Population Sex Ratio Research Articles

Sex ratios of calanoid copepods in the northern Black Sea

The adult and juvenile sex ratios in field populations of the most common species of calanoid copepods Acartia clausi Giesbrecht, 1889, Acartia tonsa Dana, 1849, Centropages ponticus Karavaev, 1895, Paracalanus parvus (Claus, 1863), and Pseudocalanus elongatus (Brady, 1865) were studied on the basis of zooplankton materials collected in the Black Sea in 2011–2017. In all analyzed species, the adult sex ratios were female-biased, but to a different extent, which reflects the peculiarities of their morphology and ecology. The highest degree of female-skewed adult sex-ratios was observed in P. parvus and P. elongatus, species in which females have seminal receptacles, and males have atrophied mouth appendages. The closest to equity sex ratio was registered in C. ponticus, a species in which females lack seminal receptacles, and males have well-developed mouthparts. Thermophilic, present in plankton only during the warm season, A. tonsa and C. ponticus demonstrated the highest average values of the proportion of males. Seasonal changes in adult sex ratios were registered only in P. elongatus. Juveniles of the fifth stage in A. clausi, A. tonsa, C. ponticus, and P. elongatus had average sex ratios close to 1:1 with a slight bias towards the prevalence of females. In copepodites of P. parvus, this bias was expressed to a much greater extent, which is possibly due to the counting method, when immature hermaphrodites were referred to as females. The microscope images of the mandibles of the analyzed species are given.

Demographic Recovery of a Reef Fish Population Over 30 Years of Spawning Aggregation Site Protection

Over 200 species of reef fish around the world form spawning aggregations to reproduce at specific times and locations. The locations of many reef fish spawning aggregations in the Caribbean have been known and fished for decades. Red Hind (Epinephelus guttatus), a species of grouper important in Caribbean fisheries, migrate to form spawning aggregations which have historically experienced intense fishing pressure. The Red Hind Bank Marine Conservation District (MCD) was established in the United States Virgin Islands to protect a known Red Hind spawning aggregation site. The MCD was closed seasonally to fishing in 1990 and then permanently in 1999. Our goal was to evaluate the success of this marine conservation effort by assessing how the Red Hind population at the spawning aggregation responded to changing levels of protection. We documented Red Hind population demographics at the spawning aggregation site in the MCD during peak spawning events from 2018 to 2020. After 30 years of protection, the mean size of Red Hind at the spawning aggregation increased by >35% and the population sex ratio of females to males was less skewed compared to population characteristics at the spawning aggregation prior to protection. To evaluate stock status relative to management benchmarks, we used length-based stock assessment models that includedin situsize distribution data spanning 1988 to 2020 to estimate population spawning potential ratio (SPR) over time. We found that the SPR of the Red Hind population at the spawning aggregation prior to protection was 0.32 (95% CI: 0.25, 0.39) and under seasonal protection, The SPR increased slightly to 0.35 (95% CI: 0.28, 0.42). Under permanent protection, The SPR increased to its highest value yet at 0.49 (95% CI: 0.42, 0.56), which is above the benchmark value considered sustainable for many fish species. Our work demonstrates demographic recovery of the protected Red Hind spawning population and highlights the value of using size distribution data to evaluate the response of data-limited reef fish populations to seasonal and permanent protection at spawning aggregation sites.

Long-term trends and drought: Spatiotemporal variation in juvenile sex ratios of North American ducks.

Sex ratios affect population dynamics and individual fitness, and changing sex ratios can be indicative of shifts in sex‐specific survival at different life stages. While climate and landscape changes alter sex ratios of wild bird populations, long‐term, landscape scale assessments of sex ratios are rare. Further, little work has been done to understand changes in sex ratios in avian communities. In this manuscript, we analyze long‐term (1961–2015) data on five species of ducks across five broad climatic regions of the United States to estimate the effects of drought and long‐term trends on the proportion of juvenile females captured at banding. As waterfowl have a 1:1 sex ratio at hatch, we interpret changes in sex ratios of captured juveniles as changes in sex‐specific survival rates during early life. Seven of 12 species‐region pairs exhibited evidence for long‐term trends in the proportion of juvenile females at banding. The proportion of juvenile females at banding increased for duck populations in the western United States and typically declined for duck populations in the eastern United States. We only observed evidence for an effect of drought in two of the 12 species‐region pairs, where the proportion of females declined during drought. As changes to North American landscapes and climate continue and intensify, we expect continued changes in sex‐specific juvenile survival rates. More broadly, we encourage further research examining the mechanisms underlying long‐term trends in juvenile sex ratios in avian communities.

