Sand Cricket Research Articles

The Art of Sculpture in Public Space in China: The Wasteland Art Project

With the development of public art in China, artists have been experimenting with the artistic form and means of expression of public sculpture. Previously marginalised by public sculpture, wild non-urban areas have also begun to attract the attention of Chinese artists. The Wasteland art project, implemented in Guazhou, Gansu province, is very indicative in this regard. Sculptor Dong Shubin, a professor at Tsinghua University Academy of Fine Arts, is the initiator of this project and an experimental artist who aims to create a sustainable artistic community in the Gobi Desert in the northwest of the country. He believes that an artist should draw inspiration from a natural environment that is familiar to them, rather than simply imitate others or emphatically separate themselves from the general mass of people. After creating works such as Children of the Earth, Infinity, and Wind Talkers, Dong Shubin and his colleagues are gradually creating a Wasteland Art complex in the Gobi Desert.

Effect of rearing density on female investment in reproduction and melanotic encapsulation response in the sand cricket (Gryllus firmus) (Orthoptera: Gryllidae)

Abstract The density-dependent prophylaxis hypothesis posits that because pathogens are expected to be transmitted among conspecifics in crowded conditions, individuals living in such conditions should minimize their chance of infection and maximize survival by elevating their baseline immunity. Further, if individuals developing in crowded conditions indeed allocate more resources to immunity then resource allocation to other life-history traits, such as reproduction, should decline. We tested these hypotheses by rearing sand crickets (Gryllus firmus) at either low or high density in the laboratory and quantified immune function (melanotic encapsulation response) and reproductive investment (ovary mass, egg size) at adulthood. The results did not support the density-dependent prophylaxis hypothesis, but we did find that rearing density significantly affected investment in two reproductive traits, with average ovary mass and egg size both being larger in low-density crickets. We discuss possible explanations for the lack of a trade-off between immunity and reproduction in our study.

Fluctuating Asymmetry in the Polymorphic Sand Cricket (Gryllus firmus): Are More Functionally Important Structures Always More Symmetric?

Simple SummaryAsymmetry in bilateral structures occurs when animals experience perturbations during development. This fluctuating asymmetry (FA) may serve as a reliable indicator of the functional importance of a structure. For example, locomotor structures often display lower levels of FA than other paired structures, highlighting that selection can maintain symmetry in traits important for survival or reproduction. Species that have multiple distinct morphs with unique behaviors and morphologies represent an attractive model for studying the relationship between symmetry and function. The sand field cricket (Gryllus firmus) has two separate morphs that allow us to directly test whether individuals maintain higher levels of symmetry in the structures most vital for maximizing fitness based on their specific life strategy. Longwing (LW) individuals can fly but postpone reproduction until after a dispersal event, whereas shortwing (SW) individuals cannot fly but begin reproducing in early adulthood. We quantified FA across a suite of key morphological structures indicative of investment in growth, reproduction, and flight capability for males and females across the morphs. Although we did not find significant differences in FA across traits, as predicted, locomotor compensation strategies may reduce selective pressures on symmetry or developmental patterns may limit the optimization between trait form and function.Fluctuating asymmetry (FA) may serve as a reliable indicator of the functional importance of structures within an organism. Primary locomotor structures often display lower levels of FA than other paired structures, highlighting that selection can maintain symmetry in fitness-enhancing traits. Polyphenic species represent an attractive model for studying the fine-scale relationship between trait form and function, because multiple morphs exhibit unique life history adaptations that rely on different traits to maximize fitness. Here, we investigated whether individuals of the wing polyphenic sand field cricket (Gryllus firmus) maintain higher levels of symmetry in the bilateral structures most vital for maximizing fitness based on their specific life history strategy. We quantified FA and directional asymmetry (DA) across a suite of key morphological structures indicative of investment in somatic growth, reproduction, and flight capability for males and females across the flight-capable longwing (LW) and flight-incapable shortwing (SW) morphs. Although we did not find significant differences in FA across traits, hindwings lacked DA that was found in all other structures. We predicted that functionally important traits should maintain a higher level of symmetry; however, locomotor compensation strategies may reduce the selective pressures on symmetry or developmental constraints may limit the optimization between trait form and function.

