Beak Width Research Articles

Effect of intestinal microbiota on duck short-beak and dwarf syndrome caused by novel goose parvovirus

Short-beak and dwarf syndrome (SBDS) is caused by infection with novel goose parvovirus (NGPV), which leads to intestinal dysbiosis, developmental delay, short beak, lameness, and paralysis in ducks and is the cause of skeletal health problems. NGPV infection can cause intestinal microbial disturbances, but it is still unclear whether the intestinal microbiota affects the pathogenicity of NGPV. Here, the effects of intestinal microbiota on NGPV-induced SBDS in Cherry Valley ducks were assessed by establishing a duck model for gut microflora depletion/reestablishment through antibiotics (ABX) treatment/fecal microbiota transplanted (FMT). By measuring body weight, beak length, beak width and tarsal length, we found that SBDS clinical symptoms were alleviated in ducks treated with ABX, but not in FMT ducks. Next, we conducted a comprehensive analysis of bone metabolism, gut barrier integrity, and inflammation levels using quantitative real-time PCR (qPCR), enzyme linked immunosorbent assay (ELISA), biochemical analysis and histological analysis. The results showed that ABX treatment improved bone quality reduced bone resorption, mitigated tissue lesions, protected intestinal barrier integrity, and inhibited systemic inflammation in NGPV-infected ducks. Moreover, cecal microflora composition and short-chain fatty acids (SCFAs) production were examined by bacterial 16S rRNA sequencing and gas chromatography. The results revealed that ABX treatment mitigated the decreased abundance of Firmicutes and Bacteroidota in NGPV-infected ducks, as well as increased SCFAs production. Furthermore, ABX treatment reduced the mucosa-associated lymphoid tissue lymphoma translocation protein 1 (Malt1) and nuclear factor κB (NF-κB) expression, which are correlated with systemic inflammation in SBDS ducks. These findings suggested that intestinal microflora depletion alleviated NGPV-induced SBDS by maintaining intestinal homeostasis, inhibiting inflammatory response and alleviating bone resorption. These results provide evidence for the pivotal role of intestinal microbiota in the process of SBDS and contribute a theoretical basis for the feasibility of microecological preparation as a method to control SBDS.

Seed-Bird co-occurrence networks in cocoa agroforests: Morphological matching analysis reveals shading effects on network organization

Tropical forests are highly vulnerable to ongoing deforestation, which often involves converting land for agricultural use. While tropical agroforests have been promoted as wildlife-friendly systems, limited information is available on the ability of agroforests to provide diverse fruits that attract birds and thus contribute to essential ecological processes, such as seed dispersal. Here, we evaluated the organization of tropical seed-bird co-occurrence networks in cocoa agroforests of the Brazilian Atlantic Forest. Specifically, we investigated the influence of (i) landscape and local predictors in shaping the structure of seed-bird co-occurrence networks; and (ii) species traits in explaining their interactive role in the networks. We constructed matrices of presence-absence interactions based on morphological matching among the beak width of frugivorous bird species and the size of ornithochorous seed species (both native and exotic species), using field data of seed rain and understory bird surveys from 15 cocoa agroforests. We further evaluated both the effects of landscape forest cover and local shading on five network indices and how functional traits of birds and seeds explain their importance to the network. In total, we obtained 467 events of potential plant-bird interactions, which revealed a modular pattern. We also observed that only canopy shading significantly affected network connectance, and seed diameter was a significant predictor in explaining tree species contribution in the network. Therefore, our findings show that cocoa agroforests with greater shading will have greater opportunities for interactions between frugivorous birds and plants. We also observed that plants with small seeds play a more relevant role in the co-occurrence interaction network. Based on findings, we emphasized that cocoa agroforests likely maintain certain mutualistic relationships to ensure ecosystem functionality and demonstrate that co-occurrence networks have great potential for future seed dispersal networks in agricultural ecosystems.

