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Museum Specimens (museum + specimen)
Selected AbstractsMUSEUM SPECIMENS AND PHYLOGENIES ELUCIDATE ECOLOGY'S ROLE IN COEVOLUTIONARY ASSOCIATIONS BETWEEN MITES AND THEIR BEE HOSTSEVOLUTION, Issue 6 2007Pavel B. Klimov Coevolutionary associations between hosts and symbionts (or parasites) are often reflected in correlated patterns of divergence as a consequence of limitations on dispersal and establishment on new hosts. Here we show that a phylogenetic correlation is observed between chaetodactylid mites and their hosts, the long-tongued bees; however, this association manifests itself in an atypical fashion. Recently derived mites tend to be associated with basal bee lineages, and vice versa, ruling out a process of cospeciation, and the existence of mites on multiple hosts also suggests ample opportunity for host shifts. An extensive survey of museum collections reveals a pattern of infrequent host shifts at a higher taxonomic level, and yet, frequent shifts at a lower level, which suggests that ecological constraints structure the coevolutionary history of the mites and bees. Certain bee traits, particularly aspects of their nesting behavior, provide a highly predictive framework for the observed pattern of host use, with 82.1% of taxa correctly classified. Thus, the museum survey and phylogenetic analyses provide a unique window into the central role ecology plays in this coevolutionary association. This role is apparent from two different perspectives,as (a) a constraining force evident in the historical processes underlying the significant correlation between the mite and bee phylogenies, as well as (b) by the highly nonrandom composition of bee taxa that serve as hosts to chaetodactylid mites. [source] Converse Bergmann cline in a Eucalyptus herbivore, Paropsis atomaria Olivier (Coleoptera: Chrysomelidae): phenotypic plasticity or local adaptation?GLOBAL ECOLOGY, Issue 3 2008Mark K. Schutze ABSTRACT Aim, To measure latitude-related body size variation in field-collected Paropsis atomaria Olivier (Coleoptera: Chrysomelidae) individuals and to conduct common-garden experiments to determine whether such variation is due to phenotypic plasticity or local adaptation. Location, Four collection sites from the east coast of Australia were selected for our present field collections: Canberra (latitude 35°19, S), Bangalow (latitude 28°43, S), Beerburrum (latitude 26°58, S) and Lowmead (latitude 24°29, S). Museum specimens collected over the past 100 years and covering the same geographical area as the present field collections came from one state, one national and one private collection. Methods, Body size (pronotum width) was measured for 118 field-collected beetles and 302 specimens from collections. We then reared larvae from the latitudinal extremes (Canberra and Lowmead) to determine whether the size cline was the result of phenotypic plasticity or evolved differences (= local adaptation) between sites. Results, Beetles decreased in size with increasing latitude, representing a converse Bergmann cline. A decrease in developmental temperature produced larger adults for both Lowmead (low latitude) and Canberra (high latitude) individuals, and those from Lowmead were larger than those from Canberra when reared under identical conditions. Main conclusions, The converse Bergmann cline in P. atomaria is likely to be the result of local adaptation to season length. [source] Field sampling bias, museum collections and completeness of the fossil recordLETHAIA, Issue 4 2005AARON HUNTER Museum specimens, particularly old collections, typically lack comprehensive field data and determination of substrate, sampling biases, etc., is problematic. Diversity at the generic level of all identifiable latest Cretaceous (Campanian,Maastrichtian) echinoderm remains in major museum collections from the Mons (southern Belgium) and Danish (Jylland (Jutland) and Sjælland (Zealand)) basins were compared to those of the Liège-Limburg Basin. The last-named has been studied in detail, including microscopical analysis of ossicles picked from bulk samples. Echinoids of the Mons Basin show similarities to those of the Liège-Limburg Basin, but crinoids, asteroids and ophiuroids remain poorly known from the former. Echinoderms of the Danish Basin resemble those of similar chalk lithofacies in the Liège-Limburg Basin, despite significant geographical separation. These disparities can be explained, at least in part, by collector bias in sampling methodology, although differences in substrate presumably also had an influence. [source] Museum specimens reveal changes in the population structure of northern Fennoscandian domestic reindeer in the past one hundred yearsANIMAL GENETICS, Issue 3 2010G. Bjørnstad Summary Traditional reindeer herding of northern Fennoscandia has been based on seasonal movements independent of national borders. At the beginning of the 19th century, these yearly movements of reindeer were excessive, but during that century the borders between the Fennoscandian countries were closed. By analysing a 190-base pair fragment of the mitochondrial DNA control region in 79 museum samples, we show that the reindeer of northern Fennoscandia were one homogenous population shortly after the national borders were closed. However, anthropogenic activity has effectively ended genetic exchange within northern Fennoscandia and has made the reindeer population within this region heterogeneous. Genetic input of eastern origin is also suggested within the extant Russian reindeer of the Kola Peninsula. [source] Evaluating the Predicted Local Extinction of a Once-Common MouseCONSERVATION BIOLOGY, Issue 4 2005OLIVER R.W. PERGAMS Chicago; declinación de especies comunes; extinción pronosticada; Peromyscus leucopus; Peromyscus maniculatus bairdii Abstract:,In an earlier paper (Pergams & Nyberg 2001) we found that the proportion of the prairie deer mouse (Peromyscus maniculatus bairdii), among all local Peromyscus museum specimens collected in the Chicago region, had significantly declined over time. This proportion changed from about 50% before 1900 to <10% in the last 25 years. Based on this proportion a regression model predicted the local extinction of the prairie deer mouse in 2009. To evaluate that prediction, we estimated current deer mouse abundance by live trapping small mammals at 15 preserves in Cook and Lake counties, Illinois (USA) at which prairie deer mice had previously been caught or that still contained their preferred open habitat. In 1900 trap nights, 477 mammals were caught, including 251 white-footed mice (P. leucopus), but only one prairie deer mouse. The observed proportion of Peromyscus that were prairie deer mice, 0.4%, was even lower than the 4.5% predicted for 2000. Here we also introduce a simple, new community proportions model, which for any given geographic region compares the proportions of species recently caught with the proportions of species in museums. We compared proportions of seven species collected in Cook and Lake