New research that some are dubbing a second “Silent Spring” shows that neonicotinoid insecticides have an adverse effect on non-target invertebrate species, such as birds. Neonicotinoids are a class of insecticides chemically related to nicotine; in fact the name neonicotinoid literally means “new nicotine-like insecticides.” The new research, discussed in the journal Nature, shows that insects constitute a substantial part of the diet of many bird species during the breeding season and that because of this, neonicotinoid, meant to be eaten by bugs, makes its way easily to insectivorous bird populations, killing both bugs and birds. Researchers say that in the Netherlands, local bird population trends were significantly lower in areas with higher surface-water concentrations of the insecticide. Once the insecticide reached concentrations of more than 20 nanograms per litre, bird populations appear to decline by 3.5 percent on average annually, according to the researchers. Results of the research may suggest that the full impact of neonicotinoids on the natural environment is currently misunderstood and may be more dangerous for birds than has been reported in the past. The researchers note that more studies are needed but that future legislation should take into account the possible cascading effects of neonicotinoids on the environment and wildlife.