Life-history Components Research Articles

How to behave when marooned: the behavioural component of the island syndrome remains underexplored.

Animals on islands typically depart from their mainland relatives in assorted aspects of their biology. Because they seem to occur in concert, and to some extent evolve convergently in disparate taxa, these changes are referred to as the ‘island syndrome’. While morphological, physiological and life-history components of the island syndrome have received considerable attention, much less is known about how insularity affects behaviour. In this paper, we argue why changes in personality traits and cognitive abilities can be expected to form part of the island syndrome. We provide an overview of studies that have compared personality traits and cognitive abilities between island and mainland populations, or among islands. Overall, the pickings are remarkably slim. There is evidence that animals on islands tend to be bolder than on the mainland, but effects on other personality traits go either way. The evidence for effects of insularity on cognitive abilities or style is highly circumstantial and very mixed. Finally, we consider the ecological drivers that may induce such changes, and the mechanisms through which they might occur. We conclude that our knowledge of the behavioural and cognitive responses to island environments remains limited, and we encourage behavioural biologists to make more use of these ‘natural laboratories for evolution’.

Selection on dispersal drives evolution of metabolic capacities for energy production in female wing-polymorphic sand field crickets, Gryllus firmus.

Life history and metabolism covary, but the mechanisms and individual traits responsible for these linkages remain unresolved. Dispersal capability is a critical component of life history that is constrained by metabolic capacities for energy production. Conflicting relationships between metabolism and life histories may be explained by accounting for variation in dispersal and maximal metabolic rates. We used female wing‐polymorphic sand field crickets, Gryllus firmus, selected either for long wings (LW, flight‐capable) or short wings (SW, flightless) to test the hypothesis that selection on dispersal capability drives the evolution of metabolic capacities. While resting metabolic rates were similar, long‐winged crickets reached higher maximal metabolic rates than short‐winged crickets, resulting in improved running performance. We further provided insight into the mechanisms responsible for covariation between life history and metabolism by comparing mitochondrial content of tissues involved in powering locomotion and assessing the function of mitochondria isolated from long‐ and short‐winged crickets. Our results demonstrated that larger metabolic capacities in long‐winged crickets were underpinned by increases in mitochondrial content of dorsoventral flight muscle and enhanced bioenergetic capacities of mitochondria within the fat body, a tissue responsible for fuel storage and mobilization. Thus, selection on flight capability correlates with increases in maximal, but not resting metabolic rates, through modifications of tissues powering locomotion at the cellular and organelle levels. This allows organisms to meet high energetic demands of activity for life history. Dispersal capability should therefore explicitly be considered as a potential factor driving the evolution of metabolic capacities.

Activity patterns of Hawaiian forest birds in a fragmented and continuous landscape

Activity patterns are a key component of avian life history and behavior, and decisions about how activity periods are structured can have important fitness implications. Despite the importance of activity patterns, individual variability in activity is poorly studied in small birds. We used automated radio telemetry to track Hawaiian forest birds from three dietary guilds in a continuous forest, and in a similar forest that was naturally fragmented in the 1800s by lava flows but supports stable populations of native birds. We generated kernel density profiles of activity (KDEs) over the full tracking period of each bird and used the KDEs to derive seven activity metrics that characterized daily activity patterns. We identified three distinct activity strategies using a cluster analysis of the activity metrics and assessed day‐to‐day variability in activity strategy to understand intraindividual consistency in activity behavior. We also evaluated the influence of landscape structure, dietary guild and sex on the suite of activity metrics using constrained ordination. Most birds (61%) exhibited high levels of sustained activity throughout the day, while 23% showed irregular activity most of the day followed by a peak in the late afternoon, and 16% were mainly active in the morning. Though activity patterns varied by sex and dietary guild, landscape structure had the strongest influence on activity patterns. Birds sustained high levels of activity throughout the day in the fragmented landscape regardless of dietary guild, suggesting they needed to be more active to obtain necessary resources. However, activity patterns of birds in the fragmented landscape varied more day‐to‐day, indicating they retained a method for adjusting behavior to match internal and external conditions. This study reveals how a diverse suite of tropical birds has adapted to long‐term fragmentation in Hawaiʻi and demonstrates the utility of automated radio telemetry for studying the activity strategies of birds.

Sex-specific developmental trajectories in an extremely sexually size dimorphic spider.

