Nonhuman primates, our closest biological relatives, play important roles in the livelihoods, cul... more Nonhuman primates, our closest biological relatives, play important roles in the livelihoods, cultures, and religions of many societies and offer unique insights into human evolution, biology, behavior, and the threat of emerging diseases. They are an essential component of tropical biodiversity, contributing to forest regeneration and ecosystem health. Current information shows the existence of 504 species in 79 genera distributed in the Neotropics, mainland Africa, Madagascar, and Asia. Alarmingly, ~60% of primate species are now threatened with extinction and ~75% have declining populations. This situation is the result of escalating anthropogenic pressures on primates and their habitats— mainly global and local market demands, leading to extensive habitat loss through the expansion of industrial agriculture , large-scale cattle ranching, logging, oil and gas drilling, mining, dam building, and the construction of new road networks in primate range regions. Other important drivers are increased bushmeat hunting and the illegal trade of primates as pets and primate body parts, along with emerging threats, such as climate change and anthroponotic diseases. Often, these pressures act in synergy, exacerbating primate population declines. Given that primate range regions overlap extensively with a large, and rapidly growing, human population characterized by high levels of poverty, global attention is needed immediately to reverse the looming risk of primate extinctions and to attend to local human needs in sustainable ways. Raising global scientific and public awareness of the plight of the world's primates and the costs of their loss to ecosystem health and human society is imperative.
Orangutans produce alarm calls called kiss-squeaks, which they sometimes modify by putting a hand... more Orangutans produce alarm calls called kiss-squeaks, which they sometimes modify by putting a hand in front of their mouth. Through theoretical models and observational evidence, we show that using the hand when making a kiss-squeak alters the acoustics of the production in such a way that more formants per kilohertz are produced. Our theoretical models suggest that cylindrical wave propagation is created with the use of the hand and face as they act as a cylindrical extension of the lips. The use of cylindrical wave propagation in animal calls appears to be extremely rare, but is an effective way to lengthen the acoustic system; it causes the number of resonances per kilohertz to increase. This increase is associated with larger animals, and thus using the hand in kiss-squeak production may be effective in exaggerating the size of the producer. Using the hand appears to be a culturally learned behavior, and therefore orangutans may be able to associate the acoustic effect of using the hand with potentially more effective deterrence of predators.
Human speech shows an unparalleled richness in geographic variation. However, few attempts have b... more Human speech shows an unparalleled richness in geographic variation. However, few attempts have been made to understand this linguistic diversity from an evolutionary and comparative framework. Here, we a) review extensively what is known about geographic variation of acoustic signals in terrestrial mammals, using common terminology adopted from linguistics to define different forms of variation (i.e. accents and dialects), and b) examine which factors may determine this variation (i.e. genetic, environmental and/or social). Heretofore, terminology has been used inconsistently within and across taxa, and geographic variation among terrestrial mammals has never been defined as in human speech. Our results show that accents, phonologically different varieties, occur widely in terrestrial mammals. Conversely, dialects, lexically and phonologically different varieties, have only been documented thus far in great white-lined bats, red deer, chimpanzees and orangutans. Although relatively rare among terrestrial mammals, dialects are thus not unique to humans. This finding also implies that such species possess the capacity for acoustic learning. Within primates, the two great apes showing dialects are those who also show extensive cultures in the wild, suggesting that, in hominoids, intricacy of acoustic geographic variation is potentially associated with cultural complexity; namely, both have derived from selection increasingly favoring social learning across varied contexts, including the acoustic domain.
Monitoring of animal populations is essential for conservation management. Various techniques are... more Monitoring of animal populations is essential for conservation management. Various techniques are available to assess spatiotemporal patterns of species distribution and abundance. Nest surveys are often used for monitoring great apes. Quickly developing technologies, including unmanned aerial vehicles (UAVs) can be used to complement these ground-based surveys, especially for covering large areas rapidly. Aerial surveys have been used successfully to detect the nests of orang-utans. It is unknown if such an approach is practical for African apes, which usually build their nests at lower heights, where they might be obscured by forest canopy. In this 2-month study, UAV-derived aerial imagery was used for two distinct purposes: testing the detectability of chimpanzee nests and identifying fruiting trees used by chimpanzees in Loango National Park (Gabon). Chimpanzee nest data were collected through two approaches: we located nests on the ground and then tried to detect them in UAV ph...