<i>Corrigendum to:</i> Extensive species diversification and marked geographic phylogenetic structure in the Mesoamerican genus <i>Stenopelmatus</i> (Orthoptera: Stenopelmatidae: Stenopelmatinae) revealed by mitochondrial and nuclear 3RAD data

The Jerusalem cricket subfamily Stenopelmatinae is distributed from south-western Canada through the western half of the United States to as far south as Ecuador. Recently, the generic classification of this subfamily was updated to contain two genera, the western North American <i>Ammopelmatus</i>, and the Mexican, and central and northern South American <i>Stenopelmatus</i>. The taxonomy of the latter genus was also revised, with 5, 13 and 14 species being respectively validated, declared as nomen dubium and described as new. Despite this effort, the systematics of <i>Stenopelmatus</i> is still far from complete. Here, we generated sequences of the mitochondrial DNA barcoding locus and performed two distinct DNA sequence-based approaches to assess the species’ limits among several populations of <i>Stenopelmatus</i>, with emphasis on populations from central and south-east Mexico. We reconstructed the phylogenetic relationships among representative species of the main clades within the genus using nuclear 3RAD data and carried out a molecular clock analysis to investigate its biogeographic history. The two DNA sequence-based approaches consistently recovered 34 putative species, several of which are apparently undescribed. Our estimates of phylogeny confirmed the recent generic update of Stenopelmatinae and revealed a marked phylogeographic structure within <i>Stenopelmatus</i>. Based on our results, we propose the existence of four species-groups within the genus (the <i>faulkneri</i>, <i>talpa</i>, Central America and <i>piceiventris</i> species-groups). The geographic distribution of these species-groups and our molecular clock estimates are congruent with the geological processes that took place in mountain ranges along central and southern Mexico, particularly since the Neogene. Our study emphasises the necessity to continue performing more taxonomic and phylogenetic studies on <i>Stenopelmatus</i> to clarify its actual species richness and evolutionary history in Mesoamerica.

Extensive species diversification and marked geographic phylogenetic structure in the Mesoamerican genus

The Jerusalem cricket subfamily Stenopelmatinae is distributed from south-western Canada through the western half of the United States to as far south as Ecuador. Recently, the generic classification of this subfamily was updated to contain two genera, the western North American Ammopelmatus, and the Mexican, and central and northern South American Stenopelmatus. The taxonomy of the latter genus was also revised, with 5, 13 and 14 species being respectively validated, declared as nomen dubium and described as new. Despite this effort, the systematics of Stenopelmatus is still far from complete. Here, we generated sequences of the mitochondrial DNA barcoding locus and performed two distinct DNA sequence-based approaches to assess the species’ limits among several populations of Stenopelmatus, with emphasis on populations from central and south-east Mexico. We reconstructed the phylogenetic relationships among representative species of the main clades within the genus using nuclear 3RAD data and carried out a molecular clock analysis to investigate its biogeographic history. The two DNA sequence-based approaches consistently recovered 34 putative species, several of which are apparently undescribed. Our estimates of phylogeny confirmed the recent generic update of Stenopelmatinae and revealed a marked phylogeographic structure within Stenopelmatus. Based on our results, we propose the existence of four species-groups within the genus (the faulkneri, talpa, Central America and piceiventris species-groups). The geographic distribution of these species-groups and our molecular clock estimates are congruent with the geological processes that took place in mountain ranges along central and southern Mexico, particularly since the Neogene. Our study emphasises the necessity to continue performing more taxonomic and phylogenetic studies on Stenopelmatus to clarify its actual species richness and evolutionary history in Mesoamerica.

Generic relationships of New World Jerusalem crickets (Orthoptera: Stenopelmatoidea:Stenopelmatinae), including all known species of Stenopelmatus.