counties and examined by Hoffmeister (1989) with proportions of these species that we caught. Ten percent of the museum community was prairie deer mice, but only 0.2% of our catch was. The current local scarcity of the prairie deer mouse is consistent with the regression-based prediction of its eminent local extinction. More conservation attention should be paid to changes in relative abundance of once-common species. Resumen:,En un artículo previo (Pergams & Nyberg 2001) encontramos que la proporción de Peromyscus maniculatus bairdii, entre todos los especimenes de museo de Peromyscus recolectados en la región de Chicago, había declinado significativamente. Esta proporción cambió de 50% antes de 1900 a <10% en los últimos 25 años. Con base en esta proporción, un modelo de regresión pronosticó la extinción local de P. m. bairdii en 2009. Para evaluar esa predicción, estimamos la abundancia actual de P. m. bairdii mediante el trampeo de mamíferos pequeños en 25 reservas en los condados Cook y Lake, Illinois (E.U.A.) en las que se había capturado a P. m. bairdii previamente o que aun contenían su hábitat abierto preferido. En 1900 noches-trampa, capturamos a 477 mamíferos, incluyendo a 251 P. leucopus pero solo a un P. m. bairdii. La proporción observada de P. m. bairdii, 0.4%, fue menor a 4.5% pronosticado para 2000. Aquí también introducimos un modelo, nuevo y sencillo, de proporciones de la comunidad que compara, para cualquier región geográfica, las proporciones de especies recientemente capturadas con la proporciones de especies en los museos. Comparamos las proporciones de siete especies recolectadas en los condados Cook y Lake y examinadas por Hoffmeister (1989) con las proporciones de especies que capturamos. Diez por ciento de la comunidad de museos era P. m. bairdii, pero solo 0.2% de nuestra muestra lo fue. La actual escasez local de P. m. bairdii es consistente con la predicción de su inminente extinción local con base en la regresión. La conservación debe prestar mayor atención a los cambios en la abundancia relativa de una especie anteriormente común. [source] Significance of Specimen Databases from Taxonomic Revisions for Estimating and Mapping the Global Species Diversity of Invertebrates and Repatriating Reliable Specimen DataCONSERVATION BIOLOGY, Issue 2 2004RUDOLF MEIER More specifically, we demonstrate for a specimen database assembled during a revision of the robber-fly genus Euscelidia (Asilidae, Diptera) how nonparametric species richness estimators (Chao1, incidence-based coverage estimator, second-order jackknife) can be used to (1) estimate global species diversity, (2) direct future collecting to areas that are undersampled and/or likely to be rich in new species, and (3) assess whether the plant-based global biodiversity hotspots of Myers et al. (2000) contain a significant proportion of invertebrates. During the revision of Euscelidia, the number of known species more than doubled, but estimation of species richness revealed that the true diversity of the genus was likely twice as high. The same techniques applied to subsamples of the data indicated that much of the unknown diversity will be found in the Oriental region. Assessing the validity of biodiversity hotspots for invertebrates is a formidable challenge because it is difficult to decide whether species are hotspot endemics, and lists of observed species dramatically underestimate true diversity. Lastly, conservation biologists need a specimen database analogous to GenBank for collecting specimen records. Such a database has a three-fold advantage over information obtained from digitized museum collections: (1) it is shown for Euscelidia that a large proportion of unrevised museum specimens are misidentified; (2) only the specimen lists in revisionary studies cover a wide variety of private and public collections; and (3) obtaining specimen records from revisions is cost-effective. Resumen:,Sostuvimos que los millones de registros de especimenes publicados en miles de revisiones taxonómicas en décadas anteriores son una fuente de información costo-efectiva de importancia crítica para la incorporación de invertebrados en decisiones de investigación y conservación. Más específicamente, para una base de datos de especimenes de moscas del género Euscelidia (Asilidae, Diptera) demostramos como se pueden utilizar estimadores no paramétricos de riqueza de especies (Chao 1, estimador de cobertura basado en incidencia, navaja de segundo orden) para (1) estimar la diversidad global de especies, (2) dirigir colecciones futuras a áreas que están sub-muestreadas y/o probablemente tengan especies nuevas y (3) evaluar si los sitios globales de importancia para la biodiversidad basados en plantas de Myers et al. (2000) contienen una proporción significativa de invertebrados. Durante la revisión de Euscelidia el número de especies conocidas fue más del doble, pero la estimación de riqueza de especies reveló que la diversidad real del género probablemente también era el doble. Las mismas técnicas aplicadas a las sub-muestras de datos indicaron que gran parte de la diversidad no conocida se encontrará en la Región Oriental. La evaluación de la validez de sitios de importancia para la biodiversidad de invertebrados es un reto formidable porque es difícil decidir si las especies son endémicas de esos sitios y si las listas de especies observadas subestiman dramáticamente la diversidad real. Finalmente, los biólogos de la conservación requieren de una base de datos de especimenes análoga a GenBank, para obtener registros de especimenes. Dicha base de datos tiene una triple ventaja sobre la información obtenida de colecciones de museos digitalizadas. (1) Se muestra para Euscelidia que una gran proporción de especimenes de museo no revisados están mal identificados. (2) Sólo las listas de especimenes en estudios de revisión cubren una amplia variedad de colecciones privadas y públicas. (3) La obtención de registros en revisiones es costo-efectiva. [source] A new dimension in combining data?ACTA ZOOLOGICA, Issue 1 2010The use of morphology, phylogenomic data in metazoan systematics Abstract Giribet, G. 2010. A new dimension in combining data? The use of morphology and phylogenomic data in metazoan systematics. ,Acta Zoologica (Stockholm) 91: 11,19 Animal phylogenies have been traditionally inferred by using the character state information derived from the observation of a diverse array of morphological and anatomical features, but the incorporation of molecular data into the toolkit of phylogenetic characters has shifted drastically the way researchers infer phylogenies. A main reason for this is the ease at which molecular data can be obtained, compared to, e.g., traditional histological and microscopical techniques. Researchers now routinely use genomic data for reconstructing relationships among animal phyla (using whole genomes or Expressed Sequence Tags) but the amount of morphological data available to study the same phylogenetic patterns has not grown accordingly. Given the disparity between the amounts of