Compensatory frugivory in migratory Sylvia warblers: geographical responses to season length

Seasonal shifts in the diets of Garden Warblers Sylvia borin , Blackcaps S. atricapilla and Lesser Whitethroats S. curruca at a North German site were studied from samples obtained by flushing the digestive tract of the birds. The significance of seven species of berries and pulpy fruits in the diet of these species while feeding in riparian vegetation during the premigratory and migratory seasons was assessed and compared with the pattern of frugivory shown by the same species in southern Germany. Because of the short time span between hatching and onset of migration, first-year long- and medium-distance migratory Sylvia warblers from northern Europe are forced to accelerate their juvenile development. Presumably to meet the higher nutritional demands of an accelerated development, juvenile Garden Warblers and Blackcaps in northern Germany ate relatively more fruit during premigration than Blackcaps in southern Germany. Fruit occurred in about 90% of their diet samples during both premigration and migration. However, this might not hold true for experienced adult birds. Garden Warblers accelerated the rate of fattening and reduced the time needed to prepare for migration when feeding on a mixed fruit diet. There were indications that Blackcaps directly influenced the fruit choice of Garden Warblers when fruits preferred by both species were scarce. Blackcaps and Garden Warblers showed subtle differences in their seasonal preferences for black elder Sambucus nigra and woody nightshade Solanum dulcamara .     

Migration strategies of sylviid warblers: chance patterns or community dynamics?

The effects of community dynamics in birds on the optimisation of their migratory strategies is a neglected area. For three years, we captured migrating warblers on autumn passage at a coastal site in western Britain. We used canonical correspondence analysis (CCA) to assess spatio‐temporal patterns of occurrence, and principal components analysis (PCA) to assess morphological variation. We calculated Euclidean distance in ordination and morphological space to assess separation between species pairs, and used Monte‐Carlo simulations to assess the probability of pattern occurring by chance.
Ordination revealed five species‐groups separated by habitat type and time of passage. Reed Warbler Acrocephalus scirpaceus and Sedge Warbler A. schoenobaenus (Group 1) occurred in wet habitats and peaked simultaneously. In drier habitats with scrub, a first wave of Blackcap Sylvia atricapilla (Group 2) significantly preceded Grasshopper Warbler Locustella naevia, Willow Warbler Phylloscopus trochilus, Whitethroat Sylvia communis and Lesser Whitethroat Sylvia curruca (Group 3), which in all but one case (Lesser Whitethroat) significantly preceded Garden Warbler Sylvia borin (Group 4); peak numbers of Chiffchaffs Phylloscopus collybita and a second wave of Blackcaps (Group 5) occurred later still. Age effects were found only in Acrocephalus, with adults peaking before juveniles.
For seven out of eight pairings within genera, separation in time of passage increased significantly in species that were morphologically similar. The only exception was Blackcap and Lesser Whitethroat which differed substantially in both passage time and morphology. Monte‐Carlo simulations showed that chance was unlikely to be responsible for ordination patterns, nor for inter‐specific variation in passage time and its relationship with species morphology.
These data provide annually consistent evidence that migrating sylviid warblers are separated ecologically by habitat use, time of passage and morphology: we cannot refute the hypothesis that community dynamics have influenced niche use and autumn migratory strategy. We call for further tests of the ‘migrant interaction’ hypothesis in other geographical locations and taxa, particularly where migrants are allopatric and interact ecologically only on migration.     

Fruit tracking between sites and years by birds in Mediterranean wintering grounds

Knowledge of the ability of birds to track spatiotemporal variation in fruit distribution is essential for understanding plant-frugivore interactions. Arguably, although total fruit availability sets an upper limit to the number of birds that can exploit a habitat patch, not all species can equally distribute abundance according to variation in fruit resources. To explore this, we studied bird and fruit abundance in 1999–2005 in Mediterranean scrublands and woodlands of southern Spain. We analysed whether changes of fruit abundance in eight different sites during six winters could predict numerical changes of a set of frugivorous passerines of the area (blackcap Sylvia atricapilla , Sardinian warbler S. melanocephala , robin Erithacus rubecula , song thrush Turdus philomelos and blackbird T. merula ). We also investigated if all frugivores together tracked fruits better than individual species, thereby supporting a shared use of resources. Results showed strong inter-specific differences. Only the most abundant species (blackcaps and robins) tracked the spatial patterning of food despite strong differences in the use of space (vagrant and territorial, respectively). This suggests plastic behaviour of territorial robins, with individuals changing from strictly territorial to wandering, a flexibility that would favour between-site numerical arrangements according to food resources. Annual changes in bird numbers were independent of the availability of fruits, except for blackcaps, an abundant vagrant bird that tracked inter-winter changes in fruit abundance. The abundance of blackcaps fitted the spatiotemporal patterning of fruit resources better than the whole guild of frugivorous birds, inconsistent with the idea that these species track together the changing availability of fruit resources.     

