Range-wide post- and pre-breeding migratory networks of a declining neotropical-nearctic migratory bird, the blackpoll warbler.

Identifying the drivers of population declines in migratory species requires an understanding of how individuals are distributed between periods of the annual cycle. We built post- (fall) and pre-breeding (spring) migratory networks for the blackpoll warbler (Setophaga striata), a Neotropical-Nearctic songbird, using tracking data from 47 light-level geolocators deployed at 11 sites across its breeding range. During pre-breeding migration, two stopover nodes (regions) on the U.

Atmospheric pressure predicts probability of departure for migratory songbirds.

Background: Weather can have both delayed and immediate impacts on animal populations, and species have evolved behavioral adaptions to respond to weather conditions. Weather has long been hypothesized to affect the timing and intensity of avian migration, and radar studies have demonstrated strong correlations between weather and broad-scale migration patterns. How weather affects individual decisions about the initiation of migratory flights, particularly at the beginning of migration, remains uncertain.

Songbirds initiate migratory flights synchronously relative to civil dusk.

Background: Each spring and fall billions of songbirds depart on nocturnal migrations across the globe. Theory suggests that songbirds should depart on migration shortly after sunset to maximize their potential for nightly flight duration or to time departure with the emergence of celestial cues needed for orientation and navigation. Although captive studies have found that songbirds depart during a narrow window of time after sunset, observational studies have found that wild birds depart later and more asynchronously relative to sunset than predicted.

Spatial structure in migration routes maintained despite regional convergence among eastern populations of Swainson's Thrushes.

Background: Migratory connectivity links the different populations across the full cycle and across the species range and may lead to differences in survival among populations. Studies on spatial and temporal migratory connectivity along migration routes are rare, especially for small migratory animals.

Methods: We used an automated radio-telemetry array to assess migratory connectivity en route and between early and later stages of the fall migration of the eastern populations of Swainson's Thrush, and to assess the variation of migration pace between consecutive detection from the different receiving stations along the migratory journey.

Prosthetic Rehabilitation of a Repaired Cleft Palate with Use of a Two-Part Hinged Magnet Retained Removable Prosthesis.

The presence of a cleft lip and palate is associated with a number of complications and the oral rehabilitation for the improvement of speech, function and esthetics can involve conventional and surgical orthodontics, distraction osteogenesis, fixed and removable prosthodontics, providing obturation of open defects if required. This clinical report describes the prosthodontic management of a patient with a repaired cleft lip and palate with significant maxillary hypoplasia and primary concern of aesthetics with the use of a two-part hinged magnet retained removable prosthesis.

Nocturnal departure timing in songbirds facing distinct migratory challenges.

Most migratory songbirds travel between their breeding areas and wintering grounds through a series of nocturnal flights. The timing of their departures defines the potential flight duration and thus the distance covered during a migratory night. Yet, migratory songbirds show substantial variation in their nocturnal departure timing.

Migratory blackpoll warblers () make regional-scale movements that are not oriented toward their migratory goal during fall.

Background: Regional scale movement patterns of songbirds are poorly known largely due to difficulties tracking small organisms at broad scales. Using an array of over 100 automated radio telemetry towers, we followed Blackpoll Warblers () during fall migration in the Gulf of Maine region, and assessed how their regional scale movement pathways varied with age, distance to natal origin, and capture date.

Results: Many individuals had movement paths that were not oriented towards their migratory goal ('indirect movement patterns'), regardless of age, distance to natal origin, or time of season.

Migratory orientation in a narrow avian hybrid zone.

Background: Zones of contact between closely related taxa with divergent migratory routes, termed migratory divides, have been suggested as areas where hybrid offspring may have intermediate and inferior migratory routes, resulting in low fitness of hybrids and thereby promoting speciation. In the Rocky Mountains of Canada there is a narrow hybrid zone between Audubon's and myrtle warblers that is likely maintained by selection against hybrids. Band recoveries and isotopic studies indicate that this hybrid zone broadly corresponds to the location of a possible migratory divide, with Audubon's warblers migrating south-southwest and myrtle warblers migrating southeast.

Corticosterone and timing of migratory departure in a songbird.

Bird migration entails replenishing fuel stores at stopover sites. There, individuals make daily decisions whether to resume migration, and must also decide their time of departure. Variation in departure timing affects the total time required to complete a migratory journey, which in turn affects fitness through arrival time at the breeding and wintering grounds.

Towards a conceptual framework for explaining variation in nocturnal departure time of songbird migrants.

Most songbird migrants travel between their breeding areas and wintering grounds by a series of nocturnal flights. The exact nocturnal departure time for these flights varies considerably between individuals even of the same species. Although the basic circannual and circadian rhythms of songbirds, their adaptation to migration, and the factors influencing the birds' day-to-day departure decision are reasonably well studied, we do not understand how birds time their departures within the night.

An Investigation Into the Integrity of Fit of Provisional Crowns Using Current Proprietary Temporary Crown Materials.

