Do birds select the plastics debris used for nest construction? A case study in a Mediterranean agricultural landscape.

Plastic pollution is becoming a global problem due to its ubiquitous occurrence and the impacts detected for many species. However, the research about plastics in nests of terrestrial bird species has remained relatively overlooked in comparison to those devoted to marine ecosystems. Here we study the occurrence and patterns of use of anthropogenic material in nests of two passerine birds, the Eurasian magpie (Pica pica) and the European serin (Serinus serinus), breeding in an orange tree cultivation in Mediterranean Spain. Our results show that both species use extensively plastic debris as nest material; almost 71% of the European serin nests and 96% of nests of Eurasian magpies contained plastic debris. Furthermore, by analyzing the plastic debris availability in the agricultural landscape surveyed we confirmed a selection pattern in the two species. Thus, both species preferably select plastic filaments over other plastic debris. The Eurasian magpie does not select plastic based on size or color but the European serin avoid black plastics prefer smaller fragments in comparison to the average size available. Moreover, we suggest the apparent similarity of plastic filaments with the natural materials typically used by these species, as well as how they use the plastic in their nests could influence their selection behavior. More studies focused on terrestrial birds inhabiting human modified habitats could offer a deeper approach to how plastic debris interacts with wildlife in different ways.

Characterization of an alkylresorcinol synthase that forms phenolics accumulating in the cuticular wax on various organs of rye (Secale cereale).

Alkylresorcinols are bioactive compounds produced in diverse plant species, with chemical structures combining an aliphatic hydrocarbon chain and an aromatic ring with characteristic hydroxyl substituents. Here, we aimed to isolate and characterize the enzyme that forms the alkylresorcinols accumulating in the cuticular wax on the surface of all above-ground organs of rye. Based on sequence homology with other type-III polyketide synthases, a candidate alkylresorcinol synthase was cloned. Yeast heterologous expression showed that the enzyme, ScARS, is highly specific for the formation of the aromatic resorcinol ring structure, through aldol condensation analogous to stilbene synthases. The enzyme accepts long-chain and very-long-chain acyl-CoA starter substrates, preferring saturated over unsaturated chains. It typically carries out three rounds of condensation with malonyl-CoA prior to cyclization, with only very minor activity for a fourth round of malonyl-CoA condensation and cyclization to 5-(2'-oxo)-alkylresorcinols or 5-(2'-hydroxy)-alkylresorcinols. Like other enzymes involved in cuticle formation, ScARS is localized to the endoplasmic reticulum. ScARS expression patterns were found correlated with alkylresorcinol accumulation during leaf development and across different rye organs. Overall, our results thus suggest that ScARS synthesizes the cuticular alkylresorcinols found on diverse rye organ surfaces.

Effects of a short workplace exercise program on body composition in women: A randomized controlled trial.

Physical inactivity and poor diet cause alterations in body composition, which in turn increases risk factors for cardiovascular and metabolic diseases. Sixty-three women from different work environments were randomly assigned to an intervention (n = 34) or control (n = 29) group. The intervention was a short-term aerobic exercise program (12 weeks) at their workplace. Participants assigned to the control group did not perform any form of physical exercise. Body composition was measured by dual-energy X-ray absorptiometry (DXA). Diet was assessed using the Mediterranean Diet Quality Questionnaire (KIDMED) and nutrient balance by the Food Frequency Questionnaire. Researchers suggest that a short-term aerobic exercise program produces beneficial effects on body composition.

Pitch Size and Game Surface in Different Small-Sided Games. Global Indicators, Activity Profile, and Acceleration of Female Soccer Players.