Some aspects of frugivory by bird populations using coastal dune scrub in Lincolnshire

The fruit diets of Sylvia warblers, and some thrushes, were studied during 1989 at a coastal scrubland site, using faecal examination. Fruit feeding commenced as the earliest berries ripened in late July, but there were differences of timing between species. Amongst both warblers and thrushes, the larger species commenced earlier and ate more fruit. Almost all Blackcap and Garden Warbler faeces examined from early August contained some fruit remains, as did most Whitethroat faeces from mid-month. Mean fruit contents of faecal samples exceeded 80% infrequently, indicating that even the most frugivorous species always took other food, normally insects, to supplement their diet. Each species differed in their fruit diet: Blackcaps, and to a lesser extent Garden Warblers, ate Woody Nightshade berries in preference to Blackberries, as they are structurally adapted for feeding on the former plant. Only inexperienced juveniles of other species regularly chose the Nightshade berries. Elder berries, abundant from late August, became the preferred fruit for all Sylvia species. Using data from an earlier investigation, 1 it is shown that by feeding on Elder berries, migrating Blackcaps can obtain 75–90% of their daily energy requirements in 10% of daylight hours.     

Venous drainage of the pelvic fins of rays (subclass elasmobranchii: Superorder Batoidea)

A contrast radiographic study of pelvic fin drainage in rays reveals considerable differences in patterns of drainage among the species studied. The “typical” shark pattern of drainage, to the lateral abdominal vein, is also found in rays with shark-like morphology. However, variation in the connections of pelvic fin veins to muscular and cutaneous vessels of the pectoral fin occurs in the more “derived” batoid groups, with marked differences between rays of similar external morphology and mode of locomotion. There is a positive association between the pattern of fin drainage and the number of radial cartilages in the posterior (metapterygial) lobe of the pectoral fin. Variation in shark pelvic fin drainage may also be related to differences in pectoral fin morphology.     

Fruit consumption in migratory passerines is limited by water ingestion rather than by body water balance

Many insectivorous passerines become frugivorous during migration. Because water may facilitate the digestion of dry fruits, some passerines may benefit from staging in stopover sites that offer access to drinking water. In autumn, water consumption by blackcaps Sylvia atricapilla staging in Israel was found to induce a shift from insectivory to frugivory. We tested two alternative hypotheses concerning the mechanism facilitating consumption of the relatively dry fruits which are common in this region: 1) water intake facilitates the passage of fruits within the digestive tract when these two resources are simultaneously ingested, and 2) improved body water balance allows the consumption and ingestion of large amounts of dry fruits. Blackcaps were subjected to five treatments that included temporal separation of water and fruit consumption, as well as subcutaneous water injection to maintain balanced body water in water‐deprived birds. Fruit consumption rate was measured daily. We found that only simultaneous provisioning of water and fruits significantly increased fruit consumption rate, implying that drinking water directly improves fruit digestion within the digestive system. Furthermore, the fuel deposition rate increased with increased fruit consumption rate. These results emphasize the importance of water availability for the ecology and conservation of migrating passerines.     

Morphological variation in tomato: a comprehensive study of quantitative trait loci controlling fruit shape and development

Variation in fruit morphology is a prevalent characteristic among cultivated tomato. The genetic and developmental mechanisms underlying similarities and differences in shape between the fruit of two elongated tomato varieties were investigated. Fruit from two F2 populations constructed from either Solanum lycopersicum cv. Howard German or cv. Banana Legs crossed with S. pimpinellifolium accession LA1589, and one BC1 population constructed with S. lycopersicum Howard German as the recurrent parent, were analysed for shape by using a new software program Tomato Analyzer. Quantitative trait loci (QTLs) controlling 15 individual shape attributes were mapped by both single and multitrait composite interval mapping in each population. In addition, principal components analysis and canonical discriminant analysis were conducted on these shape attributes to determine the greatest sources of variation among and between the populations. Individual principal components and canonical variates were subjected to QTL analysis to map regions of the genome influencing fruit shape in the cultivars. Common and unique regions, as well as previously known and novel QTLs, underlying fruit morphology in tomato were identified. Four major loci were found to control multiple fruit shape traits, principal components, and canonical variates in the populations. In addition, QTLs associated with the principal components better revealed regions of the genome that varied among populations than did the QTL associated with canonical variates. The QTL identified can be compared across additional populations of tomato and other fruit-bearing crop species.     

