Socioecological Niches Research Articles

Why Do Farmers Disadopt Successful Innovations? Socio-Ecological Niches and Rice Intensification

The adoption of innovations in rice cultivation is presumed to operate in a rational manner, wherein new technologies or practices that successfully increase productivity or resource efficiency are adopted by target farmers based on cost-benefit calculations. In contrast, this paper examines a case of a public initiative to promote the system of rice intensification (SRI), wherein farmers widely disadopted the technique despite reporting increasing yields and reduced water consumption. To explain this paradox, we use the concept of the socio-ecological niche to examine a range of social and institutional factors that shape farmers’ decision-making. These included (1) access to land and labour; (2) water management capacity; (3) the quality of networks for knowledge sharing. The research suggests that small variations in these categories among otherwise similar smallholder households can markedly shape farmers’ risk perceptions and tangible outcomes with SRI. The implication is that agricultural innovations should be judged within their wider social context rather than on narrow evaluations of agronomic efficiency. Importantly, this must involve greater feedback mechanisms from smallholders with a variety of socio-economic profiles to help shape the character of agricultural innovations and extension strategies.

Differential functional organization of amygdala-medial prefrontal cortex networks in macaque and human

Over the course of evolution, the amygdala (AMG) and medial frontal cortex (mPFC) network, involved in behavioral adaptation, underwent structural changes in the old-world monkey and human lineages. Yet, whether and how the functional organization of this network differs remains poorly understood. Using resting-state functional magnetic resonance imagery, we show that the functional connectivity (FC) between AMG nuclei and mPFC regions differs between humans and awake macaques. In humans, the AMG-mPFC FC displays U-shaped pattern along the corpus callosum: a positive FC with the ventromedial prefrontal (vmPFC) and anterior cingulate cortex (ACC), a negative FC with the anterior mid-cingulate cortex (MCC), and a positive FC with the posterior MCC. Conversely, in macaques, the negative FC shifted more ventrally at the junction between the vmPFC and the ACC. The functional organization divergence of AMG-mPFC network between humans and macaques might help understanding behavioral adaptation abilities differences in their respective socio-ecological niches.

Sex differences in white matter tracts of capuchin monkey brains.

Nonhuman primates exhibit sexual dimorphism in behavior, suggesting that there could be underlying differences in brain organization and function. Understanding this neuroanatomical variation is critical for enhancing our understanding of the evolution of sex differences in the human brain. Tufted capuchin monkeys (Sapajus [Cebus] apella) represent a phylogenetically diverse taxa of neotropical primates that converge on several behavioral characteristics with humans relevant to social organization, making them an important point of comparison for studying the evolution of sex differences in primates. While anatomical sex differences in gray matter have previously been found in capuchin monkeys, the current study investigates sex differences in white matter tracts. We carried out tract-based spatial statistical analysis on fractional anisotropy images of tufted capuchin monkeys (15 female, 5 male). We found that females showed significantly higher fractional anisotropy than males in regions of frontal-parietal white matter in the right cerebral hemisphere. Paralleling earlier findings in gray matter, male and female fractional anisotropy values in these regions were nonoverlapping. This complements prior work pointing toward capuchin sex differences in limbic circuitry and higher-order visual regions. We propose that these sex differences are related to the distinct socioecological niches occupied by male and female capuchins. Capuchin neuroanatomical sex differences appear to be more pronounced than in humans, which we suggest may relate to human adaptations for prolonged neurodevelopmental trajectories and increased plasticity.