López-Fernández, J, Gallardo, L, Fernández-Luna, Á, Villacañas, V, García-Unanue, J, and Sánchez-Sánchez, J. Pitch size and game surface in different small-sided games. Global indicators, activity profile, and acceleration of female soccer players. J Strength Cond Res 33(3): 831-838, 2019-The aim of this research was to evaluate the influence of game surface and pitch size on the movement profile in female soccer players during small-sided games (SSGs) of 4 v 4. Sixteen women played 3 different 4-a-side (400, 600, and 800 m) on 3 surfaces (ground [GR], artificial turf [AT], and natural grass [NG]). Time-motion variables were assessed through GPS devices (Spi Pro X, GPSports, Australia). Ground had the worst outputs on most variables. NG achieved higher results than AT in terms of total distance (SSG 400 [+37.000 m; p = 0.006]; SSG 600 [+59.989 m; p < 0.001]; and SSG 800 [+42.284 m; p = 0.001]). However, the smaller SSG (400) had the lowest values on most variables. However, although the middle SSG (600) presented higher output than the bigger one (800) for body load (NG [+7.745 a.u.; p < 0.001]; AT [+8.207 a.u.; p < 0.001]; and GR [+5.879 a.u.; p < 0.001]), it had lower results for high-intensity distance (NG [-13.15 m; p = 0.025] and AT [-13.59 m; p = 0.026]). Despite women's performance being higher on AT than GR, the NG surface still showed the highest outcomes in the most intense SSG. Moreover, although the performance increases in bigger pitches, if the size is too large the outputs could be reduced.

Activation of Glutamatergic Fibers in the Anterior NAc Shell Modulates Reward Activity in the aNAcSh, the Lateral Hypothalamus, and Medial Prefrontal Cortex and Transiently Stops Feeding.

Although the release of mesoaccumbal dopamine is certainly involved in rewarding responses, recent studies point to the importance of the interaction between it and glutamate. One important component of this network is the anterior nucleus accumbens shell (aNAcSh), which sends GABAergic projections into the lateral hypothalamus (LH) and receives extensive glutamatergic inputs from, among others, the medial prefrontal cortex (mPFC). The effects of glutamatergic activation of aNAcSh on the ingestion of rewarding stimuli as well as its effect in the LH and mPFC are not well understood. Therefore, we studied behaving mice that express a light-gated channel (ChR2) in glutamatergic fibers in their aNAcSh while recording from neurons in the aNAcSh, or mPFC or LH. In Thy1-ChR2, but not wild-type, mice activation of aNAcSh fibers transiently stopped the mice licking for sucrose or an empty sipper. Stimulation of aNAcSh fibers both activated and inhibited single-unit responses aNAcSh, mPFC, and LH, in a manner that maintains firing rate homeostasis. One population of licking-inhibited pMSNs in the aNAcSh was also activated by optical stimulation, suggesting their relevance in the cessation of feeding. A rewarding aspect of stimulation of glutamatergic inputs was found when the Thy1-ChR2 mice learned to nose-poke to self-stimulate these inputs, indicating that bulky stimulation of these fibers are rewarding in the sense of wanting. Stimulation of excitatory afferents evoked both monosynaptic and polysynaptic responses distributed in the three recorded areas. In summary, we found that activation of glutamatergic aNAcSh fibers is both rewarding and transiently inhibits feeding. SIGNIFICANCE STATEMENT: We have established that the activation of glutamatergic fibers in the anterior nucleus accumbens shell (aNAcSh) transiently stops feeding and yet, because mice self-stimulate, is rewarding in the sense of wanting. Moreover, we have characterized single-unit responses of distributed components of a hedonic network (comprising the aNAcSh, medial prefrontal cortex, and lateral hypothalamus) recruited by activation of glutamatergic aNAcSh afferents that are involved in encoding a positive valence signal important for the wanting of a reward and that transiently stops ongoing consummatory actions, such as licking.

D1 and D2 antagonists reverse the effects of appetite suppressants on weight loss, food intake, locomotion, and rebalance spiking inhibition in the rat NAc shell.

Obesity is a worldwide health problem that has reached epidemic proportions. To ameliorate this problem, one approach is the use of appetite suppressants. These compounds are frequently amphetamine congeners such as diethylpropion (DEP), phentermine (PHEN), and bupropion (BUP), whose effects are mediated through serotonin, norepinephrine, and dopaminergic pathways. The nucleus accumbens (NAc) shell receives dopaminergic inputs and is involved in feeding and motor activity. However, little is known about how appetite suppressants modulate its activity. Therefore, we characterized behavioral and neuronal NAc shell responses to short-term treatments of DEP, PHEN, and BUP. These compounds caused a transient decrease in weight and food intake while increasing locomotion, stereotypy, and insomnia. They evoked a large inhibitory imbalance in NAc shell spiking activity that correlated with the onset of locomotion and stereotypy. Analysis of the local field potentials (LFPs) showed that all three drugs modulated beta, theta, and delta oscillations. These oscillations do not reflect an aversive-malaise brain state, as ascertained from taste aversion experiments, but tracked both the initial decrease in weight and food intake and the subsequent tolerance to these drugs. Importantly, the appetite suppressant-induced weight loss and locomotion were markedly reduced by intragastric (and intra-NAc shell) infusions of dopamine antagonists SCH-23390 (D1 receptor) or raclopride (D2 receptor). Furthermore, both antagonists attenuated appetite suppressant-induced LFP oscillations and partially restored the imbalance in NAc shell activity. These data reveal that appetite suppressant-induced behavioral and neuronal activity recorded in the NAc shell depend, to various extents, on dopaminergic activation and thus point to an important role for D1/D2-like receptors (in the NAc shell) in the mechanism of action for these anorexic compounds.

