of domestic water in the high-rise buildings typical of Hong Kong often comes from a tank located... more of domestic water in the high-rise buildings typical of Hong Kong often comes from a tank located on the building's roof, suggesting that the risk factor of domestic water may also be important in Hong Kong. Reports suggest that acanthamoeba keratitis is an emerging disease in south and east Asia 4 where there has been an increase in the use of contact lenses. 5 With substantial cultural, social, environmental, and climatic differences between Asia and elsewhere, we believe studies to determine risk factors for this disorder are a matter of urgency.
To address claims of human exceptionalism, we determine where humans fit within the greater mamma... more To address claims of human exceptionalism, we determine where humans fit within the greater mammalian distribution of reproductive inequality. We show that humans exhibit lower reproductive skew (i.e., inequality in the number of surviving offspring) among males and smaller sex differences in reproductive skew than most other mammals, while nevertheless falling within the mammalian range. Additionally, female reproductive skew is higher in polygynous human populations than in polygynous nonhumans mammals on average. This patterning of skew can be attributed in part to the prevalence of monogamy in humans compared to the predominance of polygyny in nonhuman mammals, to the limited degree of polygyny in the human societies that practice it, and to the importance of unequally held rival resources to women’s fitness. The muted reproductive inequality observed in humans appears to be linked to several unusual characteristics of our species—including high levels of cooperation among males...
The purpose of this paper is to apply [a model that predicts changes in heterozygosity as a funct... more The purpose of this paper is to apply [a model that predicts changes in heterozygosity as a function of mating structure] to estimate the genetic effects of mating patterns on Sanday Orkney Islands [Scotland] and to compare these results with those from previous analyses of two French West Indian island populations. (EXCERPT)
The frequently reported observation that nomadic populations have lower fertility than their sett... more The frequently reported observation that nomadic populations have lower fertility than their settled counterparts is often attributed to what are perceived as harsh, stressful conditions under which the nomads live. But the consequences of the hypothesized stresses for the reproductive biology or demography of these populations have been documented only a little. Traditionally, the Turkana of northwest Kenya are nomadic herders, but increasing numbers have settled on agricultural development schemes. We used an array of hormonal assays along with anthropometric indexes of nutritional status and interviews covering reproductive history, recent menstruation, diet, and health to compare reproductive function in nomadic and settled Turkana women. First morning urine samples were collected for three consecutive days during a series of surveys. Human choriogonadotropin (hCG; a marker for pregnancy), luteinizing hormone (LH; an indicator of ovulation), and pregnanediol glucuronide (PdG; an indicator of postovulatory luteal function) were assessed in the field with commercially available dipstick enzyme immunoassays. These assays along with the interview data allowed us to determine the reproductive status (e.g., pregnant or cycling, and if cycling, which phase of the ovarian cycle) of 166 nomadic and 194 settled Turkana women. The cross-sectional classifications allowed inferences of conception rates and normality of ovarian function. Follow-up surveys provided rates of pregnancy loss. Compared with the settled women, the nomadic women exhibited lower pregnancy rates and cycling nomadic women were less likely to show evidence of ovulation or luteal function. These results suggest that reproductive function of the nomadic women is diminished relative to the settled women. However, the settled women experienced a much higher rate of pregnancy loss, which may mean that their effective fecundability is in fact lower than that of the nomadic women. This study is the first to apply such a wide range of hormonal assays in the field. It demonstrates that field-based assays are feasible and robust and can play an important role in epidemiological and biodemographic studies, even in remote locations under conditions that would ordinarily be considered incompatible with on-site laboratory analysis.
In this paper we examine how the 2008/09 drought in northern Tanzania contributed to and catalyze... more In this paper we examine how the 2008/09 drought in northern Tanzania contributed to and catalyzed the transformation of governance concerning the management of natural resources from traditional informal institutions among the Maasai to formal village-based institutions. Our central argument is that village governance in northern Tanzania represents a new, formal institution that is supplementing and in some important ways obviating traditional, informal institutions. Further, this replacement is central to what appears to be a transformation of the social-ecological system embracing the rangelands and pastoral/agro-pastoral people in northern Tanzania. In this paper, we document the basis for our claims concerning the institutional shift and discuss its implications for livelihoods and social relationships.
