threat and conservation status

Current Population

According to the World Wildlife Fund the number of chimpanzees in the world ranges from 150,000- 250,000.  The majority of chimpanzees still living in their natural habitat can be found in different parts of Africa (central Africa)

In particular, Gabon, Democratic Republic of Congo,Cameroon contain the largest amount of chimpanzees.  Other places such as Senegal, Mali, the Cabinda enclave of Angola, Equatorial Guinea, and Sudan contain smaller populations that are at serious risk. Côte d'Ivoire, Ghana, Guinea-Bissau, Nigeria, Burundi and Rwanda also contain endangered populations of chimpanzees.  Over the last 20 years, the chimp population in  Côte d'Ivoire has decreased by about 90%! 

Within these locations, chimps are divided in 4 main groups: central, western, eastern, and Nigerian- Cameroon.  The population for this group is estimated at about 115,000!!

Central chimpanzees are the largest of the groups and live mostly around Gabon, Cameroon, and Congo.  You can find this group of chimps living around undisturbed forest areas.

Western chimpanzees are a smaller group that lives mostly around Côte D'Ivoire.  The total population for this group is about 15,000- 21,000!!

Eastern chimpanzees range from the Ubangi River/Congo River in Central African Republic and DRC, to western Uganda, Rwanda and western Tanzania

Nigerian- Cameroon chimpanzees are the smallest of these sub-populations with only about 1,500 chimps!!  They live mostly in  Nigeria and Cameroon

As we can see the wildlife population of chimpanzees is small and getting smaller.  

On the flip side we have chimpanzees across the world that are living in zoos/ wild life parks.  For example, here is a map of the United States; the starts indicate zoos that have chimpanzees

According to the Chimpanzee Species Survival Plan (SSP), one benefit to chimpanzees living in zoos is the increase in life span.  zoo chimps tend to live longer than chimps in the wild.  Here is a list of some of the oldest living chimps that are being cared for in zoos: 

Name                   Zoo                        Age

Lil Mama     Lion Country Safari          72

Bon Bon         Dallas Zoo                    52

Cobby         San Francisco Zoo           52

 (kinda makes you want to go to the zoo, huh?)

Potential threats

2 of the main threats to the chimpanzee population are habitat loss and degradation, and hunting.

Habitat loss: the larger the human population grows, the greater need for more land.  Unfortunately, when humans are looking for new places to build or farm we are choosing places that are home to many chimp populations.  The increase in building on their land results in habitat patching which means there is space in between chimp groups and that keeps them isolated from each other with little to no room to roam.  Because of the increase in deforestation in Western Africa, the amount of chimpanzees living naturally has decreased greatly, many chimps in the area are living in zoos or reservations.

Hunting has also contributed to the large decline in the chimpanzee population.  In many areas poaching for meat and infants is the quite relevant.  Hunters often capture infant chimps to sell them as pets.  Chimps are often hurt by traps to catch other animals.  A study in Congo showed the amount of chimps being killed surpassed the amount of chimps being born. The term bush meat is intended to describe the hunting of animals in the wild.  the bush meat trade is causing great damage, not only to the chimpanzee population but to the wildlife population as a whole.

(pictures are too graphic too post but are helpful in understanding the pain and suffering these animals are going through)

Conservation status

Two major organizations addressing the decline in chimpanzee population are World Wildlife Fund and Bushmeat Crisis Task Force. 

The World Wildlife Fund is attempting to preserve the great ape population by: establishing, strengthening, and managing protected areas, developing chimp- focused eco-tourism, stopping illegal killing of chimps.  The WWF is doing this by working with the government in protecting the wild life areas where chimps are living.  They are attempting to figure out different ways to stop the bushmeat trade which will decrease the number of animals being killed for sport or food.

The Bushmeat Crisis Task Force concerns themselves with bushmeat that is illegally obtained.  This means the use of illegal methods for hunting (snares), hunting of endangered, threatened, or protected species, hunting in areas that are already being protected, and unsustainable offtake for commercial trade

The Crisis Task Force is addressing these problems through education and anti- poaching operations.  Through educating the people of these places where bush meat is most relevant, its in the hopes of the Task Force that the government will put strict rules into effect that will lessen the occurrence of illegally killing animals.