Unveiling the urban colonization of the Asian water monitor (Varanus salvator) across its distribution range using citizen science.

Background: This study aims to investigate the urban colonization of the Asian water monitor (Varanus salvator) across its entire range of distribution, addressing the paucity of research on this species in urban ecosystems. The research spans the geographic range of the Asian water monitor, focusing on urbanized areas where the species accumulates more observations (Bangkok, Colombo, Jakarta, Kuala Lumpur and Singapore). Methods: We conducted a systematic review to comprehensively assess the current knowledge of the species' presence in cities. Additionally, citizen science data from repositories like GBIF (Global Biodiversity Information facility ) were utilized to analyze the distribution patterns of V. salvator in urban environments. To elucidate urban distribution and correct collection biases, observations were weighted by sampling effort, using as a proxy all squamate occurrences available from 2010-2023, including V. salvator. Results: Despite the widespread presence of the Asian water monitor in numerous cities within its distribution range, the available studies on the topic appear to be scarce. Existing research primarily consists of descriptive reports on diet and behavior. Our findings indicate that V. salvator predominantly colonizes green patches in urban areas, such as parks and small gardens. Larger cities exhibit higher records, potentially due to both permanent populations and increased citizen science reporting. Conclusions: The Asian water monitor, as the largest lizard with established populations in cities, remains scarcely studied on a broader scale. However, the urban design of each city seems relevant to understand the distribution patterns within each context. Our study highlights the need for further research to explore the ecological and human dimensions associated with the species' presence in urban environments.

Feeding ecology of the common wood pigeon (Columba palumbus) in a major European city.

Urban configuration and food availability influence birds' foraging behaviour and constitute key factors for understanding how they exploit cities. Here, we conducted a field survey in the city of Madrid (Spain) from winter 2021 to autumn 2022 to understand how the common wood pigeon (Columba palumbus) exploits the food resources provided by urban parks and streets across different seasons. The proportion of observations away from parks increased during winter and spring, and the proportion of observations of wood pigeons eating on the ground was the greatest in summer. The common wood pigeon fed from 45 tree species, 60% of which were exotic ornamental species. Most tree species used as food sources coincided with those widely planted in parks, streets and avenues. The preferred trees varied throughout the year, with a greater incidence of exotic species in winter and spring. Our results show that the diversity of trees available in cities and the use of non-native plants with contrasting phenological patterns compared with the local flora are crucial elements in explaining the successful establishment of the common wood pigeon in the city.

Anthropogenic debris as nest material in three swift species: New insights into the interactions of atmospheric pollution with wildlife.

Plastic pollution has become a global concern, affecting many species around the world. While well-documented for marine ecosystems, the impact of plastic pollution on terrestrial ecosystems is comparatively limited. In fact, only recently have some studies begun to explore the occurrence, pathways, and impacts of plastic in the atmosphere and on terrestrial species. Here, we assess the presence of synthetic material in nests of three swift species breeding in the Western Palearctic: the common swift (Apus apus), the pallid swift (Apus pallidus), and the alpine swift (Tachymarptis melba). Using data from 487 nests spanning 25 colonies and seven European countries, we show that 36.5 % of the examined nests contained anthropogenic materials, mainly plastic debris. Notably, Pallid swifts' nests, with 85 % of the total nests examined with plastic, rank among birds with the highest plastic content in nests. We also demonstrate that the probability of finding plastic in the nest increased substantially with the human footprint of the landscape. Last, we recorded four cases of swifts entangled in their own nest, a low proportion compared to other species studied previously. Our study provides compelling evidence that plastic pollution may also be considered a concern for other terrestrial species, particularly for birds with highly aerial lifestyles, such as other swifts. The correlation with the human footprint suggests that areas with higher human activity contribute more significantly. Moreover, the entanglement cases, although low, indicate a threat to bird health and welfare. To our knowledge, our study is the first to report a direct interaction between floating plastic debris in the atmosphere and any species. Understanding this interaction is key, not only due to the lack of research on the topic, but also because it highlights that plastic pollution is a multifaceted environmental issue affecting various ecosystem categories, and the broader implications of atmospheric plastic circulation on wildlife and ecosystems health.