There have been few investigations of intrauterine mortality in non-Western populations that have... more There have been few investigations of intrauterine mortality in non-Western populations that have used techniques capable of detecting early pregnancy loss. We report here the initial results of a prospective study of fetal loss among the Turkana of northwest Kenya. Over 300 nomadic and settled women provided early morning urine samples for 3 consecutive days. Chorionic gonadotropin (hCG), a marker for pregnancy, and markers of ovarian cyclicity (LH, PdG) were determined with solid-phase enzyme immunoassays. Pregnancy was detected in 11% of nomadic women and in 22% of sedentary women of reproductive age. Follow-up surveys revealed that 45% of all pregnancies among settled women were lost; nearly 70% of pregnancies detected in the first trimester were lost. In contrast, none of the nomadic women experienced fetal loss. Because of the small sample sizes, these results must be interpreted cautiously. Nevertheless, even a conservative estimate of the fetal loss rate among the settled women is high compared with Western experience. Anthropometric data suggest that nutritional stress may contribute to the difference between the two populations. There is also some indication that risk of fetal loss in the settled population is associated with parity. The high rate of loss among the settled women along with the difference between the nomadic and settled samples supports the contentions that there may be substantial variation among populations in intrauterine mortality and that the contribution of fetal loss to fertility differences among populations may be more important than has been suspected.
The Turkana, like other East African pastoral groups, are known for their tall adult stature, ach... more The Turkana, like other East African pastoral groups, are known for their tall adult stature, achieved despite a blunted growth spurt during adolescence and continued growth into the early 20s. To investigate the hormonal mechanisms associated with the pattern of slow and continued adolescent growth, we collected data on hormonal status, height, weight, and trunk skinfolds and ethnographic self-reports of testicular maturation in a cross-sectional sample of 35 nomadic and 37 settled Turkana males aged 14-24. Hormonal determinations included testosterone (T), sex hormone-binding globulin (SHBG), and dehydroepiandrosterone (DHEA) in blood, in addition to urinary DHEA. Self-reports of testicular maturation showed no difference between settled and nomadic
Currently-available models used for predicting human caloric requirements do not reflect the grea... more Currently-available models used for predicting human caloric requirements do not reflect the great variability in activity patterns observed among populations, and are insensitive to important anthropometric, demographic, and-environmental variables. They are thus inadequate for application to many populations and problems of anthropological interest. We present a model for determining caloric requirements which more accurately accommodates the effects of variation in activity and ih anthropometrics on individual needs, and which predicts population requirements based on individual needs and demographic parameters. The model is tested on four populations (the Andean community of Nu~oa, Peru~ the Dobe !Kung of Botswana, and two New Guinean villages) and is found to provide consistently better estimates of caloric requirements than are generated by the Food and Agriculture~World Health Organization's model. This model shouM be useful to anthropologists and human ecologists concerned with problems involving human energy consumption, such as the efficiency of subsistence strategies, optimum family composition, or certain consequences of increased labor migration or technological change.