The New World Jerusalem crickets currently consist of 4 genera: Stenopelmatus Burmeister, 1838, with 33 named entities; Ammopelmatus Tinkham, 1965, with 2 described species; Viscainopelmatus Tinkham, 1970, with 1 described species, and Stenopelmatopterus Gorochov, 1988, with 3 described species. We redefine the generic boundaries of these 4 genera, synonymize Stenopelmatopterus under Stenopelmatus, and synonymize Viscainopelmatus under Ammopelmatus. We then discuss, and illustrate, all the types of the species of Stenopelmatus, all of which only occur south of the United States' border. We recognize as valid the following 5 described Mexican and Central American species: S. ater, S. piceiventris, S. sartorianus, S. talpa, and S. typhlops. We declare the following 13 described Mexican and Central American Stenopelmatus taxa as nomen dubium: S. calcaratus, S. erythromelus, S. guatemalae, S. histrio, S. lessonae, S. lycosoides, S. mexicanus, S. minor, S. nieti, S. sallei, S. sumichrasti, S. toltecus, and S. vicinus. We designate a neotype for S. talpa and lectotypes for S. ater, S. guatemalae, S. histrio, S. lessonae, S. mexicanus, S. minor, S. nieti, S. sallei, S. sumichrasti, and S. toltecus. We assign a type locality for S. piceiventris. We concur with the previous synonymy of S. politus under S. sartorianus. We describe 14 new species of Stenopelmatus from Mexico, Honduras and Ecuador, based on a combination of adult morphology, DNA, calling song drumming pattern, distribution, and karyotype: S. chiapas sp. nov., S. cusuco sp. nov., S. diezmilpies sp. nov., S. durango sp. nov., S. ecuadorensis sp. nov., S. faulkneri sp. nov., S. honduras sp. nov., S. hondurasito sp. nov., S. mineraldelmonte sp. nov., S. nuevoleon sp. nov., S. perote sp. nov., S. saltillo sp. nov., S. sanfelipe sp. nov., and S. zimapan sp. nov. We transfer the following 16 described United States taxa, plus S. cephalotes from the "west coast of North America", from Stenopelmatus to Ammopelmatus: A. cahuilaensis, A. californicus, A. cephalotes, A. fasciatus, A. fuscus, A. hydrocephalus, A. intermedius, A. irregularis, A. longispinus, A. mescaleroensis, A. monahansensis, A. navajo, A. nigrocapitatus, A. oculatus, A. pictus, and A. terrenus, along with the Mexican taxon A. comanchus: these species will be discussed in a subsequent paper (Weissman et al. in prep). We believe that all new Jerusalem cricket species descriptions should include, at a minimum, calling drum (most important) and DNA information.

Mating with sexually attractive males provides female Gryllus firmus field crickets with direct but not indirect fitness benefits

Females choose to mate with certain males to accrue either genetic or direct benefits, and male sexual attractiveness evolved to advertise those benefits to potential mates. Sexually attractive males are expected to be of higher genetic quality and thus possess greater body condition and perhaps greater disease resistance. Positive covariance between male sexual attractiveness and disease resistance should thus provide females an avenue for acquiring genes related to better disease resistance for their offspring. We support the hypothesis that sexually attractive males are in better body condition, but we did not support the hypothesis that they are more disease resistant. Contrary to prediction, the offspring of more attractive males were neither in better body condition nor more disease resistant than the offspring of less attractive males, thus suggesting that females do not gain indirect genetic benefits by mating with attractive males. We supported the hypothesis that females receive more material benefits from mating with more attractive males as females laid more eggs when mated to males having greater sexual attractiveness. The mechanism underlying this effect is unclear at present but could be due to more ejaculatory products (i.e., more sperm or seminal substances) being passed by more attractive mates or due to female processes such as cryptic female choice. Females are generally the choosier sex when it comes to finding mate. Choosiness benefits females because by mating with a preferred, sexually attractive male, females can accrue better or more material resources that they require for breeding or superior genes for their offspring. We experimentally tested whether and how mating with sexually attractive males benefits female sand crickets (Gryllus firmus). In line with prediction, we found that females laid more eggs when they copulated with attractive males rather than unattractive males. Contrary to prediction, however, our tests revealed that the offspring of attractive males were not significantly more disease resistant or more sexually attractive than the offspring of less attractive males. Not surprisingly, we found little evidence of strong heritability in these traits and that daughters of sexually attractive males were no less fit than sons (and vice versa).

Sand crickets (Gryllus firmus) have low susceptibility to entomopathogenic nematodes and their pathogenic bacteria.

