Monitoring and Research on Wading Birds in the Water Conservation Areas ofthe Everglades: The 1996 Nesting season

This project was initiated to continue monitoring reproductive responses of wading birds in the central Everglades, and to investigate two areas of research considered key to understanding and managing wading birds: nestling energetics, and factors affecting food availability. This report summarizes the first of two years of work. (101 page document

Wading Bird Nesting Success in the Water Conservation Areas of the Everglades, 1993

This report documents breeding numbers, reproductive success, and foraging dispersion of long-legged wading birds in the Water Conservation Areas (WCAs) of the Everglades during the first six months of 1993. Briefly, the 1993 spring had abnormally high water and windy conditions throughout the season, and produced poor nesting effort, low to moderate nesting success, and low production of young. Some species, like Wood Storks and White Ibises, did not nest at all in the WCAs. Others, like Great Egrets and Tricolored Herons, showed considerably tenacity under the extremely poor nesting conditions. The 1993 season provided a rare chance to record the reproductive responses of wading birds during sustained high water conditions. (108 page document

Factors affecting breeding status of wading birds in the Everglades.

This goals of this research and monitoring effort are to document nesting effort and roughly categorize success of nesting by wading birds in the central Everglades of Florida, and to investigate the causes of nonbreeding in a high proportion of the adult wading birds in the ecosystem The latter goal has focused on breeding of White Ibises (Eudocimus albus) and has been approached through 1) understanding the nutritional, behavioral, and hormonal aspects of normal breeding in a captive colony ofScarlet Ibises (considered conspecific to White Ibises) in central Florida, and 2) comparing breeding and nonbreeding wild White Ibises in the Everglades, in their physiology, nutritional state, breeding phenology, contaminant load, and hormonal status. This report covers work on this project between January and November, 2000. (81 page docoument

Doppler Probe of Accretion onto a T Tauri star

The YY Ori stars are T Tauri stars with prominent time-variable redshifted absorption components that flank certain emission lines. One of the brightest in this class is S CrA, a visual double star. We have obtained a series of high-resolution spectra of the two components during four nights with the UVES spectrograph at the Very Large Telescope. We followed the spectral changes occurring in S CrA to derive the physical structure of the accreting gas. We found that both stars are very similar with regard to surface temperature, radius, and mass. Variable redshifted absorption components are particularly prominent in the SE component. During one night, this star developed a spectrum unique among the T Tauri stars: extremely strong and broad redshifted absorption components appeared in many lines of neutral and ionized metals, in addition to those of hydrogen and helium. The absorption depths of cooler, low ionization lines peak at low velocities - while more highly ionized lines have peak absorption depths at high velocities. The different line profiles indicate that the temperature and density of the accretion stream increase as material approaches the star. We derive the physical conditions of the flow at several points along the accretion funnel directly from the spectrum of the infalling gas. We estimated mass accretion rates of about 10^(-7) solar masses per year, which is similar to that derived from the relation based on the strength of H alpha emission line. This is the first time the density and temperature distributions in accretion flows around a T Tauri star have been inferred from observations. Compared with predictions from standard models of accretion in T Tauri stars, which assume a dipole stellar magnetic field, we obtained higher densities and a steeper temperature rise toward the star.Comment: Replaces 1408.1846 4 pages, 4 figures. Appears in Astronomy and Astrophysics, 201

The Routine Use of Antibiotics to Promote Animal Growth Does Little to Benefit Protein Undernutrition in the Developing World

Some persons argue that the routine addition of antibiotics to animal feed will help alleviate protein undernutrition in developing countries by increasing meat production. In contrast, we estimate that, if all routine antibiotic use in animal feed were ceased, there would be negligible effects in these countries. Poultry and pork production are unlikely to decrease by more than 2%. Average daily protein supply would decrease by no more than 0.1 g per person (or 0.2% of total protein intake). Eliminating the routine use of in-feed antibiotics will improve human and animal health, by reducing the development and spread of antibiotic-resistant bacteri

Genomic plasticity and rapid host switching can promote the evolution of generalism : a case study in the zoonotic pathogen Campylobacter

This work was supported by the Biotechnology and Biological Sciences Research Council (BBSRC) grant BB/I02464X/1, the Medical Research Council (MRC) grants MR/M501608/1 and MR/L015080/1, and the Wellcome Trust grant 088786/C/09/Z. GM was supported by a NISCHR Health Research Fellowship (HF-14–13).Peer reviewedPublisher PD

Timing and magnitude of net methylmercury effects on waterbird reproductive output are dependent on food availability.

