Continental North Research Articles

Can intrinsic factors explain population declines in North American breeding shorebirds? A comparative analysis

AbstractMany shorebirds that breed in North America are declining. These trends reflect global patterns in shorebird populations. Here we ask what factors make some shorebird species more prone to decline than others. Specifically, we test the influence of migratory behaviour (route and distance), biogeography (population size and range), life history (body size, clutch size) and sexual selection (social mating system and testis size) on population trends in North American breeding shorebirds. Using phylogenetic comparative methods, we show that species that migrate across continental North America are more prone to decline than species that do not. Our finding that continental migrants are associated with population decline indicates that intrinsic factors may play an important role in predisposing a species to decline. Previous studies within the class Aves have failed to identify migration route as a correlate of decline or extinction risk. Two other intrinsic factors (oceanic migrants and threats on the non‐breeding grounds) were also important in our overall models, although neither was significant alone. The moderate explanatory power of our variables indicates that other factors are also important for explaining shorebird declines. We suggest that contemporary threats, most notably habitat loss and degradation at migratory stopover sites, are likely to be important.

Response to Comment on "Ivory-billed Woodpecker ( Campephilus principalis ) Persists in Continental North America"

Claims that the bird in the Luneau video is a normal pileated woodpecker are based on misrepresentations of a pileated's underwing pattern, interpretation of video artifacts as plumage pattern, and inaccurate models of takeoff and flight behavior. These claims are contradicted by experimental data and fail to explain evidence in the Luneau video of white dorsal plumage, distinctive flight behavior, and a perched woodpecker with white upper parts.

Comment on "Ivory-billed Woodpecker ( Campephilus principalis ) Persists in Continental North America"

We reanalyzed video presented as confirmation that an ivory-billed woodpecker (Campephilus principalis) persists in Arkansas (Fitzpatrick et al., Reports, 3 June 2005, p. 1460). None of the features described as diagnostic of the ivory-billed woodpecker eliminate a normal pileated woodpecker (Dryocopus pileatus). Although we support efforts to find and protect ivory-billed woodpeckers, the video evidence does not demonstrate that the species persists in the United States.

How College/University Presidents around the World Make Decisions

The world is rapidly changing into a different kind of world where the wealth of a nation is defined by the educational level of its people. Higher education institutions throughout the world provide the means to meet today's information and knowledge requirements dictated by the ever-fluid global marketplace. Colleges and universities offer courses and programmes allowing nations to reap the benefits of an educated workforce and compete globally. College/university presidents by their position wield great power and authority to direct their respective institutions. Decisions made by presidents of colleges/universities have significant consequences on complex transnational tertiary education issues. If college/university presidents around the world are expected to make similar types of decisions to foster a borderless transnational tertiary education system, then it is important to know more about the substance of their work and how they make administrative and fiscal management decisions. The purpose of this global study was to identify ‘pre-choice’ factors employed by presidents of higher education institutions around the world when making decisions. Seven college/university presidents, one participant on each continent (North America, South America, Africa, Asia, Australia and Europe, with an island representative as a substitute for Antarctica) was selected to accommodate global distribution.

On the long‐term context for late twentieth century warming

Previous tree‐ring–based Northern Hemisphere temperature reconstructions portray a varying amplitude range between the “Medieval Warm Period” (MWP), “Little Ice Age” (LIA) and present. We describe a new reconstruction, developed using largely different methodologies and additional new data compared to previous efforts. Unlike earlier studies, we quantify differences between more traditional (STD) and Regional Curve Standardization (RCS) methodologies, concluding that RCS is superior for retention of low‐frequency trends. Continental North American versus Eurasian RCS series developed prior to merging to the hemispheric scale cohere surprisingly well, suggesting common forcing, although there are notable deviations (e.g., fifteenth to sixteenth century). Results indicate clear MWP (warm), LIA (cool), and recent (warm) episodes. Direct interpretation of the RCS reconstruction suggests that MWP temperatures were nearly 0.7°C cooler than in the late twentieth century, with an amplitude difference of 1.14°C from the coldest (1600–1609) to warmest (1937–1946) decades. However, we advise caution with this analysis. Although we conclude, as found elsewhere, that recent warming has been substantial relative to natural fluctuations of the past millennium, we also note that owing to the spatially heterogeneous nature of the MWP, and its different timing within different regions, present palaeoclimatic methodologies will likely “flatten out” estimates for this period relative to twentieth century warming, which expresses a more homogenous global “fingerprint.” Therefore we stress that presently available paleoclimatic reconstructions are inadequate for making specific inferences, at hemispheric scales, about MWP warmth relative to the present anthropogenic period and that such comparisons can only still be made at the local/regional scale.

