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Extinctions in Madagascar: the loss of the subfossil fauna.

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Abstract

Outlines the evidence concerning 1) geographical and chronological patterns of extinction and 2) the chronology and nature of human occupation of the island. Examines competing hypotheses about the relationships between these phenomena, and finally presents a revised model of the human role in Malagasy extinctions, where it is argued that ecological transformation resulted from the substitution of domestic bovids for the native terrestrial herbivores. Causal factors suggested are competition, habitat destruction and fragmentation, and adventitious hunting. -after Author

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... The debate about human colonization of Madagascar is complex (Dewar and Wright, 1993;Wright and Rakotoarisoa, 2003). It can be documented by the study of subfossil faunas (Battistini and Vérin, 1967;Burney, 1997Burney, , 2003Dewar, 1984Dewar, , 1997Dewar, , 2003Guérin, 2002;Muldoon, 2010). Hitherto the oldest evidence of anthropic activities on the island dated to a few centuries BC or AD at sites in the South-West of Madagascar (MacPhee and Burney, 1991;Perez et al., 2003Perez et al., , 2005. ...
... There is an active debate about the causes of the extinction of large Malagasy subfossil taxa (Battistini and Vérin, 1967;Burney, 1997Burney, , 2003Burney et al., 1997;Dewar, 1984Dewar, , 1997Dewar, , 2003Guérin, 2002;MacPhee, 1986;Mahé and Sourdat, 1972;Muldoon, 2010); one of the main hypothesis is the "Blitzkrieg". No significant accumulation of remains resulting from hunting was found. ...
... À Madagascar, un autre type de matériel scientifique permet de pallier ce problème, il s'agit des faunes subfossiles. Par le passé, la biodiversité dans ce pays était bien plus importante qu'aujourd'hui et l'homme a eu des impacts sur celle-ci au cours du temps (Battistini et Vérin, 1967 ;Burney, 1997Burney, , 2003Dewar, 1984Dewar, , 1997Dewar, , 2003Guérin, 2002 ;Muldoon, 2010). Les plus anciennes traces d'activités anthropiques ont été retrouvées sur des mammifères subfossiles, soit des hippopotames (MacPhee et Burney, 1991), soit des lémuriens de grande taille, comme les paléopropithèques (Perez et al., 2003(Perez et al., , 2005. ...
... The debate about human colonization of Madagascar is complex (Dewar and Wright, 1993;Wright and Rakotoarisoa, 2003). It can be documented by the study of subfossil faunas (Battistini and Vérin, 1967;Burney, 1997Burney, , 2003Dewar, 1984Dewar, , 1997Dewar, , 2003Guérin, 2002;Muldoon, 2010). Hitherto the oldest evidence of anthropic activities on the island dated to a few centuries BC or AD at sites in the South-West of Madagascar (MacPhee and Burney, 1991;Perez et al., 2003Perez et al., , 2005. ...
... There is an active debate about the causes of the extinction of large Malagasy subfossil taxa (Battistini and Vérin, 1967;Burney, 1997Burney, , 2003Burney et al., 1997;Dewar, 1984Dewar, , 1997Dewar, , 2003Guérin, 2002;MacPhee, 1986;Mahé and Sourdat, 1972;Muldoon, 2010); one of the main hypothesis is the "Blitzkrieg". No significant accumulation of remains resulting from hunting was found. ...
... À Madagascar, un autre type de matériel scientifique permet de pallier ce problème, il s'agit des faunes subfossiles. Par le passé, la biodiversité dans ce pays était bien plus importante qu'aujourd'hui et l'homme a eu des impacts sur celle-ci au cours du temps (Battistini et Vérin, 1967 ;Burney, 1997Burney, , 2003Dewar, 1984Dewar, , 1997Dewar, , 2003Guérin, 2002 ;Muldoon, 2010). Les plus anciennes traces d'activités anthropiques ont été retrouvées sur des mammifères subfossiles, soit des hippopotames (MacPhee et Burney, 1991), soit des lémuriens de grande taille, comme les paléopropithèques (Perez et al., 2003(Perez et al., , 2005. ...
... Large body size and diurnal habits would have made the megafauna easy hunting targets for humans. However, the dearth of direct evidence for butchery at archaeological sites in Madagascar and the absence of a gamedependent Stone Age culture (Dewar and Wright, 1993) argue against a human overkill (or ''Blitzkrieg'') hypothesis (Dewar, 1984). Indeed, the pattern of extinction speaks against Martin's (1967Martin's ( , 1984 prediction of a rapid extinction wave, since many species survived the advent of humans by at least a thousand years (Burney, 1999;Burney et al., 2004). ...
... And, whereas there is recent folk memory of the existence of megafauna (Godfrey, 1986;Burney and Ramilisonina, 1999) and even of rituals associated with their killing (Molet, 1951;Haring, 1979), the conspicuous absence of their skeletal remains from archaeological sites spanning the last 1000 years bears testimony to a culture that did not depend on megafaunal hunting for its subsistence. Instead, giant lemurs and other megafauna may have succumbed to natural or human-induced habitat modification or to diseases introduced by humans or their commensals (Humbert, 1927;Mahe´and Sourdat, 1972;Dewar, 1984;MacPhee and Marx, 1997; see review by Burney, 1999). Indeed, a key factor contributing to megafaunal extinctions worldwide may be slow reproductive rates, not large body size per se (Johnson, 2002; see also Dewar, 1984). ...
... Instead, giant lemurs and other megafauna may have succumbed to natural or human-induced habitat modification or to diseases introduced by humans or their commensals (Humbert, 1927;Mahe´and Sourdat, 1972;Dewar, 1984;MacPhee and Marx, 1997; see review by Burney, 1999). Indeed, a key factor contributing to megafaunal extinctions worldwide may be slow reproductive rates, not large body size per se (Johnson, 2002; see also Dewar, 1984). ...
... (2) (Dewar, 1984). ...
... Anecdotal information summarized by Godfrey (1986) strongly supports the notion that at least one kind of Malagasy hippo survived until the modern era. However, the youngest 14C date, on material of Hippopotamus [emerlei from Itampolo, is 980 ± 200 rcyrbp (Mahe and Sourdat, 1972;Dewar, 1984). Nevertheless, the ubiquity of hippo remains in sites of apparently recent vintage and the widespread oral tradition of the hippolike lalomena (Flacourt, 1661) justify our inclusion of this species and its undated relative H. madagaseariensis (nee Hexaprotodon, contra Harris [1991]) in Table 2. ...
... In the western Indian Ocean, studies of island biogeography and the impacts of human settlement on faunal biota have been largely limited to the late Holocene and have focused on Madagascar [17][18][19] or oceanic islands such as the Mascarenes [20][21][22][23][24] and Comoros [21,[25][26][27][28]. The continental islands of eastern Africa, including the Lamu, Mafia, and Zanzibar archipelagos, lack faunal records with sufficient time-depth to permit analysis of the effects of post-LGM island formation, with one important exception. ...
... The only other African islands with archaeological records possibly predating island formation, Bioko and Elobey in Equatorial Guinea [83][84], have neither firm dates nor published faunal data. Comparisons to oceanic islands such as Mauritius and Seychelles, or to the island-continent of Madagascar, are less appropriate as these hosted unique endemic fauna whose disappearance, in many cases, has been unambiguously linked to human occupation [18,22,[85][86]. Therefore, comparative case studies must be sought outside African contexts, for example in the post-LGM breakup of Santarosae Island into some of the present-day Californian Channel Islands. ...