The entomopathogenic nematode, Steinernema scapterisci, a specialist parasite of crickets, has been successfully used to combat the southern mole cricket, Neoscapteriscus borellii, which is an invasive pest of turf grass. As an entomopathogenic nematode, S. scapterisci causes rapid death of the insects it infects and uses bacteria to facilitate its parasitism. However, our understanding of the relative contributions of the nematode, S. scapterisci, and its bacterial symbiont, Xenorhabdus innexi, to parasitism remains limited. Here we utilized the sand cricket, Gryllus firmus, as a model host to evaluate the contributions of the EPNs S. scapterisci and S. carpocapsae, as well as their symbiotic bacteria, X. innexi and X. nematophila, respectively, to the virulence of the nematode-bacterial complex. We found that G. firmus has reduced susceptibility to infection from both S. scapterisci and the closely related generalist parasite S. carpocapsae, but that S. scapterisci is much more virulent than S. carpocapsae. Further, we found that N. borellii has reduced susceptibility to X. nematophila, and that G. firmus has reduced susceptibility to X. nematophila, X. innexi, and Serratia marcescens, much more so than other insects that have been studied. We found that the reduced susceptibility of G. firmus to bacterial infection is dependent on development, with adults being less susceptible to infection than nymphs. Our data provide evidence that unlike other EPNs, the virulence of S. scapterisci to crickets is dependent on the nematode rather than the bacterial symbiont that it carries and we speculate that S. scapterisci may be evolving independence from X. innexi.

“The new children of the earth”

AbstractThis article analyzes Larissa Lai's novel Salt Fish Girl (2002) as a case of dystopian fiction marked by a concern with the dangers of the “Anthropocene” and the oppression of what lies beyond the scope of prescriptive definitions of humanity. Taking as point of departure Braidotti's posthuman theory and her post‐anthropocentric approach to embodied difference, I focus on the feminist and lesbian stance of Lai's novel. For this purpose, I explore issues such as the characters' zoe‐centred, non‐hierarchical fusion with nature, the link to the maternal through fish smell (traditionally associated with female genitalia, here reclaimed and embraced), together with the subversive potential of female bonding, and of alternative modes of motherhood and reproduction as opposed to hetero‐patriarchal utilitarian techno‐scientific control.1

Morphometry, Behavior, and Ecology of the Jerusalem Cricket,Stenopelmatus talpa

The biology of Jerusalem crickets, genus Stenopelmatus Burmeister 1838 (Orthoptera: Stenopelmatidae), is not well known. Recent accounts suggested that Jerusalem crickets had sexual dimorphism and adult females were cannibalistic. The aim of this study was to determine whether there was sexual dimorphism and cannibalism, as shown by North American species of Stenopelmatus, in the endemic Mexican Jerusalem cricket Stenopelmatus talpa Burmeister 1838. Behavioral traits and morphometric analyses indicated S. talpa did not show sexual dimorphism, but females tended to have larger features than did males, except the hind femur of males tended to be larger than that of females. S. talpa nymphs are cannibalistic, and the cannibalism was violent. Results were discussed and related to ecological data presented. This is the first report of this kind of data for a Mexican species of the genus Stenopelmatus.

A new method for statistical detection of directional and stabilizing mating preference

Lay Summary Quantifying mating preferences is essential to understand how sexual selection shapes both mating systems and sexual dimorphisms. We present a new method for detecting and quantifying both stabilizing and directional mating preferences and demonstrate the experimental and statistical advantages of this method over previous approaches. We illustrate the method using data from a mate choice experiment in which female sand crickets were provided a choice of 2 males. Both directional and stabilizing preference are identified for components of the male call song.

The scolopidial accessory organ in the Jerusalem cricket (Orthoptera: Stenopelmatidae)

Multiple mechanosensory organs form the subgenual organ complex in orthopteroid insects, located in the proximal tibia. In several Ensifera (Orthoptera), a small chordotonal organ, the so-called accessory organ, is the most posterior part of this sensory complex. In order to document the presence of this accessory organ among the Ensifera, the chordotonal sensilla and their innervation in the posterior tibia of two species of Jerusalem crickets (Stenopelmatidae: Stenopelmatus) is described. The sensory structures were stained by axonal tracing. Scolopidial sensilla occur in the posterior subgenual organ and the accessory organ in all leg pairs. The accessory organ contains 10–17 scolopidial sensilla. Both groups of sensilla are commonly spatially separated. However, in few cases neuronal fibres occurred between both organs. The two sensillum groups are considered as separate organs by the general spatial separation and innervation by different nerve branches. A functional role for mechanoreception is considered: since the accessory organ is located closely under the cuticle, sensilla may be suited to detect vibrations transferred over the leg's surface. This study extends the known taxa with an accessory organ, which occurs in several taxa of Ensifera. Comparative neuroanatomy thus suggests that the accessory organ may be conserved at least in Tettigoniidea.