Adult body size, development time, and growth rates are components of organismal life histories, which crucially influence fitness and are subject to trade-offs. If selection is sex-specific, male and female developments can eventually lead to different optimal sizes. This can be achieved through developmental plasticity and sex-specific developmental trajectories. Spiders present suitable animals to study differences in developmental plasticity and life history trade-offs between the sexes, because of their pronounced sexual dimorphism. Here, we examine variation in life histories in the extremely sexually size dimorphic African hermit spider (Nephilingis cruentata) reared under standardized laboratory conditions. Females average 70 times greater body mass (and greater body size) at maturity than males, which they achieve by developing longer and growing faster. We find a small to moderate amount of variability in life history traits to be caused by family effects, comprising genetic, maternal, and early common environmental effects, suggesting considerable plasticity in life histories. Remarkably, family effects explain a higher variance in male compared to female life histories, implying that female developmental trajectories may be more responsive to environment. We also find sex differences in life history trade-offs and show that males with longer development times grow larger but exhibit shorter adult longevity. Female developmental time also correlates positively with adult body mass, but the trade-offs between female adult mass, reproduction, and longevity are less clear. We discuss the implications of these findings in the light of evolutionary trade-offs between life history traits.

Evolutionary and plastic variation in larval growth and digestion reveal the complex underpinnings of size and age at maturation in dung beetles.

Age and size at maturity are key life‐history components, yet the proximate underpinnings that mediate intra‐ and interspecific variation in life history remain poorly understood. We studied the proximate underpinnings of species differences and nutritionally plastic variation in adult size and development time in four species of dung beetles. Specifically, we investigated how variation in insect growth mediates adult size variation, tested whether fast juvenile growth trades‐off with developmental stability in adult morphology and quantified plastic responses of digestive systems to variation in food quality. Contrary to the common size–development time trade‐off, the largest species exhibited by far the shortest development time. Correspondingly, species diverged strongly in the shape of growth trajectories. Nutritionally plastic adjustments to growth were qualitatively similar between species but differed in magnitude. Although we expected rapid growth to induce developmental costs, neither instantaneous growth rates nor the duration of larval growth were related to developmental stability in the adult. This renders the putative costs of rapid growth enigmatic. We further found that larvae that encounter a challenging diet develop a larger midgut and digest more slowly than animals reared on a more nutritious diet. These data are consistent with the hypothesis that larvae invest into a more effective digestive system when exposed to low‐quality nutrition, but suggest that species may diverge readily in their reliance on these mechanisms. More generally, our data highlight the complex, and often hidden, relationships between immature growth and age and size at maturation even in ecologically similar species.

Reproductive effort affects subsequent horn growth in sexually dimorphic male ungulates

Trade-offs between reproductive effort and subsequent growth in males are not well explored, despite their relevance in questions of individual energy allocation. Regarding the growth of sexual secondary characters in polygynous breeding male mammals, indeed, no conclusive studies exist. We investigated in male Alpine ibex (Capra ibex) the relationship between their behavioral reproductive effort, current horn size, and subsequent horn growth. While controlling for age, no evidence was found for male behavioral reproductive effort during the rut being affected by their horn size. On the other hand, reproductive effort significantly decreased age-specific horn growth during the following summer. Our study provides evidence that growth of secondary sexual characters is traded against behavioral investments in reproduction in a male mammal. It bears important implications for the understanding of energy allocation between various life-history components and the evolutionary ecology of secondary sexual characters.

Childhood unpredictability, life history, and intuitive versus deliberate cognitive styles

Cognitive style is a major component of individuals' life history and everyday life. However, individual variations in cognitive styles are not well understood from an evolutionary functional perspective. Through two studies, we investigated how childhood unpredictability might be related to deliberate or intuitive cognitive styles. Study 1, in which we surveyed 301 undergraduate students, revealed that lower childhood unpredictability was a predictor of slower life-history strategies, and such strategies in turn predicted higher self-reported deliberate cognitive style. In Study 2 (N = 269), we experimentally manipulated mortality cues and subsequently assessed participants' deliberate responses by using the Cognitive Reflection Test. The results indicated that individuals who experienced higher childhood unpredictability, relative to those who had low childhood unpredictability, displayed a smaller proportion of deliberate responses when exposed to mortality cues but not when exposed to control cues. These results imply that childhood unpredictability might predispose individuals to specific cognitive styles that serve distinct adaptive functions. This is manifested as both long-term propensities in life-history development and short-term behavioral tendencies in threatening situations.

An assessment of terminology for intraspecific diversity in fishes, with a focus on "ecotypes" and "life histories".