Evolution of cortical geometry and its link to function, behaviour and ecology

Studies in comparative neuroanatomy and of the fossil record demonstrate the influence of socio-ecological niches on the morphology of the cerebral cortex, but have led to oftentimes conflicting theories about its evolution. Here, we study the relationship between the shape of the cerebral cortex and the topography of its function. We establish a joint geometric representation of the cerebral cortices of ninety species of extant Euarchontoglires, including commonly used experimental model organisms. We show that variability in surface geometry relates to species’ ecology and behaviour, independent of overall brain size. Notably, ancestral shape reconstruction of the cortical surface and its change during evolution enables us to trace the evolutionary history of localised cortical expansions, modal segregation of brain function, and their association to behaviour and cognition. We find that individual cortical regions follow different sequences of area increase during evolutionary adaptations to dynamic socio-ecological niches. Anatomical correlates of this sequence of events are still observable in extant species, and relate to their current behaviour and ecology. We decompose the deep evolutionary history of the shape of the human cortical surface into spatially and temporally conscribed components with highly interpretable functional associations, highlighting the importance of considering the evolutionary history of cortical regions when studying their anatomy and function.

Diversity in Socioecological Niches in the Andes (DISENIA): an isotope-based project

This new project studies the diversity of socioecological niches across the agropastoral transition in the Andes, utilising a multi-isotope approach to track human territories and allocate subsistence tasks. During the agropastoral period, we discriminate different diachronic niches with varying extents of maize farming and altitudinal mobility.

The evolution of primate vocal communication: a social route

There is no doubt that different factors determine the evolutionary trajectory of a species' communication abilities. Beyond habitat, social life is likely a selection pressure. The hypothesis positing that living in a complex social system requires complex communication skills has gained ground. However, the measures used classically to tackle this question (i.e. number of call types and group size) fail to capture some of the subtleties of the evolution of communication systems. Integrative approaches comparing closely related species to highlight the possible relationship between the characteristics of their social systems, their ecological niche and associated vocal communication systems are required to further our understanding of this evolutionary puzzle. We first addressed this topic in two sympatric guenons, Diana monkeys and Campbell’s monkeys. Interspecies competition, and the niche specialisations this creates, appeared to be a key evolutionary driver of their repertoires. While most of their vocal units were shared, we found a diversification of alarm calls and socially meaningful vocal combinations, as well as a differential use of inconspicuous (less detectable) call structures. This was linked to differences in group size and degree of exposition to predators. Secondly, we compared the acoustic structures in macaques belonging to four species with contrasting social styles. We found that tolerant (Tonkean and crested) macaques displayed higher levels of vocal diversity (number of vocal units) and flexibility (degree of gradation) than intolerant (Japanese and rhesus) macaques in agonistic and affiliative (but not neutral) contexts. Lastly, because the core of communication is represented not only by what is expressed by an isolated caller, but also by the way vocal interactions are structured, we explored ‘conversational rules’ in apes. We found no relationship between classical social (group size, interaction rates) and vocal (repertoire size, call rates) complexity metrics. However, close call interaction patterns differed in line with the nature of societies. Orang-utan, the most solitary species, preferentially used repeated and isolated calls apparently outside of any vocal interactions. Chimpanzee, the most competitive species displayed a high proportion of overlapping vocalisations. Vocal turn-taking predominated in the most tolerant species (bonobo and gorilla). Even if primate vocal repertoires change slowly over evolutionary time, making them good phylogenetic indicators, socio-ecological niches may induce considerable local divergence at different levels: vocal repertoire composition, acoustic structure and contextual use of calls, and vocal interaction patterns.

Heterogeneity in resource competition covaries with individual variation in long-term social relationships

Abstract Resource competition among conspecifics is central to social evolution, as it serves as one of the primary selective pressures of group living. This is because the degree of competition for resources impacts the costs and benefits of social interactions. Despite this, how heterogeneity in resource competition drives variation in the type and quantity of long-term social relationships individuals foster has been overlooked. By measuring male mating competition and female foraging competition in a highly social, long-lived mammal, we demonstrate that individual variation in long-term intrasexual social relationships covaries with preferred habitat and experienced resource competition, and this effect differs based on the sex of the individual. Specifically, greater resource competition resulted in fewer social preferences, but the magnitude of the effect varied by both habitat and sex, whereas for social avoidances, both the directionality and magnitude of the effect of resource competition varied by habitat and sex. Together our work shows how fine-scale variation in individual socioecological niches (i.e., unique physical and social environments) can drive extensive variation in individual social behavior (here long-term relationships) within a population, thereby broadening current theories of social evolution.