North Sea storm surge statistics based on projections in a warmer climate: How important are the driving GCM and the chosen emission scenario?

Climate models, simulating the effect of plausible future emission concentrations (scenarios), describe for the future an increase of high wind speeds over Northwest Europe during winter. With the help of a hydrodynamic model of the North Sea, these atmospheric future conditions are used to project storm surge heights for the Northwest European Shelf Sea. Four different projections are presented, all generated with the same Regional Climate Model, which itself is driven with two different Global Climate Model scenarios both exposed to two different emission scenarios. The analyses are carried out for a 30‐year time‐slice at the end of the 21st century. All four ensemble members point to a significant increase of storm surge elevations for the continental North Sea coast of between 15 and almost 25 cm. However, the different storm surge projections are not statistically distinguishable from each other but can provide a range of possible evolutions of surge extremes in a warmer climate.

Early Uses of the Ivory-Billed Woodpecker

I read with considerable pleasure the account of the ivory-billed woodpecker's survival in “Ivory-billed woodpecker ( Campephilus principalis ) persists in continental North America” (J. W. Fitzpatrick et al. , Reports, 3 June, p. [1460][1]) and “Rediscovery of the ivory-billed woodpecker” (D. S. Wilcove, Perspectives, 3 June, p. [1422][2]). The relatively intensive use of ivory-bill skulls in specific items of Native American material culture may suggest that the very low population density and infrequent encounter rates noted for recent populations may not have applied, at least to the same degree, to ivory-bill populations in the past. The Ioway—a group from the American midcontinent not generally associated with the southeastern old-growth bottomland forests identified as the range of the ivory-bill—used the skull of female ivory-bills as central elements in a series of Buffalo clan-related pipe bundles ([1][3]). A single pipe stem associated with the Pigeon clan used seven male ivory-bill heads as decoration. Pileated woodpeckers ( Dryocopus pileatus ) are also sometimes used, and one pipe whose clan associations are unclear included one male ivory-bill scalp, with the scalps of four pileated woodpeckers spaced along the shaft. The ivory-bill's widespread depictions in prehistoric art may also suggest that it was a more familiar sight than would be suggested by its relatively reclusive descendants. It appears, for example, on both engraved shell and ceramics from late prehistoric sites from Florida to Oklahoma ([2][4]); one particular style of engraved shell gorget, the so-called Cox Mound style, depicts four ivory-bills in rotation symmetry around the margins of the design, surrounding a looped square and cross-in-circle. Scholars differ regarding the meaning of the woodpecker heads ([3][5]). Although rarity may have been one factor in the selection of ivory-bill body parts for ceremonial objects, its use as a recognizable iconographic symbol suggests a greater degree of familiarity. 1. [↵][6] 1. A. Skinner , Ethnology of the Ioway Indians, (Bulletin of the Milwaukee Public Museum, Milwaukee, WI, 1926), vol. 5. 2. [↵][7] 1. J. P. Brain, 2. P. Phillips , Shell Gorgets: Styles of the Late Prehistoric and Protohistoric Southeast (Peabody Museum Press, Cambridge, MA, 1996). 3. [↵][8] George Lankford has suggested they represent the four winds (4); Barker suggests sentinels (5). 4. 1. R. Townsend 1. G. Lankford , in Hero Hawk and Open Hand: American Indian Art of the Ancient Midwest and South, R. Townsend, Ed. (Yale Univ. Press, New Haven, CT, 2004), pp. 217-218. 5. 1. A. Barker , Archaeology 55((no. 4)), 44 (2002). [OpenUrl][9][Web of Science][10] [1]: /lookup/doi/10.1126/science.1114103 [2]: /lookup/doi/10.1126/science.1114507 [3]: #ref-1 [4]: #ref-2 [5]: #ref-3 [6]: #xref-ref-1-1 View reference 1 in text [7]: #xref-ref-2-1 View reference 2 in text [8]: #xref-ref-3-1 View reference 3 in text [9]: {openurl}?query=rft.jtitle%253DArchaeology%26rft.volume%253D55%26rft.issue%253D%2528no.%2B4%2529%26rft.spage%253D44%26rft.atitle%253DARCHAEOLOGY%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx [10]: /lookup/external-ref?access_num=000185642900027&link_type=ISI