Conservation biology : the journal of the Society for Conservation Biology, Jan 29, 2015
Community-based conservation programs in developing countries often assume that heteronomous moti... more Community-based conservation programs in developing countries often assume that heteronomous motivation (e.g. extrinsic incentives such as economic rewards and pressure or coercion to act) will motivate local communities to adopt conservation behaviors. However, this may not be as effective or sustainable as autonomous motivations (e.g. an intrinsic desire to act due to inherent enjoyment or self-identification with a behavior and through freedom of choice). This paper analyses the comparative effectiveness of heteronomous versus autonomous approaches to community-based conservation programs, using the example of Sumatran orangutan (Pongo abelii) conservation in Indonesia. Comparing three case study villages employing differing program designs, we found that heteronomous motivations (e.g. income from tourism) led to a change in self-reported behavior towards orangutan protection. However, they were ineffective in changing self-reported behavior towards forest (i.e. orangutan habitat...
Proceedings of the National Academy of Sciences of the United States of America, 2015
The high species richness of tropical forests has long been recognized, yet there remains substan... more The high species richness of tropical forests has long been recognized, yet there remains substantial uncertainty regarding the actual number of tropical tree species. Using a pantropical tree inventory database from closed canopy forests, consisting of 657,630 trees belonging to 11,371 species, we use a fitted value of Fisher's alpha and an approximate pantropical stem total to estimate the minimum number of tropical forest tree species to fall between ∼40,000 and ∼53,000,…
Balancing economic development with international commitments to protect biodiversity is a global... more Balancing economic development with international commitments to protect biodiversity is a global challenge. Achieving this balance requires an understanding of the possible consequences of alternative future scenarios for a range of stakeholders. We employ an integrated economic and environmental planning approach to evaluate four alternative futures for the mega-diverse island of Borneo. We show what could be achieved if the three national jurisdictions of Borneo coordinate efforts to achieve their public policy targets and allow a partial reallocation of planned land uses. We reveal the potential for Borneo to simultaneously retain B50% of its land as forests, protect adequate habitat for the Bornean orangutan (Pongo pygmaeus) and Bornean elephant (Elephas maximus borneensis), and achieve an opportunity cost saving of over US$43 billion. Such coordination would depend on enhanced information sharing and reforms to land-use planning, which could be supported by the increasingly international nature of economies and conservation efforts.
Orangutans produce alarm calls called kiss-squeaks, which they sometimes modify by putting a hand... more Orangutans produce alarm calls called kiss-squeaks, which they sometimes modify by putting a hand in front of their mouth. Through theoretical models and observational evidence, we show that using the hand when making a kiss-squeak alters the acoustics of the production in such a way that more formants per kilohertz are produced. Our theoretical models suggest that cylindrical wave propagation is created with the use of the hand and face as they act as a cylindrical extension of the lips. The use of cylindrical wave propagation in animal calls appears to be extremely rare, but is an effective way to lengthen the acoustic system; it causes the number of resonances per kilohertz to increase. This increase is associated with larger animals, and thus using the hand in kiss-squeak production may be effective in exaggerating the size of the producer. Using the hand appears to be a culturally learned behavior, and therefore orangutans may be able to associate the acoustic effect of using the hand with potentially more effective deterrence of predators.
Expansion of oil palm plantations has led to extensive wildlife habitat conversion in Southeast A... more Expansion of oil palm plantations has led to extensive wildlife habitat conversion in Southeast Asia [1]. This expansion is driven by a global demand for palm oil for products ranging from foods to detergents [2], and more recently for biofuels [3]. The negative impacts of oil palm development on biodiversity [1, 4, 5], and on orangutans (Pongo spp.) in particular, have been well documented [6, 7] and publicized [8, 9]. Although the oil palm is of African origin, Africa's production historically lags behind that of Southeast Asia. Recently, significant investments have been made that will likely drive the expansion of Africa's oil palm industry [10]. There is concern that this will lead to biodiversity losses similar to those in Southeast Asia. Here, we analyze the potential impact of oil palm development on Africa's great apes. Current great ape distribution in Africa substantially overlaps with current oil palm concessions (by 58.7%) and areas suitable for oil palm production (by 42.3%). More importantly, 39.9% of the distribution of great ape species on unprotected lands overlaps with suitable oil palm areas. There is an urgent need to develop guidelines for the expansion of oil palm in Africa to minimize the negative effects on apes and other wildlife. There is also a need for research to support land use decisions to reconcile economic development, great ape conservation, and avoiding carbon emissions.