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With rising sea levels at the end of the Pleistocene, land-bridge or continental islands were formed around the world. Many of these islands have been extensively studied from a biogeographical perspective, particularly in terms of impacts of island creation on terrestrial vertebrates. However, a majority of studies rely on contemporary faunal distributions rather than fossil data. Here, we present archaeological findings from the island of Zanzibar (also known as Unguja) off the eastern African coast, to provide a temporal perspective on island biogeography. The site of Kuumbi Cave, excavated by multiple teams since 2005, has revealed the longest cultural and faunal record for any eastern African island. This record extends to the Late Pleistocene, when Zanzibar was part of the mainland, and attests to the extirpation of large mainland mammals in the millennia after the island became separated. We draw on modeling and sedimentary data to examine the process by which Zanzibar was most recently separated from the mainland, providing the first systematic insights into the nature and chronology of this process. We subsequently investigate the cultural and faunal record from Kuumbi Cave, which provides at least five key temporal windows into human activities and faunal presence: two at the end of the Last Glacial Maximum (LGM), one during the period of post-LGM rapid sea level rise and island formation, and two in the late Holocene (Middle Iron Age and Late Iron Age). This record demonstrates the presence of large mammals during the period of island formation, and their severe reduction or disappearance in the Kuumbi Cave sequence by the late Holocene. While various limitations, including discontinuity in the sequence, problematize attempts to clearly attribute defaunation to anthropogenic or island biogeographic processes, Kuumbi Cave offers an unprecedented opportunity to examine post-Pleistocene island formation and its long-term consequences for human and animal communities.
... Hautes Terres malgaches étaient déjà couvertes d'une mosaïque de forêts rupicoles et de savanes, maintenue par un régime naturel de feu et par la mégafaune (Dewar 1984;Burney 1987aBurney , 1997Dewar & Burney 1994). La colonisation humaine, l'utilisation du feu pour l'élevage, l'agriculture et la chasse, ont réduit la couverture forestière en faveur des espèces herbacées et aussi exotiques (Burney et al. 2004), et ont transformé ces forêts sclérophylles en un type de forêt à canopée ouverte (Kull et al. 2005). ...
... The upper areas, characterized by steep slopes that exceed 60° in the rocky, quartzitic outcrops, are thus less used for cattle. Ibity appears to be following the same transformation process that took place earlier in the original mosaic of the Malagasy highlands, where humans likewise used fire to raise livestock and for agriculture, reducing forest cover in favor of herbaceous, sometimes exotic species (Dewar 1984;Burney 1987b;Ratsirarson & Goodman 2000). ...
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Currently loss and transformation of habitats are the main threats which cause the decrease of biological diversity. In Madagascar, 90% of plants species are endemic of the island and most of the plant formations types are at present strongly degraded or replaced by secondary formations resulting from human activities. Tapia woodland, dominated by the endemic tree Uapaca bojeri, is a sclerophyllous vegetation type limited in the Malagasy highlands. This vegetation type, adapted and resistant to the natural fire regime, is very fragmented today, covering a surface equivalent to 132 255ha on the island. In order to increase the protection of tapia woodland, a new protected area was established on Ibity massif. The current state of the woody vegetation is the result of the interaction of some factors as soil type, climate, human traditional practices and fire. Although fire is one of the phenomena that determine the dynamics of this vegetation, the current fire regime is also one of the main causes of degradation. The objective of this thesis is to study the role of fire on the demographic cycle and on some main processes for installation and recruitment. Thus, germination, plant phenology and seedlings resistance after burnt were studied. This research shows that the current problem of tapia woodland are 1) the reduction of flowering and fruiting by high fire frequencies; 2) the reduction of germination percent after seed exposure with high temperatures, and 3) high seedlings mortality after burnt, in particular when the quantity of fuel is raised. Installation and recruitment of woody species are limited by fire, which has a negative effect on natural regeneration. Fire management around the protected area is thus necessary for its conservation
... Evidence of the earliest human arrival by 2000 B.P. is bolstered by a dramatic decrease in tree pollens and increase in tiny pieces of charcoal in old soil sediments, indicating fires and deforestation, at exactly the same time, that suggests clearing for agriculture (Burney, 1993). A few centuries later several species of large animals on the island became extinct, such as the dwarf hippo (Hippopotamus lemerlei), the elephant bird (Aepyornis), giant turtle (Testudo grandidieri), and several species of giant lemurs (Battistini & Vérin, 1967;Dewar, 1984). It is thought that a combination of human hunting, habitat destruction, and climate drying led to their demise (Dewar, 1984;Burney, 1993). ...
... A few centuries later several species of large animals on the island became extinct, such as the dwarf hippo (Hippopotamus lemerlei), the elephant bird (Aepyornis), giant turtle (Testudo grandidieri), and several species of giant lemurs (Battistini & Vérin, 1967;Dewar, 1984). It is thought that a combination of human hunting, habitat destruction, and climate drying led to their demise (Dewar, 1984;Burney, 1993). It is possible that the ancestors of the Mikea were involved in all of this. ...
... Controversy exists regarding the drivers of past and ongoing extinctions of Madagascar's endemic fauna. Some scenarios attribute species loss to human activities such as hunting, landscape burning and the introduction of invasive species to the island (Dewar, 1984;Virah-Sawmy et al., 2016), but climate change in the form of aridification may have also played a significant role in this process (Mah e and Sourdat, 1972;Burney et al., 2004;Virah-Sawmy et al., 2010). Southwestern Madagascar is an ideal region to study late Holocene ecological change, because this region has a high diversity of endemic species and some of the earliest evidence for humans on the island (Perez et al., 2003;Burney et al., 2004;Douglass and Zinke, 2015). ...
... Humans and their associated domesticated animals (e.g. dogs, cattle, goats and sheep) spread across the island during the past 1000 years (V erin and Battistini, 1971;Dewar, 1984;Wright et al., 1993). Landscape modification, disease and direct interspecific interactions associated with this spread may have contributed to the decline of endemic taxa (Battistini, 1971;MacPhee, 1997;Godfrey and Jungers, 2003;Burney et al., 2004;Crowley, 2010;Burns et al., 2016;Crowley et al., 2017). ...
Article
Most endemic species with body masses >10 kg on Madagascar went extinct within the past 1000 years. The extent to which human predation, anthropogenic landscape transformation and aridification may separately or together explain this extinction pattern remains controversial. We present nitrogen isotope (δ¹⁵N) values of individual amino acids preserved in bones from now‐extinct Pachylemur insignis and extant Propithecus verreauxi from two subfossil sites in south‐western Madagascar: Tsirave and Taolambiby. The amino acid‐specific approach allows us to identify environmental signals that are otherwise difficult to recognize in bulk collagen δ¹⁵N values. Specifically, we use the δ¹⁵N values of source amino acids (phenylalanine and lysine) as a proxy for habitat aridity between ca. 4000 years ago and present and the spacing of δ¹⁵N values between trophic and source amino acids to quantify trophic levels for these two lemur species. Despite paleoenvironmental evidence for lowering water tables and the expansion of relatively arid savanna between 4000 and 1000 years ago, our isotope data suggest that these lemurs did not live in increasingly arid habitats and did not change their trophic level. Together, our results support the hypothesis that aridity alone did not play a major role in late Holocene megafaunal extinctions in south‐western Madagascar.
... (2) (Dewar, 1984). ...
... Anecdotal information summarized by Godfrey (1986) strongly supports the notion that at least one kind of Malagasy hippo survived until the modern era. However, the youngest 14C date, on material of Hippopotamus [emerlei from Itampolo, is 980 ± 200 rcyrbp (Mahe and Sourdat, 1972;Dewar, 1984). Nevertheless, the ubiquity of hippo remains in sites of apparently recent vintage and the widespread oral tradition of the hippolike lalomena (Flacourt, 1661) justify our inclusion of this species and its undated relative H. madagaseariensis (nee Hexaprotodon, contra Harris [1991]) in Table 2. ...