Fertility Decline, Small Families, and Son Selection in the Arab World: The Controversial Convergence of Contraceptive and Repro‐genetic Technologies

AbstractThe Arab world has experienced one of the most dramatic fertility declines in modern history, the result of both contraceptive technologies and couples’ desires for smaller families. Assisted reproductive and genetic technologies have also become widespread across the region, leading to new practices of in vitro fertilization (IVF) with sex selection. This article examines the desire for small families with sons, and the introduction of the repro‐genetic technology of preimplantation genetic screening (PGS) for son selection. Islamic opinions on sex selection are divided, but permissive fatwas have fueled practices of son selection in some Arab countries, including the United Arab Emirates, the focus of this study. As shown in this article, the “bioethical aftermath” of these repro‐genetic practices may include son preference and daughter discrimination, with future distortions of population sex ratios across the Arab world.

P-256 The influence of artificial intelligence embryo scoring on male-female sex ratio

Abstract Study question Are there correlations among male-female sex ratio, human blastocyst ploidy status and artificial intelligence (AI)-based morphokinetics embryo selection? Summary answer Embryo selection based on morphological evaluation by time-lapse system (TLS) with AI technology could lead to a female-biased sex ratio of resulting newborns. What is known already As of now, there have been only limited attempts to evaluate how AI-based TLS embryo selection for priority transfer could affect male-to-female sex ratio in human population, and the results of different publications were contradicting. However, the morphokinetic assessment was made without calculating the embryos KID Score (Embryos with Known Implantation Data), which significantly improves and make faster the decision-making process. Study design, size, duration This is a monocentric, retrospective study from October 2019 to December 2021 including 251 blastocysts with PGT-A results. Embryos were cultured in time-lapse incubator (EmbryoScope, Vitrolife) up to the time of trophectoderm biopsy. All embryos were evaluated based on the KIDscoreTM D5 algorithm (Vitrolife) under routine supervision by experienced embryologists. The PGT-A results were obtained by using next-generation sequencing (NGS) platform from Medical Genomics LLC laboratory (Illumina MiSeq, Illumina). Participants/materials, setting, methods Sample size was 251 embryos from 101 women (mean female age was 36.0 ± 5.6 years). All embryos were divided in four groups in accordance with their final KID score: <2.5 ( n = 7), 2.6-5.0 ( n = 33), 5.1-7.5 ( n = 123) and >7.5 ( n = 88). The embryos with sex chromosome abnormalities were also included in research to assess the frequency of occurrence in embryos with low and high KID score. Main results and the role of chance As expected, the percentage of aneuploid blastocysts, as well as the rate of sex chromosome abnormalities, decreased with increasing the embryo KID score. The highest male-female sex ratio among all embryos was observed for the group with KID score <2.5 (1.33), and gradually decreased to values of 0.92 and 0.74 in groups with KID score 5.1-7.5 and >7.5, respectively. At the same time, the highest male-female sex ratio among euploid blastocysts was maximal in the group with KID score 2.6-5.0. The obtained data contradict results of some other studies, which reported faster development of male embryos (which should mean their higher KID score). However, the KID score was not evaluated in them, and thus these results cannot be directly compared to ours. Limitations, reasons for caution Most patients in this study had complicated reproductive history, with repeated failures in IVF programs, often with a stop in embryo development. Also, the present investigation is retrospective. A following multicenter researches with larger sample size and cross-centered validation of embryologist-performed annotation is considered in our future approach. Wider implications of the findings Obtained data doesn’t allow to establish the female-gender prevalence among embryos. Nevertheless, further accumulation of knowledge about relation between KID Embryo Score and embryo gender can be used for presumptive sex determination in special cases with sex-linked diseases, where poor embryo morphology doesn’t allow to perform biopsy for genetic analysis. Trial registration number -

The Improved Leslie Model for population Forecasting

Based on China’s population data from 1953 to 2020, the Leslie model combines the fertility rate of women of childbearing age by region and age, the sex ratio of the birth population, the mortality rate, the migration rate between urban and rural areas by age, the curve fitting migration function, and the application of ARIMA to predict mortality rates to construct a discrete population dynamics system in order to predict China’s future population development trajectory. The improved Leslie, Leslie, BP and Malthus models were compared in terms of error rates. The improved Leslie model was more stable than the rest of the models and had an average error rate of 0.09%, with good model generalization ability. The results show that the improved Leslie model predicts that the total population will slowly increase under the national regulation policy, and will reach a peak by around 2045 and then decline.