Nonhuman primates, our closest biological relatives, play important roles in the livelihoods, cul... more Nonhuman primates, our closest biological relatives, play important roles in the livelihoods, cultures, and religions of many societies and offer unique insights into human evolution, biology, behavior, and the threat of emerging diseases. They are an essential component of tropical biodiversity, contributing to forest regeneration and ecosystem health. Current information shows the existence of 504 species in 79 genera distributed in the Neotropics, mainland Africa, Madagascar, and Asia. Alarmingly, ~60% of primate species are now threatened with extinction and ~75% have declining populations. This situation is the result of escalating anthropogenic pressures on primates and their habitats— mainly global and local market demands, leading to extensive habitat loss through the expansion of industrial agriculture , large-scale cattle ranching, logging, oil and gas drilling, mining, dam building, and the construction of new road networks in primate range regions. Other important drivers are increased bushmeat hunting and the illegal trade of primates as pets and primate body parts, along with emerging threats, such as climate change and anthroponotic diseases. Often, these pressures act in synergy, exacerbating primate population declines. Given that primate range regions overlap extensively with a large, and rapidly growing, human population characterized by high levels of poverty, global attention is needed immediately to reverse the looming risk of primate extinctions and to attend to local human needs in sustainable ways. Raising global scientific and public awareness of the plight of the world's primates and the costs of their loss to ecosystem health and human society is imperative.
Orangutans produce alarm calls called kiss-squeaks, which they sometimes modify by putting a hand... more Orangutans produce alarm calls called kiss-squeaks, which they sometimes modify by putting a hand in front of their mouth. Through theoretical models and observational evidence, we show that using the hand when making a kiss-squeak alters the acoustics of the production in such a way that more formants per kilohertz are produced. Our theoretical models suggest that cylindrical wave propagation is created with the use of the hand and face as they act as a cylindrical extension of the lips. The use of cylindrical wave propagation in animal calls appears to be extremely rare, but is an effective way to lengthen the acoustic system; it causes the number of resonances per kilohertz to increase. This increase is associated with larger animals, and thus using the hand in kiss-squeak production may be effective in exaggerating the size of the producer. Using the hand appears to be a culturally learned behavior, and therefore orangutans may be able to associate the acoustic effect of using the hand with potentially more effective deterrence of predators.
Human speech shows an unparalleled richness in geographic variation. However, few attempts have b... more Human speech shows an unparalleled richness in geographic variation. However, few attempts have been made to understand this linguistic diversity from an evolutionary and comparative framework. Here, we a) review extensively what is known about geographic variation of acoustic signals in terrestrial mammals, using common terminology adopted from linguistics to define different forms of variation (i.e. accents and dialects), and b) examine which factors may determine this variation (i.e. genetic, environmental and/or social). Heretofore, terminology has been used inconsistently within and across taxa, and geographic variation among terrestrial mammals has never been defined as in human speech. Our results show that accents, phonologically different varieties, occur widely in terrestrial mammals. Conversely, dialects, lexically and phonologically different varieties, have only been documented thus far in great white-lined bats, red deer, chimpanzees and orangutans. Although relatively rare among terrestrial mammals, dialects are thus not unique to humans. This finding also implies that such species possess the capacity for acoustic learning. Within primates, the two great apes showing dialects are those who also show extensive cultures in the wild, suggesting that, in hominoids, intricacy of acoustic geographic variation is potentially associated with cultural complexity; namely, both have derived from selection increasingly favoring social learning across varied contexts, including the acoustic domain.
Monitoring of animal populations is essential for conservation management. Various techniques are... more Monitoring of animal populations is essential for conservation management. Various techniques are available to assess spatiotemporal patterns of species distribution and abundance. Nest surveys are often used for monitoring great apes. Quickly developing technologies, including unmanned aerial vehicles (UAVs) can be used to complement these ground-based surveys, especially for covering large areas rapidly. Aerial surveys have been used successfully to detect the nests of orang-utans. It is unknown if such an approach is practical for African apes, which usually build their nests at lower heights, where they might be obscured by forest canopy. In this 2-month study, UAV-derived aerial imagery was used for two distinct purposes: testing the detectability of chimpanzee nests and identifying fruiting trees used by chimpanzees in Loango National Park (Gabon). Chimpanzee nest data were collected through two approaches: we located nests on the ground and then tried to detect them in UAV ph...
Conservation biology : the journal of the Society for Conservation Biology, Jan 29, 2015
Community-based conservation programs in developing countries often assume that heteronomous moti... more Community-based conservation programs in developing countries often assume that heteronomous motivation (e.g. extrinsic incentives such as economic rewards and pressure or coercion to act) will motivate local communities to adopt conservation behaviors. However, this may not be as effective or sustainable as autonomous motivations (e.g. an intrinsic desire to act due to inherent enjoyment or self-identification with a behavior and through freedom of choice). This paper analyses the comparative effectiveness of heteronomous versus autonomous approaches to community-based conservation programs, using the example of Sumatran orangutan (Pongo abelii) conservation in Indonesia. Comparing three case study villages employing differing program designs, we found that heteronomous motivations (e.g. income from tourism) led to a change in self-reported behavior towards orangutan protection. However, they were ineffective in changing self-reported behavior towards forest (i.e. orangutan habitat...