References

http://wwf.panda.org/what_we_do/endangered_species/great_apes/chimpanzees/

http://www.lpzoosites.org/chimp-ssp/locations.htm

http://www.honoluluzoo.org/chimpanzee.htm

http://www.bushmeat.org/bushmeat_and_wildlife_trade/solutions

Socioecological Adaptations by Chimpanzees from Animal Behaviour

Researchers Hockings, Anderson, and Matsuzawa, authors of "Socioecological adaptations by chimpanzees, Pan troglodytes verus, inhabiting an anthropogenically impacted habitat" as published in the scholarly journal, Animal Behaviour collected data in Bossou, Guinea over a year long period to examine the living conditions of a group of chimpanzees there. In examining "party size" in both crop raids and wild feeds, they were able to observe the ways in which chimpanzees band together in various ecological environments. This particular study explores the ways in which this particular group of chimpanzees behaves within an agricultural-forest region.

The introduction of the study briefly discussed the realities of human invasion of the forest regions of Guinea and suggests that such intrusions may have a significant affect on chimp resource consumption, activity budgets, party cohesiveness, and other factors directly affecting life for the chimps in the region. One important point of discussion in the beginning portion of the article is the idea that agricultural development by humans directly affects all species of a particular region, both in ways that we can observe directly and others that take more exploration and foresight.

Behavioral flexibility is noted as a process that occurs not just in instances of agricultural development, but also in situations where climate and seasonal changes warrant adaptation from a given species to benefit survival. Climate changes can limit availability of food, but heightened access to human food can change the behaviors particular species exhibit in a given region. The authors cite a study that found that other species of monkeys were found to spend less time foraging for food with an increased access to human food.

Behaviors observed by the researchers were divided into several categories- feeding, moving, resting, and social. Single focal individuals were noted, and the researchers also included mention that the other individuals being observed were not always exhibiting the same behavior as the focal individual.

This article in particular is important in that it gives us an insight into the affect human populations have on the well-being of various animal species. Minor intrusions can make significant changes in the overall lifestyle of an animal. In some respects, small differences were found in instances such as party cohesiveness, but significant differences were found in the area of activity budgets. More studies focusing on similar and different animal behaviors will allow for a more definitive outlook on chimp life.

Source: Socioecological adaptations by chimpanzees, Pan troglodytes verus, inhabiting an anthropogenically impacted habitat from Animal Behaviour by Kimberley J. Hockings, James R. Anderson, and Tetsuro Matsuzawa. USD students may find the article via Copley Library at http://0-www.sciencedirect.com.sally.sandiego.edu/science/article/pii/S0003347212000036.

Territorial Behavior

What is a territory? In order to understand the territorial behaviors of chimpanzees, its important to know what we mean by territory. A territory is an area that is taken up by a community which includes all of its resources like food, mates, or breeding sites.  A home range is an area where chimpanzees can eat, breed, and raise their young. What's the difference you ask?  Not much, the main difference is a territory is defended by the group where a home range is unprotected.Chimpanzees exhibit a behavior known as boundary (territory) patrolling.  The males chimpanzees of a social community will walk around their territory in a straight line.  These chimps walk along the edge of their territory  and the neighboring territory in slience, searching for any predators or other chimpanzees from other communities.  If the group comes across another chimpanzee they will attack it in attempt to kill the chimp.  These attacks do not stop at other male chimpanzees, they have been recorded attacking female chimpanzees and their young and eating the remains.  How can animals that seem so sweet have these episodes of hatred and violence?  Most researchers feel the main reasons behind patrolling are: food availability, hunting activity, presence of estrous females, intruder pressure, and male party size.  Other studies confirm the idea that patrolling takes place in order to increase the size of their territory.  It makes sense that with a larger territory comes more food and larger variety of estrous females.  These patrol groups are usually made up of males, on occasion a female will join the group but they are usually infertile.  The average patrol time is 2- 2.5 hours.  Research on the Ngogo Community shows there is strength in numbers, especially when there is an increase of males within the community.  