Morphometric Analysis and Interrelationship of Seven Indonesian Hornbill Species (Aves, Bucerotidae) Utilizing Principal Component and Cluster Analyses

In this comprehensive study, we examined 15 distinct morphometric characteristics within seven Indonesian hornbill species. Precise measurements of these morphometric traits were obtained using 0.1 mm calipers and a 1000 mm measuring tape. Our analysis encompassed a total of 85 individuals representing seven hornbill species: Anthracoceros albirostris (18 individuals), A. malayanus (4 individuals), Aceros cassidix (3 individuals), Rhyticeros plicatus (7 individuals), R. undulatus (36 individuals), Buceros bicornis (1 individual), and B. rhinoceros (16 individuals). To elucidate the morphometric ratio data, we employed a robust analytical approach involving the Principal Component Analysis (PCA), Discriminant Analysis, and Cluster Analysis. Our findings underscored a clear separation between hornbill genera, primarily attributed to a combination of PC1 (pertaining to body length) and PC3 (associated with beak morphology). Key morphometric traits that delineated these genera on PC1 included tail length, beak length, horn length, total length, and wing length. Meanwhile, on PC3 (characterizing beak morphology), the distinguishing features encompassed beak width, horn width, and tarsus length. Additionally, our analysis unveiled the characteristics that distinguish species within the genera Anthracoceros and Rhyticeros to be a composite of tail length and head length. This discerning morphometric data facilitated the clustering of seven hornbill species into two distinct groups: Group I comprised A. albirostris and A. malayanus, while Group II included R. plicatus, R. undulatus, A. cassidix, B. rhinoceros, and B. bicornis. Notably, these groups exhibited a 31.93% degree of similarity. This dataset holds immense potential for facilitating genetic classification and comparative studies of Indonesian hornbills.

MORPHOMETRIC TRAITS AND THEIR ASSOCIATION WITH SEX IN THE KEEL-BILLED TOUCAN RAMPHASTOS SULFURATUS

Sexing monomorphic birds is essential for reproduction in conservation programs. In ramphastids (toucans) species, males have longer beaks than females, making beak morphometry potentially useful for sexing. In this study, we measured the following traits: curved beak length, total culmen length, straight beak length, curved and straight length of the ventral line of the gnathotheca, beak width, lateral area of the rhinotheca, and cloacal opening in 44 Keel-billed Toucans, as well as previously reported morphometric data from 17 additional individuals. Measurements were obtained using two methods (manual and image processing software), and the reliability between the two methods was assessed using the intraclass correlation coefficient (ICC). Individuals of unknown sex were sexed via PCR tests. The ICC showed poor reliability between the two measurement methods, so we only used manual measurements for comparisons between the sexes. We used GLMMs to determine whether the morphometric traits we measured could be used to determine sex in keel-billed toucans. In addition, we evaluated GLMMs to determine which morphometric trait was the strongest predictor of sex in this species. Beak length was longer in adult males than in females. The GLMMs indicated that beak traits associated with sex in this species are beak curved length, beak straight length, straight length of the ventral line of the gnathotheca, and total culmen length. The straight length of the ventral line of the gnathotheca was the strongest predictor of sex in the Keel-billed Toucan. Unlike previous research, the development of GLMMs allows us to determine the probability of a toucan’s sex based on continuous variables, facilitating sexing and allowing us to evaluate the reliability of the estimation of the sexing of each toucan. This method is an alternative for situations where other sexing methodologies cannot be performed.

Measurement of some body parts of muscovy duck (Carina moschata) at age 3 weeks old fed by pellet feed under an intensive farming system

This study was aimed to measure and determine the size of some body parts of the muscovy duck (Carina moschata) and their relationship with body weight. The research was be carried out for two months from August to September 2023 in local Intensive Muscovy Duck farm, Kademangan area, Blitar, East Java. The research material use were 60 muscovy ducks (unsexed), aged 3 weeks old, and reared in intensive farming system. This study used experiment quantitative methods (measurement). Muscovy duck sampling was carried out by random sampling. The variables observed were body weight, beak length, beak width, head length, head circumference, neck length, neck circumference, wing length, back length, chest length, chest width, shank length, shank circumference, and leg membrane width. Measurements were made on each individual using a measuring tape. The data obtained were tabulated and analyzed using normality test, correlation test and regression test. The results showed that there is a positive correlation between the morphological dimensions of livestock, including membrane width, shank length, beak width, wing length, head width, head length, neck length, shank circumference, beak length, breast length, breast width, neck circumference, back length, and body weight. And the length of the back has the largest contribution of 54% to the body weight of muscovy ducks (Carina moschata) aged 3 weeks old.