Small-scale spatial variation in the interactions between Prunus mahaleb and fruit-eating birds

We studied fleshy fruit consumption by birds on individualPrunus mahaleb trees in four plots in northwestern Spain.We found large variation among trees in the relative contribution of differentbird species to fruit removal. This variation, which occurred on a scale ofmeters, was correlated with the distance from the tree to nests ofPhoenicurus ochruros, a major fruit consumer, and with thekind of microhabitat surrounding each tree. In the four plots studied, treeslocated farther away from P. ochruros nests receivedrelatively fewer visits by this species, and relatively more byTurdusmerula and Sylvia atricapilla. These three mainconsumer species differed in the kinds of microhabitats (rocks, loose stones,bare or grassy soil, and woody vegetation) where they flew after visitingP. mahaleb, and thus they probably created differentpatterns of seedfall. This study adds to the evidence that environmentalfactorsextrinsic to plants, and acting at different spatial scales, greatly influencethe identity of the fruit consumers visiting individual trees. This influenceundermines the chances that fruit traits become evolutionary modified so as toattract those consumers providing the best seed dispersalservicesto the plants.     

Seed size variation and its effect on germination and seedling performance in the clonal herb Convallaria majalis

Variation in seed size is common both within and among plant species. This study examined within-species variation in seed weight, and its implications for some components of fitness in the clonal herb Convallaria majalis. This species produces berries containing 4.1 seeds on average. The average seed weight was 16.5 mg, with a coefficient of variation of 32.7%. Seed packaging in fruits was on average 12.5%, and showed a slight tendency to increase with fruit weight. A trade-off was found between seed weight and seed number both within fruits and within ramets. The probability and timing of germination was not influenced by seed size. A field experiment and indirect evidence suggested that post-dispersal seed predation was not related to seed size. Increasing seed weight conferred an advantage to developing seedlings. This advantage was enhanced if a seedling was growing in the close vicinity of a seedling of another species. It is suggested that seed size variation in C. majalis primarily is the result of resource variation during fruit development. A conflict between parents and offspring may however contribute to increase seed size variation.     

Dietary generalists and nutritional specialists: Feeding strategies of adult female blue monkeys (Cercopithecus mitis) in the Kakamega Forest,Kenya

Generalist primates eat many food types and shift their diet with changes in food availability. Variation in foods eaten may not, however, match variation in nutrient intake. We examined dietary variation in a generalist‐feeder, the blue monkey (Cercopithecus mitis), to see how dietary food intake related to variation in available food and nutrient intake. We used 371 all‐day focal follows from 24 adult females (three groups) in a wild rainforest population to quantify daily diet over 9 months. We measured food availability using vegetation surveys and phenology monitoring. We analyzed >700 food and fecal samples for macronutrient content. Subjects included 445 food items (species‐specific plant parts and insect morphotypes) in their diet. Variation in fruit consumption (percentage of diet and total kcal) tracked variation in availability, suggesting fruit was a preferred food type. Fruits also constituted the majority of the diet (by calories) and some fruit species were eaten more than expected based on relative availability. In contrast, few species of young leaves were eaten more than expected. Also, subjects ate fewer young leaves (based on calories consumed) when fruit or young leaves were more available, suggesting that young leaves served as fallback foods. Despite the broad range of foods in the diet, group differences in fiber digestibility, and variation that reflected food availability, subjects and groups converged on similar nutrient intakes (grand mean ± SD: 637.1 ± 104.7 kcal overall energy intake, 293.3 ± 46.9 kcal nonstructural carbohydrate, 147.8 ± 72.4 kcal lipid, 107.8 ± 12.9 kcal available protein, and 88.1 ± 17.5 kcal structural carbohydrate; N = 24 subjects). Thus, blue monkeys appear to be food composition generalists and nutrient intake specialists, using flexible feeding strategies to regulate nutrient intake. Findings highlight the importance of simultaneously examining dietary composition at both levels of foods and nutrients to understand primate feeding ecology.     