Notes and Double Knocks from Arkansas

In the search for ivory-billed woodpeckers ( Campephilus principalis ) in the Big Woods region of eastern Arkansas [“Ivory-billed woodpecker ( Campephilus principalis ) persists in continental North America,” Reports, 3 June, p. [1460][1]], our unattended digital autonomous recording units (ARUs) recorded over 17,000 hours of ambient sound at 153 sites between 18 December 2004 and 31 May 2005. Review and analysis of these recordings are ongoing, and a full account will be published when analyses are complete. Here we briefly describe examples of the possible nasal “kent” notes and “doublek-nock” display drums mentioned in our Report and provide them as supporting online material (SOM) ([1][2]). ![Figure][3] A painting of the ivory-billed woodpecker and the device used to record its calls.CREDITS: (PAINTING) LARRY CHANDLER; (PHOTO) SUSAN SPEAR, CORNELL LABORATORY OF ORNITHOLOGY On four different mornings in January 2005, a single ARU in the White River National Wildlife Refuge (NWR) recorded a sequence of kent-like vocalizations. The four sequences, which lasted 8 to 41 s and contained between 11 and 26 notes, are extremely similar; the recording of 29 January (audio S2) is typical of them. In the same area, experienced observers have heard blue jays ( Cyanocitta cristata ) produce atypical notes resembling these ARU recordings. Quantitative comparisons of these kent-like sounds with sounds of known ivory-bills (SOM text; audio S1), white-breasted nuthatch ( Sitta carolinensis ), and the most kent-like notes of blue jay in the collection of the Cornell Laboratory of Ornithology's Macaulay Library indicate that the notes recorded by the ARU are most similar to those of ivory-bills. Sounds that are strikingly similar to the double knocks of other Campephilus woodpeckers (SOM text; audio S3) were recorded by ARUs in several areas of the White River and Cache River NWRs. One recording (audio S4), made 1.3 km from the site of the kent-like notes discussed above at 0645 local time on 24 January, includes a low-amplitude, apparently distant double knock followed 3.5 s later by a higher-amplitude, apparently closer double knock. Although the sequence and cadence of this recording match an exchange between two individuals of a Campephilus woodpecker, the relative amplitude of the separate strikes in each double knock is atypical (SOM text). Additional descriptions and discussion of our acoustic data are available at [www.birds.cornell.edu/ivory/field/listening][4]. Further acoustic monitoring and field observation (including intensive efforts to record a large sample of the vocal repertoire of local blue jays) are planned for the areas where these recordings were made. 1. [↵][5]The SOM is available on Science Online at . [1]: /lookup/doi/10.1126/science.1114103 [2]: #ref-1 [3]: pending:yes [4]: http://www.birds.cornell.edu/ivory/field/listening [5]: #xref-ref-1-1 View reference 1 in text

Phylogenetic affinities and inter‐island differentiation in the Vitelline Warbler Dendroica vitellina, a West Indian endemic

The Vitelline Warbler Dendroica vitellina is endemic to the Cayman Islands and Swan Islands in the West Indies. This study examined the phylogenetic affinities of the Vitelline Warbler and assessed mitochondrial differentiation among the three Cayman Island populations. Species‐level phylogenetic analyses based on 3639 nucleotides of mitochondrial DNA (mtDNA) sequence were used to place the Vitelline Warbler in the larger Dendroica radiation. These analyses confirmed that the Vitelline Warbler is the sister taxon of the Prairie Warbler Dendroica discolor, a species that breeds in continental North America. The magnitude of mitochondrial differentiation between these sister taxa (2.4%) supports their current classification as separate taxonomic species. Additional comparisons based on the 1041‐nucleotide NDII gene sequence from 26 Vitelline Warblers provided evidence of within‐species genetic structure. NDII haplotypes from Grand Cayman vs. Cayman Brac/Little Cayman differed by 6–10 nucleotide substitutions, and no haplotypes were shared among these island groups, supporting the current separation of the Cayman Island populations into two subspecies. These patterns support the biogeographical scenario that the Vitelline Warbler was derived from a mainland population of the Prairie Warbler. This may have occurred due to a loss of migration in ancestral populations or from over‐water dispersal of a mainland resident population.

