Current status of the western lowland gorilla (Gorilla gorilla gorilla) and bonobo (Pan

Current status of the western lowland gorilla (Gorilla gorilla gorilla) and bonobo (Pan paniscus): Is there any realistic hope for their conservation? Introduction to Ape Conservation As a result of their highly advanced behaviors and complex societies, great apes have captivated the minds and hearts of people throughout the world. Further increasing their charisma and significance, these great ape species are the closest living relatives to humans. This relationship makes them exceedingly useful for learning about human evolution and other innate aspects of human biology. As important elements in the understanding of human behavior and as essential flagship species for African wildlife, the protection and recovery of great apes species is crucial for overall conservation of world biodiversity. Sadly, due to high levels of destructive and unsustainable human activities throughout Africa, humans have become extremely detrimental to their closest relatives, even threatening them with extinction. In particular, bonobos (Pan paniscus) and lowland gorillas (Gorilla gorilla gorilla) are threatened by various human activities, including logging, commercial poaching, agriculture, and disease transmission. Although conservationists have been working to protect these species for decades, both are still listed on the IUCN Red List of Threatened Species, with bonobos categorized as Endangered and lowland gorillas categorized as Critically Endangered (IUCN 2012). These current classifications illustrate that past conservation actions have not worked. One reason for inadequacy of these actions is that the threats jeopardizing both species are still occurring throughout their natural region. Additionally, there are many challenges that great ape conservationists have encountered during their work to protect these species. One particularly challenging aspect in any conservation project is public opposition. Although great apes are the

closest relatives to humans, many people still do not understand the importance of their protection and survival, especially when it means the termination of human activities. Subsequently, conservationists are also faced with the continued loss and destruction of great ape habitats due to human population and economic growth. While public opposition and ongoing detrimental human activities are major problems for great ape conservation, protection and recovery programs are further hindered by political instability, regional conflict, and a lack of knowledge on both the species and their habitats. Lastly, great ape ecology, especially their reproduction, creates a slow maximum population growth rate, which makes great apes intrinsically threatened with extinction. While these are challenges to the conservation of all ape species, they are particularly pertinent to the protection and recovery of lowland gorillas and bonobos in Africa. To save these species from future extinction, conservationists need to learn from former shortcomings, find solutions to the challenges of ape conservation, and establish new, more effective projects towards the protection of bonobos and lowland gorillas. Furthermore, because of their close evolutionarily relationship, some conservationists now believe that the best method to protect each specific ape species is to create programs that incorporate all species of great apes together. The establishment of such programs have increased tremendously in recent years. For example, in 2000, the Great Ape Conservation Act was passed by the Untied States to help conserve and protect the four great ape species: chimpanzees, bonobos, gorillas, and orangutans; this act also established the Great Ape Conservation Fund to provide funding for programs and research in ape conservation worldwide (Donovan 2011). Many other programs have also been recently initiated for the protection and recovery of these charismatic and indispensable species.

Overall, the success of bonobo and lowland gorilla conservation can only increase when more information is known about their ecologies, the threats causing the decreases in their populations have been eliminated, and more comprehensive great ape conservations programs have been established. Ecology of Bonobos and Lowland Gorillas As previously stated, both bonobos and lowland gorillas are species within the great ape, or Hominidae, family (Stanford 2006). Consequently, the species demonstrate various similarities in their ecology, though differences do exist. For example, while both species live in Western Equatorial Africa, the countries and forest types in which they inhabit are different. Currently, bonobo populations are only found in the Democratic Republic of Congo within the southern region of the Congo Basin (Mohneke and Fruth 2008). Conversely, the ranges of lowland gorilla populations include many countries such as Gabon, Congo, Cameroon, and Nigeria (Doran and McNeilage 1998). Although the two species occupy different regions, they both prefer to live in dense forests, though the particular type of forest is distinct for each species. Reinartz et al. (2006) specified that bonobos tend to live in semi-deciduous primary forests that incorporate sections of evergreen forest; additionally, they are known to explore seasonally inundated swamps and secondary forests in search of food. In contrasts, lowland gorillas have been observed at the highest densities within secondary forests where there is an abundance of herbaceous vegetation, especially monocots (Matthews and Matthews 2004). Within these forests, both bonobos and lowland gorillas are mostly frugivorous, but supplement their diets with other food items particularly when fruit is less available. Within bonobo diets, individuals will also include terrestrial herbaceous vegetation (THV), as well as

