Selenium Accumulation in European Starlings Nesting in a Selenium-Contaminated Environment

Abstract

I compared selenium (Se) levels in blood, liver, egg, and diet samples from European Starlings (Sturnus vulgaris) nesting at Kesterson Reservoir, Merced County, California and the surrounding area. Concentrations were highest in adult and nestling blood (8.3 and 5.5 µg g−1, respectively), nestling liver (7.5 µg g−1), and eggs (4.6 µg g−1) from nest boxes in interior parts of Kesterson compared to those from the perimeter (adult and nestling blood = 4.0 and 1.4 µg g−1, respectively, nestling liver = 4.7 µg g−1, eggs = 2.8 µg g−1) and off-site (nestling blood = 3.8 µg g−1, liver = 4.3 µg g−1, egg = 2.7 µg g−1). No hatching failure or embryo effects were observed. Although I found strong positive relationships in Se levels among tissues and eggs, variability of dietary exposure and differences in depuration rates across tissues confounds prediction of Se concentration. Nevertheless, I found blood Se to be a good indicator of dietary exposure that can be sampled nondestructively.

Arthropod communities in a selenium-contaminated habitat with a focus on ant species

“…Except for nesting or burrowing arthropods, such as ants and some spiders, which remain relatively sedentary over longer periods, it is very likely that several insects analyzed may have been travelling between habitats in search of food. Overall concentrations for arthropods reported in our study are similar to those found in previously sampled invertebrates from this habitat (Santolo and Yamamoto, 1999;Santolo, 2007). Several studies have investigated the impacts of disturbance on ant diversity (Hoffmann and Andersen, 2003 [and references therein]).…”

“…The use of the reservoir as a repository for drainage water was then terminated and the ponds were filled in and the vegetation plowed in an effort to prevent further exposure to wildlife. Scientists have continued to monitor wildlife in the area, with most studies focusing on birds and small mammals (Ohlendorf et al, 1988;Santolo, 2009Santolo, , 2007. A few publications have reported on the accumulation of selenium by invertebrates at Kesterson (Ohlendorf, 2002;Ohlendorf et al, 1988;Santolo and Yamamoto, 1999;Santolo, 2007), but no published information is available as to the impact on ants, pollinators, or terrestrial insects at the population or community level.…”

Use of Site-Specific Data for Modeling Selenium Bioaccumulation by Terrestrial Animals

“…Plant [ (Santolo 2007) were used to describe the relation between passerine diet and blood Se concentrations (r 2 = 0.47, n = 9, P = 0.042). In addition, we assumed that Se uptake from plant and invertebrate diets was less than complete and used an initial correction factor of 0.70.…”

Environmental contaminants and chromosomal damage associated with beak deformities in a resident North American passerine

“…Concentrations were similar to or well below levels of 10 elements tested and were ruled out as a likely cause of beak deformities among the endangered southwestern willow flycatcher ( Empidonax trailli extimus ) . For selenium, however, the relationship between liver concentrations in adults and nestlings and concentrations in eggs has been found to be quite variable , so confirmatory testing for inorganic elements in chickadee eggs would more conclusively rule out any effects. The highly toxic, sometimes teratogenic, organic form of mercury (MeHg) was detected in only 3 of 9 adult chickadees tested, and levels were 100‐fold lower than background concentrations measured in liver tissue of other North American passerines and well below concentrations demonstrated to cause chronic or lethal effects in birds .…”