... 1.5 Les causes de la disparition des subfossiles 20 L'extinction des faunes subfossiles, en particulier des animaux de grande taille comme les Aepyornis ou les lémuriens géants comme Archaeoindris ou Megaladapis, a suscité de nombreuses questions et interprétations des premiers scientifiques. Même aujourd'hui, il existe beaucoup de théories (Battistini & Vérin, 1967 ;Mahé & Sourdat, 1972 ;MacPhee, 1986 ;Burney, 1997Burney, , 2003Burney et al., 1997 ;Dewar, 1984Dewar, , 1997Dewar, , 2003Guérin, 2001 ;Muldoon, 2001) tentant d'expliquer cette disparition mais aucune n'est satisfaisante et elles suscitent plus d'interrogations que de réponses. Il est probable qu'il n'y a pas une seule cause mais un ensemble de facteurs défavorables. ...
... La chasse est pratiquée de façon limitée. Il n'existe que de rares restes d'animaux subfossiles montrant qu'ils ont fait l'objet de cette pratique comme à Andrahomana (Dewar, 1984). Des pendeloques ou des outils ont été retrouvés dans des sites, mais s'agit-il de trophées ou ontils fait l'objet d'une récupération (Ampasambazimba, Lamboharana, Taolambiby, Beloha-Anavoha) (Burney, 1984) ? ...
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Madagascar is one of the most important hotspot of the world biodiversity. Among the numerous endemic animals living in the island, the lemurs are the more emblematic. Within the primate order, this group is one of the most diversified. If their origin is still not clear, numerous extinct subfossils species have been recorded for at least 26 000 years, the more recent ones being only a few hundred years old. The lemurs are mentioned in ancient texts or legends because of their size which made an impression on people. The causes of their extinction remain poorly known. Historically, the majority of the subfossil sites were known in two geographical areas: the South-West and the Center of Madagascar, which shared a few species. More recently, some subfossils have been discovered in the North of the island, but almost nothing was known in the North-West of Madagascar until 1997 when explorations were undertaken in the framework of a collaboration between malagasy and french researchers.Currently, 19 sites are known and many subfossils were discovered. A new species of extinct lemur was described, Palaeopropithecus kelyus. Numerous non-lemur taxa are recorded (micro-and macrofauna) and contribute to understand the history of the past biodiversity and palaeoenvironments.This fair collaboration is also a human adventure. The different participants of the two countries take an equal part in the fieldwork, the studies, the technical and academic training of the students at the University of Mahajanga, and the popularization of the results. Through exhibitions the new Malagasy generations are sensitized to the preservation of their geological and natural heritage.
... (2) (Dewar, 1984). ...
... Anecdotal information summarized by Godfrey (1986) strongly supports the notion that at least one kind of Malagasy hippo survived until the modern era. However, the youngest 14C date, on material of Hippopotamus [emerlei from Itampolo, is 980 ± 200 rcyrbp (Mahe and Sourdat, 1972;Dewar, 1984). Nevertheless, the ubiquity of hippo remains in sites of apparently recent vintage and the widespread oral tradition of the hippolike lalomena (Flacourt, 1661) justify our inclusion of this species and its undated relative H. madagaseariensis (nee Hexaprotodon, contra Harris [1991]) in Table 2. ...
... The role of humans in the extinction of Madagascar's megafauna has been a key concern (Dewar 1984(Dewar , 1997(Dewar , 2003Burney 1997;Burney et al. 2003;Crowley 2010;Goodman and Jungers 2014). There is evidence for human consumption of locally extinct fauna at Andavakoera Gorge in the north (Dewar and Rakotovololona 1992) and Andranosoa in the south (Rasamuel 1984), as well as signs that people at the site of Talaky in the southwest were using Aepyornis eggs during the ninth to fourteenth centuries AD (Battistini et al. 1963;Parker Pearson 2010: 89-90). ...
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In the first issue of Azania Pierre Vérin outlined the state of research in Madagascar in 1966. He described three key areas: the nature and origin of human settlement, the influence of Islam and the Swahili world and the archaeology of the historically attested highland kingdoms. In this article we outline the state of archaeological knowledge today, demonstrating the continuing importance of these themes, but also showing how they have been expanded and reshaped through subsequent research. We finish by assessing the potential and challenges that the future holds for archaeology in Madagascar.
... Extremely little is known of the evolutionary history of Madagascar's giant elephant birds. The island's Cenozoic terrestrial vertebrate record is notoriously poor, and thus far all fossil finds are restricted to the last 80,000 years [404][405][406]. What little we do know comes from subfossil bones and eggshells, the latter of which are extremely abundant in some areas. ...
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The extant diversity of the avian clade Palaeognathae is composed of the iconic flightless ratites (ostriches, rheas, kiwi, emus, and cassowaries), and the volant tinamous of Central and South America. Palaeognaths were once considered a classic illustration of diversification driven by Gondwanan vicariance, but this paradigm has been rejected in light of molecular phylogenetic and divergence time results from the last two decades that indicate that palaeognaths underwent multiple relatively recent transitions to flightlessness and large body size, reinvigorating research into their evolutionary origins and historical biogeography. This revised perspective on palaeognath macroevolution has highlighted lingering gaps in our understanding of how, when, and where extant palaeognath diversity arose. Towards resolving those questions, we aim to comprehensively review the known fossil record of palaeognath skeletal remains, and to summarize the current state of knowledge of their evolutionary history. Total clade palaeognaths appear to be one of a small handful of crown bird lineages that crossed the Cretaceous-Paleogene (K-Pg) boundary, but gaps in their Paleogene fossil record and a lack of Cretaceous fossils preclude a detailed understanding of their multiple transitions to flightlessness and large body size, and recognizable members of extant subclades generally do not appear until the Neogene. Despite these knowledge gaps, we combine what is known from the fossil record of palaeognaths with plausible divergence time estimates, suggesting a relatively rapid pace of diversification and phenotypic evolution in the early Cenozoic. In line with some recent authors, we surmise that the most recent common ancestor of palaeognaths was likely a relatively small-bodied, ground-feeding bird, features that may have facilitated total-clade palaeognath survivorship through the K-Pg mass extinction, and which may bear on the ecological habits of the ancestral crown bird.
... The accumulated evidence suggests that humans may have collapsed these ecosystems through a combination of impacts, including overhunting (e.g. MacPhee and Burney, 1991;Perez et al. 2005); landscape modifi cation (e.g., Burney, 1993;Burney et al., 2003) and perhaps other interacting factors, such as invasive species and climatic desiccation (Dewar, 1984;Burney, 1999). ...
Chapter
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Madagascar's living lemurs (order Primates) belong to a radiation recently ravaged by extirpation and extinction. There are three extinct and five extant families (two with extinct members) of lemurs on an island of less than 600,000 square kilometers. This level of familial diversity characterizes no other primate radiation. The remains of up to seventeen species of recently extinct (or subfossil) lemurs have been found alongside those of still extant lemurs at numerous Holocene and late Pleistocene sites in Madagascar. The closest relatives of the lemurs are the lorisiform primates of continental Africa and Asia; together with the lemurs, these comprise the suborder Strepsirrhini. With regard to extinct lemurs, morphological, developmental, and molecular data support a sister taxon relationship for the Palaeopropithecidae (four genera) and the Indriidae. This chapter describes the systematic paleontology of subfossil lemurs of Madagascar.
