Effects of Food and Temperature on Drosophila melanogaster Reproductive Dormancy as Revealed by Quantification of a GFP-Tagged Yolk Protein in the Ovary

When exposed to harsh environmental conditions, such as food scarcity and/or low temperature, Drosophila melanogaster females enter reproductive dormancy, a metabolic state that enhances stress resistance for survival at the expense of reproduction. Although the absence of egg chambers carrying yolk from the ovary has been used to define reproductive dormancy in this species, this definition is susceptible to false judgements of dormancy events: e.g. a trace amount of yolk could escape visual detection; a fly is judged to be in the non-dormancy state if it has a single yolk-containing egg chamber even when other egg chambers are devoid of yolk. In this study, we propose an alternative method for describing the maturation state of oocytes, in which the amount of yolk in the entire ovary is quantified by the fluorescence intensity derived from GFP, which is expressed as a fusion with the major yolk protein Yp1. We show that yolk deposition increases with temperature with a sigmoidal function, and the quality of food substantially alters the maximum accumulation of yolk attainable at a given temperature. The Yp1::GFP reporter will serve as a reliable tool for quantifying the amount of yolk and provides a new means for defining the dormancy state in D. melanogaster.

Automated VHF-Radio Telemetry Reveals Resource-Driven Site Utilisation Patterns in a Small-Bodied, Highly Mobile Bird (Erythrura Gouldiae)

BackgroundInformation on site utilisation and movement is essential for managing species' resource requirements. Collecting these data requires frequent location sampling of multiple individuals, which can be challenging for small-bodied animals due to the often-large size of animal-borne satellite-based telemetry devices. We show how coded VHF-radio nano-transmitters and an array of passive receivers to collect location data at sufficient frequency and accuracy can be utilised to test whether the highly mobile and small-bodied Gouldian finch adheres to optimal foraging theory within a landscape of high spatiotemporal heterogeneity.MethodsCoded VHF-radio nano-transmitters (0.23 g wt.) were attached to 38 Gouldian finches (Erythrura gouldiae; < 12g bd. wt). Tagged birds were then detected by an array of 6 passive VHF-radio receivers (~ 530 m detection range) spread over 120 km2. We tracked the tagged birds during two sessions corresponding with high and low abundance of their primary food resource (Sorghum spp. seed). The mean and total duration that an individual spent within any receiver detection field (residence time) were used as dependants in a generalised linear mixed model approach within a Bayesian framework to assess the influence of tracking session, life stage, receiver site, and release site. Network analysis revealed the importance of specific areas for the finches within the receiver array using the proportional time a bird spent within any receiver's detection field and the movement between adjacent detection fields. ResultsThe daily mean and total duration that a tagged individual spent within a receiver detection field decreased by ~50% between periods of high and low seed availability, while the extent of movements across the landscape increased with a decline in seed resources. These data support the hypothesis that the Gouldian finch adheres to optimal foraging theory to survive periods of food scarcity. ConclusionsThe data collected via passive telemetry technology support the hypothesis that the Gouldian finch adheres to optimal foraging theory and uses alternative behavioural strategies to survive periods of food scarcity. Specifically, we found that Gouldian finches reduced the time spent foraging within a patch, increased the frequency of transit flights among patches, and expanded the size of their activity space as grass resources declined.

Usability Evaluation of Food Wastage Mobile Application: A Case of Pakistan

The continuous rise in food scarcity is creating an alarming situation in underdeveloped countries and Pakistan is no exception. According to the Global Hunger Report published in 2020, Pakistan was ranked 88th among 107 countries, with 28.5% of the population under-nourished. To address the situation, food resources need to be more effectively utilized. To reduce food wastage, various efforts have been made to identify the issues associated with the lack of adoption of food wastage mobile application(s). Using purposeful sampling and data from 150 respondents collected from a public sector university and a software house, participants’ experience in using selected food wastage mobile applications were evaluated. In terms of usability parameters, the study proposes improvements in the prototype design.