Fast‐paced city life? Tempo and mode of phenotypic changes in urban birds from Switzerland

Humans' large influence on the environment has constructed many new ecological niches, such as in urban areas. Phenotypic changes, including morphological ones related to human influence, are known from a small number of bird species. The amount of change in a given time period, that is, the rate of change, may vary. Rates of change (both evolutionary and through phenotypic plasticity) are reportedly rapid in human-influenced settings, although this is disputed. We present new data on changes in beak dimensions and rates of change over historical time periods in four urban bird species (Common Chaffinch, European Greenfinch, Eurasian Blackbird, House Sparrow) from three Swiss cities (Basel, Bern, Geneva). Our study shows that beak dimensions have changed little in most investigated urban bird populations over the past century. Only in Genevan Blackbirds there was evidence for an increase in beak length over the past 65 years; Bernese Chaffinches appear to be trending toward a decrease in beak width over the past 55 years. Rates of change in our sample in comparison with literature records showed that compared to populations less influenced by humans, urban evolutionary rates appear to be similar. Although in accordance with previous findings about other urban bird species, our study exemplifies the difficulty to find universal patterns in tempo and mode of phenotypic evolution in urban areas, even when considering the same taxa. Our data contribute to the expanding field of urban evolutionary biology, which is particularly important regarding the growing urban habitats worldwide.

Morphological characterization and the significance of sexual differences in size among Lipochromic Mosaic Canary bird raised in the Wilaya of Tlemcen Northwest of Algeria

The lipochromic mosaic canary is a cage bird breed present with different coat colors, red, and yellow, this breed presents a significant sexual dichromatism. Dichromatism in lipochromic mosaic canaries is explained by differential carotenoid degradation in the integument, rather than sex-specific variation in physiological functions such as pigment uptake or transport. Males have an intense color compared to females and especially at the shoulders and head. We studied sexual size dimorphism (SSD) because this study aimed to investigate whether gender has an impact on thirteen body measurements which are (Head Length, Head Width, Distance Between the Eyes, Beak Length, Beak Width, Chest Circumference, Body Length, Body Width, Wing Length, Sternum Length, Upper Tarsus Length, Lower Tarsus Length, and Tail Length) in 40 native lipochromic mosaic canaries (19 males and 21 females) raised in the Wilaya of Tlemcen Northwest of Algeria. The results showed that there were differences between genders for three characters that are CC (Chest Circumference), BL (Body Length), and WL (Wing Length). Males had more developed measurable traits than females.

Beyaz ve Kahverengi Varyetelerine Göre Japon Bıldırcın’larının (Coturnix coturnix japonica) Canlı Ağırlık ve Zoometrik Yapılarının Belirlenmesi

This study was carried out to determine some zoometric measurements and body weights in two different varieties of Japanese Quail (Coturnix coturnix japonica), white and brown. For this purpose, live weights and variables of twelve different body measurements were evaluated in 30 white and brown varieties (15 males, 15 females), a total of 60 six-week-old quails housed under the same nutritional and environmental conditions. Although higher values were obtained in terms of average body weights at six weeks of age compared to many of the literature reports, there was no difference in terms of the two-color varieties compared in this study, while females were found to be significantly heavier than males. While white quails had higher values than brown ones in terms of head width, beak width, beak length, sternum length, tarsus length and wing length, females had higher values in live weight, body length, chest circumference and tarsus diameter variables according to gender. Positive correlations were found between body weights of six-week-old Japanese quails and the variables of skull length, body length, sternum length, middle finger length, wing length, chest circumference and tarsus diameter. Considering the fact that the consumption of quail will increase for the spread of quail breeding, it can be recommended to carry out more comprehensive studies on the factors that will enable people to prefer quail in nutrition.

Identification of polymorphic loci in the deiodinase 2 gene and their associations with head dimensions in geese.