... Research suggests that the drivers of environmental change are more diverse and nuanced than simply population growth and poverty. It is true that humans have played a significant role in shaping the island's landscapes and contributed to species extinctions through hunting, forest clearance, livestock practices and the introduction of non-native species(Dewar 1984, Burney et al. 2004, Dewar 2014. It is also clear that population growth and poverty can constrain the livelihood choices of rural households(Casse et al. 2004, Scales 2011, Scales 2014b. ...
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The history of conservation policy and practice in Madagascar over the last 30 years shows that the Malagasy government, donors and non - governmental organisations (NGOs) have not been short of bold solutions, with ambitious attempts to involve local communities in resource management as well as expand protected areas. While there have been notable achievements, continued threats to the island’s flora and fauna, as well as the negative impacts that conservation policy has often had on rural livelihoods, show that there is still much to be done. So what are the lessons from the past and the challenges ahead? In this paper I provide a broad overview of recent research in the social sciences on conservation and development in Madagascar. I argue that conservation science and policy have often been based on overly simplistic understandings of human-environment interactions and sometimes even plain myths. This has contributed to a narrow policy vision, with important issues and ecosystems receiving less attention. Furthermore, conservation policy continues to be based on a highly uneven distribution of costs and benefits. In order to address these limitations, research and policy must do more to deal with differences in perceptions, priorities and power and be will­ing to embrace trade - offs between various conservation and development goals.
... More recently there have been vertebrate extinctions in Madagascar, Hawaii, and New Zealand. Several mammals, birds, and giant tortoises became extinct in Madagascar between man's arrival at about 500 A.D. and 1100 A.D. (Dewar, 1984). After the Hawaiian Islands were settled by the Polynesians, possibly as early as 400 A.D., the land bird fauna was reduced by extinction to half its former size (Olson & James, I 982a, l 982b). ...
... The upper areas, characterized by steep slopes that exceed 60° in the rocky, quartzitic outcrops, are less used for cattle. Ibity appears to be following the same transformation process that likely occurred earlier throughout much of the Malagasy highlands, where humans likewise used fire as a management tool for raising livestock and crops, reducing forest cover in favor of herbaceous, sometimes exotic species [56][57][58]. ...
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Globally, the number of protected areas (PAs) has increased exponentially during the last 25 years, particularly in biodiversity-rich developing countries. Many recent initiatives have integrated local-scale socio-economic development into both design and management. Because the rates of deforestation and species extinction are increasing in most parts of the world, substantial efforts have been made to build and strengthen local environmental organizations, to establish new protected areas (NPAs), and to improve natural resource management. An NPA was recently established at Ibity Massif in central Madagascar, where a community-based conservation project is being coordinated by the Missouri Botanical Garden (MBG). In December 2008, a temporary protection order was issued, and definitive establishment of the NPA, which falls under Category V of the IUCN PA system, is expected before the end of 2015. This initiative has involved significant outreach and community education programs to raise awareness of Ibity’s conservation and economic importance and the threats to its biodiversity, along with ongoing efforts to reduce fire frequency and implement ecological restoration projects with significant local community participation. In order to ensure th e sustainability of this NPA, a co-management plan has been implemented involving MBG, local authorities, and the local population. This study describes the diagnostic process undertaken at Ibity in order to: 1) disseminate the data gathered to inform establishment of the NPA; and 2) summarize the initial state of the environment on the massif prior to the implementation of a management plan, as a baseline for assessing the NPA’s effectiveness. © Swanni T. Alvarado, Elise Buisson, Stéphanie M. Carrière, Harison Rabarison, Charlotte Rajeriarison, Mamisoa Andrianjafy, Fleuria M. Randriatsivery, Margiane H. Rasoafaranaivo, Jeannie Raharimampionona, Porter P. Lowry II and Chris Birkinshaw.
... The debate over Madagascar's human settlement has been central to questions of anthropogenic impact on the island, notably via activities that may have contributed to the extinction of endemic fauna (Godfrey and Douglass, in press). Theories regarding anthropogenic drivers of extinction include potential overhunting, habitat modification, and forms of direct or indirect competition between endemic and introduced animals (Dewar, 1984(Dewar, , 1997Burney, 1997Burney, , 1999Hixon et al., 2018;Godfrey et al., 2019). Teasing apart drivers of extinction requires further clarification of anthropogenic landscape change, including in regions with long histories of foraging and the management of wild resources. ...
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Archaeologists interested in the evolution of anthropogenic landscapes have productively adopted Niche Construction Theory (NCT), in order to assess long-term legacies of human-environment interactions. Applications of NCT have especially been used to elucidate co-evolutionary dynamics in agricultural and pastoral systems. Meanwhile, foraging and/or highly mobile small-scale communities, often thought of as less intensive in terms of land-use than agropastoral economies, have received less theoretical and analytical attention from a landscape perspective. Here we address this lacuna by contributing a novel remote sensing approach for investigating legacies of human-environment interaction on landscapes that have a long history of co-evolution with highly mobile foraging communities. Our study is centered on coastal southwest Madagascar, a region inhabited by foraging and fishing communities for close to two millennia. Despite significant environmental changes in southwest Madagascar's environment following human settlement, including a wave of faunal extinctions, little is known about the scale, pace and nature of anthropogenic landscape modification. Archaeological deposits in this area generally bear ephemeral traces of past human activity and do not exhibit readily visible signatures of intensive land-use and landscape modification (e.g., agricultural modifications, monumental architecture, etc.). In this paper we use high-resolution satellite imagery and vegetative indices to reveal a legacy of human-landscape co-evolution by comparing the characteristics-vegetative productivity and geochemical properties-of archaeological sites to those of locations with no documented archaeological materials. Then, we use a random forest (RF) algorithm and spatial statistics to quantify the extent of archaeological activity and use this analysis to contextualize modern-day human-environment dynamics. Our results demonstrate that coastal foraging communities in southwest Madagascar over the past 1,000 years have extensively altered the landscape. Our study thus expands the temporal and spatial scales at which we can evaluate human-environment dynamics on Madagascar, providing new opportunities to study early periods of the island's human history when mobile foraging communities were the dominant drivers of landscape change.
... Understanding the chronology of extinction in relation to climate change and anthropogenic factors helps test extinction hypotheses. It has been suggested that dwarf hippopotamuses and other endemics in Madagascar coexisted with humans for up to a thousand or more years before the former became extinct (Dewar 1984;MacPhee and Burney 1991). But direct A modern African pygmy hippopotamus (Choeropsis liberiensis). ...
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2013 Island Faunas, In: Grzimek's Animal Life Encyclopedia: Extinction Edited by Melissa McDade, pp. 177-185 Gale-Centage Learning, Farmington Hills, MI • • • • • Island faunas While extinctions are part of evolution, studying this process on islands has long posed unique challenges and questions. Animals living on islands rather than on continental landmasses tend to be more vulnerable to extinction caused either by natural events or humans (Martin and Steadman 1999; van der Geer et al. 2010). This tendency has led to the belief that islands, as a result of their isolation, can serve as ideal controlled laboratories for the study of many ecological processes, including extinctions (cf. MacArthur and Wilson 1967). This view, however, is changing with the realization that seas are frequently not the barrier they were believed to be previously, particularly in relation to human colonization and impacts. Nonetheless, islands remain critical locations for examining the nature of extinctions. Types of islands Continental islands are those that lie on the continental shelf of a larger landmass and include New Guinea, Sicily, and Great Britain. Microcontinental islands are a specialized type of continental island that results when a continent is rifted (broken apart); examples include Madagascar and New Zealand. Many of these types of islands throughout the world were, at various times in the past, connected by land bridges to the mainland or are located only a short distance from continental masses. Oceanic islands, by contrast, are those that do not sit on continental shelves, and they tend to be remote. These islands often contain unique animals as a result of their isolation. Thus, it is likely that endemic animals did not arrive on most oceanic islands by land bridges, contrary to suggestions by some researchers. In the Mediterranean, one of the most studied areas, only Sicily has clear evidence of such a connection, although some also believe that Sardinia, Corsica, and the Balearics may have been connected to the mainland at the beginning of the Tertiary period some 65 million years ago (summarized in Simmons 1999). In addition to the geological evidence, Paul Y. Sondaar (1977, 1986) presents a convincing argument against the land bridge theory, noting that it does not account for the composition of most island faunas. Instead, the so-called "island sweepstakes" route proposed in 1940 by George Gaylord Simpson seems more likely. This theory refers to instances in which animals may venture far from the coast, reach an isolated island from which they cannot return, and be forced to settle there.