small vertebrates and invertebrates (Malenky and Stiles 1991, Donovon 2011). Lowland gorillas also consume THV when fruit cannot be found. However, unlike bonobos, gorilla diets contain a much larger proportion of this vegetation, with individuals capable of sustaining themselves through its consumption for an extended period of fruit scarcity; along with fruit and THV, lowland gorillas have been observed consuming various insects, but only if they are easily obtained (Conklin-Brittain et al. 2001). While the differences in diet are slight, they have greatly influenced the divergence of the social dynamics of both species. Probably one of the most important differences between bonobos and lowland gorillas is that bonobos have a matriarchal fission-fusion society, while lowland gorillas form a patriarchal cohesive grouping. In the matriarchal bonobo society, females have a higher status than males. This dominance is maintained through strong social bonds established by the performance of femalefemale sexual behaviors; these communal sexual behaviors are also used by bonobos to reduce tensions and allow for a more peaceful feeding (White and Wrangham 1988). Peaceful feedings are further increased by the fission-fusion group pattern of bonobos since smaller foraging parties result in less competition for food. Conversely, the patriarchal society of lowland gorillas are led by a one or two dominant males, called silverbacks (White and Wrangham 1988). Within their cohesive group, lowland gorillas stay together during foraging and nesting. As a result, there is a higher degree of within-group scramble competition for resources (Stokes et al. 2003). Another consequence of gorilla society is that females must disperse and join other groups following the death of the dominant silverback; unfortunately, this immigration can result in infanticide if the females still have dependent offspring when the male dies (Stokes et al. 2003).

Both bonobos and lowland gorilla have an intrinsically low reproductive output and, therefore, a low maximum population growth rate. These natural rates are the product of relatively long periods of gestation and maternal care, as well as a fairly late onset of ovulation. Specifically, bonobos have a gestation of around 240 days and care for their offspring for about 4 years, with an interbirth interval of 4.5 years (Bolser and Savage-Rumbaugh 1989, Hashimoto et al. 1996). Similarly, lowland gorillas continue their maternal care for around 5 years after a gestation of approximately 255 days (Bellem et al. 1995). Furthermore, it is a common observation that most great ape species only have a single offspring per pregnancy. As a result of the large amount of time invested by each female to raise just one offspring, both bonobos and lowland gorillas have an inherently low population growth rate, making them intrinsically at risk of extinction. This risk is also influenced by the other aspects of bonobo and lowland gorilla ecology, especially their habitats and diets. Threats to Bonobo and Lowland Gorillas Both bonobos and lowland gorillas are currently vulnerable to extinction and have been added to the International Union for Conservation of Nature (IUCN) Red List of Threatened Species. In 1996, both species were classified as Endangered (IUCN SSC 1996). While bonobos have continued to be listed in this category, lowland gorillas were reclassified as Critically Endangered in 2007 (Hopkin 2007). These classifications are the ramifications of the countless threats facing bonobos and lowland gorillas in their natural habitat, many of which are caused by human activities. Although bonobos and lowland gorillas do not live in the same countries, they are both confronted by many of the same threats. One of the largest threats to both species is habitat loss and destruction. As a result of the increasing human population in Africa, as well as

the people s desire for economic development, many of the forests that bonobos and lowland gorillas inhabit are being eliminated. In the Democratic Republic of Congo, a large amount of the deforestation is occurring because of logging operations (Laporte et al. 2007). This destruction is extremely detrimental to bonobo survival because the Democratic Republic of Congo is currently the only country where bonobos are found. In one assessment at Lake Tumba-Lake Maindombe, Inogwabini et al. (2008) observed that the majority of the southern forested area, which would be appropriate for bonobo habitat, was now part of various logging concessions. Furthermore, within the entire Central Congo Basin, approximately 46 percent of the land is under logging concession (Inogwabini et al. 2005). Along with the Democratic Republic of Congo, many other nations in Western Equatorial Africa are experiencing similar rates of deforestation. Regarding the forests that populations of lowland gorillas occupy, the largest amount of deforestation has been the result of logging, mining, and slash-and-burn agriculture (Remus 2000). Over the past decades, these operations have become more abundant and widespread because of the increase in roads throughout these forested countries. In particular, Laporte et al. (2007) stated that Cameroon and Equatorial Guinea had the highest logging road densities in Central Africa, which allowed the majority of their forests to be cut down at least once. Cameroon and Equatorial Guinea are two countries that have supported numerous populations of lowland gorilla in the past, so this high degree of deforestation is extremely threatening to their survival and conservation. The establishment of roads throughout forested areas has also allowed for an increase in bushmeat hunting since it creates a greater ability for poachers to travel within the forests and then transport out their harvests (Rizkalla et al. 2007). The bushmeat market has also grown