Three methods of direct provisional crown construction were investigated for accuracy of marginal fit. A modified proprietary crown coping was compared to Bis GMA and isobutyl methacrylate resin provisional crowns with margins modified by using a flowable composite and 'bead on' isobutyl methacrylate respectively. Measurement was at 50x magnification at seven sites over the fit surface.

Prosthodontic Rehabilitation for a Patient with Ellis-Van Creveld Syndrome: A Case Report.

Patients suffering from Ellis-Van-Creveld syndrome are a challenge for dental management. Aesthetics are a major concern with limited manual dexterity, making choice of treatment critical. A 38 year old female diagnosed with Ellis-Van-Creveld syndrome presented with stained teeth and un-aesthetic smile and related that to her low self-esteem and depression.

Differential fall migratory routes of adult and juvenile Ipswich Sparrows (Passerculus sandwichensis princeps).

Background: Island breeding birds present an ideal system for studying migratory movements in passerines because their populations are clearly demarcated, and individuals must depart on migration from a single location. The Ipswich Sparrow (Paserculus sandwichensis princeps) is a subspecies of the Savannah Sparrow that breeds exclusively on Sable Island, Nova Scotia, Canada and winters along the Atlantic coast of North America. We used a network of 34 automated VHF telemetry receivers to track radio-tagged adult and juvenile Ipswich Sparrows from their breeding island southward through the first half of their fall migratory journey.

Adult and hatch-year blackpoll warblers exhibit radically different regional-scale movements during post-fledging dispersal.

Using a broad-scale automated telemetry array, we explored post-fledging movements of blackpoll warblers breeding in Atlantic Canada. We sought to determine the full spatial scale of post-fledging dispersal, to assess support for three hypotheses for regional-scale post-fledging movement, and to determine whether learning influenced movement during this period. We demonstrated that both young and adults moved over distances more than 200 km prior to initiating migration.

An Investigation into the Accuracy of Two Currently Available Dental Impression Materials in the Construction of Cobalt-Chromium Frameworks for Removable Partial Dentures.

This study investigated the suitability of irreversible hydrocolloid as an impression material for cobalt-chromium framework construction. Scans of casts derived from (1) alginate and (2) addition-cured polyvinylsiloxane impressions were superposed on to a control. The differences within and between groups were compared at fixed landmarks.

An overview on the Effects of 10% and 15% Carbamide Peroxide and its Relationship to Dentine Sensitivity.

The purpose of this overview was to review the available literature to determine if there was any evidence that the application of 10% and 15% carbamide peroxide in tooth whitening procedures resulted in tooth (dentine) sensitivity. The conclusions from the review would indicate that tooth whitening with either 10% or 15% carbamide peroxide is an effective and safe treatment when under a dental professionals' supervision. Reported side-effects were considered mild to moderate in nature and were transient in duration.

Automated telemetry reveals age specific differences in flight duration and speed are driven by wind conditions in a migratory songbird.

Background: Given that winds encountered on migration could theoretically double or half the energy expenditure of aerial migrants, there should be strong selection on behaviour in relation to wind conditions aloft. However, evidence suggests that juvenile songbirds are less choosy about wind conditions at departure relative to adults, potentially increasing energy expenditure during flight. To date, there has yet to be a direct comparison of flight efficiency between free-living adult and juvenile songbirds during migration in relation to wind conditions aloft, likely because of the challenges of following known aged individual songbirds during flight.

Transoceanic migration by a 12 g songbird.

Many fundamental aspects of migration remain a mystery, largely due to our inability to follow small animals over vast spatial areas. For more than 50 years, it has been hypothesized that, during autumn migration, blackpoll warblers (Setophaga striata) depart northeastern North America and undertake a non-stop flight over the Atlantic Ocean to either the Greater Antilles or the northeastern coast of South America. Using miniaturized light-level geolocators, we provide the first irrefutable evidence that the blackpoll warbler, a 12 g boreal forest songbird, completes an autumn transoceanic migration ranging from 2270 to 2770 km (mean ± s.

Bird interactions with offshore oil and gas platforms: review of impacts and monitoring techniques.

Thousands of oil and gas platforms are currently operating in offshore waters globally, and this industry is expected to expand in coming decades. Although the potential environmental impacts of offshore oil and gas activities are widely recognized, there is limited understanding of their impacts on migratory and resident birds. A literature review identified 24 studies and reports of bird-platform interactions, most being qualitative and half having been peer-reviewed.

Landscape movements of migratory birds and bats reveal an expanded scale of stopover.

Many species of birds and bats undertake seasonal migrations between breeding and over-wintering sites. En-route, migrants alternate periods of flight with time spent at stopover--the time and space where individuals rest and refuel for subsequent flights. We assessed the spatial scale of movements made by migrants during stopover by using an array of automated telemetry receivers with multiple antennae to track the daily location of individuals over a geographic area ~20 × 40 km.