Effects of Prenatal Environment Are Revealed by Post-natal Challenges: Embryonic Hormone Exposure, Adrenocortical Function and Food in Seabird Chicks

The interaction between prenatal environments and postnatal environments is an important source of phenotypic variability. We examined the ability of prenatal steroid exposure and postnatal energy restriction to explain adrenocortical function and fledging age in captive seabird chicks. We proposed and tested two hypotheses: (1) the strength of prenatal effects is attenuated by challenging postnatal environments (postnatal override) and (2) the strength of prenatal effects increases with the severity of postnatal challenges (postnatal reveal). We reared common murre (Uria aalge) chicks and measured prenatal exposure to corticosterone (CORT) and testosterone (T) from allantoic waste. Adrenocortical function was assessed after 10 d of ad lib. feeding and then after 5 and 10 d on controlled diets. Postnatal override predicts that prenatal steroids will explain more phenotypic variation before implementation of energy restriction; postnatal reveal predicts that the contribution of prenatal steroids will increase with duration and severity of energy restriction. Energy restriction increased secretion of baseline CORT and the adrenocortical response to the standardized stressor of handling and restraint. The ability of prenatal steroids to explain baseline CORT increased with duration of energy restriction, and for day 20 free baseline CORT, there was a significant interaction between kilojoules per day and prenatal CORT levels; severity of restriction strengthened the relationship between prenatal hormone levels and postnatal hormone levels. Both maximum CORT at day 20 and fledging age were best explained by diet treatment and day 15 or day 20 baseline CORT, respectively. Overall, prenatal CORT increased fledging age and baseline secretion of CORT, while prenatal T decreased them. However, prenatal effects on adrenocortical function were apparent only under the energy restriction conditions. Thus, we found some support for the postnatal reveal hypothesis; our results suggest that some prenatal effects on phenotype may be more likely to manifest in challenging postnatal environments

The role of perceptions and social norms in shaping women’s fertility preferences: a case study from Ethiopia

The population–environment–food nexus is a sustainability challenge for the Global South, and for Africa in particular, where rapid human population growth typically overlaps with high levels of food insecurity and environmental degradation. In this context, it is important to understand the reasons driving high fertility in these regions. Here, we examined possible determinants of women’s fertility preferences in rural southwestern Ethiopia. Using a survey tool (n = 120), we assessed women’s perceptions of four key environmental stressors, namely food insecurity, environmental degradation, human population growth, and land scarcity. Through statistical modelling we tested whether there was a relationship between perceptions of future trends in these stressors and women’s fertility preferences; expressed as their desired number of children and use of family planning methods. This analysis was complemented by a qualitative content analysis of the survey’s open-ended questions, to contextualize and interpret the quantitative data. Our quantitative results indicated that perceptions of future trends in key stressors had little effect on fertility preferences of respondents, with the exception of perceptions of human population growth. Our qualitative data suggested that this may be due to the influence of social-cultural norms and religion, decision-making with the husband, as well as a perceived utilitarian value of children. These findings have important implications for the development of interventions to slow down human population growth. Our findings suggest the need to look beyond improved physical access to family planning, and develop a new suite of deliberative approaches that engage with social norms, religion, and gender equity

Leverage points for improving gender equality and human well-being in a smallholder farming context

How transformative processes could be facilitated to improve gender equality and consequently, human well-being, is a key question for moving towards a just and sustainable future. Focusing on southwestern Ethiopia where significant changes in formal institutions related to gender have occurred, we applied the concept of systemic leverage points. We show that changes in formal structures facilitated changes in perceived visible gender gaps, such as increased participation of women in public activities. These, in turn, played an enabling role for changes in community norms, and (to a lesser degree) triggered reconsideration of perceptions about women’s capacities. Both women and men perceived more equal gender relations as being associated with better well-being at the household level. Our results highlight the important role of interactions between leverage points for gender equality, suggesting important insights can be gained by studying interactions, compared to when shallow (e.g., visible gaps) or deeper leverage points (e.g., social norms) are analyzed in isolation. Our study also demonstrated the general suitability of a leverage-points perspective in gender research, including as an analytical frame to complement gender transformative approaches

The governance of land use strategies : Institutional and social dimensions of land sparing and land sharing

Agricultural land use is a key interface between the goals of ensuring food security and protecting biodiversity. “Land sparing” supports intensive agriculture to save land for conservation, whereas “land sharing” integrates production and conservation on the same land. The framing around sparing versus sharing has been extensively debated. Here, we focused on a frequently missing yet crucial component, namely the governance dimension. Through a case-study in Ethiopia, we uncovered stakeholder preferences for sparing versus sharing, the underlying rationale, and implementation capacity challenges. Policy stakeholders preferred sparing whereas implementation stakeholders preferred sharing, which aligned with existing informal institutions. Implementation of both strategies was limited by social, biophysical, and institutional factors. Land use policies need to account for both ecological patterns and social context. The findings from simple analytical frameworks (e.g., sparing vs. sharing) therefore need to be interpreted carefully, and in a social-ecological context, to generate meaningful recommendations for conservation practice

Fat or lean : Adjustment of endogenous energy stores to predictable and unpredictable changes in allostatic load