Gender shifts in Germanic and Slavic: semantic motivation for neuter?

In Steinmetz 1997, 2001 it has been argued that the gender systems of the Germanic languages are of two types: neuter-default, exemplified by Icelandic and Faroese, and masculine-default as exemplified by West Germanic and Continental North Germanic. The neuter-default systems appear to continue the gender system of Proto-Germanic while the masculine-default systems resulted from a gender shift wherein the original system was restructured. The restructured, masculine-default systems are characterized by a relative paucity of neuter nouns which generally fall into definable semantic clusters, some of which are of special interest because of possible cognitive implications. There is also evidence that a similar gender shift occurred early in the history of Slavic resulting in an even more striking attrition of neuter nouns. For example, a source of lexical statistics for Russian Obratnyj Slovar’ Russkogo Jazyka (1974) (Reverse Dictionary of the Russian Language) reveals that neuter nouns account for no more than one-fifth of the nominal lexicon, and that most of these are derivatives, leaving about only 200 root nouns which are neuter, and which, as elsewhere in Slavic, are overtly marked by the ending – o (orthographically – o or – e). The present paper points out that many Russian neuter nouns like okno ‘window’ or pole ‘field’ correspond to neuter nouns in German, e.g. Fenster, Feld. Such nouns often fall into identifiable semantic categories, e.g. the notion of openings for German Fenster ‘window’, Tor ‘gate’, Loch ‘hole’, etc. The paper views the relative paucity of neuter nouns in Russian in comparison with Germanic and argues that certain neuter nouns which have neuter counterparts in German and other Germanic languages can be regarded as remnants of earlier, larger neuter clusters. Examples include jajco ‘egg’, corresponding to German Ei, Scandinavian (and English) egg, and koleso ‘wheel’, which is cognate with the English word and with other nouns like Dutch wiel or Scandinavian hjul, and synonymous with German Rad, all of which are neuter. Many of these clusters have lost members in historical times, cf. Russian glaz (masculine) ‘eye’ which has nearly replaced earlier oko (neuter). The paper contends that persistently neuter nouns in Germanic and Slavic reveal the existence of certain semantic classes that otherwise would perhaps escape detection.

Biotelemetry of New World thrushes during migration: Physiology, energetics and orientation in the wild

Billions of songbirds migrate between continents each year, but we have yet to obtain enough information on in-flight physiology and energetics to fully understand the migratory behavior of any one species. New World Catharus thrushes are common nocturnal migrants amenable to biotelemetry, allowing us to measure physiological parameters during migratory flight in the wild. Here, we review work by the authors on Catharus thrush in-flight physiology during spring migration in continental North America and present new data on individual variation in energy use during migratory flight. Previous work demonstrated that (1) a number of simple behavioral rules are sufficient to explain the initiation of individual migratory flights made by Catharus thrushes, (2) the thrushes used a magnetic compass to orient during the night rather than celestial cues and that they calibrated this magnetic compass each day using cues associated with the setting sun, (3) in total, Catharus thrushes used approximately twice as much energy during stopovers than they used during migratory flight, and (4) thrushes may use more energy when thermoregulating on cold days than on days when they make short migratory flights. Recently, we built upon this work and used newly-developed transmitters to measure heart rate, wingbeat frequency and respiration rate of free-flying Swainson's Thrushes (C. ustulatus). We found a large amount of between-individual variation in average heart rate after ascent (range 12.06-14.81 Hz, mean ± SD, 13.48 ± 0.75, n = 10), average wingbeat frequency after ascent (10.25-11.75 Hz, 10.82 ± 0.49, n = 10), and the difference between the two variables (1.5-3.84 Hz, 2.53 ± 0.76, n = 8). Both heart rate and wingbeat frequency were significantly higher during ascent than later in the flight. We propose biotelemetry as a means to understand energetic trade-offs and decisions during natural migratory flight in songbirds. To further our knowledge of intercontinental songbird migration and the connectivity between wintering and breeding sites, we outline plans for a satellite-based global tracking system for <1 g transmitters.