larger over the recent decades because of the economic benefit that it supplies to the traders and the nation. This market is so profitable that, even in 1998, it was described as a billion dollar industry for the countries in Central Africa (Wilkie and Carpenter 1998). For many local people, it is believed to be more advantageous to choose the hunting, sale, and consumption of primate meat over their conservation. Some indigenous groups have even discontinued their adherence with traditional taboos concerning hunting and consumption (Eves et al. 2002). This bushmeat crisis has prompted a serious decline in many bonobos and lowland gorillas populations. Sadly, poaching is not limited to unprotected areas, now becoming a threat for populations in national parks and reserves. For example, a high degree of illegal hunting has been observed in the Salonga National Park, which until recently, was the only protected area for bonobos in the Democratic Republic of Congo; within the park, bonobos are threatened by poaching that is purposefully aimed towards their capture, opportunistic hunters, and nonselective hunting techniques that are used to obtain other species, like cable snares and pitfalls (Hart et al. 2008). Matthews and Matthews (2004) observed that similar hunting threats face lowland gorillas throughout their forested habitats, with the highest hunting operations usually occurring in logging concessions. Overall, a large proportion of current and past population declines are the result of increased logging and hunting pressures throughout African forests. Regrettably, these two operations are not the only threats against bonobos and lowland gorillas. Another troubling event that has placed these populations at risk of extinction is the spread of infectious diseases. While disease transmission affects both species, this threat is the most influential on lowland gorilla populations. Lowland gorillas are specifically threatened by frequent outbreaks of the Ebola virus spreading through their populations. These outbreaks are so

destructive that Walsh et al. (2003) hypothesized that it would take 75 years or more for lowland gorilla populations to recover their abundance to pre-outbreak size. One study that illustrates the detrimental ramifications from these outbreaks occurred at the Lossi Sanctuary in the Republic of Congo; there, researchers observed that an Ebola outbreak killed 95.8% of the monitored groups during its spread from October 2003 to January 2004 (Bermejo et al. 2006). Many researchers now believe that the Ebola virus is spread between distant gorilla populations through bats that consume the same fruits as lowland gorillas in the dry season (Leroy et al. 2005). However, researchers have not yet discovered how to prevent its transmission from this reservoir host or between individual gorillas. This knowledge, plus the development of a vaccine, is the only way to stop future outbreaks from annihilating the already critically endangered lowland gorilla populations. Bonobos and lowland gorillas are faced with many threats that have caused significant declines in their populations across Western Africa. Besides being intrinsically threatened with extinction because of their low reproductive output, these great apes are also threatened by various destructive human activities and the outbreaks of infectious diseases. Consequently, conservation organizations have tried to work with African governments and local people to protect bonobos and lowland gorillas and help restore their populations. Unfortunately, there are many challenges that are inherent to great ape conservation, with additional challenges arising for projects occurring in the developing nations that are trying to improve their economies. Challenges to Ape Conservation One of the largest challenges to ape conservation is that not much information is currently known about the status of either species. While some estimates have been made for

their population sizes, ranges, and the percentage in which they have declined over the past decades, the assessments of different researchers have often been conflicting. Additionally, the collection methods for these estimates have been unreliable at times (Mohneke and Fruth 2008). It is particularly difficult to study and monitor these species because they live in dense forests, making them harder to find and track (Matthews and Matthews 2004). A further impediment to this calculation is the fission-fusion society of bonobos. This society type complicates the ability of trackers to obtain accurate population counts since observing one foraging party is not representative of the total group size. Hence, many trackers estimate population size by counting the number of nests observed, though even this method is known to lack preciseness (Stokes et al. 2003). As previously stated, the current economic growth and its subsequent destruction of ape habitat is another challenge that conservationists have been confronted with. While work is being done to educate the local people on the benefits of protecting their nearby forests and its primate species, many residents still desire the economic benefits of deforestation and hunting. Logging is presently one of the largest activities in Western Equatorial Africa and a substantial source of income. (Perez et al. 2005). As a result, most of the local people oppose the establishment of protected areas or do not follow the logging bans in that area. Further, the desire for economic growth and development has prompted the creation of numerous new roads throughout the dense forests (Inogwabini et al. 2008). These roads make the forests more easily accessible to loggers and allow for faster transportation of their harvests. Altogether, there is a substantial challenge created when the local people are opposed to conservation actions. Without the support of the locals and their compliance with logging bans, the habitats for the bonobos and lowland gorillas

