Comment on “Exposure to mercury and Aroclor 1268 congeners in least terns (Sternula antillarum) in coastal Georgia, USA” by G. L. Robinson, G. L. Mills, A. H. Lindell, S. H. Schweitzer and S. M. Hernandez, Environmental Science: Processes & Impacts, 2015, 17, 1424

2016 ◽  
Vol 18 (2) ◽  
pp. 289-291 ◽  
Author(s):  
P. C. Fuchsman ◽  
M. H. Henning ◽  
V. S. Magar
Keyword(s):  
Environmental Science ◽  
Least Terns ◽  
Least Tern ◽  
Aroclor 1268

Omissions in Robinson et al.'s interpretation of Aroclor 1268 concentrations in least tern eggs alter the study's conclusions.

Exposure to mercury and Aroclor 1268 congeners in least terns (Sternula antillarum) in coastal Georgia, USA

2015 ◽  
Vol 17 (8) ◽  
pp. 1424-1432 ◽  
Author(s):  
Gabrielle L. Robinson ◽  
Gary L. Mills ◽  
Angela H. Lindell ◽  
Sara H. Schweitzer ◽  
Sonia M. Hernandez
Keyword(s):  
Superfund Site ◽  
Least Terns ◽  
Least Tern ◽  
Aroclor 1268

We demonstrate the previously undocumented transport of a rare PCB mixture (Aroclor 1268) from a Superfund site in Georgia, and compare mercury loads among sample types, using least tern samples.

Mixed evidence for effects of stewardship on Least Tern reproductive success in coastal Mississippi

The Condor ◽  
2020 ◽  
Author(s):  
Abigail J Darrah
Keyword(s):  
Sandy Beaches ◽  
Chick Survival ◽  
Least Terns ◽  
Least Tern ◽  
Daily Nest Survival ◽  
Coastal Birds ◽  
Total Productivity ◽  
Work Shifts ◽  
Breeding Seasons ◽  
Positive Effect

Abstract Disturbance from human activity can cause reduced productivity of coastal birds that nest on sandy beaches. A common method to protect coastal birds from human disturbance is the use of signs and fencing to close off a section of beach used for breeding. This management action requires public compliance and might require enforcement, such as in the use of volunteer stewards stationed at protected colonies that provide education and enforcement. I assessed the effectiveness of active stewardship as a conservation measure to protect nesting Least Terns (Sternula antillarum) in coastal Mississippi by determining if colony-level productivity (fledglings produced per nest) was correlated with stewardship effort (hours that stewards protected each colony), the rate of disturbance from human and natural sources, and additional factors. Observers surveyed 24 Least Tern colonies in Harrison County, Mississippi, twice weekly during the 2017–2019 breeding seasons to record the number of nests present, the fate of marked nests, predator tracks within the colony, and the number of fledglings produced per colony. Concurrently, during their work shifts, stewards recorded all sources and durations of disturbance events that caused the terns to flush or respond with defense. Least Tern daily nest survival increased with colony size and stewardship effort, and was lower during intervals that included weekends and evidence of owl presence. Total productivity was negatively associated with avian predator disturbance rate and the total time adults spent flushed, but was not associated with stewardship effort. The results of this study demonstrate that active stewardship can have a positive effect on Least Tern productivity by increasing nest success, whereas current stewardship practices were not sufficient to increase chick survival, even in a system with a paucity of ground predators.

scholarly journals Habitat Characteristics and Nest Success of Snowy Plovers Associated with California Least Tern Colonies

The Condor ◽  
2001 ◽  
Vol 103 (4) ◽  
pp. 785-792
Author(s):  
Abby N. Powell
Keyword(s):  
Social Factors ◽  
San Diego ◽  
Nest Success ◽  
Habitat Characteristics ◽  
Egg Predation ◽  
Sterna Antillarum ◽  
Charadrius Alexandrinus ◽  
Least Terns ◽  
Least Tern ◽  
Snowy Plovers

AbstractNest success of Snowy Plovers (Charadrius alexandrinus) was estimated at six sites in San Diego County, California, to determine the effects of habitat characteristics and social factors on predation risk. Egg predation was expected to be lower for plovers nesting among Least Terns (Sterna antillarum) because of benefits associated with nesting under the “protective umbrella” of a colonial species. Snowy Plovers nested adjacent to objects and in areas with more vegetation cover than random sites in beach and fill habitats and in areas with more debris cover in beach and salt pan habitats. Estimated nest success from 1994–1997 was 50%, and most predation was attributed to corvids, primarily Common Ravens (Corvus corax). Social factors, including distance to nearest Least Tern and Snowy Plover nests, predicted nest success whereas habitat characteristics did not. Nest success was greatest for plovers nesting closest to an active tern nest and nesting at intermediate distances to conspecifics. Nest success also varied among years and sites, with two sites consistently less successful over the four years. Nests within tern colonies received some mitigation of egg predation. Plover nests initiated prior to the arrival of Least Terns were less likely to hatch eggs than later nests; nevertheless, Snowy Plovers in southern California initiated nesting well before Least Terns.Características del Hábitat y Éxito de la Nidada de Charadrius alexandrinus Asociados a Colonias de Sterna antillarumResumen. Para determinar los efectos de las características del hábitat y factores sociales sobre el riesgo de depredación, estimé el éxito de las nidadas de Charadrius alexandrinus en seis sitios del Condado de San Diego, California. Se esperaba que la depredación de huevos fuera menor para los C. alexandrinus que anidan junto a Sterna antillarum debido a los beneficios de anidar bajo un “paraguas protector” de una especie colonial. En playas y hábitats rellenados, C. alexandrinus anidó con mayor frecuencia en lugares adyacentes a objetos y en áreas con mayor cobertura de vegetación que en sitios aleatorios y en áreas con mayor cobertura de desechos vegetales en playas y salinas. El éxito estimado de las nidadas entre 1994–1997 fue de 50%, y la mayor tasa de depredación fue atribuida a córvidos, principalmente a la especie Corvus corax. Factores sociales como distancia al nido más cercano de S. antillarum y C. alexandrinus predijeron el éxito de la nidada, mientras que las características del hábitat no lo hicieron. El éxito de la nidada fue mayor para los individuos de C. alexandrinus que nidificaron más cerca de un nido activo de S. antillarum y que nidificaron a distancias intermedias de conespecíficos. El éxito de la nidada también varió entre años y sitios. Dos sitios presentaron consistentemente un menor éxito durante los cuatro años de estudio. Los nidos ubicados dentro de la colonia presentaron una leve disminución en la depredación de huevos. Los huevos de nidos de C. alexandrinus iniciados antes de la llegada de S. antillarum tuvieron una menor probabilidad de eclosión que huevos de nidos más tardíos. Sin embargo, C. alexandrinus comenzó a nidificar bastante antes que S. antillarum en California del Sur.

Whistleblowers in Environmental Science, Prevention of Suppression Bias, and the Need for a Code of Protection

2000 ◽  
Author(s):  
Elihu Richter ◽  
Colin L. Soskolne ◽  
Joseph LaDou ◽  
Tamar Berman
Keyword(s):  
Environmental Science
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