Carolina Digital Repository (University of North Carolina at Chapel Hill), 2014
Analyzing people's decisions can reveal key variables that affect their behaviors. Despite the de... more Analyzing people's decisions can reveal key variables that affect their behaviors. Despite the demonstrated utility of this approach, it has not been applied to livelihood decisions in the context of conservation initiatives. We used ethnographic decision modeling in combination with qualitative comparative analysis (QCA) to examine the herding decisions of Maasai households living near Tarangire National Park (TNP) during recent and historical droughts. The effects of the establishment of TNP on herding practices during drought were different than anticipated based on the size and reliability of several prominent resource areas that are now within the park. We found little evidence of people relying on these swamps and rivers for watering cattle during historical droughts; rather, these sites were more commonly used as grazing areas for small stock and wet-season grazing areas for cattle to avoid disease carried by calving wildebeest. Yet during the 2009 drought, many herders moved their livestockespecially cattle from outside of the study areatoward TNP in search of grazing. Our analysis of herding decisions demonstrates that resource-use decisions are complex and incorporate a variety of information beyond the size or reliability of a given resource area, including contextual factors (e.g., disease, conflict, grazing) and household factors (e.g., social capital, labor, herd size). More broadly, this research illustrates that pairing decision modeling with QCA is a structured approach to identifying these factors and understanding how opportunities, constraints, and perceptions influence how people respond to changes in resource access.
Annals of the New York Academy of Sciences, Feb 1, 1994
This study was undertaken to clarify environmental and behavioral influences on reproductive perf... more This study was undertaken to clarify environmental and behavioral influences on reproductive performance of Turkana women. It is part of a broader, long-term, multidisciplinary study of the ecosystem of this region.
Human biology seeks to understand human variation and the biological, environmental, social, and ... more Human biology seeks to understand human variation and the biological, environmental, social, and historical influences on that variation. Views of the nature of both variation and environment have changed during the past 100 years. Typological approaches to nature and human diversity shifted to an evolutionary perspective during the first half of the 20th century. In the second half, widespread human biological variation was documented and interpreted in terms of adaptation to the environment. Environmental physiology and reproductive ecology continue to document environmental influences on human biological functioning, but with (1) an expanded concept of environment that acknowledges more fully the interactions among its physical, biotic, and social aspects and (2) an expanded theoretical basis, drawing on evolutionary ecology and life history theory, acknowledging tradeoffs and changing constraints and opportunities over the lifetime. Human biology gains from greater interaction with other fields, such as political ecology, but also contributes to them.
American Journal of Physical Anthropology, Nov 1, 1993
Turkana tribespeople reside in a semi-arid savanna ecosystem in northwest Kenya. For over a decad... more Turkana tribespeople reside in a semi-arid savanna ecosystem in northwest Kenya. For over a decade, Ngisonyoka Turkana nomads have been studied within a multidisciplinary framework that embraces ecology, anthropology, and human population biology. Original research objectives of the South Turkana Ecosystem Project were to study nomads longitudinally and within the context of the dry savanna ecosystem. These objectives have been expanded to incorporate settled Turkana who were nomads in the recent past, but who, for a variety of reasons, have taken up a life of sedentary cultivation. The research described here focused on comparisons of growth patterns of nomadic and settled infants from birth to 24 months of age. Infants were measured (recumbent length, weight, head circumference, arm and calf circumference, and selected skinfolds) in 1989 and 1990. Settled infants were slightly longer, but nomadic infants were heavier and fatter. Head circumferences were the same. Some variation was observed by season and year of measurement (from comparative surveys). Both groups showed pronounced weight faltering after 6 months of age when compared with U.S. NCHS reference values. Head circumference faltering was moderate and recumbent length faltering was only slight after 12 months of age. Comparisons of Turkana infant growth in the two populations can contribute indirectly to a better understanding of infant nutritional status, probable morbidity, and other factors, some of which may be linked to female reproduction.
... to Johnson (1999), the size of a herder's social network influences his herding ... more ... to Johnson (1999), the size of a herder's social network influences his herding success ... also Ellis et al., 1993; Moran, 1990) and focused on adaptive individual strategies that generate ... this context, Sieff (1999) provided a rare glimpse of acquisitions among the Datoga of Tanzania ...
