Nesting behaviour influences species-specific gas exchange across avian eggshells

Carefully controlled gas exchange across the eggshell is essential for the development of the avian embryo. Water vapour conductance (GH2O) across the shell, typically measured as mass loss during incubation, has been demonstrated to optimally ensure the healthy development of the embryo while avoiding desiccation. Accordingly, eggs exposed to sub-optimal gas exchange have reduced hatching success. We tested the association between eggshell GH2O and putative life-history correlates of adult birds, ecological nest parameters and physical characteristics of the egg itself to investigate how variation in GH2O has evolved to maintain optimal water loss across a diverse set of nest environments. We measured gas exchange through eggshell fragments in 151 British breeding bird species and fitted phylogenetically controlled, general linear models to test the relationship between GH2O and potential predictor parameters of each species. Of our 17 life-history traits, only two were retained in the final model: wet-incubating parent and nest type. Eggs of species where the parent habitually returned to the nest with wet plumage had significantly higher GH2O than those of parents that returned to the nest with dry plumage. Eggs of species nesting in ground burrows, cliffs and arboreal cups had significantly higher GH2O than those of species nesting on the ground in open nests or cups, in tree cavities and in shallow arboreal nests. Phylogenetic signal (measured as Pagel's λ) was intermediate in magnitude, suggesting that differences observed in the GH2O are dependent upon a combination of shared ancestry and species-specific life history and ecological traits. Although these data are correlational by nature, they are consistent with the hypothesis that parents constrained to return to the nest with wet plumage will increase the humidity of the nest environment, and the eggs of these species have evolved a higher GH2O to overcome this constraint and still achieve optimal water loss during incubation. We also suggest that eggs laid in cup nests and burrows may require a higher GH2O to overcome the increased humidity as a result from the confined nest microclimate lacking air movements through the nest. Taken together, these comparative data imply that species-specific levels of gas exchange across avian eggshells are variable and evolve in response to ecological and physical variation resulting from parental and nesting behaviours

Navigating Identity: The Intersection of Social and Biological Identity from the WWII Battle of Tarawa

The 1943 Battle of Tarawa resulted in the loss of approximately 1000 U.S. service members on or around Betio Island, Tarawa Atoll, Republic of Kiribati. Nearly half the casualties were accounted for following the battle. The Defense POW/MIA Accounting Agency (DPAA) has worked to identify the remaining ~510 unaccounted-for service members, with successful identification of ~160 service members to date. Demographic data pulled from historical documentation of the U.S. losses indicate a relatively homogeneous population (99% White, 81% between the ages of 17 to 23 years, and only two individuals documented with a religious preference other than Protestant or Catholic). Using this demographic data as a framework, three case studies are presented to demonstrate how a holistic biosocial approach to identity building could facilitate forensic identifications. The temporal and sociocultural contextualization of analyses enables anthropologists to navigate the inconsistencies between 21st century and historical (1940s) social identity concepts and overcome challenges to identification. The case studies demonstrate how biological evidence, genetic evidence, and material culture (material evidence) differently contribute to the social identity of an individual and can impact identification efforts when analytical conclusions are incongruent with historical documentation. The first case examines how morphometric biological affinity assessments are biased by the fluidity of social identity concepts when complex morphological and metric indicators of biological affinity are not represented in the historical race categories for the U.S. Battle of Tarawa casualties. The second case demonstrates how biogeographic genetic affinity predictions, through a discussion of the G2a4 haplogroup, need to be examined holistically in the context of other lines of evidence. The third case highlights how material evidence can further define social identity beyond physicality, genetic structure, and race. The challenges of interpreting identity from human remains, as highlighted through these examples, are common among anthropologists working in disaster victim identification and other humanitarian contexts. Thus, it is imperative for anthropologists to be self-aware of implicit biases toward the current prevailing definitions of biological and social identity and to consider historical perceptions of identity when working in these contexts

Baylisascaris procyonis in raccoons (Procyon lotor) in eastern Tennessee

Raccoon (Procyon lotor) carcasses (n=118) were collected from July through December 2007 throughout eastern Tennessee. Necropsies were performed, and Baylisascaris procyonis was collected from the gastrointestinal tract of infected carcasses. Prevalence rates were determined for the overall sample population, males and females, and adults and juveniles. The sample population had a B. procyonis prevalence of 12.7%. Males and females had a prevalence of 15% and 11%, respectively; prevalence in adults and juvenile was 13% and 12.6%, respectively. There were no significant differences in prevalence rates between the different groups. Baylisascaris procyonis is an ascarid infection of raccoons that can infect humans and over 100 species of other animals. The presence of infection in raccoons, paired with the expansion of human populations in eastern Tennessee, is likely to lead to increased interactions between humans and raccoons and therefore an increased risk of human and domestic animal exposure to B. procyonis

The hydrological regime of a forested tropical Andean catchment.

The hydrology of tropical mountain catchments plays a central role in ecological function, geochemical and biogeochemical cycles, erosion and sediment production, and water supply in globally important environments. There have been few studies quantifying the seasonal and annual water budgets in the montane tropics, particularly in cloud forests. We investigated the water balance and hydrologic regime of the Kosñipata catchment (basin area: 164.4 km2) over the period 2010–2011. The catchment spans over 2500 m in elevation in the eastern Peruvian Andes and is dominated by tropical montane cloud forest with some high-elevation puna grasslands. Catchment-wide rainfall was 3112 ± 414 mm yr−1, calculated by calibrating Tropical Rainfall Measuring Mission (TRMM) 3B43 rainfall with rainfall data from nine meteorological stations in the catchment. Cloud water input to streamflow was 316 ± 116 mm yr−1 (9.2% of total inputs), calculated from an isotopic mixing model using deuterium excess (Dxs) and δD of waters. Field streamflow was measured in 2010 by recording height and calibrating to discharge. River run-off was estimated to be 2796 ± 126 mm yr−1. Actual evapotranspiration (AET) was 688 ± 138 mm yr−1, determined using the Priestley and Taylor–Jet Propulsion Laboratory (PT-JPL) model. The overall water budget was balanced within 1.6 ± 13.7%. Relationships between monthly rainfall and river run-off follow an anticlockwise hysteresis through the year, with a persistence of high run-off after the end of the wet season. The size of the soil and shallow groundwater reservoir is most likely insufficient to explain sustained dry-season flow. Thus, the observed hysteresis in rainfall–run-off relationships is best explained by sustained groundwater flow in the dry season, which is consistent with the water isotope results that suggest persistent wet-season sources to streamflow throughout the year. These results demonstrate the importance of transient groundwater storage in stabilising the annual hydrograph in this region of the Andes

Weather-monitoring instrumentation for plant disease management programs and epidemiological studies, Station Bulletin, no.519

The Bulletin is a publication of the New Hampshire Agricultural Experiment Station, College of Life Sciences and Agriculture, University of New Hampshire, Durham, New Hampshire

Growth and feed standards for broilers -- 1973, Station Bulletin, no.502

The Bulletin is a publication of the New Hampshire Agricultural Experiment Station, College of Life Sciences and Agriculture, University of New Hampshire, Durham, New Hampshire

Potential for energy conservation in feeding livestock and poultry in the United States, Station Bulletin, no.506

The Bulletin is a publication of the New Hampshire Agricultural Experiment Station, College of Life Sciences and Agriculture, University of New Hampshire, Durham, New Hampshire