Carceral and Colonial Memory During Pandemic Times in the Philippines

#CommunityPantryPH is a mutual aid movement that began in the Philippines in April 2021 during the COVID-19 pandemic. The movement is founded on the slogan ‘give what you can afford, take what you need.’ Instead of the movement receiving an overwhelming welcome, especially within conditions of food scarcity and health insecurity during the long-lasting pandemic, the Duterte government attacked volunteers with ‘red-tagging’ tactics—the malicious calling out of individuals as communists, which may result in harm both online and in real life to those red-tagged. The public response also circulated myths about the supposed indolence of Filipinos receiving aid and how the volunteers are fanning a culture of dependence among the poor. In this article, I introduce the concepts of ‘carceral memory’ and ‘colonial memory’ in understanding colonially inherited punitive, civilising, and self-deprecatory logics that have become embedded in postcolonial disciplinary regimes, and which suppress dissent and shape popular attitude and consciousness in the Global South.

Short term effects of restricted food availability and peripheral leptin injections in redheaded bunting, Emberiza bruniceps

Migratory birds need continued food supply and efficient metabolic machinery to meet high energy demands of the magnanimous feat of flight. Two questions are important i.e. as to 1) how a bird adapts to a temporary food constrain on a daily basis, and 2) how peripheral leptin, an anorectic hormone, impacted feeding and migratory behaviour in buntings? The aim of this study was to induce a non-photoperiodic tweak in the physiology of redheaded buntings through exogenous leptin administration and study its effect on their food intake and migratory behaviour. Groups of male redheaded buntings, Emberiza bruniceps (n=17) were transferred from short (8L: 16D) to long (16L: 8D) days and presented with food only either for first (morning food presence, MFP) or second (evening food presence, EFP) half of the 16h lighted phase, while control group received food ad libitum. Total daily food intake (FI) did not differ significantly between the MFP, EFP and controls, but hourly FI in MFP and EFP indicated increased activity differences based on time of food availability and bird’s tendency to cache food/ recompense for food scarcity during migration. In another experiment, a chemical tweak in bird’s FI was induced by peripheral administration of leptin, to add to current understanding of transition in buntings’ metabolic efficiency during high energy demanding migratory journey. Exogenous leptin appeared to safeguard cadaveric effect of exogenous injection in migrating buntings through promoting blood cholesterol and reduced liver fibrosis. Food restriction in the morning was better responded by buntings than that in evening. Therefore, migratory buntings exhibited diurnal variation in response to food scarcity.

Anticipated Food Scarcity and Food Preferences

In the recent decade, marketing literature has acknowledged the advantages of applying an evolutionary lens to understand consumer behavior in different domains. Food choice context is one such domain, having implications for societal well-being, especially for public health and addressing environmental issues. In this thesis, I investigate how mechanisms that have emerged as adaptations to food scarcity—frequent throughout human history—affect modern consumers’ food preferences, potentially leading to maladaptive outcomes. In Paper I, we highlight that selection pressures adjusted humans to forage in ancestral, hostile environments when they were wandering between periods of food scarcity and food sufficiency. Consequently, consumers often fail to choose foods appropriate to their current needs in contemporary retail contexts. Rather than attempting to override these hardwired and evolutionarily outdated food preferences, we recommend policymakers leverage them in such a way that facilitates healthier food choices. A series of studies reported in Paper II show that exposing people to climate change-induced food scarcity distant in time and space shifts their current food preferences. Specifically, people exposed to such video content exhibit a stronger preference toward energy-dense (vs. low-calorie) foods than their peers exposed to a control video. In Paper III, we aimed to account for potential confounds stemming from the control video used in studies reported in Paper II. Additionally, we strived to conceptually replicate these earlier findings by exposing participants to subtle cues to food scarcity—a winter forest walk. Although not all studies yielded significant results at conventional levels, this empirical package—when taken together—corroborated the earlier findings. Despite that studies described in Papers II–III provided a shred of empirical evidence showing a potency of food scarcity cues in increasing preferences toward energy-dense (vs. low-calorie) products, it was still unclear what drove such a shift in food liking. Thus, in Paper IV, we have developed and psychometrically validated the Anticipated Food Scarcity Scale (AFSS), measuring the degree to which people perceive food resources as becoming less available in the future. Aside from being a candidate mechanism partially explaining findings reported in Papers II–III, anticipated food scarcity (AFS) is also related to some aspects of prosociality. Studies presented in this thesis suggest that when environmental cues to food scarcity are present, people show a stronger preference toward energy-dense (vs. low-calorie) foods than their peers unexposed to such cues. Policymakers should consider these results when designing climate change and other similar campaigns, as such communication often depicts food scarcity. Additional research may explore the possibility that exposure to food scarcity cues affects food choices. Considering that we found AFS correlated with certain prosocial attitudes, it is a new psychological construct that warrants future investigation through multidisciplinary research.