Fruit size in wild olives: implications for avian seed dispersal

1. The response of frugivorous birds to an enlargement of fruit size, and the consequences for both birds and plants, are analysed for the interaction between avian seed dispersers and olives ( Olea europaea) .
2. The enlargement of fruit size promotes a shift in frugivorous birds' feeding behaviour, from swallowing fruits whole to pecking pieces of pulp. The relative frequency of olive consumption using each feeding behaviour was assessed by combining field data on frequency of appearance of olive pulp and seeds with data from laboratory trials.
3. Sardinian Warblers ( Sylvia melanocephala ) and European Robins ( Erithacus rubecula ) were mainly peckers both on cultivated and wild olives. Blackcaps ( Sylvia atricapilla ) consumed wild olives mainly by swallowing but consumed cultivated olives (larger than the wild ones) primarily by pecking. Song Thrushes ( Turdus philomelos ) were primarily swallowers of both types of fruits.
4. Laboratory trials with Song Thrushes, Blackcaps and European Robins showed that: (a) all were able to peck fruits; (b) fruit size determined a shift from swallowing to pecking, as pecking frequency increased with the enlargement of the fruit size; (c) all the species had an increased fruit handling failure rate when trying to swallow increasingly large fruits; and (d) from the birds' perspective, small shifts in fruit size may have important consequences on fruit profitability.
5. Pecking on olives turns the mutualistic fruit–frugivore interaction into a fruit-pulp predator interaction, thus arising a conflict between the plant and frugivorous birds.
6. This study shows that heavy dependence on fruit is not always simply related to seed dispersal. The same frugivorous bird species can act as a seed disperser or a pulp predator for the same plant species. The threshold between these roles is highly influenced by the ratio gape size/fruit size.     

Associations between physical isolation and geographical variation within three species of Neotropical birds

We studied effects of physical isolation on geographical variation in mtDNA RFLP polymorphisms and a suite of morphological characters within three species of neotropical forest birds; the crimson-backed tanager Ramphocelus dimidiatus, the blue-gray tanager Thraupis episcopus, and the streaked saltator Saltator albicollis. Variation among populations within continuous habitat on the Isthmus of Panama was compared with that among island populations isolated for about 10000 years. Putative barriers to dispersal were influential, but apparent isolation effects varied by species, geographical scale, and whether molecular or morphological traits were being assessed. We found no geographical structuring among the contiguous, mainland sampling sites. Migration rates among the islands appeared sufficient to maintain homogeneity in mtDNA haplotype frequencies. In contrast, variation in external morphology among islands was significant within two of three species. For all species, we found significant variation in genetic and morphological traits between the island (collectively) and mainland populations. Interspecific variation in the effects of isolation was likely related to differential vagility. These data generally corroborate other studies reporting relatively great geographical structuring within tropical birds over short distances. Behaviourally based traits - low vagility and high ‘sensitivity’ to geographical barriers - may underlie extensive diversification within neotropical forest birds, but more extensive ecological and phylogeographic information are needed on a diverse sample of species.     

Why are fruit traits of Cistus ladanifer (Cistaceae) so variable: A multi-level study across the western Mediterranean region

Variation is the raw material for evolution. Differences among populations in the expression of traits related to plant fitness may result from natural selection, phenotypic plasticity (in response to local conditions), and developmental instability (manifested as high intra-individual variation in repeated patterns or characters). Cistus ladanifer is a highly polymorphic plant distributed in the Mediterranean and the only species in the family (Cistaceae, 180 species) with a variable number of valves per fruit. We herein analysed the variation in the number of valves (5–12) and seeds (318–1185) per fruit in 36 populations (607 individuals, 1821 fruits) at different levels: temporal, geographical, ecogeographical, taxonomic, and phylogeographical. In addition, we tested whether an increased number of fruit valves influences pre-dispersal seed predation. Large variation in the number of valves and seeds per fruit among populations, individuals, and years was reported. The number of ovules and seeds per valve increased with a higher number of fruit valves. Geographical and taxonomic variables did not significantly explained this fruit variation. On the contrary, we found a negative relationship between the number of fruit valves and altitude and a positive relationship with precipitation. We argue that ecogeographical factors, in addition to some phylogeographical and phylogenetic signals, are involved in the multiplication of carpels during the development of the ovary wall. This, coupled with the results of the evolutionary history of Cistus in previous studies, indicates active evolutionary processes in C. ladanifer populations.     