Time investments in rituals are associated with social bonding, affect and subjective health: a longitudinal study of Diwali in two Indian communities.

Rituals are performed within specific socio-ecological niches, yet the different effects of the same ritual form across different niches (community contexts) remains unclear. Here, using longitudinal measures over a two-week period during Diwali (the Indian festival of light), we investigate the relationship between ritual time allocation and social cohesion in two Indian communities. First, the positive effects of ritual on social bonding, perceived health and affect were highest on the focal day of the festival. Second, we observed anticipatory effects of ritualistic commitment on affect prior to the main day of the festival. Third, social bonding patterns were similar in the two Indian settings, indicating that Diwali fosters social cohesion across diverse social ecologies (cultural niches). However, individually focused emotional benefits appear to dampened in more cosmopolitan environments. Finally, time investments reveal diminishing marginal utilities for ritual activities on social cognition. Ritual time investments were linked to greater affect and family cohesion up to a certain limit. We argue that attention to the diminishing returns of ritual time investments on social cohesion across diverse human ecologies is an important horizon for future cross-cultural investigations. This article is part of the theme issue 'Ritual renaissance: new insights into the most human of behaviours'.

Primate mosaic brain evolution reflects selection on sensory and cognitive specialization.

The mammalian brain is composed of numerous functionally distinct structures that vary in size within and between clades, reflecting selection for sensory and cognitive specialization. Primates represent a particularly interesting case in which to examine mosaic brain evolution since they exhibit marked behavioural variation, spanning most social structures, diets and activity periods observed across mammals. Although studies have consistently demonstrated a trade-off between visual and olfactory specialization in primates, studies of some regions (for example, the neocortex) have produced conflicting results. Here, we analyse the socioecological factors influencing the relative size of 33 brain regions, using updated statistical techniques and data from more species and individuals than previous studies. Our results confirm that group-living species and those with high-quality diets have expanded olfactory or visual systems, depending on whether they are nocturnal or diurnal. Conversely, regions associated with spatial memory are expanded in solitary species and those with low-quality diets, suggesting a trade-off between visual processing and spatial memory. Contrary to previous work, we show that diet quality predicts relative neocortex size at least as well as, if not better than, social complexity. Overall, our results demonstrate that primate brain structure is largely driven by selection on sensory and cognitive specializations that develop in response to divergent socioecological niches.

Does socio-ecology drive differences in alertness between wolves and dogs when resting?

Variation in resting behaviour across animals may be driven by adaptations towards their environment. Wolves and dogs seem promising models to examine this idea as they share a common ancestor, but occupy different socio-ecological niches. While wolves generally avoid humans, hunt, defend their territory, and raise offspring cooperatively, most dogs live in human-shaped environments. Hence, we hypothesized wolves to be more alert towards their environment than dogs, i.e. the degree of activation along the sleep-wake continuum (alertness) should be greater in wolves than in dogs. We estimated alertness via cardiac output. We tested similarly raised and kept pack-living wolves and dogs in two different behavioural conditions: (1) inactive wakefulness: animal is lying, head in an upward position with eyes opened, (2) resting: animal is lying, head in downward position with eyes mainly closed. In contrast to our expectations, we found that in both conditions wolves had a lower heart rate and higher heart rate variability than dogs, i.e. wolves might be less alert/more relaxed than dogs. Although our results are preliminary, we suggest that the higher alertness of dogs compared to wolves is potentially driven by differences in their socio-ecology (i.e. domestication) causing greater attention of dogs to human behaviour.

