchin, and my personal favorite the white faced capuchin. These capuchins are New World monkeys, in the family Cebidae alongside other fine primates such as marmosets, tamarins, and squirrel monkeys. Instead of trying to cover general facts about all of the capuchins I will concentrate the rest of this report on the white faced capuchin monkey, cebus capucinus. The white faced capuchin resides in Central America, in countries like Panama, Nicaragua, Costa Rica, and Honduras. Some white faced capuchins have even been found in Argentina, giving them one of the widest ranges of dwelling among New World Monkeys. They live in a wide variety of forests ranging from dry to wet but they prefer tropical evergreens and dry forests. These capuchins like being underneath a canopy but usually hang out about half way up the forest line, but they’re not strangers to the finding food on the ground either. They often live in areas with high humidity. These cute little white faced monkeys weigh between 4.5 and 9 pounds and their bodies reach lengths of up to 17 inches. Their locomotion mode is quadrupedalism, but they also excel at climbing and leaping. These little guys have prehensile tails that can be used to help them achieve better standing posture or to pick up food. The white faced capuchin can live up to 55 years in captivity, and up to 30 years in the wild- these are the maximum possible ages they can reach though making their life expectancy much less than these year counts. Males become sexually mature around age 8, while females reach that peak by age 4. Females normally do not birth offspring until they’re about 7 years old, and have one baby about every two years. It normally takes about 160 days or about 5 months for a baby white faced capuchin to fully develop and come into the world. These monkeys are polygamous and often have many different mates, the alpha males get first pick of their mate while lesser males are also eventually allowed a mate. These highly communicative socialite monkeys live in groups of 18 to 20 with evenly distributed males and females. The ladies stay in the group that they’re born into while the males leave at age 4 to find a new group. These monkeys are very active and energetic during the day and retire to the trees to sleep at night. Their society is heavily based on trust, which these cute little guys build through socializing. White faced capuchin monkeys have the largest brain to body size ratio of any primate other than humans. They usually engage in hand sniffing to get to know new friends, and also suck on each others tails and nails to socialize. The younger capuchins observe adults and learn from them to develop valuable climbing and hunting skills. These little guys eat a wide variety of plants and animals, including fruits and nuts as well as small vertebrates. Their diet is 2/3 fruit, about a third animal material, and a little bit of plant substance. The small vertebrates that they enjoy consuming are lizards, birds, tree rats, and squirrels. They will eat almost anything that they can get their adorable little hands on. Capuchins are used a lot in cinema because they’re very intelligent and cute primates. They have recently begun using capuchins to help handicapped people enjoy a better quality of life, sort of like a guide dog for a blind person. The capuchins develop personal relationships with their human while helping them around the house to turn on lights and other activities. Watch this inspiring video to learn more! (This is not a white faced capuchin, yet still a capuchin) http://www.youtube.com/watch?v=vRzp9O9Qc1o These wonderful animals probably have many other real world applications, and though they are easily trained they were not meant to live in captivity. Many of their behavior in captivity is remarkable, but it is unnatural.

Some photos of capuchins…Image

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References Consulted

Long, John. “Cebus Capucinus.” Animal Diversity Web. University of Michigan, n.d. Web. 30 Jan. 2014. <http://animaldiversity.ummz.umich.edu/accounts/Cebus_capucinus/&gt;.

YouTube- Helping Hands Video

Photos:: quickmoviefacts.com, animalstime.com