Dating the 1700 Cascadia Earthquake: Great Coastal Earthquakes in Native Stories

Research Article| March 01, 2005 Dating the 1700 Cascadia Earthquake: Great Coastal Earthquakes in Native Stories Ruth S. Ludwin; Ruth S. Ludwin 1Department of Earth and Space Sciences, University of Washington Search for other works by this author on: GSW Google Scholar Robert Dennis; Robert Dennis 2Huu-ay-aht First Nation Search for other works by this author on: GSW Google Scholar Deborah Carver; Deborah Carver 3Carver Geologic, Inc. Search for other works by this author on: GSW Google Scholar Alan D. McMillan; Alan D. McMillan 4Department of Anthropology, Douglas College Search for other works by this author on: GSW Google Scholar Robert Losey; Robert Losey 5Department of Anthropology, University of Alberta Search for other works by this author on: GSW Google Scholar John Clague; John Clague 6Department of Earth Sciences, Simon Fraser University Search for other works by this author on: GSW Google Scholar Chris Jonientz-Trisler; Chris Jonientz-Trisler 7FEMA Region X Search for other works by this author on: GSW Google Scholar Janine Bowechop; Janine Bowechop 8Makah Museum and Cultural Center Search for other works by this author on: GSW Google Scholar Jacilee Wray; Jacilee Wray 9Olympic National Park Search for other works by this author on: GSW Google Scholar Karen James Karen James 10Bainbridge Island, Washington Search for other works by this author on: GSW Google Scholar Author and Article Information Ruth S. Ludwin 1Department of Earth and Space Sciences, University of Washington Robert Dennis 2Huu-ay-aht First Nation Deborah Carver 3Carver Geologic, Inc. Alan D. McMillan 4Department of Anthropology, Douglas College Robert Losey 5Department of Anthropology, University of Alberta John Clague 6Department of Earth Sciences, Simon Fraser University Chris Jonientz-Trisler 7FEMA Region X Janine Bowechop 8Makah Museum and Cultural Center Jacilee Wray 9Olympic National Park Karen James 10Bainbridge Island, Washington Publisher: Seismological Society of America First Online: 09 Mar 2017 Online ISSN: 1938-2057 Print ISSN: 0895-0695 © 2005 by the Seismological Society of America Seismological Research Letters (2005) 76 (2): 140–148. https://doi.org/10.1785/gssrl.76.2.140 Article history First Online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Ruth S. Ludwin, Robert Dennis, Deborah Carver, Alan D. McMillan, Robert Losey, John Clague, Chris Jonientz-Trisler, Janine Bowechop, Jacilee Wray, Karen James; Dating the 1700 Cascadia Earthquake: Great Coastal Earthquakes in Native Stories. Seismological Research Letters 2005;; 76 (2): 140–148. doi: https://doi.org/10.1785/gssrl.76.2.140 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietySeismological Research Letters Search Advanced Search Although scientific recognition of the earthquake hazard presented by the Cascadia subduction zone (CSZ) is relatively recent, native peoples have lived on the Cascadia coast for thousands of years, transferring knowledge from generation to generation through storytelling. This paper considers the ways in which information on coastal earthquakes is presented in native traditions and estimates the date of the most recent event from them. The primary plate-boundary fault of the CSZ separates the oceanic Juan de Fuca Plate from the continental North America Plate (Figure 1). It lies about 80 km offshore and extends roughly parallel to the... You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

The black flies (Simuliidae) of North America

A ROM Publication in Science A Comstock Book Published in association with the Royal Ontario Museum There is much more to black flies than you can learn in the woods on a warm spring day. This book compiles the authors' previously unpublished research and nearly all of the published information on North American black flies. All aspects of black flies are treated within the context of a worldwide perspective, including natural history and ecology, cytology and morphology, phylogeny and classification, economic impact, pest management, natural enemies, history of research, study methods, and identification. Each of the 254 species known from the continent north of Mexico, including 43 new species, is treated in detail. Each species account summarizes all pertinent information on taxonomy, morphology, cytology, physiology, molecular systematics, and bionomics. The book is copiously illustrated with more than 1,100 figures, including color drawings of larvae and adult thoraxes, by some of the world's foremost scientific illustrators. Additional figures and photographs show chromosomal and morphological features, portraits of important researchers, control efforts, natural enemies, oviposition behavior, and cladograms. Detailed distribution maps show the range of each species. A Comstock Book published in Association with the Royal Ontario Museum