Wild chimpanzees (Pan troglodytes troglodytes) exploit tortoises (Kinixys erosa) via percussive technology

Chimpanzees (Pan troglodytes), one of humankinds’ closest living relatives, are known to hunt and consume the meat of various animal taxa. Although some researchers have presented indirect evidence that chimpanzees may also prey on tortoises, until now, direct observations of this behaviour did not exist. Here, we provide systematic descriptions of the first observations of chimpanzee predation on tortoises (Kinixys erosa). We made these unprecedented observations on newly habituated chimpanzees (Pan troglodytes troglodytes) of the Rekambo community, living in the Loango National Park, Gabon. The behaviour qualified as customary, that is occurring in most or all adult males, involved a distinct smashing technique, and resulted frequently in food sharing with other group members. Our observations shed new light on the hitherto little understood percussive technology of chimpanzees, and expand our current knowledge on chimpanzees’ dietary and predatory repertoires with respect to reptiles. We also report a case of food storage and discuss it in the context of future-oriented cognition. Our findings suggest the need for more nuanced interpretations of chimpanzees’ cognitive skills in combination with an in-depth understanding of their unique socio-ecological niches. They further emphasize the importance of nonhuman primate field observations to inform theories of hominin evolution.

Modelling Animal Interactive Rhythms in Communication

Time is one crucial dimension conveying information in animal communication. Evolution has shaped animals’ nervous systems to produce signals with temporal properties fitting their socio-ecological niches. Many quantitative models of mechanisms underlying rhythmic behaviour exist, spanning insects, crustaceans, birds, amphibians, and mammals. However, these computational and mathematical models are often presented in isolation. Here, we provide an overview of the main mathematical models employed in the study of animal rhythmic communication among conspecifics. After presenting basic definitions and mathematical formalisms, we discuss each individual model. These computational models are then compared using simulated data to uncover similarities and key differences in the underlying mechanisms found across species. Our review of the empirical literature is admittedly limited. We stress the need of using comparative computer simulations – both before and after animal experiments – to better understand animal timing in interaction. We hope this article will serve as a potential first step towards a common computational framework to describe temporal interactions in animals, including humans.

ARE FARMERS SEARCHING FOR AN AFRICAN GREEN REVOLUTION? EXPLORING THE SOLUTION SPACE FOR AGRICULTURAL INTENSIFICATION IN SOUTHERN MALI

SUMMARYDevelopment actors, including the African Union, the Alliance for a Green Revolution in Africa and bilateral donors, promote a technology-driven sustainable intensification of agriculture as a way to feed a growing world population and reduce rural poverty. A broader view of smallholder agriculture in the context of rural livelihoods suggests that technological solutions alone are unlikely to meet these goals. Analysis of the solution space for agricultural interventions in a high potential area of southern Mali shows that intensification can lift most farm households out of extreme poverty and guarantee their food self-sufficiency. However, the most effective options do not fit the usual definition of sustainable intensification, increasing production per unit land while protecting the natural environment. Cropland expansion combined with the good yields seen in on-station experiments can nearly eliminate extreme poverty, while the biggest impact may come from taking advantage of peak seasonal prices for crops like groundnut. Other profitable alternatives can include meat production with small ruminants or sales of milk from cows. However, off-farm employment opportunities like gold mining outperform currently attainable agricultural options in terms of profitability. Options for rural households should fit within the households’ socio-ecological niches and respond to their priorities in order to be successful. Given the relatively low impact of (sustainable) intensification technologies alone, a rethinking of the role of agricultural research in development is needed in order to align interventions with farmer priorities and meet development goals.

An evolutionary framework outlining the integration of individual social and spatial ecology.