ObjectiveThis study was conducted to clone and compare the molecular characteristics of the deiodinase 2 (DIO2) gene between Sichuan White geese and Landes geese, and to analyze the association between polymorphisms of the DIO2 gene and head dimensions in Tianfu meat geese.MethodsThe coding sequence of the DIO2 gene was cloned by polymerase chain reaction and vector ligation and aligned by DNAMAN software. A total of 350 Tianfu meat geese were used to genotype the polymorphisms of the DIO2 gene and measure the head dimensions. Association analysis between the polymorphisms of the DIO2 gene and head dimensions was carried out.ResultsAn 840-bp coding sequence of the DIO2 gene was obtained and comparison analysis identified four polymorphic loci between Sichuan White geese and Landes geese. Further analysis showed that the dominant alleles for the four polymorphic loci were G, G, A, and T and the frequency of the heterozygous genotype was higher than that of the homozygous genotype in Tianfu meat geese. Compared to that in the population of non-knob geese of Tianfu meat geese, the head dimensions in the population of knob geese were significantly higher except for nostril height. However, in the non-knob geese, beak width 1, beak width 2, nostril length, cranial width 1, and maxillary length had significant differences among different genotypes or haplotypes/diplotypes.ConclusionThese results suggested that polymorphisms of the DIO2 gene could be considered molecular markers to select larger heads of geese in the population of non-knob geese.

Automated Bird Species Recognition System Based on Image Processing and Svm Classifier

Here, in this study we can learn about Bird species recognition. In forest areas cameras are fixed at various locations which capture images periodically. From those images the birds living in such dense forest areas can be identified. It would be useful if we can able to classify the species of birds with the help of those images. But that is not an easy task because of the variations in the light effects, illumination and camera viewpoints. So we need to involve image processing techniques for preprocessing the captured image and also deep learning techniques are to be implemented for classifying the images. For classification purpose training is to be done with the help of image data set. Here we propose a method of discriminating birds by means of the ratio of the distance between eye and beak to that of the beak width. By combining this mythology with image processing and SVM classification technique a new bird species recognition algorithm is proposed. The proposed new methodology will improve the accuracy in classifying.

Growth Patterns, Body Weight, and Morphometric of KUB Chicken, Sentul Chicken and Arab Chicken

The purpose of this research was to determine the body weight, weight gain and morphometric characteristics of several local chicken strains. The research materials were KUB chicken, Sentul chicken, and Arab chicken. The method used was an experiment with a sample of 82 chickens from each strain. Data collected include body weight, weight gain, beak length, beak width, head length, head circumference, head height, neck length, neck circumference, wing length, back length, back height, chest length, chest width, shank length, shank circumference, tibia length, tibia circumference, third finger length, and pubic bone distance. Data collected were analyzed using the average difference test (t-test). The average value vector of body measurements of chicken lines was analyzed using the T²-Hotelling statistical test. Main Component Analysis statistical test was used to identify the shape and size characteristics of each chicken strain. The results showed that the body weight and morphometrics of KUB chickens at 3 months were significantly different (P<0.05) with Sentul chickens and Arab chickens. KUB chicken`s body weight gain at 3 months was not significantly different (P>0.05) from Sentul chickens, but it was significantly different (P<0.05) from Arab chickens. Body weight, weight gain, and morphometrics of KUB chickens were higher than Sentul chickens and Arab chickens. The size indicator in KUB chickens was the tibia length while in Sentul chickens and Arab chickens was chest length. The characteristic of KUB chickens was the back length, Sentul chickens was tibia length, and Arab chickens was the shank circumference.

Beak morphology predicts apparent survival of crossbills: due to selective survival or selective dispersal?