Carolina Digital Repository (University of North Carolina at Chapel Hill), 2010
Over the past four decades, Maasai pastoralists in Tanzania have adopted agriculture, integrating... more Over the past four decades, Maasai pastoralists in Tanzania have adopted agriculture, integrating it with their traditional pastoralism. This livelihood diversification has complex origins and profound implications for Maasai social organization, culture, and demography, and ultimately for their health and well being and for the local and regional environment. In this paper, we examine the process by which this engagement with, and increasing dependence upon, agriculture came about in Ngorongoro District, northern Tanzania. The process there was more complex and influenced by a wider variety of factors than has been reported by previous descriptions of Maasai livelihood diversification. It generally involved two stages: planting a garden first, and later expanding the garden to a farm. We found that some households adopted cultivation out of necessity, but far more did so by choice. Among the latter, some adopted cultivation to reduce risk, while for others it was a reflection of changing cultural and social norms. Motivations for adopting cultivation differed among people of different wealth categories. Diversification was part of wider cultural changes, and was also influenced by power differentials among Maasai age sets and by government policies.
Members of the Turkana tribe include settled and nomadic peoples who reside in the southern part ... more Members of the Turkana tribe include settled and nomadic peoples who reside in the southern part of Turkana District in the semiarid region of northwest Kenya. Nomadic Ngisonyoka Turkana keep livestock (camels, cattle, sheep, goats, donkeys), subsist principally on livestock products, and move camps frequently in search of forage for the livestock; settled Turkana cultivate foods along the principal rivers. Both nomadic and settled Turkana are subject to limited food resources on seasonal and long-term bases. Protein from meat, blood, and milk is sufficient in the diet, but food energy is limited, as are body fat reserves. Previous work has documented a decline in maternal adiposity with age in a large sample of the relatively lean nomadic women, and a negative association of fat stores with parity in a smaller sample of nomadic women. The problem of maternal depletion of fat energy reserves as a function of female reproductive history is explored in this study through anthropometry in a relatively large sample (N = 312) of nomadic and settled women. Both nomadic and settled women displayed some parity-related losses in fat stores. The relationship was stronger in the nomads, even after controlling for age.
Carolina Digital Repository (University of North Carolina at Chapel Hill), 2013
Recent work in ecology suggests that the diversity of responses to environmental change among spe... more Recent work in ecology suggests that the diversity of responses to environmental change among species contributing to the same ecosystem function can strongly influence ecosystem resilience. To render this important realization more useful for understanding coupled human-natural systems, we broaden the concept of response diversity to include heterogeneity in human decisions and action. Simply put, not all actors respond the same way to challenges, opportunities, and risks. The range, prevalence, and spatial and temporal distributions of different responses may be crucial to the resilience or the transformation of a social-ecological system, and thus have a bearing on human vulnerability and well-being in the face of environmental, socioeconomic, and political change. Response diversity can be seen at multiple scales (e.g., household, village, region) and response diversity at one scale may act synergistically with or contrary to the effects of diversity at another scale. Although considerable research on the sources of response diversity has been done, our argument is that the consequences of response diversity warrant closer attention. We illustrate this argument with examples drawn from our studies of two East African pastoral populations and discuss the relationship of response diversity to characteristics of social-ecological systems that can promote or diminish resilience.
It is noted that the Turkana people of northwestern Kenya are one of a handful of societies that ... more It is noted that the Turkana people of northwestern Kenya are one of a handful of societies that continues to pursue a nomadic way of life. The book is a multicontributor, multidisciplinary study (18 papers in five parts) of the Turkana, arising from a unique research project which ran ...
Carolina Digital Repository (University of North Carolina at Chapel Hill), 2014
This paper brings together over two decades of research concerning the patterns and processes of ... more This paper brings together over two decades of research concerning the patterns and processes of livelihood diversification through migration among Maasai pastoralists and agro-pastoralists of northern Tanzania. Two case studies, one from the Ngorongoro Conservation Area and the other from the Simanjiro plains, jointly demonstrate the complexity of migration within a single ethnic group. We analyze the relationship between wealth and migration and examine some of the consequences of migration for building herds, expanding cultivation, and influencing political leadership. We further argue that migration in Maasai communities is becoming a cultural norm and not only a response to economic conditions.
of domestic water in the high-rise buildings typical of Hong Kong often comes from a tank located... more of domestic water in the high-rise buildings typical of Hong Kong often comes from a tank located on the building's roof, suggesting that the risk factor of domestic water may also be important in Hong Kong. Reports suggest that acanthamoeba keratitis is an emerging disease in south and east Asia 4 where there has been an increase in the use of contact lenses. 5 With substantial cultural, social, environmental, and climatic differences between Asia and elsewhere, we believe studies to determine risk factors for this disorder are a matter of urgency.