Social perception of mesocarnivores within hunting areas differs from actual species abundance.

Analyzing how similar social perception and ecological field data are might help identify potential biases in identifying and managing human-carnivore conflicts. We analyzed the degree of similarity between the perceived and field-measured relative abundance to unveil whether attitude towards carnivores of two groups of stakeholders, namely hunters and other local people, is underpinned or it is instead biased by alternative factors. Our results indicate that, in general, mesocarnivore perceived abundances were generally different to actual species abundance. We also found that the perceived abundance and attributed damage to small game species were related with respondents' ability to identify the carnivore species. We underline the existence of bias and the need to increase people knowledge on species distribution and ecological characteristics before adopting decisions when managing human-carnivore conflicts, especially for stakeholders that are directly involved in.

Correction: Sex, personality and conspecific density influence natal dispersal with lifetime fitness consequences in urban and rural burrowing owls.

[This corrects the article DOI: 10.1371/journal.pone.0226089.].

Nesting innovations in neotropical parrots associated to anthropogenic environmental changes.

Parrots are among the most diverse and widely distributed groups of birds and one of the most threatened bird orders mainly due to habitat loss and illegal poaching. Most parrots are obligate cavity nesters, so the logging of mature trees and the transformation of natural cliffs represent important threats to their conservation. Here, we report novel observations of Neotropical parrots nesting in previously unrecorded substrates. We show the first documented case of the cliff-nesting burrowing parrots trying to breed at ground level in an abandoned burrowing owl cavity. Additionally, we provide the first documented observations of this species attempting to nest in building cavities in three urbanized areas of Argentina. Moreover, we report data from four countries of 148 pairs of eight species typically breeding in tree cavity using palm tree bracts as nest sites. Behavioral plasticity in nest sites may allow parrots to maximize their nesting success by exploiting alternative breeding substrates. Moreover, these novelties could contribute to cope with habitat loss and further transformation. However, further research is needed to assess the consequences of these nesting innovations in terms of individual fitness and population dynamics as well as potential factors promoting their appearance.

Intraspecific competition and individual behaviour but not urbanization affect the dietary patterns of a generalist avian predator.

Urbanization has reshaped ecosystems and changed natural processes, driving an intense transformation of biomes, biotic community composition and diversity. Despite the growing interest in studying urban ecology over the last decades, the consequences of these changes on species occupying these ecosystems are not yet fully understood. Trophic generalism and tolerance to human disturbance have been proposed as two key traits in the colonization of urban environments. However, most studies focused on species' average traits, paying less attention to the potential role of inter-individual variability. Here, we examined diet specialization in urban and rural breeding pairs, as well as its relationship with individual behaviour and intraspecific competition, using the burrowing owl as a study model. Our results show that both urban and rural breeding pairs behaved as trophic specialists. The diet of burrowing owl breeding pairs followed a gradient from coleopteran- to micromammal-dominated, which is related to individual behaviour (bolder individuals consuming more coleopterans than shyer ones). Besides, pairs distant from others showed a more diverse diet than those experiencing higher levels of intraspecific competition. Models fitted separately for each habitat showed that the proportion of micromammals in the diet of urban breeding pairs was related to their behavior, while the diet of rural pairs was not affected by individual behavior but by intraspecific competition. However, despite the strong selection of tame and more explorative individuals in urban environments and the higher density they reach in this habitat type, they did not differ in their degree of diet specialization from rural conspecifics. Although it would be necessary to evaluate prey availability on a small scale, our results suggest that burrowing owl breeding pairs behave as specialists, despite the generalist character of the species, and that this specialization is not affected by the occupation of urban environments but to individual behaviour and intraspecific competition.

How Can We Improve Running Events? The IPA4RE Questionnaire and Its Potential Impact on the Experience of Runners.