will continue to be destroyed. Until African governments and their citizens no longer choose economic growth over the protection of nature, conservationist will find it difficult to protect bonobos and lowland gorillas in their natural habitats. Similar to the challenge of economic growth, conservationists also experience the problem of political instability and conflict within the natural regions of both primate species. Past and present political instability has caused major problems in the conservation programs for protecting these species. Without a stable government, there is no continuity to conservation projects. As a result, many previously established protected areas often become neglected, with recent programs being left unfinished (Struhsaker et al. 2005). Furthermore, in regions where corruption is high and there is a considerable amount of political and economic decline, antilogging and poaching enforcement can become nonexistent. During these times of instability and civil wars, the only way to continue the protection of both species is through non-government organizations (NGOs) and research projects sponsored by other nations (Tranquilli et al. 2012). While including the regional and national governments in conservation projects is important, the success of protected areas depends on the continuity of enforcement and funding. Therefore, there is currently a need for greater support from more stable countries and organizations (Struhsaker et al. 2005). Without this support, conservationists are faced with the inability to establish and sustain protected areas and other programs. As a result of these challenges facing conservationists, many of the previously established projects for the conservation and protection of bonobos and lowland gorillas have failed to achieve their original goals. These shortcomings are illustrated by the continued classification of bonobos as Endangered and lowland gorillas as Critically Endangered by the IUCN.

Current Conservation Projects To stop and reverse the persistent decline in bonobo and lowland gorilla populations, numerous, more progressive conservation programs have been recently established. The development of these modern projects are aimed at dealing with the challenges facing ape conservation and mending the failures that accompanied past project. While several of these programs are species-specific in their design and protection, others have been created with an emphasis on integrating the conservation of all great ape species. Furthermore, because of the need for more support from local villages, a large effort is being made to educate and integrate the local people into these conservation projects. In the Democratic Republic of Congo, a community-based reserve called the Bonobo Peace Forest was recently established during the early 2000s. Developed through the collaboration of Congolese scientists, government officials, and local village leaders, this reserve strives to connect conservation with sustainable development (Martin 2005). To fulfill this goal, park management has stopped forcing the local people off the protected area, and instead have included them in the efforts to conserve the bonobo populations. It is believed that, since these locals have lived within bonobo habitat for centuries, they will want to protect it from degradation and know how to live sustainably on its resources (Martin 2005). The preservation of this area presently occurs at eleven forest sites, which protects more than 50,000 square miles for bonobo habitation in the Democratic Republic of Congo (BCI 2012). In addition, the program provides economic and educational opportunities, as well as increased medical access for the local people in exchange for their contribution in conserving the bonobo habitat. Overall, the

Bonobo Peace Forest illustrates how a conservation program can integrate the local people into its actions, a process which has been determined to be a necessity for success. A similar project, named PROGEPP was established in 1999 for lowland gorilla conservation in Nouabalé-Ndoki National Park. The PROGEPP aims to integrate the timber industry, local community, and the protection of the region s biodiversity into a system for ecosystem management (Elkan and Elkan 2002). To accomplish this, the Wildlife Conservation Society collaborated with the Congolese Ministry of Forestry Economy and the Congolaise Industrielle des Bois (CIB) (Poulsen et al. 2010). As the largest logging company in Congo, the integration of the CIB has been essential for reducing the impacts of logging on the park s wildlife. In addition to promoting low impact forest harvesting strategies, the program has also led to the establishment of hunting zones and increased regulation of the bushmeat transport through education and eco-guard surveillance (Elkan and Elkan 2002). These activities have resulted in benefits for both the local people and the protection of the lowland gorilla populations. Consequently, the IUCN named the PROGEPP a model for future wildlife management within regions of logging concessions (Poulsen et al. 2010). Through the integration with the local businesses and people, recently developed conservation programs like the Bonobo Peace Forest and PROGEPP have been successful in achieving their goals for the protection of bonobo and lowland gorilla populations, respectively. However, while these projects are successful in their species-specific plans, conservationists believe that additional projects that focus on protecting great apes as a whole are needed. Although this is a new concept, many of these programs have been established in the past decade. In 2000, the Great Ape Conservation Act and its associated Great Ape Conservation