... The island of Madagascar (589 500 km 2 ) is inhabited by a diverse avian fauna, which includes numerous endemic taxa (MILON et al. 1973, BENSON 1984, LANGRAND 1990, GOODMAN et al. 1997, YAMAGISHI et al. 1997, SINCLAIR & LAMGRAND 1998. The historical past of the avifauna is less known (see DEWAR 1984). Most of the reports focused on the giant, flightless elephant birds from the endemic family Aepyornithidae (see MONNIER 1913, LAMBRECHT 1933, LAMBERTON 1934, WIMAN 1935, MLÍKOVSKÝ 2003. ...
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A rare collection of 61 subfossil bird bones from Andrahomana cave in southern Madagascar was descri-bed. The collection is housed in the Naturhistorisches Museum Wien, Austria. Together, 10 species from 8 families were identified. Two of the species (Puffinus sp,. and Coua sp.) are probably extinct. Zusammenfassung Eine seltene Sammlung 61 subfossiler Vogelknochen aus der Andrahomana-Höhle in Süd-Madagaskar wurde beschrieben. Die Sammlung liegt im Naturhistorischen Museum Wien, Österreich. Insgesamt konn-ten 10 Arten aus 8 Familien identifiziert werden. Zwei von den Arten (Puffinus sp. und Coua sp.) sind wahrscheinlich ausgestorben.
... For instance, the Honey Bee project documented more than fourteen hundred innovative practices in dry regions of some African countries to prove that local people have rich knowledge in resource use and conservation (Gupta, 1999). Also various studies in other countries outside Africa such as America (Kidwell, 1991;Leon-Portilla, 1980;Turner, 1991;Pinkerton, 1989), India (Meilinda, 2006), Indonesia (Emsley, 1991;Heeds, 1991;Hoddy, 1991;Kuhnlein and Turner, 1991;Warren, 1997), and Australia (Davis, 1988;Johannes, 1993;Miyako, 2006) Middleton (1999), are not found there anymore because local people, acclaimed by Dewar (1984) and Tattersall (1982) to have had understanding of the environment hunted them to extinction (Middleton, 1999). ...
... When the European colonizers arrived, huge elephant bird eggshells still littered the beaches of the island's south and south-eastern coasts, pointing to a very recent extinction indeed. Furthermore, Madagascar also lost pigmy hippos and giant fossas (Dewar, 1984). In New Zealand, there was an equally spectacular fauna of a dozen species of moas, large terrestrial birds up to three metres tall, plus the gigantic Haast's eagle Harpagornis moorei. ...
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As Alfred Russell Wallace once wrote, we live in a zoologically impoverished world, from which most of the largest, strangest and most spectacular animals disappeared quite recently. About two thirds of all animal species larger than 50 kg (the so-called megafauna) were extinct from the late Pleistocene onwards, starting in Australia at about fifty thousand years ago and following humans' footsteps is their expansion throughout Eurasia and the Americas. The extinctions went on through the Holocene, reaching islands all around the globe, that can be seen as 'time machines' where megafauna survived for millennia after the continental extinctions, such as the Caribbean, the islands off Alaska, and Wrangel Island in the Arctic Ocean. In Madagascar and New Zealand, extinctions are but a few centuries old. These late Quaternary extinctions were a global phenomenon that begs for a global explanation. Climatic hypotheses fail to explain these patterns for several reasons, for example, there were dozens of other glacial cycles throughout the Pleistocene, without associated mass extinctions; extinctions in Australia and the islands did not coincide with glacial peaks; and climate changes cannot explain why extinctions were systematically more recent on islands. However, the pieces of the puzzle immediately fit together when we observe the clear correspondence between the dates of humans' arrival and of megafaunal extinction in each landmass. Bernardo Araujo recently analysed the chronology of extinctions of megafaunal genera around the world. He found that extinctions took place closer than expected by chance to periods of high climatic variation alone in only two of the analysed cases, to dates of human arrival alone in seventy-four cases, and to both in eight cases, with 40 cases unexplained. Thus, anthropogenic impact is the most plausible and parsimonious main cause of the late Quaternary extinctions. In a modern view, the extinctions were a long process that took several millennia to occur in most continents, with a few stragglers like the Irish elk and the North American mastodons. Low reproductive potential was the main determinant of the extinct species; the apparent selection by size is an artefact of the inverse correlation between the two variables. The absence of evolved instincts against newly arrived humans, the difficulty of conserving meat and the lack of perception of the world's finitude must have contributed to the outcome. Thus, human-megafauna interactions are an important and undervalued part of human history that merits being represented on the UNESCO World Heritage List. Furthermore, learning from the extinctions of the past is crucial to allow us to minimise extinctions in the future. Candidate sites in the Americas might include those that show consumption of megafauna (such as Monte Verde), remarkable rock paintings (such as Serra da Capivara, Brazil) and the latest American megafauna (such as Las Breas de San Felipe, Cuba).
... Anecdotal information summarized by Godfrey (1986) strongly supports the notion that at least one kind of Malagasy hippo survived until the modern era. However, the youngest 14C date, on material of Hippopotamus [emerlei from Itampolo, is 980 ± 200 rcyrbp (Mahe and Sourdat, 1972; Dewar, 1984 ). Nevertheless, the ubiquity of hippo remains in sites of apparently recent vintage and the widespread oral tradition of the hippolike lalomena (Flacourt, 1661) justify our inclusion of this species and its undated relative H. madagaseariensis (nee Hexaprotodon, contra Harris [1991]) in Table 2. ...
... An extinction of Malagasy megafauna species and rapid aridification of Malagasy flora occurred between 1,000 and 2,000 years before present (see, e.g., Burney 1993Burney , 1997Jungers et al. 1995). Researchers have attributed the ultimate cause of this environmental change to anthropogenic or natural causes (Martin 1966;Dewar 1984;Jungers et al. 1995). Yet Dewar (1997) has shown that strong supporting evidence does not exist for any one of these hypotheses. ...