molecular and morphological data, some authors have questioned entire morphological programs. In this review I discuss issues related to the combinability of genomic and morphological data, the informativeness of each set of characters, and conclude with a discussion of how morphology could be made scalable by utilizing new techniques that allow for non-intrusive examination of large amounts of preserved museum specimens. Morphology should therefore remains a strong field in evolutionary and comparative biology, as it continues to provide information for inferring phylogenetic patterns, is an important complement for the patterns derived from the molecular data, and it is the common nexus that allows studying fossil taxa with large data sets of molecular data. [source] Feather deuterium measurements reveal origins of migratory western loggerhead shrikes (Lanius ludovicianus excubitorides) wintering in MexicoDIVERSITY AND DISTRIBUTIONS, Issue 2 2007Guillermo E. Pérez ABSTRACT Understanding the winter distributions of migrant birds is important because productivity and recruitment are influenced by conditions at several locations and periods in the life cycle of individuals. The western loggerhead shrike, Lanius ludovicianus excubitorides, is a threatened species in Canada, and its decline is attributed to potential limitations on the wintering grounds. We examined patterns of stable-hydrogen isotope (,D) distributions in feathers of loggerhead shrikes, primarily of L. l. excubitorides, during winter at three regions in north and central Mexico, to establish relative abundance and origins of migrants. We also investigated potential movements of Mexican winter resident individuals. Using shrike museum specimens of known summer provenance, a shrike deuterium base map for Mexico was developed from isotopic measurement of feathers of resident shrikes and use of a recently established feather base map for raptors in North America. Stable hydrogen isotope analyses of inner secondary feather (s9) of all loggerhead shrikes examined in Mexico during winter indicated that north-central (Region A), north-eastern (Region B) and south-central (Region C) sites in Mexico consisted of 28.1%, 73.7% and 63.8% of migrant individuals from northern breeding grounds, respectively. Isotopic evidence suggested movements of a few local residents birds (7.9%) into the Chihuahuan desert from south-western USA and north-eastern Mexico to winter. [source] Typological thinking and the conservation of subspecies: the case of the San Clemente Island loggerhead shrikeDIVERSITY AND DISTRIBUTIONS, Issue 4 2000Michael A. Patten Abstract. ,Hybridization with closely related taxa poses a significant threat to endangered subspecies (e.g. outbreeding depression, inbreeding) and confounds efforts to manage and conserve these taxa through a loss of taxonomic identity, in part because of the practical necessity of defining subspecies in a typological manner. We examined nine morphological characters in 167 post-juvenile museum specimens to determine if loggerhead shrikes Lanius ludovicianus Linnaeus 1766 on San Clemente Island (off the coast of California) remain diagnosable as L. l. mearnsi Ridgway (1903); an island endemic listed as endangered by the United States Fish and Wildlife Service. Four recent shrike specimens from the island were compared to historical specimens using a bivariate scatter plot and a discriminant function (the latter was used to classify recent specimens post hoc). The few recent specimens were not diagnosable as L. l. mearnsi, but instead appear to be intergrades between L. l. mearnsi and L. l. anthonyi Mearns 1898 (the subspecies endemic to Santa Cruz, Santa Catalina, Santa Rosa and Anacapa islands), and are perhaps closer to pure anthonyi. Our data and the species' natural history and distribution suggest that shrikes currently on San Clemente Island are the result of genetic ,swamping' of mearnsi by anthonyi. Under a necessarily typological definition of a subspecies, it is evident that mearnsi is probably no longer diagnosable. However, we conclude that protection of the entire Channel Islands population of the loggerhead shrike would be the best management strategy, as the species has declined drastically throughout the islands. [source] Spatial and temporal variation in the morphology (and thus, predicted impact) of an invasive species in AustraliaECOGRAPHY, Issue 2 2006Ben L. Phillips The impact of an invasive species is unlikely to be uniform in space or time, due to variation in key traits of the invader (e.g. morphology, physiology, behaviour) as well as in resilience of the local ecosystem. The weak phylogeographic structure typical of an invasive population suggests that much of the variation in an invading taxon is likely to be generated by the environment and recent colonisation history. Here we describe effects of the environment and colonisation history on key morphological traits of an invader (the cane toad Bufo marinus). These "key traits" (body size and relative toxicity) mediate the impact of toads on Australian native predators, which often die as a consequence of ingesting a fatal dose of toad toxin. Measurements of museum specimens collected over >60 yr from a wide area show that seasonal variation in toad body size (due to seasonal recruitment) effectively swamps much of the spatial variance in this trait. However, relative toxicity of toads showed strong spatial variation and little seasonal variation. Thus, the risk to a native predator ingesting a toad will vary on both spatial and temporal scales. For native predators capable of eating a wide range of toad sizes (e.g. quolls, varanid lizards), seasonal variation in overall toad size will be the most significant predictor of risk. In contrast, gape-limited predators restricted to a specific range of toad sizes (such as snakes) will be most strongly affected by the relative toxicity of toads. Gape-limited predators will thus experience strong spatial variation in risk from toad consumption. [source] Rapid morphological change in stream beetle museum specimens correlates with climate changeECOLOGICAL ENTOMOLOGY, Issue 5 2008JENNIFER BABIN-FENSKE Abstract 1.,Climate change has been occurring at unprecedented rates and its impacts on biological populations is beginning to be well documented in the literature. For many species, however, long-term records are not available, and trends have not been documented. 2.,Using museum specimens from southern USA, we show that the stream-dwelling beetle Gyretes sinuatus has shown an 8% increase in body size and change in body shape (fineness ratio) from 1928 to 1988. Any directional morphological change observed over time could be an indicator of a microevolutionary response. 3.,During these 60 years, there have also been changes in temperature, precipitation, and location of collection sites. Unlike the global trend, mean annual temperature in the region has decreased, and furthermore, total annual precipitation has increased. By investigating how these various ecological and geographical variables may affect body size and shape, we can examine which pressures may promote larger and/or thinner beetles. 