We see the positive side of patrolling, females, food, larger territory, dominance over other communities, but to anything positive there is something negative.  What are the negative outcomes of patrolling?

A study by Sylvia J. Amsler attempts to find the costs to patrolling.  She hypothesized that chimpanzees spend more time walking and less time eating when they are on patrol.  She studied the Ngogo community for 14 months and observed 29 patrols.  The amount of work these patrollers are putting in takes a toll on their physical well being.  Needless to say, a patroller should be in tip top physical condition to perform successfully during a patrol.  If a chimp lacks the physical strength then their chances of surviving during a fight with other chimpanzee communities shrinks.  Amsler study shows that patrolling takes a toll on a chimpanzee physically.

Territorial behaviors may seem like a male- dominated characteristic but females are impacted by it as well.  Most females move from one tribe to another around puberty and will stay there through adulthood.  Other females move from one group to another depending on the males territorial behaviors.  The more a female moves from one group to another the less likely her offspring is to survive.  A main predictor of female moving is based on two things: food availability and male territorial behaviors.


References
http://onlinelibrary.wiley.com/doi/10.1002/ajp.20757/abstract
http://chimpanzeeinformation.blogspot.com/2011/01/chimpanzees-do-boundary-patrolling.html
http://www.sciencedaily.com/releases/2005/10/051018072735.htm
http://www.eva.mpg.de/primat/staff/boesch/pdf/jour_prim_ter_char.pdf
http://www.sciencedirect.com/science/article/pii/S0003347201919165

reproduction

Chimpanzees live in social communities.  Their reproductive rituals demonstrate this fact.  Males are capable of reproducing by 16 years of age.  Females reach estrus at 10 years old.  Estrus is characterized by anogential swelling which is swelling of the anus/genital area.  This swelling lets the males know they are old enough to reproduce.  Traditionally, female chimpanzees will leave their “home” communities for another social community.  During this period of transition, females are infertile although they still show the signs of maturity, swelling.  During this transition period, females will participate in sexual relations with males even though they are incapable of becoming pregnant.  This is thought to be a form of protection for the females and their young.  If a female chimpanzee enters her new social community  and gives birth without her offspring being from a member of that community then she has a chance of being rejected by the community and having her young killed by the males of the group.  This is called infanticide.  Infanticide is thought to attribute to sexual selection theory.  Infanticide induces a female’s cycle allowing her to reproduce before the 3-5 year interbirth interval period.  Once her cycle begins and is ready to mate, then the males of the new community will know the offspring is in fact a part of their community and will refrain from killing it.  Research has shown that not only males partake in infanticide.  Females have also been shown to kill the offspring of other females for reasons researchers are not definite about.  The two possible reasons for this are isolated cases of pathological behavior and/or dominance rank in females.

When is a good time? Anytime!

There has been no record of a birth season for chimpanzees but there is evidence to show that the number of estrus females in a community does change.  The number of estrous females in a community is positively related with food abundance.  The logic behind this observation is that when females become pregnant they will need more food than when they are not so they go where the food is.

Monogamy?No, thank you!

Most of the time, chimpanzee mating is very promiscuous, as stated earlier, they do live in social communities so why wouldn’t they be overly social? Although females have multiple mates throughout their estrus, they reach the max amount during the 10- day period of tumescence (swelling period).  Research has shown 3 main types of mating patterns exhibited by chimpanzees

1.      Opportunistic, non-competitive mating: characterized by a female who can mate with any male in the group

2.      Possessiveness: occurs when a males develops a short bond with a female and prevents lower- ranked males from mating with her

3.      Consortships: when a male and female leave the group to live on their own, avoiding other chimpanzees.

Mating preferences? Not so much...