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Lisa Gezon is Assistant Professor of Anthropology at the State University of West Georgia. Since 1990, she has conducted ethnographic interviews about local forest use, recent forest history, and aspects of community life throughout her extended field visits. Along with a team of researchers and conservation workers, she developed and administered socioeconomic surveys in villages south of Ankarana and west of Mt. d'Ambre in 1991. During 1992 -1993 she lived in and studied local resource use in villages around Ankarana (Gezon 1995). She returned for brief follow-up visits in 1995 and 1999. Gezon's primary field site was a commoner village named Bevary in northwestern Ankarana. She also conducted ethnographic research in the royal Antankarana village in southwestern Ankarana. Benjamin Z. Freed is Adjunct Assistant Professor of Biology at Emory University. He conducted a three-year study of primate ecology and conservation in Mt. d'Ambre. In 1989 he surveyed and interviewed local people throughout Mt. d'Ambre. He conducted follow-up interviews in northeastern and western Mt. d'Ambre during 1990 -1991. Abstract: In this manuscript we pursue the question, under what circumstances is agroforestry a viable component of conservation? We describe tree-planting and conservation efforts in two protected areas in northern Madagascar. Mt.d'Ambre and Ankarana lie close to each other, have been subject to similar historical pressures, and are administered by the same conservation authorities. Yet aspects of local ethnicity, economy, political organization, social organization, and land tenure differ. The areas also differ in forest structure and conservation pressures. We pay particular attention to the agroforestry efforts of the integrated conservation and development (ICDP) phase of conservation. We note issues particular to protected area management and to the dual needs of protecting forest resources while providing for the needs of the people living around the forests. While some potential and identifiable benefits exist, tree-planting has not always aided conservation efforts in northern Madagascar. Problems have occurred when planners have ignored local forest use, recent forest history, and socioeconomic issues (e.g., land tenure, immigration/migration, local traditions, intergroup conflict, subsistence patterns, kinship). This paper highlights factors that have deterred the overall effectiveness of tree-planting efforts in this region and identifies factors that resource managers and conservationists need to address when initiating successful projects. While critical of many aspects of the agroforestry efforts, we argue that agroforestry should not be abandoned as a component of conservation and protected area management. Such efforts may work in this region if planners: 1) encourage local participation in the development, implementation, and maintenance of these projects, working within the context of local political organization; 2) enhance and maintain long-term communication between planners and local people; 3) facilitate communication both within and between villages; 4) assure individuals or households the ultimate rights or responsibilities for land use; 5) establish a fair distribution of project benefits; and 6) separate the roles of extension workers and enforcement agents.
... Several lines of evidence (archaeological, linguistic, broad geographical screening) support this migration (e.g. Battistini et al., 1963;Vérin, 1975;Dewar, 1984;Dewar et al., 2013;Beaujard, 2011;Cox et al., 2012). Fig. 9 provides a summary of this settlement in northwestern/ northern Madagascar. ...
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The timing and causes of paleoenvironmental changes in Madagascar have been debated, specifically in respect to human activity following the settlement in the late Holocene. Here we present δ¹⁸O, δ¹³C, layer-bounding surfaces, layer-specific width, mineralogy, and distribution of macroholes from Stalagmite MA3 from Anjohibe Cave to provide a detailed understanding of the paleoenvironmental changes in northwestern Madagascar between 370 CE and 1300 CE. The stable isotope records of Stalagmite MA3 are compared with stable isotope records of Stalagmites ANJ94-5 and MA2.
... An undated, unidentified leg element of Mullerornis sp. recovered from an archaeological context from Ampasambazimba (29,30) exhibits modification that may represent natural processes (31,32), and an Aepyornis sp. tibiotarsus from Itampolo, dated to the pre-agriculture period [1297 to 1590 years B.P. (33)], exhibits postmortem rather than perimortem modification. ...
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Previous research suggests that people first arrived on Madagascar by ~2500 years before present (years B.P.). This hypothesis is consistent with butchery marks on extinct lemur bones from ~2400 years B.P. and perhaps with archaeological evidence of human presence from ~4000 years B.P. We report >10,500-year-old human-modified bones for the extinct elephant birds Aepyornis and Mullerornis , which show perimortem chop marks, cut marks, and depression fractures consistent with immobilization and dismemberment. Our evidence for anthropogenic perimortem modification of directly dated bones represents the earliest indication of humans in Madagascar, predating all other archaeological and genetic evidence by >6000 years and changing our understanding of the history of human colonization of Madagascar. This revision of Madagascar’s prehistory suggests prolonged human-faunal coexistence with limited biodiversity loss.
... formations. Burney also supports the idea that a mosaic of vegetation was present just prior to the arrivai of humans at the sites he has studied (Burney 1987a, this volume; see also Dewar 1984). ...
... Whereas it is well known that Madagascar's megafauna declined and vanished after humans arrived, the relative importance of climate and human impacts (whether through hunting or habitat modification) as triggers for megafaunal extinction continues to be debated (see Battistini, 1965;Dewar, 1984;Burney et al., 2003Burney et al., , 2004Crowley, 2010;Douglass and Zinke, 2015;Burns et al., 2016;Ekblom et al., 2016;Crowley et al., 2017;Salmona et al., 2017;Anderson et al., 2018;Douglass et al., 2018;Hixon et al., 2018). Explanations generally focus on climatic or anthropogenic pressures, or both. ...
... Furthermore, evidence suggests that humans first colonized Madagascar~2,000 years ago and subsequently had a rapid and profound impact on the native biota and their habitats [70,71]. A variety of hypotheses have been put forth to explain the decline of Malagasy flora and fauna subsequent to human colonization, including increased frequency of fire [72], drought [73], hunting [74], invasive species [75], disease [70], and synergistic anthropogenic influences [76]. Regardless of the exact mechanism(s), it is highly probable that the recent and rapid population decline inferred from our data for M. murinus has been exacerbated by subsequent anthropogenic influences beginning around 2,000 years ago. ...
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Debate continues as to whether allopatric speciation or peripatric speciation through a founder effect is the predominant force driving evolution in vertebrates. The mouse lemurs of Madagascar are a system in which evolution has generated a large number of species over a relatively recent time frame. Here, we examine speciation patterns in a pair of sister species of mouse lemur, Microcebus murinus and M. griseorufus. These two species have ranges that are disparately proportioned in size, with M. murinus showing a much more extensive range that marginally overlaps that of M. griseorufus. Given that these two species are sister taxa, the asymmetric but overlapping geographic ranges are consistent with a model of peripatric speciation. To test this hypothesis, we analyze DNA sequence data from four molecular markers using coalescent methods. If the peripatric speciation model is supported, we predict substantially greater genetic diversity in M. murinus, relative to M. griseorufus. Further, we expect a larger effective population size in M. murinus and in the common ancestor of the two species than in M. griseorufus, with a concomitant decrease in gene tree/species tree incongruence in the latter and weak signs of demographic expansion in M. murinus. Our results reject a model of peripatric divergence. Coalescent effective population size estimates were similar for both extant species and larger than that estimated for their most recent common ancestor. Gene tree results show similar levels of incomplete lineage sorting within species with respect to the species tree, and locus-specific estimates of genetic diversity are concordant for both species. Multilocus demographic analyses suggest range expansions for M. murinus, with this species also experiencing more recent population declines over the past 160 thousand years. Results suggest that speciation occurred in allopatry from a common ancestor narrowly distributed throughout southwest Madagascar, with subsequent range expansion for M. murinus. Population decline in M. murinus is likely related to patterns of climate change in Madagascar throughout the Pleistocene, potentially exacerbated by continual anthropogenic perturbation. Genome-level data are needed to quantify the role of niche specialization and adaptation in shaping the current ranges of these species.
... In the past, a diverse vertebrate herbivore assemblage of now-extinct primates, hippopotamuses, elephant birds and giant tortoises inhabited the island [21] which were suggested to have used grasslands [7]. Hippopotamuses and giant tortoises are prime grazer candidates [18,19] but carbon isotope data exist for only a few specimens from the grassy centre of the island and evidence to support a grazer assemblage is limited [19]. ...