4.,Results indicate that mean annual temperature was the most predictive variable for the change in size and shape. We suggest there is an adaptive role for temperature on body size and shape of stream dwelling organisms. 5.,We found that museum specimens can be invaluable resources of information when collection date and location information is available. We promote the use of such specimens for future studies of the morphological response to climate change. [source] A historical record of mercury contamination in southern florida (USA) as inferred from avian feather tissue: Contribution R-09888 of the Journal Series, Florida Agricultural Experiment StationENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 6 2004Peter C. Frederick Abstract During the late 1980s, the upper trophic-level biota of the Everglades (FL, USA) was recognized as being highly contaminated with mercury (Hg). However, the timing and pattern of that increase is poorly known, and no information is available about mercury contam ination in Everglades wildlife prior to 1974. We measured methylmercury concentrations in feathers of white ibises (n = 33), great egrets (n = 7), anhingas (n = 21), and great blue herons (n = 12) from museum specimens collected from 1910 through 1980 and combined them with more recent feather samples collected from live birds (1985,2000, n = 98, 37, 49, and 7, respectively). We found no evidence of contamination of museum samples with inorganic mercuric preservatives (0.01,0.28% of total Hg in feathers). All species showed relatively low concentrations of mercury through the 1970s (<5 ,l/L dry wt for anhingas, ibises, and egrets, <10 ,l/L for herons). Samples from all species taken during the 1990s showed a large and significant increase (4,5X) in MeHg concentration. This evidence suggests that most of the increase in Hg deposition during the 20th century in south Florida occurred during the last two to three decades, which is consistent with information about local source deposition. Contamination levels prior to the 1970s appear to have been associated with normal reproduction in these birds, suggesting partial evidence for a threshold of reproductive impairment. [source] Range dynamics of small mammals along an elevational gradient over an 80-year intervalGLOBAL CHANGE BIOLOGY, Issue 11 2010REBECCA J. ROWE Abstract One expected response to observed global warming is an upslope shift of species elevational ranges. Here, we document changes in the elevational distributions of the small mammals within the Ruby Mountains in northeastern Nevada over an 80-year interval. We quantified range shifts by comparing distributional records from recent comprehensive field surveys (2006,2008) to earlier surveys (1927,1929) conducted at identical and nearby locations. Collector field notes from the historical surveys provided detailed trapping records and locality information, and museum specimens enabled confirmation of species' identifications. To ensure that observed shifts in range did not result from sampling bias, we employed a binomial likelihood model (introduced here) using likelihood ratios to calculate confidence intervals around observed range limits. Climate data indicate increases in both precipitation and summer maximum temperature between sampling periods. Increases in winter minimum temperatures were only evident at mid to high elevations. Consistent with predictions of change associated with climate warming, we document upslope range shifts for only two mesic-adapted species. In contrast, no xeric-adapted species expanded their ranges upslope. Rather, they showed either static distributions over time or downslope contraction or expansion. We attribute these unexpected findings to widespread land-use driven habitat change at lower elevations. Failure to account for land-use induced changes in both baseline assessments and in predicting shifts in species distributions may provide misleading objectives for conservation policies and management practices. [source] Morphological changes in the shape of the non-pathological bony knee joint with age: a morphometric analysis of the distal femur and proximal tibia in three populations of known age at deathINTERNATIONAL JOURNAL OF OSTEOARCHAEOLOGY, Issue 4 2008S. D. Stevens Abstract This study examines possible morphological variation in the knee joint of Homo sapiens with increasing age in ostensively healthy and non-pathological distal femora and proximal tibiae. Throughout the lifetime of each individual, the hard tissue of the knee undergoes considerable remodelling as a response to biomechanical stresses, changes in bone microarchitecture and reduction of bone mineral content as a concomitant of ageing. The knee is also subject to greater levels of degenerative joint disease than any other joint. If death occurs whilst such diseases are in the earliest stages, initial bone changes may not be visually obvious in museum specimens. If such specimens are used for comparative analyses, it is hypothesised that changes might render it problematic if all ages are conglomerated into discrete samples. This study therefore investigates the degree to which the distal femur and proximal tibia change shape during ageing and, if changes are present, whether they are expressed similarly in males and females. It also examines whether changes are of greater magnitude than those morphological differences which might exist between populations. In an example population of African-Americans, results indicate that there is a statistically significant difference in shape between age groups and those differences become progressively greater between the youngest and oldest adults. Results also show that although morphological variation caused by ageing is apparent, those shape differences attributable to sexual dimorphism are more powerful. When two additional populations are analysed jointly with the African-Americans (Caucasian Americans and the European Spitalfields sample), results indicate that inter-population shape differences are considerably greater than differences caused by increasing age. Results imply that it is justifiable to combine specimens of all ages into discrete samples for comparative purposes. Copyright © 2007 John Wiley & Sons, Ltd. [source] Predators, parasitoids and pathogens: species richness, trophic generality and body sizes in a natural food webJOURNAL OF ANIMAL ECOLOGY, Issue 1 2000J. Memmott Summary 1.,A food web is presented which describes trophic interactions among the herbivores, parasitoids, predators and pathogens associated with broom, Cytisus scoparius (L.) Link. The data come from published work on the community at a single site. The web comprises a total of 154 taxa: one plant, 19 herbivores, 66 parasitoids, 60 predators, five omnivores and three pathogens. There are 370 trophic links between these taxa in the web. The taxa form 82 functionally distinct groups, called trophic species. 