Cruzes e feitiços: Identidades e trocas culturais nas práticas fúnebres em Angola

Resumo O objetivo deste artigo é refletir, através da análise de jornais e textos literários, sobre práticas, trocas culturais e conflitos nas cerimônias fúnebres em Luanda e arredores entre o final do século XIX e o início do XX. Trabalhamos com três categorias sociais: colonos (metropolitanos e descendentes), filhos da terra (nascidos em Angola que dominavam códigos culturais europeus) e gentio (africanos que, por não dominarem códigos culturais europeus, não tinham acesso aos direitos da cidadania portuguesa e podiam ser sujeitos ao trabalho forçado). Em um contexto de intensificação da presença portuguesa e de subalternização das elites da terra e do gentio, os funerais eram ocasiões privilegiadas de manifestação de diferenças e compartilhamentos. Através das práticas fúnebres, os diversos grupos sociais afirmavam suas identidades e promoviam trocas culturais que gerariam não apenas conflitos e controle, mas também formas híbridas de tratamento da morte, explicitando uma importante característica da cultura urbana luandense.

Physiological trade-off between cellular immunity and flight capability in the wing-dimorphic sand cricket, Gryllus firmus

The sand cricket, Gryllus firmus, is a wing-dimorphic species with long-wing (LW) and short wing (LW) morphs. The LW forms have very well developed wings and flight muscles and their SW counterparts have reduced wings and flight muscles, coupled with greater resource allocations to reproduction. This is the well-known oogenesis-flight syndrome, in which resources are differentially allocated to reproduction or flight. Insects have also evolved very sophisticated and robust immune systems, understood as a major adaptation that partly accounts for the long-term biological success of insects. Nodulation is the predominant cellular immune reaction to microbial infections, responsible for clearing most infecting microbes from hemolymph circulation in the first two hours after an infection. This is a biologically expensive process because in large infections millions of hemocytes are invested into melanotic nodules. These lost hemocytes are later replaced in hematopoietic organs. Honey bees and a few other insect species redirect resources from cellular immunity to another biologically expensive activity, foraging flights. These reallocations are conceived as physiological trade-offs, in which the costs of one biological function are traded off for another. Based on previous work, we posed the hypothesis that the sand cricket, Gryllus firmus, already known to reallocate resources in the oogenesis-flight syndrome, also reallocates resources from immune functions to flight. Here, we report that relative to long-wing morphs, the short-wing forms have higher immune capacity, registered in terms of nodulation reactions to the same challenge, higher hemocytic phospholipase A2 activity (an enzyme involved in immune signaling) and relatively reduced age-related immunosenescence. We infer from these data that sand crickets, and likely many insect species, reallocate resources between flight, reproduction and immunity. Such trade-offs may support other functions, such as foraging and mate finding, as well.

Multi-population comparison of resource exploitation by island foxes: Implications for conservation

Imperiled island foxes are inherently resource-limited by their insular ecology. We examined food use on all 6 islands where they occur to assess resource exploitation patterns. Over 40 different food items were identified with item use varying among islands. Sixteen items occurred with ≥10% frequency in annual fox diets: deer mice, birds, lizards, beetles, beetle larvae, Jerusalem crickets, silk-spinning sand crickets, grasshoppers, earwigs, snails, and fruits of toyon, manzanita, prickly pear cactus, ice plant, Australian saltbush, and summer holly. Foxes used a diversity of food items with variations among islands attributable to island-specific availabilities. Deer mice in particular appeared to be preferred. Foxes also exhibited extensive use of non-native items, such as ice plant fruits, European snails, and earwigs, and foxes may even be dependent on these items on some islands. To increase food security and promote population stability, we recommend (1) continuing and enhancing habitat restoration efforts on all islands, (2) increasing the abundance of native items in association with any removals of non-native species used by foxes, and (3) monitoring annual trends in abundance of key food items as well as periodic monitoring of item use by foxes to determine functional responses to changes in item availability.