An Index of Interannual Precipitation Variability in the Core of the North American Monsoon Region

Abstract Seasonal precipitation anomalies associated with the continental North American monsoon system are characterized using a land-based dataset derived from in situ observations across the southwestern United States and northwestern Mexico. Coherent regions of interannual continental precipitation variability are derived from principal component analysis, after defining separate “early” and “late” summer monsoon seasons. The gravest mode of late-season interannual variability captures precipitation anomalies in the core of the continental monsoon domain. A simple spatial average is developed as an index of this core variability. The seasonal separation allows examination of persistence of precipitation anomalies as an indicator of practical late-season predictability. Possible influences of large-scale oceanic interannual fluctuations [ENSO and Pacific decadal oscillation (PDO)] on core index precipitation anomalies are also considered. The core precipitation index exhibits considerably more early-to-late-season persistence than an ocean-centered precipitation index. Implications of these results for monthly/seasonal predictability of warm-season precipitation are discussed.

Climate change and winter damage to fruit trees in eastern Canada

Climatic conditions during the cold season represent a serious constraint to fruit production in eastern Canada. Meteorological models predict that temperatures of winter months will increase by 2 to 6°C by 2050. The possible impact of climate change on fruit trees in eastern Canada was assessed using agroclimatic indices expressing the risks associated with known causes of damage during fall, winter, and spring. Indices were calculated for 15 agricultural regions in eastern Canada for recent (1961–1990) and future periods (2010–2039 and 2040–2069) using temperature and precipitation data predicted by the Canadian Global General Circulation Model (CGCMI). Averaged across all agricultural regions, the first fall frost in 2040–2069 would be delayed by 16 d while the last spring frost (≤-2°C) would be advanced by 15 d. By 2040 to 2069, the risks of damage to fruit trees by early winter frosts in eastern Canada are likely to decrease because the shorter photoperiod at the time of the first fall frost would result in a longer hardening period. Milder winter temperatures will also reduce the cold stress as the accumulation of cold degree-days (&lt;-15°C) would be reduced and the annual minimum temperature would be increased in all regions of eastern Canada. More frequent winter thaw events, however, would result in a loss of hardiness and in a thinner snow cover that would increase the plant vulnerability to subsequent extreme sub-freezing temperatures. The risk of damage to flower buds by a late frost would increase in southern Ontario, remain almost unchanged in the Maritimes and Ottawa Valley-southern Québec regions, and decrease in the Continental North. The projected climate change should allow for the introduction of new varieties and species where fruit trees are currently grown and for an extension further north of the commercial production in eastern Canada. Key words: Overwintering, fruit production, climatic indices, winter injury, spring frost

Inonotus dryadeus in North America: new records, hosts, distribution and incidence

Summary Inonotus dryadeus is newly reported in eastern Canada (Ontario) on Acer platanoides and Acer saccharinum, both new hosts, and Ulmus americana. The host range, incidence, and available distributional data in continental North America are summarized in a table. The fungus occurs primarily on Quercus, Abies, and Tsuga. Occasionally, it is found on Picea and Pinus as well as many other hardwood trees. Colder climates and host differences in the boreal forests may be limiting distributional factors. Inonotus dryadeus appears to favour very old trees. The maximum known width of the fruiting body is revised upward to 74.9 cm.

Middleton, Colonial America - A History, 1565-1776

This third edition of Colonial America contains a new chapter on Spanish and French colonization of continental North America, although the focus remains on the English colonies. Middleton has also retained the divided organizational structure employed in earlier editions. Colonial America treats the colonies chronologically up through the end of the seventeenth century and then turns to a thematic treatment of "provincial America" during the eighteenth century before concluding his book with two chapters on the revolutionary crisis leading to independence. The revised and updated bibliography serves as a competent guide to recent work as well as a few old classics.

Multivariate discrimination among cryptic species of the mite genus Chaetodactylus (Acari: Chaetodactylidae) associated with bees of the genus Lithurgus (Hymenoptera: Megachilidae) in North America.