The ability to store energy endogenously is an important ecological mechanism that allows animals to buffer predictable and unpredictable variation in allostatic load. The secretion of glucocorticoids, which reflects changes in allostatic load, is suggested to play a major role in the adjustment of endogenous stores to these varying conditions. Although crucially important, the relationship between allostatic load and energy stores remains largely unexplorTwo contrasting hypotheses describe how stores may be adjusted: animals may use low allostatic loads to increase stores to a maximum possible ('fat and fit'), or they can attain a lean physique due to fitness advantages of a low body mass ('lean and fit'). We compiled observational and experimental data available for a long-lived seabird to examine the relationship between glucocorticoids and stored energy at two life history stages (incubation and chick-rearing). Data were collected across multiple years and colonies in the North Pacific, thereby reflecting the wide range of environmental conditions birds' encounter in the marine environment. During experimental manipulations, allostatic load was minimized by supplementing food to free-living birds. We found that the relationship between allostatic load and energy stores was clearly curvilinear at both life history stages. Observational data suggested that energy stores remained relatively stable under low allostatic load and decreased under high loads. Experimental data showed that birds did not maximize energy stores under favourable conditions but maintained energy stores below a physiologically attainable level. Energy stores remained consistently lower during chick-rearing compared to incubation across the wide range of variations in allostatic load suggesting that stage-specific trade-offs limit the accumulation of energy during favourable environmental conditions. Secretion of glucocorticoids did not appear to mediate this shift in energy stores between the life history stages. Overall, results of this study support the 'lean and fit' hypothesis. We conclude that increased energy stores may not necessarily reflect better environmental conditions experienced by individuals or predict their higher fitness. A major advantage of adopting a lean physique when environmental conditions allow may be the avoidance of additional energetic costs for moving a heavy body. In breeding seabirds, this advantage may be more important during chick-rearing. In the focal species, the secretion of glucocorticoids might be involved in regulation of energy stores within a life history stage but does not appear to mediate an adaptive shift in energy stores between the incubating and chick-rearing stages of reproduction

Livelihood strategies, capital assets, and food security in rural Southwest Ethiopia

Households combine capital assets in a process involving human agency and resourcefulness to construct livelihood strategies and generate well-being outcomes. Here, we (1) characterized types of livelihood strategies; (2) determined how different capital assets are associated with different livelihood strategies; and (3) determined how livelihood strategies differed in food security outcomes. We conducted a survey in southwestern Ethiopia and used principal component and cluster analyses. Five types of livelihood strategies, which differed mainly in food and cash crops comprising the strategy, were identified. These were, in order of decreasing food security: ‘three food crops, coffee and khat’, n = 68; ‘three food crops and khat’, n = 59; ‘two food crops, coffee and khat’, n = 78; ‘two food crops and khat’, n = 88; and ‘one food crop, coffee and khat’, n = 44. The livelihood strategy ‘three food crops, coffee and khat’ was associated with a wide range of capital assets, particularly having larger aggregate farm field size and learning from other farmers. A generalized linear model showed that livelihood strategies were significantly associated with food security outcomes. Particularly, a high number of food crops in a strategy was linked with relatively high food security. In this context, diversified livelihood strategies primarily through having a mix of food crops for subsistence, in combination with cash crops for income, are important for food security. This suggests a need to rethink dominant policy narratives, which have a narrow focus on increasing productivity and commercialization as the primary pathway to food security

Migration and stress during reproduction govern telomere dynamics in a seabird

Changes in telomere length are believed to reflect changes in physiological state and life expectancy in animals. However, much remains unknown about the determinants of telomere dynamics in wild populations, and specifically the influence of conditions during highly mobile life-history stages, for example migration.We testedwhether telomere dynamicswere associated with migratory behaviour and/orwith stress during reproduction in free-living seabirds. We induced short-term stress during reproduction in chick-rearing, black-legged kittiwakes (Rissa tridactyla), tracked winter migration with geolocators and measured telomere length before and after winter migration. We found that time spent at wintering grounds correlated with reduced telomere loss, while stress during reproduction accelerated telomere shortening. Our results suggest that different life-history stages interact to influence telomere length, and that migratory patterns may be important determinants of variation in an individual's telomere dynamics

From stories to maps: translating participatory scenario narratives into spatially explicit information

To understand future land use change, and related ecological and social impacts, scenario planning has become increasinglypopular. We demonstrate an approach for translating scenario narratives into spatially explicit land use maps. Starting from fourpreviously developed scenarios of land use change in southwestern Ethiopia we developed a baseline land use map, and rules for how to modify the baseline map under each scenario. We used the proximity-based scenario generator of the InVEST software to model the prospective land cover changes to existing forest (53%), arable land (26%), pasture (11%), and wetlands (7%), under the four future scenarios. The model results indicate that forest cover area would remain essentially the same under the “gain over grain” and “biosphere reserve” scenarios. Coffee plantations would cover almost half the landscape (49%) in the “mining green gold” scenario, whereas arable land would expand and cover more than half of the landscape (57%) in the “food first” scenario. The approach presented here integrates future land use mapping with participatory, narrative-based scenario research to assess the social-ecological outcomes of alternative futures. The translation of narratives onto maps can help researchers and stakeholders better understand and communicate potential land use changes, and facilitate a more spatially nuanced approach to managing or adapting to broad scale socioeconomic changes. Our study constitutes a methodological contribution to the management of land use change, as well as a tool to facilitate transparent policy negotiation and communication at local, government, and NGO levels

Migration and stress during reproduction govern telomere dynamics in a seabird

Changes in telomere length are believed to reflect changes in physiological state and life expectancy in animals. However, much remains unknown about the determinants of telomere dynamics in wild populations, and specifically the influence of conditions during highly mobile life-history stages, for example migration.We testedwhether telomere dynamicswere associated with migratory behaviour and/orwith stress during reproduction in free-living seabirds. We induced short-term stress during reproduction in chick-rearing, black-legged kittiwakes (Rissa tridactyla), tracked winter migration with geolocators and measured telomere length before and after winter migration. We found that time spent at wintering grounds correlated with reduced telomere loss, while stress during reproduction accelerated telomere shortening. Our results suggest that different life-history stages interact to influence telomere length, and that migratory patterns may be important determinants of variation in an individual’s telomere dynamics