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The ecology of Madagascar's grasslands is under-investigated and the dearth of ecological understanding of how disturbance by fire and grazing shapes these grasslands stems from a perception that disturbance shaped Malagasy grasslands only after human arrival. However, worldwide, fire and grazing shape tropical grasslands over ecological and evolutionary timescales, and it is curious Madagascar should be a global anomaly. We examined the functional and community ecology of Madagascar's grasslands across 71 communities in the Central Highlands. Combining multivariate abundance models of community composition and clustering of grass functional traits, we identified distinct grass assemblages each shaped by fire or grazing. The fire-maintained assemblage is primarily composed of tall caespitose species with narrow leaves and low bulk density. By contrast, the grazer-maintained assemblage is characterized by mat-forming, high bulk density grasses with wide leaves. Within each assemblage, levels of endemism, diversity and grass ages support these as ancient assemblages. Grazer-dependent grasses can only have co-evolved with a now-extinct megafauna. Ironically, the human introduction of cattle probably introduced a megafaunal substitute facilitating modern day persistence of a grazer-maintained grass assemblage in an otherwise defaunated landscape, where these landscapes now support the livelihoods of millions of people.
... The South American timing pattern seems to mimic that of North America with the major pulse of extinction occurring at the very end of the Pleistocene (Martin and Steadman 1999). Alternately, certain islands such as Wrangel Island in arctic Siberia, the West Indian Islands, and Madagascar maintained some of the typical Pleistocene megafauna after 10,000 yrs BP (Dewar 1984, Martin and Steadman 1999, Steadman et al. 2005. Essentially the argument against the climate-driven extinction is that these patterns mimic the arrival of humans, or the transition of human culture to a more advanced state, in each major global geographic region rather than consistently correlating with climate change. ...
Chapter
In order to classify trees in the Lokobe Forest, Nosy Be, as dispersed, possibly dispersed, or not dispersed by Black Lemurs(Eulemur macaco)two Black Lemur groups were habituated and observed during the day and night for all months of the year (total 1219 hours). When fruits were eaten, the species was identified, and the maturity of the fruit and treatment of the seeds noted. Black Lemur droppings were searched for seeds; these were identified and signs of damage noted. Species that had ripe fruit that were not eaten by the Black Lemur were also identified, as were fleshy-fruited species that produced little or no ripe fruits during the study. Other frugivores feeding on the fruits of black lemur-dispersed species were also noted. In order to estimate the proportion of tree species, tree trunks, and trunk basal area in the Lokobe Forest dispersed, possibly dispersed, and not dispersed by Black Lemurs, plots were installed in Lokobe’s two forest types and the trees they enclosed were identified and their dbh measured. For the slope forest Black Lemurs dispersed 57% of the represented tree species, 71% of the represented tree trunks, and 73% of the represented trunk basal area. For the ridge forest these values were 49%, 76%, and 88% respectively. Only four of the 38 black lemur-dispersed species had fruits that were also eaten by other frugivore species. These results show that the Black Lemur is very important for seed dispersal in Lokobe Forest.
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This contribution provides an analytical accounting of mammal species that have disappeared during the past 500 years—the “modern era” of this chapter. Our choice of date was dictated by several considerations, but two are paramount. ad 1500 marks more or less precisely the beginning of Europe’s expansion across the rest of the world, a portentous event in human history by any definition. It is an equally momentous date for natural history because it marks the point at which empirical knowledge of the planet began to burgeon exponentially. These two factors, linked for both good and ill for the past half-millennium, have affected every aspect of life on earth, and are thus fitting subjects to commemorate in a record such as this.
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Inferring cause and effect from the fossil record is not a wholly satisfying enterprise. The evidence is stale. Many useful details are missing, perhaps never to be found. Sequential events may be collapsed together, inverted, or mixed with evidence from other times. Few relevant parameters can be measured directly. Paleoecologists must forge ahead despite these obstacles, however, as extinction and environmental change are subjects too important to ignore.
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Traditionally primates have been described as displaying either nocturnal (active only at night) or diurnal (active only during daylight hours) activity cycles. However, researchers investigating the behavior and ecology of Malagasy prosimian primates discovered that many species in the genus Eulemur traditionally labeled as diurnal also were active at night (E. f rufus: Sussman, 1974; E. mongoz: Sussman and Tattersall, 1976; Tattersall and Sussman, 1975; E. f. mayottensis: Tattersall, 1977; Tattersall, 1979; E. rubriventer: Overdorff, 1988; E. macaco: Colquhoun, 1993; E. coronatus and E. f. sanfordi: Freed, pers. comm.). While E. mongoz appears to seasonally switch from a diurnal activity cycle to a completely nocturnal activity pattern, other species such as E. fulvus and E. rubriventer have been observed to be active irregularly during both the day and night. These observations led Tattersall (1988) and Fleagle (1988) to propose and define the word “cathemeral” as a possible label for this unusual activity pattern. However, it has not yet been determined whether activity during the day and night is a seasonal phenomenon or a year-round pattern typical for Malagasy lemurids. There is evidence that some New World primates may be active day and night. For example, howling monkeys move and feed at night, although rarely (Dahl and Hemingway, 1988). In addition, Wright (1985, 1989) observed that the traditionally nocturnal night monkey (Aotus trivirgatus) was active during the day in Paraguay presumably due to the rarity of large diurnal raptors.
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Landscapes are more than a simple function of geological, geomorphological, climatic, and botanical parameters. Animals play an important role. Their behavior, especially their trophic habits, is a major force in the forming of landscapes. Herbivores consume the products of the primary biomass production. Fire and man have been doing the same since they appeared on Earth. Moreover, both are not only herbivorous, but also carnivorous, devouring whatever animal wherever they can.
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The fossil record of the earth shows that faunal and floral extinctions increased dramatically during certain periods. These “paleo” upheavals like those at the end of Permian and Cretaceous have long provided the punctuations that geologists and paleontologists use to divide the geological periods. A challenging question in conservation science is whether the processes affecting extinction rates today are helpful in interpreting extinction in the past and, conversely, whether prehistoric extinctions are useful for understanding recent extinctions.
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This article summarizes current research on the people of Madagascar, the possible causes of megafauna extinctions, and the development from early settlements to the Malagasy states at the time of European contact. Hume, Douglas W. 2008. “Geographic Overviews, Africa (East): Madagascar and Surrounding Islands.” In Encyclopedia of Archaeology, edited by Deborah M. Pearsall, 1: 17–19. New York: Elsevier. https://doi.org/10.1016/B978-012373962-9.00175-8.
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There is no good reason why any lemur species should go extinct. Present-day lemurs, those that survived the first human onslaught on Madagascar, are small, unthreatening creatues. They are not major crop raiders; they don’t even offer much meat. They can live in small patches of forest, at population densities more like squirrels than apes or monkeys. Most are surprisingly adaptable. Even the ones we have not learned to breed in captivity live in a variety of forest types in the wild.
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It has been postulated that predation has been an important selective force in molding social behavior in mammals. However, observations of predators taking primates are rare and most cases concern relatively large diurnal primates. For the lemurs of Madagascar little quantified information is available, and it has generally been assumed that predation by carnivores and raptors is rare. Contrary to expectations there is a considerable amount of data on the topic, derived from several different sources, which is presented herein. The most detailed information on lemur predation is for Microcebus murinus. The population dynamics of this species is reviewed in light of heavy predation pressure from two owls (Tyto alba and Asio madagascariensis),particularly the implications of predation on social behavior and life-history traits of this small nocturnal primate.