Dozens of morphologically differentiated populations, subspecies and species of crossbills (genus Loxia) exist. It has been suggested that this divergence is due to variation in the conifer cones that each population specialises upon, requiring a specific beak size to efficiently separate the cone scales. If so, apparent survival should depend on beak size. To test this hypothesis, we undertook multievent capture–recapture modelling for 6844 individuals monitored during 27 years in a Pyrenean common crossbill L. curvirostra population in a forest of mountain pine Pinus uncinata. Apparent survival was indeed related to beak width, resulting in stabilizing selection around an optimum that was close to the observed mean beak width, indicating that local crossbill beak morphology is adapted to the conifer they feed upon. Both natural selection (selective mortality) and selective emigration of maladapted individuals may explain our findings. As is often the case in capture–recapture analyses but rarely recognised, we could not formally decompose apparent survival into selective mortality versus selective permanent emigration. Nonetheless, there are several indications that selective permanent emigration should not be fully excluded. First, natural selection by itself would have to be unusually strong compared to other empirical estimates to create the observed pattern of apparent survival. Second, the observed mean beak width was a bit lower than the estimated optimum beak width. This can be explained by immigration of crossbills with smaller beaks originating from southern populations, which may subsequently have left the study area permanently in response to low food intake. This is in line with a detected transient effect in the data, yet apparently little influx from crossbills from northern Europe. When permanent emigration is phenotypically selective this will have ecological and evolutionary consequences, so this possibility deserves more attention in general.

Phenotypic characterization of local female duck populations in Indonesia

Information on phenotypic traits is a prerequisite in animal genetic resource conservation and improvement. Phenotypic characteristics of 180 Indonesian female ducks collected from six populations (Alabio, Bayang, Magelang, Pegagan, Pitalah, and Rambon ducks) were studied. Data on qualitative traits were analyzed with descriptive statistics (percentages), while one-way analysis of variance was used to analyze the effect of populations on quantitative traits observed. The results revealed that the predominant plumage colors of the neck, breast, abdomen, back, secondary wings, primary wings, and thigh were brown (49.74%), brown (34.03%), brown (31.94%), brown (50.26%), dark brown (25.13%), light brown (35.08%), and brown (31.94%), respectively. The dominant bill and web color were black (77.49%) and dark brown (48.17), respectively. Variations were also found in quantitative morphological traits. The principal component analysis showed two to four principal components extracted from the factor analysis with varimax rotation, which accounted for 57.33%, 66.26%, 64.43%, 54.66%, and 77.44% of the total variance in the original variables for Alabio, Magelang, Pegagan, Pitalah, and Rambon ducks, respectively. Generally, the first factor in each population had high loadings on beak width. The observed phenotypic diversity in Indonesian local ducks could be useful in designing breeding programs and selection.

Repeated evolution of drag reduction at the air-water interface in diving kingfishers.

Piscivorous birds have a unique suite of adaptations to forage under the water. One method aerial birds use to catch fish is the plunge dive, wherein birds dive from a height to overcome drag and buoyancy in the water. The kingfishers are a well-known clade that contains both terrestrially foraging and plunge-diving species, allowing us to test for morphological and performance differences between foraging guilds in an evolutionary context. Diving species have narrower bills in the dorsoventral and sagittal plane and longer bills (size-corrected data, n = 71 species, p < 0.01 for all). Although these differences are confounded by phylogeny (phylogenetically corrected ANOVA for dorsoventral p = 0.26 and length p = 0.14), beak width in the sagittal plane remains statistically different ( p < 0.001). We examined the effects of beak morphology on plunge performance by physically simulating dives with three-dimensional printed models of beaks coupled with an accelerometer, and through computational fluid dynamics (CFD). From physically simulated dives of bill models, diving species have lower peak decelerations, and thus enter the water more quickly, than terrestrial and mixed-foraging species (ANOVA p = 0.002), and this result remains unaffected by phylogeny (phylogenetically corrected ANOVA p = 0.05). CFD analyses confirm these trends in three representative species and indicate that the morphology between the beak and head is a key site for reducing drag in aquatic species.

Structural variations and their adaptive significances in the bones of some migratory and resident birds

We investigated variations in the shape and size of some bones and their adaptive significances in both sexes of the migratory yellow breasted bunting (Emberiza aureola Pallas, 1773) and resident house sparrow (Passer domesticus Linnaeus, 1758) and tree sparrow (Passer montanus Linnaeus, 1758). Measurements of the large bones like skull, beak, orbit, sternum, coracoid, scapula, femur, tibiotarsus, humerus and metatarsus were recorded to find out variations in their measurements. The skull, cranial and sternum indices were also calculated. An attempt was also made to correlate the structural differences of these bones between migratory and nonmigratory species and also between sexes with their adaptive significances. Principal component analysis indicated 84.79% of the total variance. Discriminant function analysis shows distinct separation in the bone lengths between the resident and migratory birds while there was little overlap between the sexes. The proportion of original grouped cases correctly classified was found to be 95.0%. Migratory bunting showed significantly longer sternum, tibiotarsus, femur and humerus beside a higher sternum when compared to those of resident sparrows. On the other hand, beak width, sternum width and indices of cranium and sternum, were more in resident sparrows. Thus, our studied birds seem to possess species specific adaptations by modifying their bones to fit their modes of living and conditions for better endurance and performance.