Understanding and preserving intraspecific diversity (ISD) is important for species conservation. However, ISD units do not have taxonomic standards and are not universally recognized. The terminology used to describe ISD is varied and often used ambiguously. We compared definitions of terms used to describe ISD with use in recent studies of three fish taxa: sticklebacks (Gasterosteidae), Pacific salmon and trout (Oncorhynchus spp., “PST”), and lampreys (Petromyzontiformes). Life history describes the phenotypic responses of organisms to environments and includes biological parameters that affect population growth or decline. Life‐history pathway(s) are the result of different organismal routes of development that can result in different life histories. These terms can be used to describe recognizable life‐history traits. Life history is generally used in organismal‐ and ecology‐based journals. The terms paired species/species pairs have been used to describe two different phenotypes, whereas in some species and situations a continuum of phenotypes may be expressed. Our review revealed overlapping definitions for race and subspecies, and subspecies and ecotypes. Ecotypes are genotypic adaptations to particular environments, and this term is often used in genetic‐ and evolution‐based journals. “Satellite species” is used for situations in which a parasitic lamprey yields two or more derived, nonparasitic lamprey species. Designatable Units, Evolutionary Significant Units (ESUs), and Distinct Population Segments (DPS) are used by some governments to classify ISD of vertebrate species within distinct and evolutionary significant criteria. In situations where the genetic or life‐history components of ISD are not well understood, a conservative approach would be to call them phenotypes.

Reproductive allocation in plants: a reappraisal of the currency issue

Reproductive allocation (RA), the proportion of total resources that are invested in reproductive structures, is a key component of plant life histories. A major methodological issue is to identify the allocation currency that better estimates RA: biomass, energy or some mineral nutrient. Despite considerable effort to ascertain whether biomass could serve as an integrated estimate of the allocation of other resources, no clear guideline has emerged from the currency issue. Here, we reappraised this problem at an interspecific scale. We compiled a data base of 38 studies that estimated RA in terms of two or more different resources for 82 plant species. We tested the equivalence of allocation currencies by means of both bi‐ and multivariate correlations among currencies. We also tested for differences in allocation patterns between growth forms. RA was estimated in 18 different currencies, including biomass, energy and 16 mineral nutrients. Nitrogen, P, K, Mg and Ca were the main nutrients used as allocation currency. Growth form accounted for 20–30% of differences in the resource allocation of multiple resources. The six resources most frequently used as estimates RA were roughly equivalent at an interspecific scale. Nevertheless, covariation patterns among currencies suggested that RA in plants should be better considered as a multivariate trait and not estimated using a single currency. In particular, multivariate estimates of RA can contribute to the ongoing comparative studies of life histories and functional traits, and can shed light on resource allocation within flowers.

Nutrient availability predicts multiple stem frequency, an indicator of species resprouting capacity in tropical forests

Abstract Resprouting capacity is a key component of plant life history. While resprouting requires substantial nutrient reserves to support new growth, the influence of soil fertility on resprouting is largely unknown. We tested whether the frequency of multi‐stemmed trees, a potential indicator of resprouting history, is associated with low soil fertility, reflecting selection for conservative life histories that enhance survival, or with high fertility, reflecting greater resource availability to support regrowth. Data from the Barro Colorado Island (BCI) 50‐ha plot in Panama showed that multi‐stemmed trees are more likely to resprout during their lifetime than single‐stemmed trees, and that multiple stem frequency has a strong taxonomic signal for adult trees. To test how multiple stem frequency varies with demographic rates and nutrient allocation strategies, we compiled functional trait datasets for 71 species from lowland forest on BCI and 43 species from lower montane forest in western Panama. We also assessed environmental correlates of community‐wide multiple stem frequency in thirty‐seven 1‐ha lowland plots in the Panama Canal watershed and twelve 1‐ha montane plots in western Panama, spanning gradients of rainfall and soil fertility. Multiple stem frequency was not correlated with species demographic rates or wood density, suggesting that resprouting is unrelated to classical ‘persistence’ traits in neotropical tree species. Multiple stem frequency of tree species occurring on BCI was weakly but significantly positively correlated with regional soil phosphorus associations, but unrelated to foliar nutrient concentrations. Multiple stem frequency covaried strongly with soil and tissue nutrient status across fertility gradients. It was significantly positively correlated with nutrient allocation traits, including foliar phosphorus and wood nitrogen and phosphorus, among species sampled across soil habitats in western Panama. At the community level, the proportion of woody stems >10 cm DBH with at least one multiple stem increased with plant available soil phosphorus. Synthesis. These results suggest a novel mechanism by which soil phosphorus availability influences tree recruitment and forest dynamics by facilitating resprouting. Future experiments should seek to understand whether soil fertility mediates resprouting frequency through nutrient supply directly, or via the formation of enhanced wood nutrient reserves.