Twenty-seven morphological characters from 111 heteromorphic deutonymphs of the mite genus Chaetodactylus Rondani (Acari: Chaetodactylidae) were analyzed. The mites were collected from four species of bees of the genus Lithurgus Berthold (Hymenoptera: Megachilidae) in continental North America. Principal component and canonical variates analyses on Darroch and Mosimann shape and size-and-shape variables revealed the presence of three cryptic species. Chaetodactylus gibbosi sp. n. (Florida) is geographically isolated from C. lithurgi sp. n. distributed in Texas, New Mexico, Arizona, Colorado, and Idaho. Sympatric C. lithurgi and C. abditus sp. n. (USA: Arizona, Mexico: Socorro Is.) are seasonally isolated in Arizona. Chaetodactylus gibbosi is associated with a single bee species, Lithurgus gibbosus Smith in Florida. The host range of C. lithurgi includes bees flying predominantly in the spring: L. apicalis Cresson, L. littoralis Cockerell, and western L. gibbosus. Chaetodactylus abditus sp. n. is associated with L. planifrons Friese and L. echinocacti Cockerell, flying predominantly in the fall in Arizona. No distinct groups separated by geographic locality or size were detected in any species. A six-variable model developed by the canonical variates analysis and estimated using jackknife resampling and external validation (n = 100) is capable of classifying the three species with 100% accuracy. Factors that influenced speciation of cryptic species of Chaetodactylus associated with Lithurgus are discussed. Based on morphological and geographical data and data on mite associates, the western and eastern populations of the bee L. gibbosus are distinct. Therefore, the taxonomic status of L. gibbosus s. lat. should be reevaluated.

Geochemistry, Sr–Nd isotope composition, and tectonic setting of Holocene Pelado, Guespalapa and Chichinautzin scoria cones, south of Mexico City

Holocene Pelado, Guespalapa and Chichinautzin monogenetic scoria cones and associated lava flows located within the Sierra del Chichinautzin Volcanic Field (SCVF) at the southern margin of Mexico City were mapped and sampled for mineralogical and chemical analyses. With the exception of Parı́cutin volcano in western Mexico, few scoria cones in the Trans-Mexican Volcanic Belt have ever been sampled in greater detail. Chemical analyses of rocks indicate that mafic products (e.g. Guespalapa and Chichinautzin) from individual volcanoes in the Sierra del Chichinautzin are characterized by substantial chemical variability, whereas high-silica andesite volcanoes (e.g. Pelado) are very uniform in composition. These findings have important bearings for regional tephrochronology. As a whole, rock compositions form a continuous coherent calc–alkaline suite, explicable by polybaric fractional crystallization±assimilation associated with successive stagnation at different depths along the ascent path. Trace element and Sr–Nd isotope analyses point toward a <1-km-scale heterogeneous (enriched/depleted) mantle wedge underneath the SCVF. The recently proposed plume-origin for these rocks is not in accord with our data. Instead, magma origin is discussed in relation to the tectonically complex subduction process of the oceanic Cocos Plate underneath the continental North American Plate.

Structure, seismicity, and thermal regime of the Queen Charlotte Transform Margin

This study examines structural, seismicity, thermal, and current deformation constraints on the tectonic regime of the Queen Charlotte Margin located off the northwest coast of Canada. The margin is primarily a transcurrent boundary between the oceanic Pacific Plate and the continental North America Plate, but plate motion models indicate ∼20° of current oblique convergence that initiated ∼5 Myr. The estimated 120 km of convergence has been variously explained as accommodated by underthrusting or by crustal shortening. The near‐vertical Queen Charlotte transcurrent fault and lack of Wadati‐Benioff earthquakes argue against underthrusting. However, structural models for the margin, from receiver function and refraction studies, show little evidence of crustal thickening. The pattern of landward decreasing heat flow, gravity anomalies, an accretionary prism landward of the trench or trough, down‐bowing ocean crust and sediments horizons, and a variety of other geophysical evidence support underthrusting. Receiver function analysis on teleseismic data indicates a 10 km thick low‐velocity layer at 35 km depth, dipping 20° to the east, which is interpreted as underthrusting oceanic crust. The heat flow across the fault zone rapidly decreases landward, in agreement with predictions from a finite element thermal model of underthrusting.