Proceedings of the National Academy of Sciences of the United States of America, 2015
The high species richness of tropical forests has long been recognized, yet there remains substan... more The high species richness of tropical forests has long been recognized, yet there remains substantial uncertainty regarding the actual number of tropical tree species. Using a pantropical tree inventory database from closed canopy forests, consisting of 657,630 trees belonging to 11,371 species, we use a fitted value of Fisher's alpha and an approximate pantropical stem total to estimate the minimum number of tropical forest tree species to fall between ∼40,000 and ∼53,000,…
Balancing economic development with international commitments to protect biodiversity is a global... more Balancing economic development with international commitments to protect biodiversity is a global challenge. Achieving this balance requires an understanding of the possible consequences of alternative future scenarios for a range of stakeholders. We employ an integrated economic and environmental planning approach to evaluate four alternative futures for the mega-diverse island of Borneo. We show what could be achieved if the three national jurisdictions of Borneo coordinate efforts to achieve their public policy targets and allow a partial reallocation of planned land uses. We reveal the potential for Borneo to simultaneously retain B50% of its land as forests, protect adequate habitat for the Bornean orangutan (Pongo pygmaeus) and Bornean elephant (Elephas maximus borneensis), and achieve an opportunity cost saving of over US$43 billion. Such coordination would depend on enhanced information sharing and reforms to land-use planning, which could be supported by the increasingly international nature of economies and conservation efforts.
Orangutans produce alarm calls called kiss-squeaks, which they sometimes modify by putting a hand... more Orangutans produce alarm calls called kiss-squeaks, which they sometimes modify by putting a hand in front of their mouth. Through theoretical models and observational evidence, we show that using the hand when making a kiss-squeak alters the acoustics of the production in such a way that more formants per kilohertz are produced. Our theoretical models suggest that cylindrical wave propagation is created with the use of the hand and face as they act as a cylindrical extension of the lips. The use of cylindrical wave propagation in animal calls appears to be extremely rare, but is an effective way to lengthen the acoustic system; it causes the number of resonances per kilohertz to increase. This increase is associated with larger animals, and thus using the hand in kiss-squeak production may be effective in exaggerating the size of the producer. Using the hand appears to be a culturally learned behavior, and therefore orangutans may be able to associate the acoustic effect of using the hand with potentially more effective deterrence of predators.
Expansion of oil palm plantations has led to extensive wildlife habitat conversion in Southeast A... more Expansion of oil palm plantations has led to extensive wildlife habitat conversion in Southeast Asia [1]. This expansion is driven by a global demand for palm oil for products ranging from foods to detergents [2], and more recently for biofuels [3]. The negative impacts of oil palm development on biodiversity [1, 4, 5], and on orangutans (Pongo spp.) in particular, have been well documented [6, 7] and publicized [8, 9]. Although the oil palm is of African origin, Africa's production historically lags behind that of Southeast Asia. Recently, significant investments have been made that will likely drive the expansion of Africa's oil palm industry [10]. There is concern that this will lead to biodiversity losses similar to those in Southeast Asia. Here, we analyze the potential impact of oil palm development on Africa's great apes. Current great ape distribution in Africa substantially overlaps with current oil palm concessions (by 58.7%) and areas suitable for oil palm production (by 42.3%). More importantly, 39.9% of the distribution of great ape species on unprotected lands overlaps with suitable oil palm areas. There is an urgent need to develop guidelines for the expansion of oil palm in Africa to minimize the negative effects on apes and other wildlife. There is also a need for research to support land use decisions to reconcile economic development, great ape conservation, and avoiding carbon emissions.
1. Interactions between conservation and the social sciences are frequently characterized by eith... more 1. Interactions between conservation and the social sciences are frequently characterized by either critique (of conservation by social scientists) or co-optation (of social scientific methods and insights by conservationists). 2. This article seeks to push beyond these two dominant positions by exploring how conservationists and social scientists can engage in mutually transformative dialogue. Jointly authored by conservation scientists and social scientists, it uses the global nexus of orangutan conservation as a lens onto current challenges and possibilities facing the conservation-social science relationship. 3. We begin with a cross-disciplinary overview of recent developments in orangu-tan conservation-particularly those concerned with its social, political and other human dimensions. 4. The article then undertakes a synthetic analysis of key challenges in orangutan conservation-working across difference, juggling scales and contexts and dealing with politics and political economy-and links them to analogous concerns in the conservation-social science relationship. 5. Finally, we identify some ways by which orangutan conservation specifically, and the conservation-social science relationship more generally, can move forward: through careful use of proxies as bridging devices, through the creation of new, shared spaces, and through a willingness to destabilize and overhaul status quos. This demands an open-ended, unavoidably political commitment to critical reflexiv-ity and self-transformation on the part of both conservationists and social scientists.
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Papers by Serge Wich