Comparison of Nicotiana tabacum and Nicotiana nesophila hybrids produced by ovule culture and protoplast fusion

Summary Somatic hybrids were produced between Nicotiana tabacum and N. nesophila, two species incapable of conventional sexual hybridization. Sexual hybrids, though, could be produced between these two species by using ovule culture only when N. nesophila was female. Clones of somatic hybrids were compared with sexual hybrids. Statistically significant variation was observed between clones, but not between sexual hybrids, for pollen viability, flower morphology, leaf morphology, and trichome density. As all clones of somatic hybrids have 96 chromosomes, the variability could not be explained by interclonal variation in chromosome number. Variation between somatic hybrids could be the result of cytoplasmic segregation or recombination, mitotic recombination or small chromosomal rearrangements prior to plant regeneration. Variation between clones could be exploited as these interspecies hybrids are now being used to incorporate disease resistance into cultivated tobacco.     

The making of a bell pepper-shaped tomato fruit: identification of loci controlling fruit morphology in Yellow Stuffer tomato

The heirloom tomato cultivar Yellow Stuffer produces fruit that are similar in shape and structure to fruit produced by the bell pepper varieties of garden pepper. To determine the genetic basis of this extreme fruit type in tomato, quantitative trait loci (QTL) analysis was performed on an F(2) population derived from a cross between Yellow Stuffer and the related species, Lycopersicon pimpinellifolium, which produces a small, round fruit typical of most wild species. F(2) plants were analyzed for both fruit size and the degree to which their fruit resembled the bell pepper. Three QTL were determined to influence bell pepper shape and seven QTL influenced fruit mass. The map positions of all three bell shape and six out of seven fruit size QTL appear to be allelic to components of fruit morphology analyzed in this population and to major fruit morphology QTL reported previously, adding support to the hypothesis that the majority of fruit size and shape variation in cultivated tomato is attributable to allelic variation at a limited number of loci. However, novel loci controlling components of fruit morphology, such as elongated fruit shape, bumpiness, number of seed per fruit and flowers per inflorescence were identified in this study as well. The three bell shape loci involved are: bell2.1, bell2.2 and bell8.1, and appear to correspond to locule number2.1 ( lcn2.1) and fruit weight 2.2 ( fw2.2) and fruit shape 8.1 ( fs8.1), respectively. The Yellow Stuffer alleles at lcn2.1 and fw2.2 increase locule number and fruit size, respectively, hence contributing to the overall bell pepper shape. The Yellow Stuffer allele at fs8.1 causes convex locule walls, giving the extended, bumpy shape characteristic of bell peppers. In addition, most fruit size QTL correspond to loci controlling number of flowers per inflorescence and/or stem-end blockiness. Comparisons among previously identified fruit morphology loci in tomato, eggplant and pepper suggest that loci affecting several aspects of fruit morphology may be due to pleiotrophic effects of the same, orthologous loci in these species. Moreover, it appears that the evolution of bell pepper-shaped tomato fruit may have proceeded through mutations of some of the same genes that led to bell pepper-type fruit in garden pepper.     

Body shape, burst speed and escape behavior of larval anurans

Variation in behavior, morphology and life history traits of larval anurans across predator gradients, and consequences of that variation, have been abundantly studied. Yet the functional link between morphology and burst-swimming speed is largely unknown. We conducted experiments with two divergent species of anurans, Scaphiopus holbrookii and Rana sphenocephala , to examine how behavior and morphology influence predator vulnerability, and whether tadpole shape is related to burst-swimming performance. Scaphiopus holbrookii , a species that typically uses ephemeral pools, was more active, exhibited slower burst speeds, and was more susceptible to predation than R. sphenocephala , a species associated with more permanent aquatic sites. Our analysis of morphology and burst speed defined a shared axis of shape variation associated with burst-swimming speed regardless of species. Tadpoles with a deeper tail fin and muscle and a smaller body produced faster speeds. The nature and breadth of the morphology–speed relationship suggests it may represent a generalized ecomorphological paradigm for larval anurans.     