2.,Predators consumed significantly more species than did parasitoids: a median of two prey species per species of predator (range = 1,9), compared to a median of one host species per species of parasitoid (range = 1,4). Significant differences in the number of species consumed were also found among the five predator groups: birds (median = 4), spiders (median = 5), Coleoptera (median = 1), Diptera (median = 2) and Hemiptera (median = 7). 3.,Vulnerability, measured by numbers of consumer species, was significantly affected by the herbivores' feeding styles: externally feeding herbivores were most vulnerable and the concealed herbivores were least vulnerable. Miners were vulnerable to the most parasitoid species and externally feeding herbivores were the most vulnerable to predators. 4.,Resource species had a median vulnerability of 13 consumer species, a figure far higher than that in most published food webs. No significant relationship was found between species' vulnerability to predators and vulnerability to parasitoids. However, there was a strong negative relationship between the percentage mortality due to predation and percentage mortality due to parasitism. 5.,The broom food web contains nine orders of insects, a figure higher than previously recorded. The web also contains vertebrates, arachnids, bacteria and fungi. Most of the interactions between the orders were weak. Connectance was calculated for the complete web, the parasitoid sub-web and the predator sub-web. The connectance of the predator sub-web, a value of 0·0364, was more than an order of magnitude larger than the connectance of the entire web (0·0156) or the parasitoid sub-web (0·018). 6.,The body lengths of 52 species in the food web were estimated from field guides or museum specimens. Larger predators consumed smaller prey in 93% of predator,prey interactions. Smaller parasitoids consumed larger hosts in 79% of parasitoid,host interactions. Parasitoids were significantly smaller than predators. 7.,The 52 species were arranged in order of increasing body length along the columns and down the rows of a food web matrix. The predator sub-web was predominantly upper triangular with 8% of non-zero elements falling below the leading diagonal. The parasitoid sub-web was predominantly lower triangular with 21% non-zero elements falling above the leading diagonal. The entire web contains entries both above and below the main diagonal and thus violates a central assumption of the cascade model. [source] Diet reconstruction and historic population dynamics in a threatened seabirdJOURNAL OF APPLIED ECOLOGY, Issue 4 2007D. RYAN NORRIS Summary 1For the overwhelming majority of species, we lack long-term information on the dynamics of populations. As a consequence, we face considerable uncertainty about how to discriminate among competing hypotheses of population decline and design conservation plans. 2The marbled murrelet Brachyramphus marmoratus is a small seabird that nests in coastal old-growth forest but feeds year-round in near-shore waters of the north-eastern Pacific. Although a decline in nesting habitat is the primary reason why marbled murrelets are listed as threatened in Canada, nest predation and food availability may also influence population abundance. To examine the hypothesis that murrelet populations are influenced by variation in diet quality, we analysed stable-carbon and -nitrogen isotopes in feathers of museum specimens collected in the Georgia Basin, British Columbia. 3Between 1889 and 1996, we found a decline in stable isotopic signatures that was approximately equal to a 62% drop in trophic feeding level. We also found that the estimated proportion of fish in murrelet diet was related closely to murrelet abundance over the past 40 years, as estimated from volunteer surveys. Using these isotopic data, we modelled population size as a function of variation in reproductive rate due to changes in diet quality and found that our model matched closely the 40-year field estimates. We then applied our 107-year isotopic record to the model to back-cast estimates of population growth rate to 1889. 4Our results suggest that, up to the 1950s, murrelet populations in the Georgia Basin were capable of growing and were probably limited by factors other than diet quality. After this period, however, our results imply that murrelets were often, but not solely, limited by diet quality. 5Synthesis and applications. Protecting nesting habitat may not be sufficient to rebuild populations of this highly secretive and threatened seabird and recovery might also require the restoration of marine habitat quality, as well as a better understanding of how ocean climate affects prey abundance and reproductive rate. Combined with contemporary demographic data, stable isotope analysis of historic samples provides a unique opportunity to reconstruct population histories for species where we lack long-term information. [source] An overlooked DNA source for non-invasive genetic analysis in birdsJOURNAL OF AVIAN BIOLOGY, Issue 1 2005Márton B. Horváth Non-invasive sampling is a useful tool for genetic analyses of endangered and/or elusive species, but it is often inapplicable due to the low quality and quantity of the DNA obtained. In this study we show that the blood clot located in the superior umbilicus of the feather shaft is a better source of DNA than the previously used tip samples from moulted feathers. We found that feather clots from museum specimens provided results nearly as good as footpad and better than those from the more commonly used museum skin snips. Feather clots proved to be a good source of DNA for genetic analysis that will significantly facilitate genetic monitoring of wild bird populations. [source] Spatial patterns of disparity and diversity of the Recent cuttlefishes (Cephalopoda) across the Old WorldJOURNAL OF BIOGEOGRAPHY, Issue 8 2003Pascal Neige Abstract Aim Diversity and disparity metrics of all Recent cuttlefishes are studied at the macroevolutionary scale (1) to establish the geographical biodiversity patterns of these cephalopods at the species level and (2) to explore the relationships between these two metrics. Location Sampling uses what is known about these tropical, subtropical and warm temperate cephalopods of the Old World based on a literature review and on measurements of museum specimens. Some 111 species spread across seventeen biogeographical areas serve as basic units for exploring diversity and disparity metrics in space. Methods Landmarks describe the shape of the cuttlebone (the inner shell of the sepiids) and differences between shapes are quantified using relative warp analyses. Relative warps are thus used as the morphological axis for constructing morphospaces whose characteristics are described by disparity indices: total variance, range, and minimum and maximum of relative warps. These are analysed and then compared with the diversity (species richness) metric. Results Results show no significant latitudinal or longitudinal gradients either for diversity or for