Behaviour is the interface between an organism and its environment, and behavioural plasticity is important for organisms to cope with environmental change. Social behaviour is particularly important because sociality is a dynamic process, where environmental variation influences group dynamics and social plasticity can mediate resource acquisition. Heterogeneity in the ecological environment can therefore influence the social environment. The combination of the ecological and social environments may be interpreted collectively as the "socioecological environment," which could explain variation in fitness. Our objective was to outline a framework through which individual social and spatial phenotypes can be integrated and interpreted as phenotypes that covary as a function of changes in the socioecological environment. We propose the socioecological environment is composed of individual behavioural traits, including sociality and habitat selection, both of which are repeatable, potentially heritable and may reflect animal personality traits. We also highlight how ecological and social niche theory can be applied to the socioecological environment framework, where individuals occupy different socioecological niches. Individual sociality and habitat selection are also density-dependent, and theory predicts that density-dependent traits should affect reproduction, survival, and therefore fitness and population dynamics. We then illustrate the proximate links between sociality, habitat selection and fitness as well as the ultimate, and possibly adaptive, consequences associated with changes in population density. The ecological, evolutionary and applied implications of our proposed socioecological environment framework are broad and changes in density could influence individual fitness and population dynamics. For instance, human-induced environmental changes can influence population density, which can affect the distribution of social and spatial phenotypes within a population. In summary, we outline a conceptual framework that incorporates individual social and spatial behavioural traits with fitness and we highlight a range of ecological and evolutionary processes that are likely associated with the socioecological environment.

Gender-typed attributes and marital satisfaction among Mexican immigrant couples: A latent profile approach.

Informed by socioecological and dyadic approaches to understanding marriage, the current study examined the patterning of gender-typed attributes among 120 Mexican immigrant opposite sex couples and the subsequent links with spouses' reports of marital satisfaction. Latent profile analysis (LPA) was used to identify typologies of couples based on spouses' self-reported masculine and feminine attributes. Three couple profiles were identified: (a) Androgynous Couples, (b) Undifferentiated Couples, and (c) Mismatched Couples. Results from a mixed model ANCOVA showed profile differences in couples' marital satisfaction based on profile membership, suggesting that spouses in the Undifferentiated Profile were the least satisfied. Findings illustrate a lack of gender-typing at the individual and couple levels that challenge stereotypical and patriarchal depictions of Latino marital relationships and propose a more complex understanding of Mexican-origin spouses' gender-typed attributes than has yet been portrayed in the literature. The finding that couples with 1 androgynous partner (i.e., wives in the Mismatched Profile) reported similar levels of marital satisfaction to couples in the Androgynous Profile offers additional insights regarding how these qualities operate under the unique socioecological niches that Mexican immigrant couples inhabit-contexts that may place demands on spouses that challenge gendered and culturally bound depictions of marriage.

Commodifying snow, taming the waters. Socio-ecological niche construction in an Alpine village.

White belts of snow clad mountains all over the world each winter. Even if there is no snow, the tourism industry is able to produce the white finery at the push of the button, thereby consuming large amounts of water. Studying Damüls, a well-known ski resort in Austria’s westernmost province Vorarlberg, we can show that the development of a service sector within agro-pastoral landscapes was connected with novel water uses and massive interventions into Alpine landscapes. Human niche construction theory offers a unique avenue for studying the development of Alpine communities, but also highlights side effects accompanying the change from agrarian to tourism livelihoods. One aim of this paper is to broaden the scope of human niche construction theory. Inceptive, counteractive and relocational niche construction activities were coupled to the differentiation of actor groups. To incorporate social dynamics, indispensable for studies in environmental history, we propose the concept of socio-ecological niche construction. The paper investigates how villagers balanced resource limitations typical for an agrarian society with the differentiation of sub-niches, mediating selective forces on the population. When the valleys were industrialized, Damüls was almost given up as a permanent settlement. Then, tourists entered the stage, by and by turning the wheel of local development into a different direction. A tourism niche based on natural snow evolved from the 1930s onwards. While the socio-ecological niches of agriculture and tourism coexisted in the interwar years, this changed when ski lifts were built, embedded into a debt-based economy that made the tourism niche vulnerable to snow availability. Snow-dependency became a powerful selective force. It was mediated by the ski lift companies through a range of niche construction activities that turned water into an important resource of snowmaking systems.