Horizontal transmission of a murine retrovirus is driven by males within semi‐natural enclosures

Abstract Transmission is a key component of a pathogen's life history, but it is often difficult to obtain reliable ecological estimates of the dominant mode(s) of transmission and how host traits, such as sex, influence transmission dynamics. Here, we have developed a robust system pairing the use of semi‐natural populations of house mice Mus musculus with modern molecular viral titering approaches to evaluate the transmission dynamics of Friend Virus Complex (FVC). Semi‐natural populations were founded with female and male mice that were either ‘index’ (initially infected via intraperitoneal injection) or ‘contact’ (uninfected at the start of experiment). Three experimental population designs were implemented: female index only, male index only and both female and male index. Utilizing these enclosures, we found male–male transmission to be the predominant mode of transmission, with low rates of horizontal female transmission and no evidence of vertical transmission. Additionally, contact males that became infected harbour higher titres than females while suffering a similar amount of spleen enlargement; this, paired with a strong correlation between titre and spleen size in males, and no correlation in females, indicates FVC viral dynamics differ between the sexes. Lastly, natural transmission may be an impediment to FVC replication as infected contact animals have a lower viral titre than index animals. These results illuminate the complex life history of murine leukaemia viruses and demonstrate the important role of host sex on pathogen transmission dynamics. A free Plain Language Summary can be found within the Supporting Information of this article.

Behavior-specific occurrence patterns of Pinyon Jays (Gymnorhinus cyanocephalus) in three Great Basin study areas and significance for pinyon-juniper woodland management.

The Pinyon Jay is a highly social, year-round inhabitant of pinyon-juniper and other coniferous woodlands in the western United States. Range-wide, Pinyon Jays have declined ~ 3-4% per year for at least the last half-century. Occurrence patterns and habitat use of Pinyon Jays have not been well characterized across much of the species' range, and obtaining this information is necessary for better understanding the causes of ongoing declines and determining useful conservation strategies. Additionally, it is important to better understand if and how targeted removal of pinyon-juniper woodland, a common and widespread vegetation management practice, affects Pinyon Jays. The goal of this study was to identify the characteristics of areas used by Pinyon Jays for several critical life history components in the Great Basin, which is home to nearly half of the species' global population, and to thereby facilitate the inclusion of Pinyon Jay conservation measures in the design of vegetation management projects. To accomplish this, we studied Pinyon Jays in three widely separated study areas using radio telemetry and direct observation and measured key attributes of their locations and a separate set of randomly-selected control sites using the U. S. Forest Service's Forest Inventory Analysis protocol. Data visualizations, principle components analysis, and logistic regressions of the resulting data indicated that Pinyon Jays used a distinct subset of available pinyon-juniper woodland habitat, and further suggested that Pinyon Jays used different but overlapping habitats for seed caching, foraging, and nesting. Caching was concentrated in low-elevation, relatively flat areas with low tree cover; foraging occurred at slightly higher elevations with generally moderate but variable tree cover; and nesting was concentrated in slightly higher areas with high tree and vegetation cover. All three of these Pinyon Jay behavior types were highly concentrated within the lower-elevation band of pinyon-juniper woodland close to the woodland-shrubland ecotone. Woodland removal projects in the Great Basin are often concentrated in these same areas, so it is potentially important to incorporate conservation measures informed by Pinyon Jay occurrence patterns into existing woodland management paradigms, protocols, and practices.

Experimental evolution of adaptive divergence under varying degrees of gene flow.