Experimental evolution under varying sex ratio and nutrient availability modulates male mating success in Drosophila melanogaster.

Biased population sex ratios can alter optimal male mating strategies, and allocation to reproductive traits depends on nutrient availability. However, there is little information on how nutrition interacts with sex ratio to influence the evolution of pre-copulatory and post-copulatory traits separately. To address this omission, we test how male mating success and reproductive investment evolve under varying sex ratios and adult diet in Drosophila melanogaster, using experimental evolution. We found that sex ratio and nutrient availability interacted to determine male pre-copulatory performance. Males from female-biased populations were slow to mate when they evolved under protein restriction. By contrast, we found direct and non-interacting effects of sex ratio and nutrient availability on post-copulatory success. Males that evolved under protein restriction were relatively poor at suppressing female remating. Males that evolved under equal sex ratios fathered more offspring and were better at supressing female remating, relative to males from male-biased or female-biased populations. These results support the idea that sex ratios and nutrition interact to determine the evolution of pre-copulatory mating traits, but independently influence the evolution of post-copulatory traits.

Evidence for Sperm Limitation in the Louisiana Blue Crab Spawning Stock

AbstractMale‐targeted fishing pressure has the potential to skew population sex ratios and to result in sperm limitation in females, where the quantity or quality of sperm received during mating is insufficient for the female to achieve her full lifetime reproductive potential. Blue crabs Callinectes sapidus are heavily targeted by commercial and recreational fisheries throughout much of their range, with fishing pressure biased toward males. Additionally, blue crabs are particularly susceptible to sperm limitation because mating occurs during a short window following the female’s terminal molt and stored sperm is used to fertilize all future broods. We investigated sperm quantities in recently molted and mated female blue crabs in southeastern Louisiana to assess the potential for sperm limitation in this area. Sperm quantities were an order of magnitude lower than those previously observed in other areas. Brood production modeling indicated that most of the female blue crabs in this region are heavily sperm limited and unable to achieve their lifetime spawning potential. On a population level, this sperm limitation may be partially responsible for recent declines in landings and estimates of abundance. Although insufficient data exist to assess the precise cause of this sperm limitation, these results should be incorporated into future stock assessments and management decisions for the Louisiana blue crab spawning stock.

Factors influencing dispersal initiation and timing in a facultative cooperative breeder

AbstractNatal dispersal is a high-risk endeavor where decisions on whether and when to disperse have long-term consequences. Among facultative cooperative breeders, juveniles often forego dispersal and remain philopatric for one or more breeding seasons. This decision is key to the formation of cooperative breeding groups and could have significant effects on reproductive success. We investigated the probability and initiation of dispersal in the cooperatively breeding Brown-headed Nuthatch (Sitta pusilla) to determine the influence that social environments had on dispersal. This study was concurrent with another study where manipulation of population sex ratios increased the prevalence and size of cooperative groups. The concurrent manipulations enabled us to evaluate social effects on dispersal as a plausible mechanism driving the relationship between adult sex ratios and cooperation. We evaluated which factors best predicted whether males dispersed, and the timing of dispersal for both sexes. We considered variables related to the immediate nesting environment as well as characteristics of the local population. Social environments were related to dispersal for both males and females. Juvenile males dispersed earlier when a helper was present in the natal group. Females dispersed earlier in settings with more adult neighbors and when a lower proportion of those neighbors were males. Females with shorter tarsi relative to their siblings dispersed earlier, suggesting that size-based competitive interactions may also affect dispersal decisions. Our results suggest juveniles disperse more readily when they fledge in constrained social environments, and that competition with conspecifics is a major driver of dispersal in the Brown-headed Nuthatch.

Trisomy 14 Mosaicism Including Concomitant Uniparental Disomy: Population Frequency, Cytogenetic Profile, Sex Ratio, Maternal Age, and Obstetric History.