To address claims of human exceptionalism, we determine where humans fit within the greater mamma... more To address claims of human exceptionalism, we determine where humans fit within the greater mammalian distribution of reproductive inequality. We show that humans exhibit lower reproductive skew (i.e., inequality in the number of surviving offspring) among males and smaller sex differences in reproductive skew than most other mammals, while nevertheless falling within the mammalian range. Additionally, female reproductive skew is higher in polygynous human populations than in polygynous nonhumans mammals on average. This patterning of skew can be attributed in part to the prevalence of monogamy in humans compared to the predominance of polygyny in nonhuman mammals, to the limited degree of polygyny in the human societies that practice it, and to the importance of unequally held rival resources to women’s fitness. The muted reproductive inequality observed in humans appears to be linked to several unusual characteristics of our species—including high levels of cooperation among males...
The purpose of this paper is to apply [a model that predicts changes in heterozygosity as a funct... more The purpose of this paper is to apply [a model that predicts changes in heterozygosity as a function of mating structure] to estimate the genetic effects of mating patterns on Sanday Orkney Islands [Scotland] and to compare these results with those from previous analyses of two French West Indian island populations. (EXCERPT)
The frequently reported observation that nomadic populations have lower fertility than their sett... more The frequently reported observation that nomadic populations have lower fertility than their settled counterparts is often attributed to what are perceived as harsh, stressful conditions under which the nomads live. But the consequences of the hypothesized stresses for the reproductive biology or demography of these populations have been documented only a little. Traditionally, the Turkana of northwest Kenya are nomadic herders, but increasing numbers have settled on agricultural development schemes. We used an array of hormonal assays along with anthropometric indexes of nutritional status and interviews covering reproductive history, recent menstruation, diet, and health to compare reproductive function in nomadic and settled Turkana women. First morning urine samples were collected for three consecutive days during a series of surveys. Human choriogonadotropin (hCG; a marker for pregnancy), luteinizing hormone (LH; an indicator of ovulation), and pregnanediol glucuronide (PdG; an indicator of postovulatory luteal function) were assessed in the field with commercially available dipstick enzyme immunoassays. These assays along with the interview data allowed us to determine the reproductive status (e.g., pregnant or cycling, and if cycling, which phase of the ovarian cycle) of 166 nomadic and 194 settled Turkana women. The cross-sectional classifications allowed inferences of conception rates and normality of ovarian function. Follow-up surveys provided rates of pregnancy loss. Compared with the settled women, the nomadic women exhibited lower pregnancy rates and cycling nomadic women were less likely to show evidence of ovulation or luteal function. These results suggest that reproductive function of the nomadic women is diminished relative to the settled women. However, the settled women experienced a much higher rate of pregnancy loss, which may mean that their effective fecundability is in fact lower than that of the nomadic women. This study is the first to apply such a wide range of hormonal assays in the field. It demonstrates that field-based assays are feasible and robust and can play an important role in epidemiological and biodemographic studies, even in remote locations under conditions that would ordinarily be considered incompatible with on-site laboratory analysis.
In this paper we examine how the 2008/09 drought in northern Tanzania contributed to and catalyze... more In this paper we examine how the 2008/09 drought in northern Tanzania contributed to and catalyzed the transformation of governance concerning the management of natural resources from traditional informal institutions among the Maasai to formal village-based institutions. Our central argument is that village governance in northern Tanzania represents a new, formal institution that is supplementing and in some important ways obviating traditional, informal institutions. Further, this replacement is central to what appears to be a transformation of the social-ecological system embracing the rangelands and pastoral/agro-pastoral people in northern Tanzania. In this paper, we document the basis for our claims concerning the institutional shift and discuss its implications for livelihoods and social relationships.