Perinatal Food Deprivation Modifies the Caloric Restriction Response in Adult Mice Through Sirt1

Variations in the availability of nutritional resources in animals can trigger reversible adjustments, which in the short term are manifested as behavioral and physiological changes. Several of these responses are mediated by Sirt1, which acts as an energy status sensor governing a global genetic program to cope with changes in nutritional status. Growing evidence suggests a key role of the response of the perinatal environment to caloric restriction in the setup of physiological responses in adulthood. The existence of adaptive predictive responses has been proposed, which suggests that early nutrition could establish metabolic capacities suitable for future food-scarce environments. We evaluated how perinatal food deprivation and maternal gestational weight gain impact the transcriptional, physiological, and behavioral responses in mice, when acclimated to caloric restriction in adulthood. Our results show a strong predictive capacity of maternal weight and gestational weight gain, in the expression of Sirt1 and its downstream targets in the brain and liver, mitochondrial enzymatic activity in skeletal muscle, and exploratory behavior in offspring. We also observed differential responses of both lactation and gestational food restriction on gene expression, thermogenesis, organ masses, and behavior, in response to adult caloric restriction. We conclude that the early nutritional state could determine the magnitude of responses to food scarcity later in adulthood, mediated by the pivotal metabolic sensor Sirt1. Our results suggest that maternal gestational weight gain could be an important life history trait and could be used to predict features that improve the invasive capacity or adjustment to seasonal food scarcity of the offspring.

Anticipated Food Scarcity and Food Preferences: Ph.D. thesis

In the recent decade, marketing literature has acknowledged the advantages of applying an evolutionary lens to understand consumer behavior in different domains. Food choice context is one such domain, having implications for societal well-being, especially for public health and addressing environmental issues. In this thesis, I investigate how mechanisms that have emerged as adaptations to food scarcity—frequent throughout human history—affect modern consumers’ food preferences, potentially leading to maladaptive outcomes. In Paper I, we highlight that selection pressures adjusted humans to forage in ancestral, hostile environments when they were wandering between periods of food scarcity and food sufficiency. Consequently, consumers often fail to choose foods appropriate to their current needs in contemporary retail contexts. Rather than attempting to override these hardwired and evolutionarily outdated food preferences, we recommend policymakers leverage them in such a way that facilitates healthier food choices. A series of studies reported in Paper II show that exposing people to climate changeinduced food scarcity distant in time and space shifts their current food preferences. Specifically, people exposed to such video content exhibit a stronger preference toward energy-dense (vs. low-calorie) foods than their peers exposed to a control video. In Paper III, we aimed to account for potential confounds stemming from the control video used in studies reported in Paper II. Additionally, we strived to conceptually replicate these earlier findings by exposing participants to subtle cues to food scarcity—a winter forest walk. Although not all studies yielded significant results at conventional levels, this empirical package—when taken together—corroborated the earlier findings. Despite that studies described in Papers II–III provided a shred of empirical evidence showing a potency of food scarcity cues in increasing preferences toward energy-dense (vs. low-calorie) products, it was still unclear what drove such a shift in food liking. Thus, in Paper IV, we have developed and psychometrically validated the Anticipated Food Scarcity Scale (AFSS), measuring the degree to which people perceive food resources as becoming less available in the future. Aside from being a candidate mechanism partially explaining findings reported in Papers II–III, anticipated food scarcity (AFS) is also related to some aspects of prosociality. Studies presented in this thesis suggest that when environmental cues to food scarcity are present, people show a stronger preference toward energy-dense (vs. low-calorie) foods than their peers unexposed to such cues. Policymakers should consider these results when designing climate change and other similar campaigns, as such communication often depicts food scarcity. Additional research may explore the possibility that exposure to food scarcity cues affects food choices. Considering that we found AFS correlated with certain prosocial attitudes, it is a new psychological construct that warrants future investigation through multidisciplinary research.