Human males are typically more attracted to younger human females because of her ability to reproduce.  This is not the case in the life of a chimpanzee male.  Research has shown, males prefer females who are older than they are.  Human reproduction is restricted by female menopause which comes with age.  Chimpanzees lack this characteristic so males are not attracted to females for that reason.

References

http://obit-mag.com/articles/scientists-publish-first-chimpanzee-mourning-videos

http://www.scholastic.com/browse/article.jsp?id=3756740

http://pin.primate.wisc.edu/factsheets/entry/chimpanzee/behav

http://www.ncbi.nlm.nih.gov/pubmed/6934311

http://www.sciencedaily.com/releases/2006/11/061120130545.htm

Evolutionary Background- Close relatives- Taxonomy

Chimpanzees have been around for millions of years but the name chimpanzee originated sometime in the 1700’s.  This name is loosely translated as “ape” or “mockman”.  Chimpanzees are categorized in the family homindae, which is also home to humans, gorillas, and orangutans.   It is believed that chimpanzees spilt from humans about 4 million years ago but remain our closest relative.

Sometime around the 1950’s scientists learned that by comparing the proteins and nucleic acids of two “different” species they would be able to see just how similar or different they really are (the genetic distance). Scientists have been successful in comparing chimpanzees to humans and have discovered the difference between the two is too small to measure.  Similarities between chimpanzees and humans are seen in their blood proteins among other aspects of our DNA.  Mary Clare- King and A.C. Wilson have suggested the small differences that are seen between humans and chimpanzees are a result of regulatory mutation.  Through numerous comparisons, scientists have been able to find the comparison level between chimpanzees and humans is about 99% identical.  This percent fluctuates between 96-99% between different articles, either way; the resemblance between the two is large.  An article found on the National Geographic website states humans and chimpanzees share a common ancestor who lived over 5 million years ago.

The taxonomy of chimpanzees is as follows:

Suborder: Haplorrhini
Infraorder: Simiiformes
Superfamily: Hominoidea
Family: Hominidae (humans are here)
Genus: Pan
Species: P. troglodytes
Subspecies: P. t. schweinfurthii, P. t. troglodytes, P. t. vellerosus, P. t. verus

Both human and chimpanzee fossils have been found in the East African Rift Valley during the Middle 

Pleistocene from many years ago.  Research has been successful in showing the large similarities between chimpanzees and humans.Chimpanzees are closely related to humans and bonobos.  Many other species from the genus Pan have not survived.

References:

- http://icewater.cms.udel.edu/mast634/Refs/King-Wilson-Science-1975.pdf

- http://animals.nationalgeographic.com/animals/mammals/chimpanzee/?source=A-to-Z

- http://en.wikipedia.org/wiki/Chimpanzee#History

- http://en.wikipedia.org/wiki/Common_chimpanzee

It's What's For Dinner: Chimpanzee Eating Habits

The majority of a chimpanzee's diet consists of fruit, leaves, seeds, and insects. Variance in a chimpanzee's diet is due to the particular time of year and availability of different food in the wild. An article found on the Honolulu Zoo’s website discusses that chimps may consume over 20 different species in a given day, and over 200 different species in a given year. That’s quite a smorgasbord!

Termites a common choice for chimps because they are a great source of protein. Termites are gathered either by hand or by use of handmade tools. Birds and other mammals are sometimes on a chimp’s dinner menu, but far more rarely than fruit, veggies, or termites.

Groups of individual chimpanzees often work together to hunt for food as a team- for example, one individual will seek out the most abundant area in the forest and bring the rest of the group out to that area, or bring back food for the group. This group structure is also used to protect from prey.

Chimps also drink water, often by soaking up moisture in the leaves they eat. Fruit is also an important part of their diet, as fruit often has a great deal of moisture present in it.

We found a video from the Jane Goodall institute, demonstrating how chimpanzees use sticks as tools to engage in "termite fishing". One of the researchers says that he sometimes eats termites and that they taste like cashews. Would you ever eat one of these delicacies? You couldn’t dare us!

Here's the link to the video:

http://www.youtube.com/watch?v=inFkERO30oM&feature=related