Adaptive divergence is the key evolutionary process generating biodiversity by means of natural selection. Yet, the conditions under which it can arise in the presence of gene flow remain contentious. To address this question, we subjected 132 sexually reproducing fission yeast populations, sourced from two independent genetic backgrounds, to disruptive ecological selection and manipulated the level of migration between environments. Contrary to theoretical expectations, adaptive divergence was most pronounced when migration was either absent (allopatry) or maximal (sympatry), but was much reduced at intermediate rates (parapatry and local mating). This effect was apparent across central life-history components (survival, asexual growth and mating) but differed in magnitude between ancestral genetic backgrounds. The evolution of some fitness components was constrained by pervasive negative correlations (trade-off between asexual growth and mating), while others changed direction under the influence of migration (for example, survival and mating). In allopatry, adaptive divergence was mainly conferred by standing genetic variation and resulted in ecological specialization. In sympatry, divergence was mainly mediated by novel mutations enriched in a subset of genes and was characterized by the repeated emergence of two strategies: an ecological generalist and an asexual growth specialist. Multiple loci showed consistent evidence for antagonistic pleiotropy across migration treatments providing a conceptual link between adaptation and divergence. This evolve-and-resequence experiment shows that rapid ecological differentiation can arise even under high rates of gene flow. It further highlights that adaptive trajectories are governed by complex interactions of gene flow, ancestral variation and genetic correlations.

Mortality cost of sex-specific parasitism in wild bird populations

Sex-specific mortality is frequent in animals although the causes of different male versus female mortalities remain poorly understood. Parasitism is ubiquitous in nature with widespread detrimental effects to hosts, making parasitism a likely cause of sex-specific mortalities. Using sex-specific blood and gastrointestinal parasite prevalence from 96 and 54 avian host species, respectively, we test the implications of parasites for annual mortality in wild bird populations using phylogenetic comparative methods. First, we show that parasite prevalence is not different between adult males and females, although Nematodes showed a statistically significant but small male-biased parasite prevalence. Second, we found no correlation between sex-biased host mortalities and sex-biased parasite prevalence. These results were consistent in both blood and gastrointestinal parasites. Taken together, our results show little evidence for sex-dependent parasite prevalence in adults in wild bird populations, and suggest that parasite prevalence is an unlikely predictor of sex difference in adult mortalities, not withstanding sampling limitations. We propose that to understand causes of sex-biased mortalities, more complex analyses are needed that incorporate various ecological and life history components of animals life that may include sex differences in exposure to predators, immune capacity and cost of reproduction.

The relative contribution of individual quality and changing climate as drivers of lifetime reproductive success in a short-lived avian species

Animal populations are influenced strongly by fluctuations in weather conditions, but long-term fitness costs are rarely explored, especially in short-lived avian species. We evaluated the relative contributions of individual characteristics and environmental conditions to lifetime reproductive success (LRS) of female tree swallows (Tachycineta bicolor) from two populations breeding in contrasting environments and geographies, Saskatchewan and British Columbia, Canada. Female swallows achieved higher LRS by breeding early in the season and producing more fledglings. Other measures of female quality had virtually no influence on LRS. Genetic factors did not predict LRS, as there was no correlation between life-history components for sister pairs nor between mothers and their daughters. Instead, climate variability—indexed by spring pond density (i.e., abundance of wetland basins holding water) during years when females bred—had strong positive effects on female LRS in more arid Saskatchewan but only weak positive effects of moisture conditions were detected in wetter British Columbia. Overall, several life history trait correlates of LRS were similar between populations, but local environmental factors experienced by individuals while breeding produced large differences in LRS. Consequently, variable and extreme environmental conditions associated with changing climate are predicted to influence individual fitness of distinct populations within a species’ range.

Y-chromosome haplotypes are associated with variation in size and age at maturity in male Chinook salmon.

Variation in size and age at maturity is an important component of life history that is influenced by both environmental and genetic factors. In salmonids, large size confers a direct reproductive advantage through increased fecundity and egg quality in females, while larger males gain a reproductive advantage by monopolizing access to females. In addition, variation in size and age at maturity in males can be associated with different reproductive strategies; younger smaller males may gain reproductive success by sneaking among mating pairs. In both sexes, there is a trade‐off between older age and increased reproductive success and increased risk of mortality by delaying reproduction. We identified four Y‐chromosome haplogroups that showed regional‐ and population‐specific variation in frequency using RADseq data for 21 populations of Alaska Chinook salmon. We then characterized the range‐wide distribution of these haplogroups using GT‐seq assays. These haplogroups exhibited associations with size at maturity in multiple populations, suggesting that lack of recombination between X and Y‐chromosomes has allowed Y‐chromosome haplogroups to capture different alleles that influence size at maturity. Ultimately, conservation of life history diversity in Chinook salmon may require conservation of Y‐chromosome haplotype diversity.

Terminal life history: late-life fecundity and survival in experimental populations of Drosophila melanogaster.