The benefits that a positive running experience provides to individuals have been broadly studied by the scientific community, with the finding that running sport events are a facilitating tool to attract more individuals into physical activity. This study focuses on a sport management approach to improve the quality and organizational efficiency of running sports events so that a better experience for runners can be provided. The methods of this research consist of the validation of a new questionnaire called 'The IPA4RE questionnaire'. Furthermore, an IPA analysis for a specific event was carried out. As our main findings, the most valued aspects perceived by consumers are the event atmosphere, security, event route, and convenience of bib collection and event day information. In conclusion, the IPA4RE can be used as a management tool by running event organizers to make more efficient use of their resources and provide a better experience to participants.

Plastic Debris in Nests of Two Water Bird Species Breeding on Inland Saline Lakes in a Mediterranean Biosphere Reserve.

Despite more studies being carried out to know the impacts associated with plastic debris and much effort being spent on marine ecosystems, the impacts of plastics on terrestrial and freshwater species remain largely unknown. Here, we explored the presence of anthropogenic materials in nests of two wader species, the gull-billed tern (Gelochelidon nilotica) and the black-winged stilt (Himantopus himantopus), breeding on the inland salt lakes in the "La Mancha Húmeda" Biosphere Reserve, Central Spain. We revealed the presence of anthropogenic debris, mainly macroplastics (>5 mm), in 2.4% and 12.5% of the sampled nests of the gull-billed tern and the black-winged stilt, respectively. The fragments found in nests ranged from 8 mm to 257 mm for the gull-billed tern and from 7 mm to 19 mm for the black-winged stilt. This debris showed no clear pattern of color or size and probably originated both in the agricultural activities in the surroundings and domestic refuse. Although we did not detect any pernicious impacts on adults or chicks (e.g., entangled, injured, or dead individuals), the presence of plastics and other human waste directly placed in nests located in a protected area should warn us about the ubiquity of these pollutants, and the endocrine and immunological effects, among others, that may reduce the recruitment of new animals to the population should be assessed.

Drivers of the Ectoparasite Community and Co-Infection Patterns in Rural and Urban Burrowing Owls.

Urbanization creates new ecological conditions that can affect biodiversity at all levels, including the diversity and prevalence of parasites of species that may occupy these environments. However, few studies have compared bird-ectoparasite interactions between urban and rural individuals. Here, we analyze the ectoparasite community and co-infection patterns of urban and rural burrowing owls, Athene cunicularia, to assess the influence of host traits (i.e., sex, age, and weight), and environmental factors (i.e., number of conspecifics per nest, habitat type and aridity) on its composition. Ectoparasites of burrowing owls included two lice, one flea, and one mite. The overall prevalence for mites, lice and fleas was 1.75%, 8.76% and 3.50%, respectively. A clear pattern of co-infection was detected between mites and fleas and, to less extent, between mites and lice. Adult owls harbored fewer ectoparasites than nestlings, and adult females harbored more lice than males. Our results also show that mite and flea numbers were higher when more conspecifics cohabited the same burrow, while lice showed the opposite pattern. Rural individuals showed higher flea parasitism and lower mite parasitism than urban birds. Moreover, mite numbers were negatively correlated with aridity and host weight. Although the ectoparasitic load of burrowing owls appears to be influenced by individual age, sex, number of conspecifics per nest, and habitat characteristics, the pattern of co-infection found among ectoparasites could also be mediated by unexplored factors such as host immune response, which deserves further research.

Is exercise and electrostimulation effective in improving muscle strength and cardiorespiratory fitness in children with cystic fibrosis and mild-to-moderate pulmonary impairment?: Randomized controlled trial.