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Plant biomass consumption by herbivores is a major influence on the structure of the vegetation canopy. In woodland and forests megaherbivores are most important. In the presence of dense populations of megaherbivores a multi-species fauna of smaller herbivores prevents the formation of a closed crown canopy. In the Tertiary and (outside the range of Homo) in the Quaternary there is always at least one species of megaherbivores on all continents and in all climates. Forests were generally more open and patchy, and while less carbon was stored in plant biomass, high herbivore biomass produced large quantities of methane. In the tropics of the Old World, long coevolution of hominids and megaherbivores allowed some species to adapt to human hunting. Their population density, however, was reduced. As a consequence, with an increase of tree cover and canopy closure, more carbon was sequestered and less methane emitted. Since the Middle Pleistocene Homo proceeded into other climates and continents. There, all megaherbivores became extinct, and crown canopies of forested lands began to close. Since the Lower Pleistocene anthropogenic fire regimes shaped the vegetation cover outside the humid regions. It is suggested that anthropogenic changes, through extinction of megaherbivore populations and introductuion of large-scale use of fire, have changed the albedo and influenced carbon fluxes, thus triggereing climatic feedback processes of the Quaternary.
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Researchers are divided about the relative importance of people versus climate in triggering the Late Holocene extinctions of the endemic large-bodied fauna on the island of Madagascar. Specifically, a dramatic and synchronous decline in arboreal pollen and increase in grass pollen ca 1000 yr ago has been alternatively interpreted as evidence for aridification, increased human activity, or both. As aridification and anthropogenic deforestation can have similar effects on vegetation, resolving which of these factors (if either) led to the demise of the megafauna on Madagascar has remained a challenge. We use stable nitrogen isotope (δ15N) values from radiocarbon-dated subfossil vertebrates to disentangle the relative importance of natural and human-induced changes. If increasing aridity were responsible for megafaunal decline, then we would expect an island-wide increase in δ15N values culminating in the highest values at the time of proposed maximum drought at ca 1000 yr ago. Alternatively, if climate were relatively stable and anthropogenic habitat alteration explains the palynological signal, then we would anticipate little or no change in habitat moisture, and no systematic, directional change in δ15N values over time. After accounting for the confounding influences of diet, geographic region, and coastal proximity, we find no change in δ15N values over the past 10 000 yr, and no support for a period of marked, geographically widespread aridification culminating 900-950 yr ago. Instead, increases in grasses at around that time may signal a transition in human land use to a more dedicated agro-pastoralist lifestyle, when megafaunal populations were already in decline. Land use changes ca 1000 yr ago would have simply accelerated the inevitable loss of Madagascar's megafauna.
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The debate on the peopling of Madagascar has long been dominated by historical linguistics and the observed similarities between Malagasy and Austronesian languages. It is clear from the linguistic evidence that there have been several periods of human contact with, or migration to, Madagascar—and that these also brought different domesticates to the island (Allibert 1998, 2007; Beaujard 2011a,b; Boivin et al. 2013). Genetics is currently the main tool being used to understand the peopling of Madagascar (Hurles et al. 2005; Tofanelli et al. 2009; Murray et al. 2012; Pierron et al. 2014). However, despite recent advances in the field of genetic studies we still know very little about either the first colonisation on Madagascar or about the contacts between the populations of Madagascar, the Austronesian influence zone, and the African mainland. Moreover, Vérin and Wright (1999) have warned that inferences from linguistic and genetic studies can be misleading, and that there is often a disjuncture between language and human biology on the one hand and material culture and identity on the other.
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During the Pleistocene the diversity of mammals in South America became extremely elevated. It seems that hyperdiversity reached the highest known in the world. There has been nowhere else where so many (about 37) megamammals (weighing more than 1000 kg) were found, all of which became extinct, during the last 8000–9000 years ago. Another 44 species or so of large mammals weighing more than 45 kg and less than 1000 kg also became extinct. Of course ecological factors played a huge role in leveling this out-of-balance fauna, but the intriguing question has always been about the role that human beings had to cause these mammals to go extinct. Since we are unsure of the date of arrival of human beings (which might have begun as early as 40,000 years ago), it is difficult to put an exact date on the beginning of this new ecological pressure, but between 12,000 and 8000 years ago, the last extinctions occurred, when we know that humans were living widely throughout the continent.
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Ecometric modelling relates spatial environmental variables to phenotypic characters to better understand morphological adaptation and help reconstruct past environments. Here, the community means of the dental topography metrics Dirichlet normal energy (DNE) and orientation patch count (OPC) are tested against annual precipitation and precipitation seasonality among lemurs across Madagascar. Dry, seasonal environments are expected to be associated with high DNE and OPC, as lemurs living in these environments are more likely to rely on tougher foods. Ecometric models are also used to calculate ecometric loads for lemur taxa hypothesized to be experiencing evolutionary disequilibria and to reconstruct annual precipitation and precipitation seasonality at the ~500 years BP subfossil cave site of Ankilitelo. DNE was highest in highly seasonal but wet environments. Seasonal exploitation of fallback foods and the availability of new leaves during wet periods may be most important in driving community DNE. OPC was weakly predicted by annual precipitation and seasonality but its distribution appeared to be driven by a stepwise increase in its community values in rainforest environments. The lemur fauna from Ankilitelo appears to resemble communities from moister environments than occur in the spiny desert zone in which the site is situated today.
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Reconstructing the dynamics and drivers of late Quaternary megafaunal extinctions requires direct radiometric date series that are assessed within probabilistic statistical frameworks. Extinction chronologies are poorly understood for many tropical regions, including Madagascar, which had a diverse, now-extinct Holocene large vertebrate fauna including a “megaherbivore” guild of endemic hippopotami and elephant birds. Madagascar's megaherbivores likely played vital roles in regulating ecosystem structure and nutrient cycling, but few direct dates are available for megaherbivore specimens identified to species level, with uncertainty over when and why different representatives of this guild disappeared. Here, we conduct a new investigation into Malagasy megaherbivore extinction dynamics, including 30 new AMS dates and 63 audited published dates. We use Gaussian-resampled inverse-weighted McInerny (GRIWM) analysis to estimate species-specific extinction dates for three elephant bird species (Aepyornis hildebrandti, Mullerornis modestus, Vorombe titan), eggshell representing Aepyornis or Vorombe, and two hippo species (Hippopotamus lemerlei, H. madagascariensis), and to estimate extinction dates for megaherbivore communities in different biomes. Megaherbivores persisted for millennia after first human arrival. Extinction date estimates vary significantly between biomes, with disappearance from dry deciduous forest over a millennium earlier than other biomes, possibly reflecting local variation in megaherbivore population densities or human pressures. However, megaherbivore communities including all elephant bird and hippo species persisted elsewhere across Madagascar until ∼1200-900 bp, when they collapsed suddenly. Extinctions are closely correlated in time with intensive conversion of forests to grassland at ∼1100-1000 bp, probably associated with a shift to agro-pastoralism and representing a radical change in sustainability of prehistoric human interactions with biodiversity.
Article
Native peoples have often been portrayed as natural conservationists, living a "balanced" existence with nature. It is argued that this perspective is a result of an imprecise operational definition of conservation. Conservation is defined here in contrast to the predictions of foraging theory, which assumes that foragers will behave to maximize their short-term harvesting rate. A behavior is deemed conservation when a short-term cost is paid by the resource harvester in exchange for long-term benefits in the form of sustainable harvests. An example of the usefulness of such an operational definition is presented using data on patch and prey choice decisions of a group of subsistence hunters, the Piro of Amazonian Peru. Results indicate that the area around the Piro village is depleted of prey, and that hunters allocate more time to patches where return rates are highest. This response is consistent with both a conservation strategy and foraging theory. Contrary to the expectation of the conservation strategy, however, hunters do not restrain from pursing opportunistically encountered prey in the depleted areas. The implications for conservation policy are briefly discussed.
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