disparity. Around the coast of southern Africa, disparity is high regardless of whether diversity (species richness) is high or low. In the ,East Indies' area disparity is low despite the high diversity. Main conclusions The relationship between diversity and disparity is clearly not linear and no simple adjustment models seem to fit. The number of species in a given area does not predict its disparity level. The particular pattern of southern Africa may be the result of paleogeographical changes since the Eocene, whereas that of the ,East Indies' may indicate that this area could act as a centre of origin. However, the lack of any clear phylogenetical hypothesis precludes the study from providing any explanation of the observed patterns. [source] Sexual dimorphism and dichromatism in Steere's Liocichla (Liocichla steerii)JOURNAL OF FIELD ORNITHOLOGY, Issue 4 2006Herman L. Mays Jr ABSTRACT Although sexual differences in birds can be extreme, differences between males and females in body size and plumage color are more subtle in many species. We used a genetic-based approach to determine the sex of male and female Steere's Liocichla (Liocichla steerii) and examine the degree of size dimorphism and plumage dichromatism in this apparently monomorphic species. We found that males were significantly larger than females. In addition, Steere's Liocichla have a prominent yellow plumage patch on the lores that was significantly larger in males than females for both live birds and museum specimens. We also used reflectance spectrometry to quantify the color of the yellow-green breast feathers of Steere's Liocichla and found no significant differences between males and females in brightness, intensity, saturation, or hue. However, females tended to have brighter breast plumage, particularly at long wavelengths. Collectively, these color variables were useful in discriminating birds according to sex when used in a discriminant function analysis. Our study suggests that sexual selection may be more widespread than once assumed, even among birds considered monomorphic, and emphasizes the need for additional data from tropical and subtropical species. SINOPSIS Aunque las diferencias sexuales entre algunas especies puede ser estrechas, un muchas de estas las diferencias corporales entre los sexos pudiera ser sutiles. Abordamos el asunto basados en genética para determinar el sexo en Liocichla steerii y examinamos el grado de dimorfismo sexual y dicromatismo en el plumaje en esta especie la cual aparentemente es monomórfica. Encontramos que los machos eran significativamente de mayor tamaño que las hembras. Además encontramos en los machos un parcho amarillo en los lores significativamente más grande que en las hembras, tanto en aves del estado silvestre como en pieles de museos. Usamos espectrometría para cuantificar el color de las plumas verde-amarillentas del pecho de las aves y no encontramos diferencias significativas entre los sexos, con respecto a la brillantez, insensidad, saturación o matiz color. Sin embargo, las hembras tuvieron la tendencia a tener el plumaje más brillante en el pecho particularmente en el espectro de onda larga. Colectivamente, estas variables de color fueron útiles para discriminar entre el sexo de las aves, particularmente cuando fueron examinadas utilizando un análisis discriminante de funciones. Nuestro estudio sugiere que la selección sexual pudiera estar más ampliamente distribuida que lo previamente asumido, aún en aves consideradas monomórficas. Además el trabajo enfatiza la necesidad de llevar a cabo estudios adicionales, de este tipo, tanto en especies del trópico como de la zona templada. [source] Molecular phylogeny and biogeography of Honey-buzzards (genera Pernis and Henicopernis)JOURNAL OF ZOOLOGICAL SYSTEMATICS AND EVOLUTIONARY RESEARCH, Issue 2 2004A. Gamauf Abstract A partial sequence of the cytb gene (382 bp) was amplified and sequenced from 35 individuals (mainly museum specimens) of the genus Pernis representing all valid taxa (10) and two taxa (P. p. gurneyi, P. p. japonicus) with questionable validity as well as representatives of the Old World Perninae, namely Henicopernis and Aviceda, to assess their relationships to the genus Pernis. Furthermore, Gypaetus barbatus, Neophron percnopterus, and Buteo buteo were included as outgroup taxa. In the trees derived from the sequence data, Aviceda represents the sister group of the genus Pernis. The genus Henicopernis and the Old World vultures Gypaetus andNeophron appear rather distantly related to Pernis. Within the genus Pernis, two of the described species (Pernis apivorus, Pernis ptilorhyncus) form monophyletic groups, whereas the relationships of the two clades representing three subspecies of Pernis celebensis are still uncertain. Although this study is based on comparatively short DNA-sections, the trees deduced from these sequences can be considered as a first approach for inferring the phylogenetic relationships of the genus Pernis and related genera and for addressing questions concerning the evolutionary history, biogeography, and systematics of this group. Zusammenfassung Eine Teilsequenz des Cytochrom b Gens (382 bp) wurde von 35 Individuen (hauptsächlich Museumsmaterial) der Gattung Pernis amplifiziert und sequenziert. Inkludiert wurden alle validen Taxa (10) und zwei weitere (P.p. gurneyi, P. p. japonicus) mit zweifelhaftem taxonomischen Status. Weiters wurden die übrigen Vertreter der altweltlichen Perninae (Henicopernis, Aviceda) untersucht, um deren Verwandtschaft zum Genus Pernis festzustellen. Als Außengruppen-Taxa wurden Bartgeier Gypaetus barbatus, Schmutzgeier Neophron percnopterus und Mäusebussard Buteo buteo verwendet. In den aus den Sequenzen errechneten Bäumen stellt Aviceda die Schwestergruppe der Gattung Pernis dar. Die Gattungen, Henicopernis und die Altweltgeier Gypaetus und Neophron erscheinen mit der Gattung Pernis nur entfernt verwandt. Innerhalb der Gattung Pernis formen zwei der beschriebenen Arten (P. apivorus, P. ptilorhyncus) eine monophyletische Gruppe, die Verwandtschaftsverhältnisse der beiden anderen Clades, welche die drei Unterarten von P. celebensis repräsentieren, können jedoch auf der Basis dieser Sequenz nicht eindeutig geklärt werden. Obwohl diese Analyse auf relativ kurzen DNA-Abschnitten basiert, können die aus den Sequenzen abgeleiteten Stammbäume als erster Versuch angesehen werden, die Phylogenie der Wespenbussard-Gattung Pernis und verwandter Genera mittels molekularer Methoden und unter Berücksichtigung evolutionsbiologischer, biogeographischer und systematischer Aspekte darzustellen. [source] Microevolutionary trends in the dentition of the Red fox (Vulpes vulpes)JOURNAL OF ZOOLOGICAL SYSTEMATICS AND EVOLUTIONARY RESEARCH, Issue 1 2003E. SZUMA Abstract Microevolutionary trends in dental traits were studied in a Polish population of the Red fox, Vulpes vulpes (Linnaeus, 1758). Changes in qualitative and quantitative traits over a 70-year interval were analysed in 1453 museum specimens collected between 1927 and 1996. Over that period, there