Mosaicism for trisomy of chromosome 14 (T14) is a very rare chromosomal disease in liveborn patients. Since the 1970s, when the first patients with mosaicism for T14 were reported, a number of studies on the clinical manifestations of this abnormality have been published. No information on epidemiological parameters was known except for the rarity of the disease and its predominance among female carriers. This was the first systematic review of published cases of mosaic T14 that addressed some epidemiological aspects of this abnormality. We conducted a literature review and collected information on 194 cases of regular T14 and only two cases of mosaic T14 among 21,082 tested spontaneous abortuses. Thus, the rates of nonmosaic T14 and mosaic T14 were 0.9% and 0.09‰, respectively. Additionally, we identified 76 carriers of mosaic T14, diagnosed prenatally and postnatally. Among them, there were 50 carriers of mosaicism for regular T14, 21 carriers of mosaicism due to unbalanced homologous translocation/isochromosome, and five carriers of mosaicism for unbalanced non-homologous Robertsonian translocation involving chromosome 14. The most significant findings were as follows. i) The unexplained fourfold predominance of the carriers of homologous rearrangement relative to non-homologous translocations, but the occurrence of exceptionally rare homologous rearrangements compared to non-homologous translocations in human populations; also, the ratio between these two types of rearrangements (21 and 28, respectively) differed from that in the carriers of non-mosaic UPD(14) (p < 0.005). ii) Female patients were predominant in all studied groups, irrespective of the type of the trisomic line and parental origin of the euploid cell line; there were 19 male and 57 female cases reported. iii) The differences in the maternal age between carriers of mosaicism for regular T14 with and without maternal uniparental disomy were statistically significant (average age of 35.4 and 29.8 years, respectively; p < 0.05). This is intriguing because of the common mechanism of the formation of biparental and uniparental disomy. Additionally, a complicated reproductive history was noted in 25% of the families.

Diversity in Machine Learning: A Systematic Review of Text-Based Diagnostic Applications.

As the storage of clinical data has transitioned into electronic formats, medical informatics has become increasingly relevant in providing diagnostic aid. The purpose of this review is to evaluate machine learning models that use text data for diagnosis and to assess the diversity of the included study populations. We conducted a systematic literature review on three public databases. Two authors reviewed every abstract for inclusion. Articles were included if they used or developed machine learning algorithms to aid in diagnosis. Articles focusing on imaging informatics were excluded. From 2,260 identified papers, we included 78. Of the machine learning models used, neural networks were relied upon most frequently (44.9%). Studies had a median population of 661.5 patients, and diseases and disorders of 10 different body systems were studied. Of the 35.9% (N = 28) of papers that included race data, 57.1% (N = 16) of study populations were majority White, 14.3% were majority Asian, and 7.1% were majority Black. In 75% (N = 21) of papers, White was the largest racial group represented. Of the papers included, 43.6% (N = 34) included the sex ratio of the patient population. With the power to build robust algorithms supported by massive quantities of clinical data, machine learning is shaping the future of diagnostics. Limitations of the underlying data create potential biases, especially if patient demographics are unknown or not included in the training. As the movement toward clinical reliance on machine learning accelerates, both recording demographic information and using diverse training sets should be emphasized. Extrapolating algorithms to demographics beyond the original study population leaves large gaps for potential biases.

Population Characteristic of Carcinoscorpius Rotundicauda in The Northern Coast of Rangsang Island, Riau

Carcinoscorpius rotundicauda is often found in mangrove areas and is known as mangrove horseshoe crab. The crab is a common species that was abundantly caught by fishermen but currently, it has been said to be declining. The study aimed to estimate the population density and sex ratio of C. rotundicauda. In addition, it is necessary to know the local community’s perception of the horseshoe crab. The study was conducted from March to April 2021 in the northern coast of Rangsang Island of Riau Province. Sampling was carried out using 100x1m nets at 5 selected stations. The crabs were enumerated, marked, and released. People’s perception of C. rotundicauda was obtained by using a questionnaire method. The population density of the crabs in the northern coast of Rangsang Island is 0.026/m2. The sex ratio is 1.67. Public perception of horseshoe crabs is low so it is necessary to socialize the conservation of horseshoe crabs there.

Local mate competition model alone cannot predict the offspring sex ratio in large and dense populations of a haplodiploid arthropod.

Local mate competition model alone cannot predict the offspring sex ratio in large and dense populations of a haplodiploid arthropod.

Do Genetic Drift and Gene Flow Affect the Geographic Distribution of Female Plants in Gynodioecious Lobelia siphilitica?