There have been few investigations of intrauterine mortality in non-Western populations that have... more There have been few investigations of intrauterine mortality in non-Western populations that have used techniques capable of detecting early pregnancy loss. We report here the initial results of a prospective study of fetal loss among the Turkana of northwest Kenya. Over 300 nomadic and settled women provided early morning urine samples for 3 consecutive days. Chorionic gonadotropin (hCG), a marker for pregnancy, and markers of ovarian cyclicity (LH, PdG) were determined with solid-phase enzyme immunoassays. Pregnancy was detected in 11% of nomadic women and in 22% of sedentary women of reproductive age. Follow-up surveys revealed that 45% of all pregnancies among settled women were lost; nearly 70% of pregnancies detected in the first trimester were lost. In contrast, none of the nomadic women experienced fetal loss. Because of the small sample sizes, these results must be interpreted cautiously. Nevertheless, even a conservative estimate of the fetal loss rate among the settled women is high compared with Western experience. Anthropometric data suggest that nutritional stress may contribute to the difference between the two populations. There is also some indication that risk of fetal loss in the settled population is associated with parity. The high rate of loss among the settled women along with the difference between the nomadic and settled samples supports the contentions that there may be substantial variation among populations in intrauterine mortality and that the contribution of fetal loss to fertility differences among populations may be more important than has been suspected.
The Turkana, like other East African pastoral groups, are known for their tall adult stature, ach... more The Turkana, like other East African pastoral groups, are known for their tall adult stature, achieved despite a blunted growth spurt during adolescence and continued growth into the early 20s. To investigate the hormonal mechanisms associated with the pattern of slow and continued adolescent growth, we collected data on hormonal status, height, weight, and trunk skinfolds and ethnographic self-reports of testicular maturation in a cross-sectional sample of 35 nomadic and 37 settled Turkana males aged 14-24. Hormonal determinations included testosterone (T), sex hormone-binding globulin (SHBG), and dehydroepiandrosterone (DHEA) in blood, in addition to urinary DHEA. Self-reports of testicular maturation showed no difference between settled and nomadic
Currently-available models used for predicting human caloric requirements do not reflect the grea... more Currently-available models used for predicting human caloric requirements do not reflect the great variability in activity patterns observed among populations, and are insensitive to important anthropometric, demographic, and-environmental variables. They are thus inadequate for application to many populations and problems of anthropological interest. We present a model for determining caloric requirements which more accurately accommodates the effects of variation in activity and ih anthropometrics on individual needs, and which predicts population requirements based on individual needs and demographic parameters. The model is tested on four populations (the Andean community of Nu~oa, Peru~ the Dobe !Kung of Botswana, and two New Guinean villages) and is found to provide consistently better estimates of caloric requirements than are generated by the Food and Agriculture~World Health Organization's model. This model shouM be useful to anthropologists and human ecologists concerned with problems involving human energy consumption, such as the efficiency of subsistence strategies, optimum family composition, or certain consequences of increased labor migration or technological change.