There are two life history landmarks that can be used to define the terminal period in individual Drosophila melanogaster females: the cessation of daily oviposition, which defines the start of the retired stage, and final oviposition, which defines the start of post-ovipository survival. The terminal period is a substantial component of D. melanogaster life history. Analysis of published data on the daily fecundity and survival of 3971 individually maintained, mated female flies reveals that the terminal period is far more variable within populations than other life history components, including total adult life span. It has been reported that there is a negative correlation between fecundity and duration of the terminal state in recently collected wild stocks. Here I show that the negative correlation occurs in multiple inbred and outbred lab-adapted populations as well. In terms of proportion of adult life, lower fecundity flies spend on average twice as much time in the terminal stage as higher fecundity flies from the same population. Both high and low fecundity flies experience end-of-life plateaus in mortality, with the former exhibiting higher plateau levels. The negative correlation between fecundity and terminal survival is of sufficient magnitude to create heterogeneity among the oldest old: the final 10% of survivors are predominately flies with a history of high fecundity, but about one in five is a low fecundity fly with long terminal stage.

Integrating data mining and transmission theory in the ecology of infectious diseases.

Our understanding of ecological processes is built on patterns inferred from data. Applying modern analytical tools such as machine learning to increasingly high dimensional data offers the potential to expand our perspectives on these processes, shedding new light on complex ecological phenomena such as pathogen transmission in wild populations. Here, we propose a novel approach that combines data mining with theoretical models of disease dynamics. Using rodents as an example, we incorporate statistical differences in the life history features of zoonotic reservoir hosts into pathogen transmission models, enabling us to bound the range of dynamical phenomena associated with hosts, based on their traits. We then test for associations between equilibrium prevalence, a key epidemiological metric and data on human outbreaks of rodent‐borne zoonoses, identifying matches between empirical evidence and theoretical predictions of transmission dynamics. We show how this framework can be generalized to other systems through a rubric of disease models and parameters that can be derived from empirical data. By linking life history components directly to their effects on disease dynamics, our mining‐modelling approach integrates machine learning and theoretical models to explore mechanisms in the macroecology of pathogen transmission and their consequences for spillover infection to humans.

Ecology and Evolution of Blood Oxygen-Carrying Capacity in Birds.

Blood oxygen-carrying capacity is one of the important determinants of the amount of oxygen supplied to the tissue per unit time and plays a key role in oxidative metabolism. In wild vertebrates, blood oxygen-carrying capacity is most commonly measured with the total blood hemoglobin concentration (Hb) and hematocrit (Hct), which is the volume percentage of red blood cells in blood. Here, I used published estimates of avian Hb and Hct (nearly 1,000 estimates from 300 species) to examine macroevolutionary patterns in the oxygen-carrying capacity of blood in birds. Phylogenetically informed comparative analysis indicated that blood oxygen-carrying capacity was primarily determined by species distribution (latitude and elevation) and morphological constraints (body mass). I found little support for the effect of life-history components on blood oxygen-carrying capacity except for a positive association of Hct with clutch size. Hb was also positively associated with diving behavior, but I found no effect of migratoriness on either Hb or Hct. Fluctuating selection was identified as the major force shaping the evolution of blood oxygen-carrying capacity. The results offer novel insights into the evolution of Hb and Hct in birds, and they provide a general, phylogenetically robust support for some long-standing hypotheses in avian ecophysiology.

Self-reported Health is Related to Body Height and Waist Circumference in Rural Indigenous and Urbanised Latin-American Populations

Body height is a life-history component. It involves important costs for its expression and maintenance, which may originate trade-offs on other costly components such as reproduction or immunity. Although previous evidence has supported the idea that human height could be a sexually selected trait, the explanatory mechanisms that underlie this selection are poorly understood. Despite extensive studies on the association between height and attractiveness, the role of immunity in linking this relation is scarcely studied, particularly in non-Western populations. Here, we tested whether human height is related to health measured by self-perception, and relevant nutritional and health anthropometric indicators in three Latin-American populations that widely differ in socioeconomic and ecological conditions: two urbanised populations from Bogota (Colombia) and Mexico City (Mexico), and one isolated indigenous population (Me’Phaa, Mexico). Results showed that self-reported health is best predicted by an interaction between height and waist circumference: the presumed benefits of being taller are waist-dependent, and affect taller people more than shorter individuals. If health and genetic quality cues play an important role in human mate-choice, and height and waist interact to signal health, its evolutionary consequences, including cognitive and behavioural effects, should be addressed in future research.