Variation in population sex ratio is particularly pronounced in gynodioecious angiosperms. Extremely high female frequencies in gynodioecious populations cannot be readily explained by selective forces alone. To assess the contributions of drift and gene flow to extreme sex-ratio variation, we documented sex ratio and population size in 92 populations of Lobelia siphilitica across its range and genotyped plants using plastid and nuclear genetic markers. Similarity in spatial patterns of genetic and demographic variables may suggest that drift and/or gene flow have contributed to population sex-ratio variation in L. siphilitica. We found strong spatial structuring of extremely high female frequencies: populations with >50% female plants are restricted to the south–central portion of the range. However, we did not detect any spatial structuring in population size nor metrics of genetic diversity, suggesting that extreme variation in female frequency is not strongly affected by drift or gene flow. Extreme sex-ratio variation is frequently observed in gynodioecious plants, but its causes are difficult to identify. Further investigation into mechanisms that create or maintain the spatial structure of sex ratios in gynodioecious species will provide much needed insight.

A noninvasive and integrative approach for improving density and abundance estimates of moose

AbstractAcquiring demographic data for moose (Alces alces) can be difficult because they are solitary in nature, they prefer densely vegetated and mountainous habitats, and they often occur at low density. Such data, however, are essential for long‐term population monitoring, evaluating management practices, and effective conservation. Winter aerial surveys are the standard method for estimating moose population parameters, but they can be logistically challenging, expensive, and subject to sightability correction, which necessitates the capture of study animals for initial model development. Herein, we demonstrate a noninvasive alternative approach for estimating population parameters of moose in northern Yellowstone National Park, where aerial surveys were attempted but proved ineffective. We determined individual moose genotype and sex using microsatellite polymerase chain reaction amplification of DNA extracted from fecal pellets, integrated ancillary pellet sample data (i.e., metadata) in genotype analysis to aid in the identification of matching genotypes, and used spatially explicit capture‐recapture (SECR) modeling to estimate sex‐specific density and abundance. We collected 616 samples over 3 consecutive winters (Dec 2013–Apr 2016) and within 2 sampling occasions each winter. We recorded 514 captures of 142 individual moose (69 males, 73 females). Overall density ranged between 0.062 moose/km2 and 0.076 moose/km2 and averaged 0.034/km2 for females and 0.033/km2 for males. Abundance estimates were 150 moose in 2013 (female = 76, 95% CI = 55–105; male = 74, 95% CI = 54–103), 186 in 2014 (female = 95, 95% CI = 63–142; male = 91, 95% CI = 60–138), and 160 in 2015 (female = 79, 95% CI = 58–108; male = 81, 95% CI = 59–110). Average population sex ratio was 0.99 males/female. We demonstrate that SECR analysis of fecal DNA genotypes, using metadata in genotype analysis to help identify matching moose genotypes, is a promising alternative method for estimating sex‐specific density and abundance of a low‐density moose population in a mountainous and forested landscape.

Sex ratio in the mother's environment affects offspring population dynamics: maternal effects on population regulation.

Classic population regulation theories usually concern the influence of immediate factors on current populations, but studies investigating the effect of parental environment factors on their offspring populations are scarce. The maternal environments can affect offspring life-history traits across generations, which may affect population dynamics and be a mechanism of population regulation. In cyclical parthenogens, sexual reproduction is typically linked with dormancy, thereby providing a negative feedback to population growth. In this study, we manipulated population sex ratios in the mother's environment to investigate whether this factor affected future population dynamics by regulating offspring sexual reproduction in the rotifer Brachionus calyciflorus. Compared with females in male-biased environments, those in female-biased environments produced fewer mictic (sexual) offspring, and their amictic (asexual) offspring also produced a lower proportion of mictic females at a gradient of population densities. Moreover, populations that were manipulated under male-biased conditions showed significantly smaller population sizes than those under female-biased conditions. Our results indicated that in cyclical parthenogens, mothers could adjust the sexual reproduction of their offspring in response to the current population sex ratio, thus providing fine-scale regulation of population dynamics in addition to population density.

New records of the not-so-rare males of the parthenogenetic scorpion Tityus stigmurus (Thorell, 1876) (Scorpiones: Buthidae)

Parthenogenesis and sex-ratio bias may lead to erroneous assumptions concerning the natural history of some arachnids. To help address this issue, this study provides new data on the sex ratio and geographic distribution of sexual populations of the scorpion Tityus stigmurus (Thorell, 1876). Ultraviolet light lanterns were used to detect specimens during nocturnal searches performed in both urban and non-urban environments scattered thorough northeastern Brazil. Males of T. stigmurus were reported for 10 new localities, and although we did not find males in urban environments, non-urban populations presented near symmetrical sex ratios. Such results suggest that reproductive strategies in this species may be modulated by environmental conditions. Also, the general tendency of less biased sex ratios in non-urban environments reported here is in accordance with previous studies that indicated the occurrence of geographical parthenogenesis in this species. Thereby, we propose that sexual populations of T. stigmurus are less rare than previously reported.