were qualitative trends towards increasing complication of occlusal crown surface in posterior premolars (i.e. P4, P3, P4) and I3. Other cheek teeth did not undergo directional change. Changes in trait correlations were assessed using samples from the 1960s and 1990s. The correlations between C1,C1 and M1,M2 increased, while correlation values in the incisor region (I1,I2, I1,I1, I1,I2, I3,I2), carnassial region (P4,M1, P4,M1 and M1,M1) and in P2,P1 decreased. These changes may be related to increasing dietary opportunism of the Red fox during the 20th century. Zusammenfassung In einer polnischen Population des Rotfuchses Vulpes vulpes (Linaeus, 1758) wurden Untersuchungen über den Trend von mikroevolutionären Prozessen an Merkmalen der Bezahnung angestellt. Dabei wurden die Veränderungen in qualitativen und quantitativen Merkmalen während eines Zeitraums von 70 Jahren an 1453 Museumsexemplaren, die zwischen 1927 und 1996 gesammelt worden waren, analysiert. Für diesen Zeitraum wurde ein Trend zu einer zunehmenden Komplikation in der Oberfläche der abschließenden Zahnkrone der hinteren Prämolaren (d.h. P4, P3, P4) und von I3 gefunden. Die anderen Backenzähne waren keinen direktionalen Veränderungen unterworfen. Korrelationen zwischen den Merkmalsveränderungen wurden für die Stichproben aus den 1960er- und 1990er-Jahre analysiert. Die Korrelationen zwischen C1 und C1 und zwischen M1,M2 verstärkten sich, während die Korrelationskoeffizienten in der Region der Schneidezähne (I1,I2, I1,I1, I1,I2, I3,I2), in der Region der Backenzähne und für P2,P1 abnahmen. Die Änderungen dürften auf einem zunehmenden Nahrungsopportunismus der Rotfüchse während des 20. Jahrhunderts beruhen. [source] Limb bone stresses during fast locomotion in the African lion and its bovid preyJOURNAL OF ZOOLOGY, Issue 2 2008B. Sorkin Abstract Peak stresses during fast locomotion in the humerus and tibia of the African lion have been estimated from a filmed prey pursuit sequence and skeletal dimensions of museum specimens; safety factors of the two bones have been calculated. The results are compared with the peak stresses (and the corresponding safety factors) during fast locomotion in the humerus and tibia of large (buffalo) and small (antelope) African bovids, which the lion is known to prey upon, estimated by previous authors using similar methodology. The comparison suggests that both the humerus and the tibia of a running lion have higher safety factors than those of its bovid prey running at the same speed. [source] Life on a limb: ecology of the tree agama (Acanthocercus a. atricollis) in southern AfricaJOURNAL OF ZOOLOGY, Issue 4 2002Leeann T. Reaney Abstract One hundred and sixty-four museum specimens of the tree agama Acanthocercus a. atricollis were measured and dissected to examine sexual size dimorphism, reproduction and diet. Foraging mode and behaviour were also quantified in a wild population to obtain a broader picture of their foraging ecology and to test the hypothesis that tree agamas are ambush foragers. Males and females did not differ significantly in snout,vent length (SVL) or tail length; however, mature males had larger heads than females of the same body size. The smallest female showing sexual maturity was 96 mm SVL and the smallest male was 82 mm SVL. Mean clutch size was 11.3 and was positively correlated with female body size. Reproduction was seasonal and male and female reproductive cycles were synchronous. Testicular volume was greatest during August,September and females contained enlarged follicles during August,December and showed no evidence of multiple clutching. Tree agamas fed on a broad spectrum of arthropods (10 orders), including millipedes, which other lizard taxa have been reported to avoid. Gut contents were dominated numerically by ants (92%), followed by beetles (4%). Volumetrically, orthopterans (26.8%) were most important, followed by beetles (26.3%) and ants (17.9%). Compared to adults, juvenile diet by volume was dominated by ants and consisted of fewer large prey items (e.g. beetles and orthopterans). Seasonal effects in both prey diversity and volume were evident. Tree agamas are classic ambush foragers. They spent only 4% of their time moving and made few movements per minute (mean = 0.4). When stationary, adult tree agamas positioned themselves on tree trunks (34.7%), on lateral branches (41.8%) and occasionally, on the ground (23.4%). No evidence of trophic partitioning (intraspecific niche divergence hypothesis) was found and field observations revealed that males defend territories and engage in combat. This supports the idea that selection may be favouring larger head size in males, as an outcome of male contest competition. [source] Global warming, Bergmann's rule and body mass , are they related?JOURNAL OF ZOOLOGY, Issue 4 2002The chukar partridge (Alectoris chukar) case Abstract Using museum specimens collected in Israel during the second half of the 20th century, no support was found for the hypothesis that body mass and tarsus length of chukar partridges Alectoris chukar has changed as a result of global warming. Body mass showed fluctuations during the year, reaching a maximum in late winter and spring and a minimum in summer. Bergmann's rule predicts that in warm-blooded animals, races from warm regions will be smaller than races from colder regions, and a wider explanation states that body size is positively related to latitude. Because of its topography and varied climate, Israel provides a unique opportunity to separate partly the effect of latitude from that of ambient temperature, thus testing if Bergmann's rule is related to latitude or to climatic variables. We found that body mass (and marginally also tarsus length) declined significantly with decreasing latitude in accordance with the wider explanation of Bergmann's rule, but ambient temperature explained a much smaller fraction of the variation in body mass than latitude. These results weaken the traditional explanation to Bergmann's rule that a heat conservation mechanism causes the latitudinal size variation. [source] Searching for DNA in museum specimens: a comparison of sources in a mammal speciesMOLECULAR ECOLOGY RESOURCES, Issue 3 2010M. CASAS-MARCE Abstract The number of genetic studies that use preserved specimens as sources of DNA has been steadily increasing during the last few years. Therefore, selecting the sources that are more likely to provide a suitable amount of DNA of enough quality to be amplified and at the minimum cost to the original specimen is an important step for future research. We have compared different types of tissue (hides vs. bones) from museum specimens of Iberian lynx and multiple alternative sources within each type (skin, footpad, footpad powder, claw, diaphysis, maxilloturbinal bone, mastoid process and canine) for DNA yield and probability of amplification of both mitochondrial and nuclear targets. Our results show that bone samples yield more and better DNA than hides, particularly from sources from skull, such as mastoid process and