English

The western meadowlark (Sturnella neglecta) holds a special, almost magical, place in the hearts and souls of those inhabiting the prairies of North Dakota. While it is the state bird, the meadowlark is iconic in its stature because it’s one of the first true tests that winter has relinquished its icy grip on the plains. But across the U.S. — North Dakota is no exception — meadowlark numbers are in a state of decline. According to the Cornell Lab of Ornithology, the breeding population of western meadowlarks has been declining throughout the U.S. and Canada at about 1 percent per year since at least 1966.

European Union health authorities on Tuesday warned that two products from a widely used class of insecticides may be toxic to the developing human brain and should be more strictly controlled to reduce their exposure to the public. The warning is the latest blow to a relatively new group of insecticides, called neonicotinoids, which have become more widely used in recent years because the chemicals were believed to be safer than older alternatives. One of the products, imidacloprid—made primarily by chemical company Bayer AG was until recently the world's top-selling insecticide. But this year, the EU banned many uses of imidacloprid and two other neonicotinoids for two years because of concerns that they are contributing to mass deaths of honey bees. The assessment released Tuesday by the European Food Safety Authority applies to acetamiprid, sold by DuPont and Bayer, and imidacloprid. The manufacturers of the three insecticides dispute the link between their chemicals and bee deaths. Bayer and Syngenta AG in August brought a complaint against the European Commission, the EU's executive arm, saying the restrictions are based on faulty science.

The role of common milkweed (Asclepias syriaca) in the lifecycle of the monarch butterfly has increased interest in the presence of this weed in the north central United States. An initial survey conducted in 1999 found that low densities of common milkweed occurred in approximately 50% of Iowa corn and soybean fields. In 2009, common milkweed was present in only 8% of surveyed fields, and the area within infested fields occupied by common milkweed was reduced by approximately 90% compared to 1999. The widespread adoption of glyphosate resistant corn and soybean cultivars and the reliance on post-emergence applications of glyphosate for weed control in crop fields likely has contributed to the decline in common milkweed in agricultural fields.

Pesticides applied in agriculture can affect the structure and function of nontarget populations at lower doses and for longer timespans than predicted by the current risk assessment frameworks. We identified a mechanism for this observation. The populations of an aquatic invertebrate (Culex pipiens) exposed over several generations to repeated pulses of low concentrations of the neonicotinoid insecticide (thiacloprid) continuously declined and did not recover in the presence of a less sensitive competing species (Daphnia magna). By contrast, in the absence of a competitor, insecticide effects on the more sensitive species were only observed at concentrations 1 order of magnitude higher, and the species recovered more rapidly after a contamination event. The underlying processes are experimentally identified and reconstructed using a simulation model. We conclude that repeated toxicant pulse of populations that are challenged with interspecific competition may result in a multigenerational culmination of low-dose effects.

The method used to approve pesticides in the EU needs to be revised. This was confirmed by a recent study by the Institute for Environmental Sciences Landau. According to the study, the level of fungicides measured in surface waters is often much higher than the level predicted by the current calculation model used in the approval process. Last year a study by the Institute on insecticides had a similarly alarming conclusion.

Ornithologists say 2013 will be viewed as the worst year ever recorded for one of Britain's favourite farmland birds.
They fear that there are now fewer than 1,000 breeding pairs of barn owls (Tyto alba) in England, the population of the protected bird declining by more than three-quarters over the last four years. In a typical year, conservationists estimate, Britain should be home to as many as 4,000 pairs of the birds. The birds were a common sight on farmland in Britain a century ago, but numbers had declined by 70% by the early 1980s, according to some reports. Over this summer, the trust warned that the owl was facing a "catastrophe" and now, following an end-of-year assessment, the true scale of the birds' plight has been revealed. "They have gone from scarce to rare," said David Ramsden, head of conservation at the Barn Owl Trust. "The scale of the decline is not normal." This year, occupancy of nest sites has been between 5% and 15% of previous levels, and for large parts of the country the figure has been even lower.

Unless regulators take action, one of gifts in the lyrics to “Twelve Days of Christmas,” the turtle dove, may become extinct. The dove has experienced major population decline in England over the past 20 years, due in significant part to the destruction of turtle dove habitat and food sources from increasing herbicide use in English agriculture. Other species, such as Monarch butterflies and other pollinators around the world, are also experiencing similar loses of habitat and food sources through an increase in herbicide use. These increasing rates of population decline in wild species underscore the problem that chemical-intensive agriculture plays in the degradation of natural habitats.

Rising levels of cancers and fertility problems have attracted scientists’ attention to endocrine disrupting chemicals, with some calling for strict regulation of the substances, in line with the precautionary principle. Others meanwhile, stress the worthiness of those chemicals in everyday products such as plastics and warn that the foundations of science risk being turned upside down if precautionary measures are taken. Endocrine disruptors are suspected of triggering diseases such as cancer or diabetes and contributing to people becoming overweight or infertile. The controversy has gone beyond the traditional confrontation between the chemicals industry and environmental and health activists. Among scientists, too, opinions vary on whether a link exists between these chemicals and diseases. But all parties agree on one point – that the protection of consumers and the environment must be ensured. Henk Tennekes comments that a new risk assessment is needed to evaluate the effects that chemicals have on humans and the environment and that endocrine disruptors may be a case in point.