Mercury (Hg) is a globally distributed pollutant. Its sub-lethal effects on reproduction of birds have been used as indicators of contamination and of potential demographic effects. However, studies typically used single endpoints that might not be representative of entire reproductive cycle. To estimate timing and net cumulative effects of Hg exposure under field conditions, we used observational data over 11 years from >1200 nests of great egrets breeding under temporally and spatially varying food availability and Hg exposures in the Florida Everglades. We collected measures of fish biomass and availability (>100 locations annually) and used four avian reproductive endpoints that represented the entire breeding cycle. We calculated net reproductive loss by adding estimated Hg effects on failures prior to egg laying, clutch size, hatching success and nestling survival in response to food availability and Hg exposure. To validate and assess results of the observational egret study, we ran the same analyses with data of captive breeding white ibises experimentally exposed to Hg with ad libitum food over 3 years. We found large (>50 %) reductions in great egret offspring with high Hg exposure (18 mug/g dw THg nestling feather, ~0.7 mug/g ww whole egg THg) and high food availability, and even larger reductions (up to 100 %) with high Hg exposure and low food. Timing and the relative contribution of different endpoints to overall reproductive failure varied with food availability. Failures prior to egg laying were relevant at all food availabilities and proportionally most important during high food availability (~70 % of total losses). Under high food, post-hatching failures increased moderately with increasing exposure (~10 % of total losses), and under low food, hatching failures became dominant (~50 % of total losses). Patterns of failure of captive white ibis fed ad libitum resembled those of great egrets under high food availability but differed in total magnitude. We suggest that, a) net reproductive effects of Hg in free-ranging animals are probably much higher than generally reported in studies using single endpoints, b) Hg effect sizes vary considerably among different endpoints and c) food availability is a strong driver of timing and net effects of Hg exposure.This work was supported by the U.S. Army Corps of Engineers (W912HZ-12-02-0007) and by grants of equipment from the University of Florida Institute of Food and Agricultural Sciences. Egret monitoring was performed under University of Florida IACUC permit 201708650. Fish sampling was supported by Cooperative Agreements W912HZ-11-2-0048 and W912HZ-16-2-0008 between Florida International University (FIU) and the U. S. Army Corps of Engineers and Contract 4600001083 between FIU and the South Florida Water Management District. Fish monitoring was performed under FIU IACUC permits including IACUC-08-004, -09-029, -10-026, 12-020, -13-060, and -16-033. Nestling ibises were collected from the field under Florida Fish and Wildlife Conservation Commission permit WX03527, which also allowed for their maintenance in captivity, and with a modification, re-release into the wild. Ibises were held in captivity under Institutional Animal Care and Use Committee permit D424-2006. Great egret picture in Fig. 1 was taken by J. A. Gonzalez-Oreja and used with his permission while the White Ibis image in the same figure was extracted from a picture downloaded from www.all-free-photos.com licensed under CC BY-SA 2.5. We are grateful to two anonymous reviewers whose comments greatly improved the ms

Factors affecting breeding status of wading birds in the Everglades.

This comprehensive final report summarizes the results of a four-year research and monitoring effort (1998 - 2001) designed to document nesting effort and success by wading birds, and to investigate the reproductive physiology and ecology of White Ibises (Eudocimus albus) in the Everglades ecosystem. The monitoring of nesting has been accomplished bystandardized systematic aerial and ground surveys and study of nesting success of nesting colonies in Water Conservation Areas (WCAs) 2 and 3 ofthe central Everglades. The White Ibis work was accomplished through 1) investigation of the nutritional, behavioral, and hormonal aspects of "normal" breeding in a captive colony of Scarlet Ibises (Eudocimus ruber, considered by many to be the same species as the White Ibis), and 2) documenting the physiology, nutritional state, breeding phenology, contaminant load, and hormonal status of free- living adult White Ibises in the central Everglades. (364 page document