Propagule size and sex ratio influence colonisation dynamics after introduction of a non-native lizard.

The composition of founding populations plays an important role in colonisation dynamics and can influence population growth during early stages of biological invasion. Specifically, founding populations with small propagules (i.e. low number of founders) are vulnerable to the Allee effect and have reduced likelihood of establishment compared to those with large propagules. The founding sex ratio can also impact establishment via its influence on mating success and offspring production. Our goal was to test the effects of propagule size and sex ratio on offspring production and annual population growth following introductions of a non-native lizard species (Anolis sagrei). We manipulated propagule composition on nine small islands, then examined offspring production, population growth and survival rate of founders and their descendants encompassing three generations. By the third reproductive season, per capita offspring production was higher on islands seeded with a relatively large propagule size, but population growth was not associated with propagule size. Propagule sex ratio did not affect offspring production, but populations with a female-biased propagule had positive growth, whereas those with a male-biased propagule had negative growth in the first year. Populations were not affected by propagule sex ratio in subsequent years, possibly due to rapid shifts towards balanced (or slightly female biased) population sex ratios. Overall, we show that different components of population fitness have different responses to propagule size and sex ratio in ways that could affect early stages of biological invasion. Despite these effects, the short life span and high fecundity of A. sagrei likely helped small populations to overcome Allee effects and enabled all populations to successfully establish. Our rare experimental manipulation of propagule size and sex ratio can inform predictions of colonisation dynamics in response to different compositions of founding populations, which is critical in the context of population ecology and invasion dynamics.

Endosymbionts moderate constrained sex allocation in a haplodiploid thrips species in a temperature-sensitive way

Maternally inherited bacterial endosymbionts that affect host fitness are common in nature. Some endosymbionts colonise host populations by reproductive manipulations (such as cytoplasmic incompatibility; CI) that increase the reproductive fitness of infected over uninfected females. Theory predicts that CI-inducing endosymbionts in haplodiploid hosts may also influence sex allocation, including in compatible crosses, however, empirical evidence for this is scarce. We examined the role of two common CI-inducing endosymbionts, Cardinium and Wolbachia, in the sex allocation of Pezothrips kellyanus, a haplodiploid thrips species with a split sex ratio. In this species, irrespective of infection status, some mated females are constrained to produce extremely male-biased broods, whereas other females produce extremely female-biased broods. We analysed brood sex ratio of females mated with males of the same infection status at two temperatures. We found that at 20 °C the frequency of constrained sex allocation in coinfected pairs was reduced by 27% when compared to uninfected pairs. However, at 25 °C the constrained sex allocation frequency increased and became similar between coinfected and uninfected pairs, resulting in more male-biased population sex ratios at the higher temperature. This temperature-dependent pattern occurred without changes in endosymbiont densities and compatibility. Our findings indicate that endosymbionts affect sex ratios of haplodiploid hosts beyond the commonly recognised reproductive manipulations by causing female-biased sex allocation in a temperature-dependent fashion. This may contribute to a higher transmission efficiency of CI-inducing endosymbionts and is consistent with previous models that predict that CI by itself is less efficient in driving endosymbiont invasions in haplodiploid hosts.

The impact of climate change to livelihood vulnerability for smallholders farmers in Wonogiri, Indonesia

Climate change has affected human life, especially farmers in rural areas. Their livelihoods are very dependent on the climate so that their socio-economic life becomes vulnerable. If there is a risk of crop failure, the community becomes vulnerable to poverty and hunger. This study determines the livelihood vulnerability of smallholders in Wonogiri District, Indonesia. Purposive sampling was used to select respondents in the sub-districts of Girimarto, Eromoko, and Tirtomoyo. The number of respondents was 120 households which were selected for farmers who only own less than 2 hectares of land. Descriptive statistics and modified social vulnerability index (SoVI) were used in data analysis. We measured the level of vulnerability for economic and social. The results show that climate change to social vulnerability index with SoVI scores of 0.68 for Tirtomoyo, 0.61 for Girimarto, and 0.55 for Eromoko, respectively. The differences in components between the three sample areas include regional gross domestic product (GDRP), poverty rate, population density, population growth rate, sex ratio, children, and elderly. The results of the study conclude that climate change has the potential to cause poverty levels in the three sub-districts to increase. In terms of resilience, they are quite resilient because they do not depend on government assistance. However, when climate change causes continuous crop failure, the level of resilience of farmers will also decline.