Carolina Digital Repository (University of North Carolina at Chapel Hill), 2014
Analyzing people's decisions can reveal key variables that affect their behaviors. Despite the de... more Analyzing people's decisions can reveal key variables that affect their behaviors. Despite the demonstrated utility of this approach, it has not been applied to livelihood decisions in the context of conservation initiatives. We used ethnographic decision modeling in combination with qualitative comparative analysis (QCA) to examine the herding decisions of Maasai households living near Tarangire National Park (TNP) during recent and historical droughts. The effects of the establishment of TNP on herding practices during drought were different than anticipated based on the size and reliability of several prominent resource areas that are now within the park. We found little evidence of people relying on these swamps and rivers for watering cattle during historical droughts; rather, these sites were more commonly used as grazing areas for small stock and wet-season grazing areas for cattle to avoid disease carried by calving wildebeest. Yet during the 2009 drought, many herders moved their livestockespecially cattle from outside of the study areatoward TNP in search of grazing. Our analysis of herding decisions demonstrates that resource-use decisions are complex and incorporate a variety of information beyond the size or reliability of a given resource area, including contextual factors (e.g., disease, conflict, grazing) and household factors (e.g., social capital, labor, herd size). More broadly, this research illustrates that pairing decision modeling with QCA is a structured approach to identifying these factors and understanding how opportunities, constraints, and perceptions influence how people respond to changes in resource access.
Annals of the New York Academy of Sciences, Feb 1, 1994
This study was undertaken to clarify environmental and behavioral influences on reproductive perf... more This study was undertaken to clarify environmental and behavioral influences on reproductive performance of Turkana women. It is part of a broader, long-term, multidisciplinary study of the ecosystem of this region.
Human biology seeks to understand human variation and the biological, environmental, social, and ... more Human biology seeks to understand human variation and the biological, environmental, social, and historical influences on that variation. Views of the nature of both variation and environment have changed during the past 100 years. Typological approaches to nature and human diversity shifted to an evolutionary perspective during the first half of the 20th century. In the second half, widespread human biological variation was documented and interpreted in terms of adaptation to the environment. Environmental physiology and reproductive ecology continue to document environmental influences on human biological functioning, but with (1) an expanded concept of environment that acknowledges more fully the interactions among its physical, biotic, and social aspects and (2) an expanded theoretical basis, drawing on evolutionary ecology and life history theory, acknowledging tradeoffs and changing constraints and opportunities over the lifetime. Human biology gains from greater interaction with other fields, such as political ecology, but also contributes to them.
American Journal of Physical Anthropology, Nov 1, 1993
Turkana tribespeople reside in a semi-arid savanna ecosystem in northwest Kenya. For over a decad... more Turkana tribespeople reside in a semi-arid savanna ecosystem in northwest Kenya. For over a decade, Ngisonyoka Turkana nomads have been studied within a multidisciplinary framework that embraces ecology, anthropology, and human population biology. Original research objectives of the South Turkana Ecosystem Project were to study nomads longitudinally and within the context of the dry savanna ecosystem. These objectives have been expanded to incorporate settled Turkana who were nomads in the recent past, but who, for a variety of reasons, have taken up a life of sedentary cultivation. The research described here focused on comparisons of growth patterns of nomadic and settled infants from birth to 24 months of age. Infants were measured (recumbent length, weight, head circumference, arm and calf circumference, and selected skinfolds) in 1989 and 1990. Settled infants were slightly longer, but nomadic infants were heavier and fatter. Head circumferences were the same. Some variation was observed by season and year of measurement (from comparative surveys). Both groups showed pronounced weight faltering after 6 months of age when compared with U.S. NCHS reference values. Head circumference faltering was moderate and recumbent length faltering was only slight after 12 months of age. Comparisons of Turkana infant growth in the two populations can contribute indirectly to a better understanding of infant nutritional status, probable morbidity, and other factors, some of which may be linked to female reproduction.
... to Johnson (1999), the size of a herder's social network influences his herding ... more ... to Johnson (1999), the size of a herder's social network influences his herding success ... also Ellis et al., 1993; Moran, 1990) and focused on adaptive individual strategies that generate ... this context, Sieff (1999) provided a rare glimpse of acquisitions among the Datoga of Tanzania ...