Nectar consumption of warblers after long-distance flights during spring migration

The consumption of nectar by European passerines has been reported only occasionally. In this study we investigated the occurrence and significance of nectar consumption of small passerine birds on spring migration after crossing the Mediterranean Sea. On Ventotene Island in the Tyrrhenian Sea, four migrating species of Sylvia warblers [Garden Warbler S. borin , Subalpine Warbler S. cantillans , Whitethroat S. communis , Blackcap S. atricapilld ) regularly foraged on the two most common flowering species at that time of year, Brassica fruticulosa (Cruciferae) and giant fennel Ferula communis (Umbelliferae), while other species visited flowers only occasionally or not at all. Feeding behaviour, pollen traces on the head, and the examination of pollen and sugar remains in droppings indicated that nectar was the main target of the Sylvia warblers, rather than pollen or insects on the flowers. This was confirmed by food choice experiments indicating a clear preference by Garden Warblers and Whitethroats for nectar from artificial flowers over mealworms. Although conclusive experiments are not available, we hypothesize that nectar might be a diet easy to obtain and to absorb for birds after a long-distance flight in which they have incurred a depletion of energy stores and a reduction of the digestive tract.     

基于种实性状的无患子天然群体表型多样性研究

无患子(Sapindus mukorossi Gaertn.)是我国长江以南地区传统的重要绿化树种,其果皮富含皂苷,种仁富含油脂,是国家林业局审定的新型木本油料树种之一。为揭示无患子群体间和群体内种实表型性状变异式样,采用单因素方差分析、巢式方差分析、相关分析和主成分分析等方法,对无患子13个天然群体的10个种实表型性状进行比较分析,研究其群体间和群体内种实表型多样性以及表型变异与地理生态因子间的相关性。结果表明:无患子种实表型性状变异系数平均为7.34%,在群体间和群体内均存在丰富的表型变异。表型性状分化系数平均为62.21%,群体间变异(39.93%)大于群体内(27.46%),是无患子种实表型性状变异的主要来源。多数性状在群体间差异显著,不同程度的表现出边缘群体易于分化的特点,但地理变化规律不连续,而在群体内不同性状的差异性亦不一致。种子形态受群体地理生态的影响较果实形态大,西北部群体种子趋于椭圆形,东部、南部则趋于圆球形;地理纬度、年平均气温与多数种实性状间呈显著相关,是无患子种实表型性状变异的主要地理生态影响因子。可见,无患子种实表型性状在群体间、群体内变异都较为丰富,这些变异是由遗传和环境因素共同作用的结果。群体间和群体内多层次的变异为无患子优良种质资源保育和利用提供了物质基础。     

Within‐plant variation in reproductive investment: consequences for selection on flowering time

Variation among the leaves, flowers or fruit produced by a plant is often regarded as a nuisance to the experimenter and an impediment to selection. Here, we suggest that within‐plant variation can drive selection on other plant‐level traits. We examine within‐plant variation in floral sex allocation and in fruit set and predict that such variation generates variation in male success among plants, thereby driving selection on flowering time. We tested this prediction in a simulation model estimating selection on flowering time through male fitness when floral sex allocation and/or fruit set vary directionally among flowers on plants. We parameterized the model through a quantitative literature survey of within‐plant change in sex allocation. As predicted, within‐plant variation in floral sex allocation and in fruit set probability can generate selection on flowering time through male fitness. Declining fruit set from first to last flowers on plants, as occurs in many species, selected for early flowering onset through male fitness. This result was robust to self‐incompatibility and to varying returns on male versus female investment. Selection caused by declining fruit set was strong enough to reverse the selection for late flowering that can be caused by intrafloral protandry. Our model provides testable predictions regarding selection on flowering time through male fitness. The model also establishes the intriguing possibility that within‐plant variation may influence selection on other traits, regardless of whether that variation is under selection itself.     

Within- and among-tree variation in leaf morphology of <Emphasis Type="Italic">Quercus petraea</Emphasis> (Matt.) Liebl. natural populations

Variation in leaf morphology of Quercus petraea in response to several ecological conditions has been studied extensively, although not explicitly in the context of within- and among-tree variation. This study examined leaf morphology and anatomy of Q. petraea, growing in five natural Italian populations adapted to different ecological environments, to understand the pattern of within- and among-tree variation in this species. We used an ANOVA model with both crossed and nested effects. All levels contributed significant components of variation. Within-tree variation due to branch position was large, particularly in thickness and productivity (40%). For 19 of 32 variables, the variation among trees was surprisingly lower than the within-tree variation explained by branch position. Trends in leaf morphology and anatomy with branch position exhibited the sun-shade dichotomy. Patterns of crown plasticity showed lower values in the two xeric populations. Results suggest the need for taxonomic studies to consider variation as a quantitative attribute of individual trees.