Echoes of the Ecological Handicaps Coal Complex Pollution in Dankuni area, West Bengal, India

In the course of last few years, media has drawn attention to the crisis faced by the inhabitants of the Dankuni area, Hooghly district, West Bengal, India. Innumerable instances have been brought to the limelight, which clearly indicate wide spread environmental damage in the areas lying in close proximity of the Dankuni Coal Complex. The consequences of development strategies have been extremely adverse as far as environment is concerned. In its lust for immediate gains, the industry is following a myopic policy with no concern for pollution of air, water and land. While it is important to uphold developmental initiatives like the Dankuni Coal Complex (DCC), it is equally desirable that the residents in the vicinity of such establishments do not suffer. The obsession with quantitative economic growth has bred a natural conflict between environment and development. The very location of DCC is ecologically very sensitive as it has been set up adjacent to the Dankuni Drainage Channel which invariably acts as a receptacle channel for the coal complex effluent. Further accentuating the problem are the low-lying marshes, locally known as the Bhils, whose ecology has been long withstanding the onslaught of mass production, with inadequate attention on the rapidly degrading ecosystem. This is a humble report on the dehumanizing metamorphosis that an industry brings with active support of the Government in the life of simple folks who once considered themselves to be children of the Earth, but today are ‘ecologically handicapped.’

The costs of being dark: the genetic basis of melanism and its association with fitness‐related traits in the sand cricket

Melanism is an important component of insect cuticle and serves numerous functions that enhance fitness. Despite its importance, there is little information on its genetic basis or its phenotypic and genetic correlation with fitness-related traits. Here, we examine the heritability of melanism in the wing dimorphic sand cricket and determine its phenotypic and genetic correlation with wing morphology, gonad mass and size of the dorso-longitudinal muscles (the principle flight muscles). Previously demonstrated trade-offs among these traits are significant factors in the evolution of life history variation. Using path analysis, we show that melanization is causally related to gonad mass, but not flight muscle mass. Averaged over the sexes, the heritability of melanism was 0.61, the genetic correlation with gonad mass was -0.36 and with wing morph was 0.51. The path model correctly predicted the ranking of melanization score in lines selected for increased ovary mass, increased flight muscle mass, an index that increased both traits and an unselected control. Our results support the general hypothesis that melanization is costly for insects and negatively impacts investment in early reproduction.

Notes on southern Africa Jerusalem crickets (Orthoptera: Stenopelmatidae: Sia).

The Old World Jerusalem cricket (JC) subfamily Siinae contains one genus, Sia, with two subgenera: Sia (Sia) with two fully winged species from southeast Asia, and Sia (Maxentius) with four wingless species from southern Africa. Because there is a dearth of published data about the behavior and biology of these insects, we present new field and laboratory research on southern African Sia (Maxentius), gather museum and literature information, and present guidelines for collecting and rearing specimens. While we make no taxonomic decisions, this review should be useful for future studies, including a needed taxonomic revision. We also compare results from these southern African JCs with recent investigations on related New World taxa, where fascinating biological traits and extensive cryptic biodiversity have been uncovered. DNA analysis reveals that these Old and New World JCs are polyphyletic.

Independent regulation of physiological and behavioral maturation of reproduction in female sand crickets (Gryllus firmus)

In the first days of adulthood, ovary size and sexual receptivity increase in female sand crickets ( Gryllus firmus Scudder, 1902). We tested whether these are mechanistically linked by juvenile hormone (JH), which has been implicated in gonadal development and sexual behavior in other insects. Treatment of young females with the JH analog, methoprene, accelerates oocyte maturation and triggers flight-muscle histolysis, but does not affect sexual receptivity. These results are consistent with earlier studies which suggest that physiological and behavioral components of sexual maturation in crickets are separately regulated.

Extracting the Underlying Physiological Determinants of Resource-Based Trade-Offs: A Principal Components Approach

The relationship between traits that compete for resources is influenced by variance in the acquisition and allocation of resources. The difficulty of accurately measuring these underlying physiological processes has hampered studies of resource-based trade-offs. Here, we explore the ability of principal components analysis (PCA) to extract axes corresponding to acquisition and allocation in a bivariate trade-off by comparing these axes to estimates obtained using physiological measurements. We validate the method using simulations and then test it using empirical data for the well-characterized trade-off between flight capability and reproduction in female sand crickets, Gryllus firmus. We find a high correspondence between our physiological estimates and the estimates obtained using PCA. Our results demonstrate that PCA provides a robust and efficient method for estimating acquisition and allocation directly from the traits involved in a resource-based trade-off.