Carolina Digital Repository (University of North Carolina at Chapel Hill), 2010
Over the past four decades, Maasai pastoralists in Tanzania have adopted agriculture, integrating... more Over the past four decades, Maasai pastoralists in Tanzania have adopted agriculture, integrating it with their traditional pastoralism. This livelihood diversification has complex origins and profound implications for Maasai social organization, culture, and demography, and ultimately for their health and well being and for the local and regional environment. In this paper, we examine the process by which this engagement with, and increasing dependence upon, agriculture came about in Ngorongoro District, northern Tanzania. The process there was more complex and influenced by a wider variety of factors than has been reported by previous descriptions of Maasai livelihood diversification. It generally involved two stages: planting a garden first, and later expanding the garden to a farm. We found that some households adopted cultivation out of necessity, but far more did so by choice. Among the latter, some adopted cultivation to reduce risk, while for others it was a reflection of changing cultural and social norms. Motivations for adopting cultivation differed among people of different wealth categories. Diversification was part of wider cultural changes, and was also influenced by power differentials among Maasai age sets and by government policies.
Members of the Turkana tribe include settled and nomadic peoples who reside in the southern part ... more Members of the Turkana tribe include settled and nomadic peoples who reside in the southern part of Turkana District in the semiarid region of northwest Kenya. Nomadic Ngisonyoka Turkana keep livestock (camels, cattle, sheep, goats, donkeys), subsist principally on livestock products, and move camps frequently in search of forage for the livestock; settled Turkana cultivate foods along the principal rivers. Both nomadic and settled Turkana are subject to limited food resources on seasonal and long-term bases. Protein from meat, blood, and milk is sufficient in the diet, but food energy is limited, as are body fat reserves. Previous work has documented a decline in maternal adiposity with age in a large sample of the relatively lean nomadic women, and a negative association of fat stores with parity in a smaller sample of nomadic women. The problem of maternal depletion of fat energy reserves as a function of female reproductive history is explored in this study through anthropometry in a relatively large sample (N = 312) of nomadic and settled women. Both nomadic and settled women displayed some parity-related losses in fat stores. The relationship was stronger in the nomads, even after controlling for age.
Carolina Digital Repository (University of North Carolina at Chapel Hill), 2013
Recent work in ecology suggests that the diversity of responses to environmental change among spe... more Recent work in ecology suggests that the diversity of responses to environmental change among species contributing to the same ecosystem function can strongly influence ecosystem resilience. To render this important realization more useful for understanding coupled human-natural systems, we broaden the concept of response diversity to include heterogeneity in human decisions and action. Simply put, not all actors respond the same way to challenges, opportunities, and risks. The range, prevalence, and spatial and temporal distributions of different responses may be crucial to the resilience or the transformation of a social-ecological system, and thus have a bearing on human vulnerability and well-being in the face of environmental, socioeconomic, and political change. Response diversity can be seen at multiple scales (e.g., household, village, region) and response diversity at one scale may act synergistically with or contrary to the effects of diversity at another scale. Although considerable research on the sources of response diversity has been done, our argument is that the consequences of response diversity warrant closer attention. We illustrate this argument with examples drawn from our studies of two East African pastoral populations and discuss the relationship of response diversity to characteristics of social-ecological systems that can promote or diminish resilience.
It is noted that the Turkana people of northwestern Kenya are one of a handful of societies that ... more It is noted that the Turkana people of northwestern Kenya are one of a handful of societies that continues to pursue a nomadic way of life. The book is a multicontributor, multidisciplinary study (18 papers in five parts) of the Turkana, arising from a unique research project which ran ...
Carolina Digital Repository (University of North Carolina at Chapel Hill), 2014
This paper brings together over two decades of research concerning the patterns and processes of ... more This paper brings together over two decades of research concerning the patterns and processes of livelihood diversification through migration among Maasai pastoralists and agro-pastoralists of northern Tanzania. Two case studies, one from the Ngorongoro Conservation Area and the other from the Simanjiro plains, jointly demonstrate the complexity of migration within a single ethnic group. We analyze the relationship between wealth and migration and examine some of the consequences of migration for building herds, expanding cultivation, and influencing political leadership. We further argue that migration in Maasai communities is becoming a cultural norm and not only a response to economic conditions.
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Papers by Paul Leslie