Fund was enacted by the United States (USFWS 2011). Since its creation, this foundation has provided hundreds of grants and millions of dollars to fund various programs in great ape conservation throughout Central and Western Africa. In 2011 alone, the Great Ape Conservation Fund gave 51 grants, contributed $3,869,265 and sponsored field projects in 12 African countries; these projects aimed to increase public support through outreach and education, establish more protected areas, and stop great ape poaching and trafficking (USFWS 2011). Another integrative program for great ape conservation is the Great Apes Survival Project (GRASP). Led by the United Nations Environment Programme (UNEP) and the United Nations Educational, Scientific and Cultural Organization, GRASP works towards the conservation of all great ape species and their habitats (UNEP 2005). To achieve this goal, the UNEP (2005) has issued numerous conservation actions, including an increase in the amount of surveys done on the abundance and distribution of great ape populations; from this, old protected areas are reviewed and new protected areas are established. The project also evaluates the effectiveness of government regulations and its enforcement of detrimental human activities, such as poaching, logging, mining, and agriculture, as well as the activity s effect on great ape populations (UNEP 2005). Although numerous other actions are done by GRASP, two additionally crucial projects stated by the UNEP (2005) include the establishment of sustainable development in regions near great ape habitat, as well as the preventive methods taken to avoid disease transmission within great ape populations. Overall, though GRASP has only been recently founded, its integration of multiple organizations, governments, and local people has caused conservationists to recognize it as a successful method for conserving the four endangered great ape species (UNEP 2009).

The previously discussed programs only represent a small proportion of the many conservation actions currently taking place throughout Africa for the protection and restoration of bonobos, lowland gorillas, and their habitats. For instance, additional measures have been taken to solve the various challenges that ape conservationists have previously encountered. For many conservation organizations, increasing their knowledge of bonobos and lowland gorillas is particularly important. Because of their dense forest habitats, it was difficult for former researchers to tracking individual within the forest. To reduce this complication, some researchers are now setting up their observation point on high viewing platforms above the forest; there, it is easier for the researchers to locate individuals using telescopes and other spotting scopes (Stokes et al. 2003). Many efforts have been made in this area of research because, without accurate measurements of population sizes and ranges, there is no way to determine which conservation actions are truly beneficial. An increase in public outreach and integration has also been a recent expedition for conservationists because without the support of the local people, it is unlikely that the conservation programs will be effective in protecting the ape species or their habitats. In particular, large strides have been made in public education at the Lola ya Bonobo Sanctuary in the Democratic Republic of Congo. In an assessment of the program s success, Andre et al. (2008) discovered that children who visited the sanctuary significantly improved their knowledge of conservation. This increased comprehension was measured by the ability of the children to correctly answer five true-false questions about conservation; the questions asked included 1) bonobos do not make good pets, 2) bonobos are not an endangered species, 3) hunting and snares are dangerous for bonobos, 4) planting trees is something you can do to help

bonobos, and 5) bushmeat trade threatens bonobos with extinction (figure 1; Andre et al. 2008). The results from this assessment illustrates the educational value of integrating the local people into their nearby conservation programs. By teaching children the importance of protecting biodiversity, they may become less willing to engage in the many damaging human activities occurring around them, and possibly even become an advocate for conservation. Conclusions The current listing of bonobos and lowland gorillas on the IUCN Red List illustrate that previous conservation actions have not fulfilled their goals of ending the threats facing these populations. While many of the recently founded conservation programs seem to be more successful in this preservation, more work is still needed. In particular, conservationists continue to require more information on the ecology, range, and population sizes of both bonobos and lowland gorillas. Acquiring this knowledge is the first step in creating successful conservation programs and protected areas. Associated with this is the need for further integration between protected areas and the local people. One way to create this partnership is by employing villagers as eco-guards. The establishment of an eco-guard monitoring system is beneficial to both the conservation organization and the local people since management is provided with real-time information and enforcement, while the locals are provided with a source of income (Farmer 2002). Lastly, much more research is needed on the spread, transmission, and treatment of the Ebola virus and other infectious diseases threatening these species. Without the prevention of such lethal disease outbreaks, bonobos and lowland gorillas will be unable to recover their population sizes even if the other threats are removed. In conclusion, while many conservations

actions have been done to protect these species, a substantial amount of research and projects are still needed to ensure the survival and full recovery of bonobos and lowland gorillas.

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(Source: Andre et al. 2008)