canines. However, claws offer an amplification success as high as bone sources, which makes them the preferred DNA source when no skeletal pieces have been preserved. Most importantly, these recommended sources can be sampled incurring minimal damage to the specimens while amplifying at a high success rate for both mitochondrial and microsatellite markers. [source] A set of primers conserved in genus Parnassius (Lepidoptera, Papilionidae) for amplification and sequencing of 1016 bp fragment of cytochrome oxidase subunit I from museum specimensMOLECULAR ECOLOGY RESOURCES, Issue 3 2008MACIEJ K. KONOPINSKI Abstract Four short, overlapping amplicons covering a 1016 bp fragment of mitochondrial cytochrome oxidase subunit I were developed. All four fragments were successfully amplified and sequenced in eight species of butterflies belonging to the genus Parnassius including over 100-year-old DNA from pinned museum specimens. The fragment contains sufficient variation for both inter- and intraspecific analyses. A total of 105 sites were polymorphic within 52 haplotypes found in 186 samples from Parnassius mnemosyne. [source] A minimalist barcode can identify a specimen whose DNA is degradedMOLECULAR ECOLOGY RESOURCES, Issue 4 2006MEHRDAD HAJIBABAEI Abstract A DNA barcode based on 650 bp of mitochondrial gene cytochrome c oxidase I is proving to be highly functional in species identification for various animal groups. However, DNA degradation complicates the recovery of a full-length barcode from many museum specimens. Here we explore the use of shorter barcode sequences for identification of such specimens. We recovered short sequences , i.e. ,100 bp , with a single PCR pass from more than 90% of the specimens in assemblages of moth and wasp museum specimens from which full barcode recovery was only 50%, and the latter were usually less than 8 years old. Short barcodes were effective in identifying specimens, confirming their utility in circumstances where full barcodes are too expensive to obtain and the identification comparisons are within a confined taxonomic group. [source] CARBONATE DEPOSITIONAL ENVIRONMENTS, SEQUENCE STRATIGRAPHY AND EXCEPTIONAL SKELETAL PRESERVATION IN THE MUCH WENLOCK LIMESTONE FORMATION (SILURIAN) OF DUDLEY, ENGLANDPALAEONTOLOGY, Issue 1 2007DAVID C. RAY Abstract:, The Much Wenlock Limestone Formation of the Dudley inliers, West Midlands, contains one of the world's richest and most exquisitely preserved Silurian marine biotas. However, for most museum specimens, little is known of their exact provenance and mode of preservation. Detailed comparisons between outcrops and museum collections allow the identification of five faunal-lithological associations and numerous horizons of exceptional skeletal preservation. The associations are interpreted as a series of transient carbonate mid-platform environments extending from below storm wave-base to above fair-weather wave-base. Erosive surfaces, condensed sections, flooding surfaces and the stacking patterns of genetically related bed-sets (parasequences) have allowed the formation to be interpreted as a single third-order sequence stratigraphic cycle of sea-level change. The articulated preservation of taxa such as pelmatozoan echinoderms and trilobites can be attributed to either rapid burial by obrution deposits close to fair-weather wave-base or smothering by storm sequestered muds in slightly deeper-water settings. Such intervals of exceptional preservation are commonly associated with flooding surfaces, presumably reflecting reduced likelihood of reworking once rapid burial had taken place. [source] Brief communication: Paleohistopathological analysis of pathology museum specimens: Can periosteal reaction microstructure explain lesion etiology?AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 1 2009Darlene A. Weston Abstract The assertion that the microstructure of periosteal new bone formation can be used to differentiate between disease etiologies (Schultz: Yrbk Phys Anthropol 44 2001 106,147; Schultz: Identification of pathological conditions in human skeletal remains, 2nd ed. London: Academic Press 2003 73,109) was tested in a pilot-study, using diagnosed bone specimens from St George's Hospital Pathology Museum, London, UK. Embedded bone specimens exhibiting pathological periosteal new bone formation were examined using scanning electron microscopy in back-scattered electron imaging mode (SEM-BSE). The results suggest that several histological features (i.e. Grenzstreifen, Polsters, and sinuous lacunae) deemed to be diagnostic of specific pathological conditions are of no specific diagnostic value, as they are encountered in pathological conditions of differing disease etiology. These results tie in with a previous investigation demonstrating a lack of diagnostic qualitative or quantitative characteristics seen in the macroscopic and radiographic appearance of periosteal reactions (Weston: Am J Phys Anthropol 137 2008 48,59). Am J Phys Anthropol, 2009. © 2009 Wiley-Liss, Inc. [source] Ecogeographic size variation in small-bodied subfossil primates from Ankilitelo, Southwestern MadagascarAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 2 2007Kathleen M. Muldoon Abstract Variation in body size is well documented for both extant and extinct Malagasy primates, and appears to be correlated with geographic patterns of resource seasonality. Less attention has been paid to extant lemurs in subfossil collections, although it has been suggested that subfossil forms of extant species are characterized by greater size than their modern counterpart. This trend of phyletic size change has been related to climate change, habitat fragmentation, or human hunting. However, space- and time-averaging in the subfossil samples of previous studies may have obscured more general ecogeographic patterns underlying these size differences. Our objective is to examine size variation in subfossil still-extant primates within a regional comparative context to determine if subfossil and living forms conform to similar ecogeographic patterns. We report on the subfossil still-extant primate assemblage from Ankilitelo, southwestern Madagascar (,500 yr BP) to test this hypothesis. The Ankilitelo primates were compared with museum specimens of known locality. Extant taxa were assigned to one of five distinct ecogeographic regions, including spiny thicket, dry deciduous forest, succulent woodland, lowland and subhumid rainforest. Comparisons of tooth size in extant lemurs reveal significant geographical patterns of variation within genera. In general, the primates from Ankilitelo are indeed larger than their modern counterpart. However, these differences fit an ecoregional model of size variation, whereby Ankilitelo species are comparable in size to living forms inhabiting ecoregions present near the cave today. This suggests that Malagasy primates have been subjected to similar patterns of resource seasonality for at least 500 years. Am J Phys Anthropol, 2007. © 2007 Wiley-Liss, Inc. [source] | ||||||||||||||||||||||||||||