Seasonality of Food Use and Caching in New Zealand Robins (Petroica Australis)

<p>Foraging behaviour in birds is strongly determined by temporal factors such as season and time of day. Most birds show a limited number of food use methods such as consuming, feeding to conspecifics, or discarding. A relatively small number of birds also cache food for later use. The expression of caching in birds has been attributed to numerous factors. However, noting the environmental instability experienced by most caching species, researchers tend to cite survival of future food scarcity as the predominant advantage. Recording the food use behaviour of wild birds is typically difficult and time consuming, and many studies of north-temperate food-caching birds are limited by long caching distances, protracted caching durations, and a lack of year-round data. Additionally, food-caching in Australasian passerines has received limited quantification. The naïveté of the New Zealand robin (Petroica australis) makes it ideal for behavioural observations in the wild. Robins express a wide range of food use behaviours within close proximity of observers, and cached food is retrieved within a few days. Food use can be observed year-round in a temperate environment that is relatively stable. Thus, food use decisions in robins can be assessed in a wider context. In this study, behavioural data were collected from robins inhabiting the Karori Wildlife Sanctuary in Wellington. Robin behaviour was quantified by presenting monogamous, paired birds an ephemeral food resource and observing their responses. Seasonal variation in food use differed with sex and season. Birds mediated their food use in response to the presence of conspecifics. Males dominated food use year-round. During the breeding season, males cached little, mostly feeding familial conspecifics. However, non-breeding males selfishly cached food. Conversely, female caching propensity was mediated by courtship feeding during the breeding season, and the threat of male pilferage outside of it. Birds did not appear to anticipate future food scarcity. Instead, food was cached in the season in which retrieval would be least necessary. In robins, food is opportunistically cached, mainly as a competitive response to excess food.</p>

Seasonality of Food Use and Caching in New Zealand Robins (Petroica Australis)

<p>Foraging behaviour in birds is strongly determined by temporal factors such as season and time of day. Most birds show a limited number of food use methods such as consuming, feeding to conspecifics, or discarding. A relatively small number of birds also cache food for later use. The expression of caching in birds has been attributed to numerous factors. However, noting the environmental instability experienced by most caching species, researchers tend to cite survival of future food scarcity as the predominant advantage. Recording the food use behaviour of wild birds is typically difficult and time consuming, and many studies of north-temperate food-caching birds are limited by long caching distances, protracted caching durations, and a lack of year-round data. Additionally, food-caching in Australasian passerines has received limited quantification. The naïveté of the New Zealand robin (Petroica australis) makes it ideal for behavioural observations in the wild. Robins express a wide range of food use behaviours within close proximity of observers, and cached food is retrieved within a few days. Food use can be observed year-round in a temperate environment that is relatively stable. Thus, food use decisions in robins can be assessed in a wider context. In this study, behavioural data were collected from robins inhabiting the Karori Wildlife Sanctuary in Wellington. Robin behaviour was quantified by presenting monogamous, paired birds an ephemeral food resource and observing their responses. Seasonal variation in food use differed with sex and season. Birds mediated their food use in response to the presence of conspecifics. Males dominated food use year-round. During the breeding season, males cached little, mostly feeding familial conspecifics. However, non-breeding males selfishly cached food. Conversely, female caching propensity was mediated by courtship feeding during the breeding season, and the threat of male pilferage outside of it. Birds did not appear to anticipate future food scarcity. Instead, food was cached in the season in which retrieval would be least necessary. In robins, food is opportunistically cached, mainly as a competitive response to excess food.</p>