BACKGROUND: Evidence on resistance-training programs for cystic fibrosis (CF) is limited and the possible benefits of the addition of neuromuscular electrical stimulation (NMES) are unknown. This study aimed to evaluate the effects of a supervised resistance-training program, associated or not with NMES, on muscle strength, aerobic fitness, lung function and quality of life in children with CF presenting mild-to-moderate pulmonary impairment. METHODS: This is a randomized controlled trial including CF patients aged between 6 and 17years. Subjects were randomly allocated to control (CON); exercise (EX); or exercise and NMES (EX + NMES) groups, and evaluated at baseline and at the end of an 8-week individualized exercise-program (3 days/week, 60min/session). NMES was applied in the quadriceps and the interscapular region, simultaneously to the exercises. CON group followed the CF team recommendations. The main outcome measures were lung function, cardiorespiratory fitness, functional capacity, quality of life and muscle strength. RESULTS: Twenty-seven patients, aged 12.6 ± 3.0 years, were analyzed. No significant interactions were found for cardiorespiratory fitness. Functional capacity presented significant differences, indicating a better performance in both EX and EX + NMES. No significant changes between groups were seen for quality of life and lung function. As for muscle strength, EX and EX + NMES presented large effect sizes and significant differences, compared to CON, for quadriceps (p = 0.004, η2p = 0.401), pectoral (p = 0.001, η2p = 0.487), dorsal (p = 0.009, η2p = 0.333) and handgrip (p = 0.028, η2p = 0.278). CONCLUSION: A resistance exercise-training program led to improvements in muscle strength and functional capacity in CF patients with mild-to-moderate pulmonary impairment. The addition of NMES to the training program resulted in no extra favorable effects.

The morphology of Colpocephalum pectinatum (Phthiraptera: Amblycera: Menoponidae) under scanning electron microscopy.

Here, we describe under scanning electron microscopy (SEM) the morphology of Colpocephalum pectinatum (Phthiraptera, Menoponidae), an ectoparasite found in burrowing owls, Athene cunicularia. We devote particular attention to the morphology of the main structures of the head (antennae and mouth-parts) and legs (tarsi and femoral ctenidia). Moreover, we describe the main peripheral sensory organs, located in the labial palpi and the distal end of antennae. We also detected that the structure of antennae and antennal sensilla arrangement are very similar to that described for other Colpocephalum and Menoponid species, and we discuss the function of each type of sensilla. We suggest that SEM studies combined with other microscopy and physiological techniques could be useful for elucidate the function of each structure, lice behaviour, as well as their taxonomy.

Urban life promotes delayed dispersal and family living in a non-social bird species.

In some vertebrate species, family units are typically formed when sexually mature individuals delay dispersal and independent breeding to remain as subordinates in a breeding group. This behaviour has been intensively studied in gregarious species but has also been described in non-social species where ecological and evolutionary drivers are less known. Here, we explore factors that favour delayed dispersal and family living and potential benefits associated with this strategy in a non-social, monogamous species (the burrowing owl, Athene cunicularia) occupying urban and rural habitats. Our results show that family units arise when first-year individuals, mainly males, delay their dispersal to stay in their natal nests with their parents. This delayed dispersal, while still uncommon, was more prevalent in urban (7%) than in rural (3%) habitats, and in areas with high conspecific density and productivity. Birds delaying dispersal contributed to the genetic pool of the offspring in 25% of the families analysed, but did not increase the productivity of the nests where they remained. However, their presence was related to an improvement in the body condition of chicks, which was ultimately linked to a slightly positive effect in offspring future survival probabilities. Finally, delayed dispersers were recruited as breeders in high-quality urban territories and closer to their natal nests than individuals dispersing during their first year of life. Thus, our results suggest that delaying dispersal may be mainly related to opportunities to inheriting a good quality territory, especially for males. Our study contributes to understanding the role played by habitat quality in promoting delayed dispersal and family living, not only in social but also non-social species, highlighting its impact in the ecology and evolution of animal populations.

The New Generation of Professional Soccer Talent Is Born under the Bias of the RAE: Relative Age Effect in International Male Youth Soccer Championships.

In 2019, numerous championships of youth categories soccer national teams were held. In the present study, we analyzed the existence of the Relative Age Effect (RAE) in four major male championships that, due to their importance and participating teams, most likely brought together the great bulk of the players who will dominate professional soccer in the next decade. Participants were professional and amateur youth male soccer players who participated in the last international championships: UEFA European Under-21 Championship (2017-2019); UEFA European Under-19 Championship (2019); South American Youth Football Championship (also known as Conmebol U-20) (2019); and FIFA U-20 World Cup (2019), with 823 players (20.25 ± 0.84 years). In the four championships analyzed, the existence of RAE was found for all players (p < 0.001). Analyzing the players when considering their position on the pitch and their championship, RAE was found, statistically significant, in 10 of the 16 classifications. New generations of elite soccer players arrive with a clear bias in the selection of talent; an unfair bias, based on unequal opportunities in early categories, which should be reviewed by sports authorities.