Morphometric measurements permit accurate sexing of three species of Mesoamerican ground-sparrow (Genus: Melozone)

The natural history of many tropical bird species is poorly described, preventing more detailed studies of ecology, behavior, and evolution. For most sexually monochromatic tropical bird species, we lack field methodologies to categorize the sex of adults. In this study, we describe sex-based morphological differences of three monochromatic species in the genus Melozone White-eared Ground-Sparrow, M. leucotis; Prevost's Ground-Sparrow, M. biarcuata; and Rusty-crowned Ground-Sparrow, M. kieneri. We collected six standard morphological measurements (tarsus length, tail length, wing chord length, culmen length, beak width, and beak depth) from live birds and museum specimens. We collected data from all recognized subspecies of the three Mesoamerican Melozone species. Morphological measurements capably distinguished males from females in all three species. In all cases, three or fewer morphological measurements were required to identify sex with accuracy levels that ranged from 75–100%, well beyond the 50% expected by chance. Comparisons involving all six measurements yielded accuracies that ranged from 58–93%. Our results provide the first field-based method for estimating the sex of individuals in this poorly studied genus of tropical birds. We recommend our findings be used to distinguish males from females in banding stations where Melozone ground-sparrow species occur.

QTL and quantitative genetic analysis of beak morphology reveals patterns of standing genetic variation in an Estrildid finch

The intra- and interspecific diversity of avian beak morphologies is one of the most compelling examples for the power of natural selection acting on a morphological trait. The development and diversification of the beak have also become a textbook example for evolutionary developmental biology, and variation in expression levels of several genes is known to causally affect beak shape. However, until now, no genomic polymorphisms have been identified, which are related to beak morphology in birds. QTL mapping does reveal the location of causal polymorphisms, albeit with poor spatial resolution. Here, we estimate heritability and genetic correlations for beak length, depth and width and perform a QTL linkage analysis for these traits based on 1404 informative single-nucleotide polymorphisms genotyped in a four-generation pedigree of 992 captive zebra finches (Taeniopygia guttata). Beak size, relative to body size, was sexually dimorphic (larger in males). Heritability estimates ranged from 0.47 for beak length to 0.74 for beak width. QTL mapping revealed four to five regions of significant or suggestive genome-wide linkage for each of the three beak dimensions (nine different regions in total). Eight out of 11 genes known to influence beak morphology are located in these nine peak regions. Five QTL do not cover known candidates demonstrating that yet unknown genes or regulatory elements may influence beak morphology in the zebra finch.

The secondary contact phase of allopatric speciation in Darwin's finches.

Speciation, the process by which two species form from one, involves the development of reproductive isolation of two divergent lineages. Here, we report the establishment and persistence of a reproductively isolated population of Darwin's finches on the small Galápagos Island of Daphne Major in the secondary contact phase of speciation. In 1981, an immigrant medium ground finch (Geospiza fortis) arrived on the island. It was unusually large, especially in beak width, sang an unusual song, and carried some Geospiza scandens alleles. We followed the fate of this individual and its descendants for seven generations over a period of 28 years. In the fourth generation, after a severe drought, the lineage was reduced to a single brother and sister, who bred with each other. From then on this lineage, inheriting unusual song, morphology, and a uniquely homozygous marker allele, was reproductively isolated, because their own descendants bred with each other and with no other member of the resident G. fortis population. These observations agree with some expectations of an ecological theory of speciation in that a barrier to interbreeding arises as a correlated effect of adaptive divergence in morphology. However, the important, culturally transmitted, song component of the barrier appears to have arisen by chance through an initial imperfect copying of local song by the immigrant. The study reveals additional stochastic elements of speciation, in which divergence is initiated in allopatry; immigration to a new area of a single male hybrid and initial breeding with a rare hybrid female.

