نتایج جستجو برای: herons

تعداد نتایج: 170  

2014
Janina Pagel Alejandro Martínez-Abraín Juan Antonio Gómez Juan Jiménez Daniel Oro

We used the so called "land-bridge island" or "nested-subsets" theory to test the resilience of a highly fragmented and perturbated waterbird metacommunity, after legal protection of 18 wetlands in the western Mediterranean. Sites were monitored during 28 years and two seasons per year. The metacommunity was composed by 44 species during breeding and 67 species during wintering, including shore...

2003
Gaby Zimmermann

The bioaccumulation behaviour of single PCB congeners in three trophic levels of a food chain in an aquatic ecosystem was studied. Congener-specific biotransfer factors were calculated comparing PCB concentrations in tissues of 4 water bird species with the contents measured in their food source. The coplanar PCBs were of particular interest. The maximum concentrations of individual PCB congene...

2013
Chiranjib Sur Anupam Shukla

Following the nature and its processes has been proved to be very fruitful when it comes to tackling the difficult hardships and making life easy. Yet again the nature and its processes has been proven to be worthy of following, but this time the discrete family is being facilitated and another member is added to the bio-inspired computing family. A new biological phenomenon following meta-heur...

2003
MICHEL ROBERT RAYMOND MCNEIL ALAIN LEDUC

--On a small bay of the Chacopata lagoon complex in northeastern Venezuela, we analyzed the temporal feeding activity patterns of shorebirds and other water birds, and we determined the factors or conditions related to these patterns. During daytime and nighttime observations, we measured the abundance of each species as well as environmental factors (time, wind velocity, cloudiness, tide level...

Journal: :Ecotoxicology and environmental safety 2011
Rita M Seston Timothy B Fredricks Dustin L Tazelaar Sarah J Coefield Patrick W Bradley Shaun A Roark John L Newsted Denise P Kay Matthew J Zwiernik John P Giesy

Concentrations of dioxin-like compounds, primarily polychlorinated dibenzofurans (PCDFs), in soils and sediments of the Tittabawassee River (TR) and associated floodplains downstream of Midland, Michigan (USA) were greater than upstream sites and prompted a site-specific risk assessment of great blue herons (GBH). Dietary exposure of GBH to PCDFs and polychlorinated dibenzo-p-dioxins (PCDDs) wa...

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