Antenatal Care in Nepal: A Socioecological Perspective

Globally, millions of women die during pregnancy and childbirth due to preventable causes. In Nepal, although significant improvements have been made in the availability of routine antenatal care (ANC), the need for effective initiatives still persists. Using the 2011 Nepal Demographic and Health Survey data, we examine the relationship between ecological and socioeconomic variations on the effect of ANC services between three distinct ecological zones in Nepal. We make a case for the consideration of socioecological niches in designing effective policies and programs to achieve positive maternal health outcomes. Most importantly, we demonstrate how sociocultural perspective can be one alternative for examining the cultural and contextual effects on women's health, contributing to the methodological literature on women's health. Since geography and culture are components of human ecology and form the larger socioecological system, we highlight the importance of these contextual effects on women's health in general, and the conditions under which women from diverse backgrounds may experience similar health issues.

Seven considerations about dingoes as biodiversity engineers: the socioecological niches of dogs in Australia

Australian dingoes have recently been suggested as a tool to aid biodiversity conservation through the reversal or prevention of trophic cascades and mesopredator release. However, at least seven ecological and sociological considerations must be addressed before dog populations are positively managed.Domestication and feralisation of dingoes have resulted in behavioural changes that continue to expose a broad range of native and introduced fauna to predation.Dingoes and other dogs are classic mesopredators, while humans are the apex predator and primary ecosystem engineers in Australia.Anthropogenic landscape changes could prevent modern dingoes from fulfilling their pre-European roles.Dingoes are known to exploit many of the same species they are often presumed to ‘protect’, predisposing them to present direct risks to many threatened species.The assertion that contemporary dog control facilitates the release of mesopredators disregards the realities of effective dog control, which simultaneously reduces fox and dog abundance and is unlikely to enable increases in fox abundance.The processes affecting threatened fauna are likely a combination of both top-down and bottom-up effects, which will not be solved or reversed by concentrating efforts on managing only predator effects.Most importantly, human social and economic niches are highly variable across the ecosystems where dingoes are present or proposed. Human perceptions will ultimately determine acceptance of positive dingo management.Outside of an adaptive management framework, positively managing dingoes while ignoring these seven considerations is unlikely to succeed in conserving native faunal biodiversity but is likely to have negative effects on ecological, social and economic values.

Parental investment and the optimization of human family size.

Human reproductive behaviour is marked by exceptional variation at the population and individual level. Human behavioural ecologists propose adaptive hypotheses to explain this variation as shifting phenotypic optima in relation to local socioecological niches. Here we review evidence that variation in fertility (offspring number), in both traditional and modern industrialized populations, represents optimization of the life-history trade-off between reproductive rate and parental investment. While a reliance on correlational methods suggests the true costs of sibling resource competition are often poorly estimated, a range of anthropological and demographic studies confirm that parents balance family size against offspring success. Evidence of optimization is less forthcoming. Declines in fertility associated with modernization are particularly difficult to reconcile with adaptive models, because fertility limitation fails to enhance offspring reproductive success. Yet, considering alternative measures, we show that modern low fertility confers many advantages on offspring, which are probably transmitted to future generations. Evidence from populations that have undergone or initiated demographic transition indicate that these rewards to fertility limitation fall selectively on relatively wealthy individuals. The adaptive significance of modern reproductive behaviour remains difficult to evaluate, but may be best understood in response to rising investment costs of rearing socially and economically competitive offspring.

Away from ethnocentrism and anthropocentrism: Towards a scientific understanding of “what makes us human”

The quest to understand "what makes us human" has been heading towards an impasse, when comparative psychology compares primarily individuals that are not representative of their species. Captives experience such divergent socioecological niches that they cannot stand for their wild counterparts. Only after removing ethnocentrism and anthropocentrism will we be able to progress in our understanding of "what makes us human."