First Report of Diaporthe phaseolorum var. meridionalis on Soybean Seeds from Ghana.

Fifty-nine soybean samples (Glycine max) of various varieties, grown in various agro-ecological zones of Ghana, and harvested in 1995 and 1996, were collected during May through June 1996 and sent to Denmark for analysis. Seed samples were analyzed by the blotter method: seeds were placed on three layers of moistened blotter paper in petri dishes, 10 seeds per dish, 200 or 400 seeds per sample. The seeds were incubated for 7 days at 22 ± 2°C, exposed to alternating cycles of 12 h NUV-light and 12 h darkness. Subsequently, they were analyzed microscopically for fungal infection. Phomopsis spp. were detected in 68% of the samples, at infection levels ranging from 0.25 to 21.0% (mean 3.4%). One to five isolates of Phomopsis spp. were selected at random and cultured on potato dextrose agar acidified to pH 4.5 with 90% lactic acid (APDA) for identification to species. Isolates were cultured on APDA, with and without sterile soybean stem pieces, under either NUV-light/darkness or artificial daylight/darkness cycles. Of 103 isolates, 101 isolates produced only pycnidia and were identified as P. longicolla T. W. Hobbs based on the production of aggregated pycnidia with prominent beaks (2). Seventy-seven of these isolates produced only alpha conidia whereas 24 isolates produced both alpha and beta conidia, which differs from the description by Hobbs et al. (2). Two isolates from one seed sample produced perithecia but no pycnidia. Perithecia were evenly scattered in the colony, 200 to 350 × 250 to 400 μm, and had a beak of 900 to 1500 μm. Apical beak width was 60 to 110 μm, basal beak width 70 to 120 μm. Asci were 25.0 to 37.5 × 5.0 to 7.5 μm. Ascospores were two-celled, biguttulate in each cell, and 10.0 to 12.5 × 2.5 to 4.0 μm. Based on the description by Fernández and Hanlin (1), these isolates were identified as Diaporthe phaseolorum (Cooke & Ellis) Sacc. var. meridionalis Fernández (DPM), the causal agent of southern stem canker of soybean, which has not previously been reported from any African country. Ten 14-day-old soybean seedlings were inoculated with an isolate identified as DPM by the toothpick method (3) and two seedlings inoculated with sterile toothpicks served as controls. Local expanding lesions formed after 1 week on all plants at the point of inoculation with DPM; 2 weeks after inoculation, the pathogen was reisolated from all lesions by plating stem pieces, surface sterilized in 1% NaOCl, on APDA. In control plants no lesions were seen and no mycelial growth occurred from stem pieces plated on APDA.

Quantitative trait and allozyme divergence in the Greenfinch (Carduelis chloris, Aves: Fringillidae)

Quantitative trait divergence and variability among 12 greenfinch populations across continental Europe was examined and compared to divergence in neutral genetic markers (allozymes). The added among locality variance component for 16 skeletal traits was large (mean 28%, range 4–48%) equalling a divergence of up to three SD units. The divergence in quantitative traits (Qst = 0.04-0.48) greatly exceeded that in alloymes (FST= 0.01-0.07), indicating the differentiation in quantitative traits to be larger than expected by mutation and drift alone. This conclusion was consistent also with results from the multivariate approach of Rogers & Harpending. However, genetic and morphometric distances between populations were positively correlated, even when controlling for the geographic distance separating pairs of populations. In concordance with Bergmann's rule, most traits were strongly and positively correlated with latitude, indicating latitudinally ordered genetic or/and environmental effects. However, the correlation between lower mandible width and latitude was strongly negative, demonstrating an inverse relationship between beak size and body size across the populations. These results are interpreted to reflect the re-colonization of history of northern Europe (genetic and geographic distances correlated) which has been paralleled by selection acting on quantitative traits (QST>FST)- In particular, the counter-gradient variation in beak width, a functionally important trait, is suggestive of an adaptive basis for quantitative trait divergence.