By way of introductory remarks:
Insecticides harm birds to a greater or lesser extent, depending on level of exposure, bird species, and type of insecticide.
Per the National Wildlife Federation and World Wildlife Fund, habitat loss is the primary threat to the survival of wildlife in the world, including the United States.
Clearing habitats for agriculture is the principal cause of habitat destruction.
Organic farming is less productive overall than farming that uses synthetic inputs, such as insecticides.
Organic farming systems may be more harmful to the environment and endangered species than conventional farms. Per a recent meta-analysis comparing the environmental impact of conventional versus organic agricultural systems:
“…ammonia emissions, nitrogen leaching and nitrous oxide emissions per product unit were higher from organic systems. Organic systems had lower energy requirements, but higher land use, eutrophication [a type of water pollution] potential and acidification potential per product unit.” Clark & Tilman, 2017
If conventional farmers eliminated insecticides, they would need more land to produce the same amount of food.
If only some insecticides are banned, conventional farmers will likely switch to unbanned insecticides, which may be even worse for the environment than those that were banned.
The insecticides I have in mind are neonicotinoids, which have devastated bee populations throughout the world. Seeds treated with neonicotinoids are also toxic to birds (some birds more than others). A few years ago, the European Union banned various neonicotinoids from all agricultural fields because of the harm they caused bees and birds. Follow-up studies are now trickling in from Europe and the results have been quite illuminating. Here are some findings (references at end of post):
Some farmers switched to using untreated seeds as no alternative seed treatments were available. These farmers increased other pest management practices, such as more frequent scouting for pests.
Most farmers continued to use insecticides, either switching to seeds treated with unbanned insecticides or increasing soil applications of unbanned insecticides.
Many farmers perceived that the time, cost and amount of insecticides required to protect crops increased, along with pest pressure. Alternative seed treatments were mostly perceived as being less effective than the restricted seed treatments.
After the ban, beetle-related crop losses increased in England.
Between the ban on neonicotinoids and increased resistance to older insecticides that are not banned, the authors of one study questioned the viability of crops susceptible to beetle infestation.
Neonicotinoids are not yet banned in most US states although there’s plenty of pressure for countrywide ban. However, some agronomists question the wisdom of banning neonicotinoids at this time, until less toxic substitutes are available. In one just-released study that looked at over 89,000 US farms over a 17-year period, the authors predict that a neonicotinoid ban would lead to a large increase in applications of older yet more toxic insecticides and, as a consequence, the danger to wildlife would “increase by about 102% for mammals, 53% for fish, and 59% for birds” ( Perry and Moschini (2020). They conclude that banning neonicotinoids would indeed protect bees, but “this would come at the cost of significant increases in acute toxicity exposure for mammals, fish, and birds” (ibid).
Well, that sucks.
Banning all insecticides is not the answer, because it would force farmers to convert a lot more land to crops to make up for lower productivity. While organic farms typically support more biodiversity on the land being farmed than conventional farms, it is also true that cultivated land, whether organically or conventionally farmed, is worse for biodiversity than wild habitat, so the less land farmed, the better.
Besides, conventional farmers can do a lot to protect wildlife from insecticides. Some ideas:
Targeted Insecticides. Choose ingredients targeted to specific insect species and the least harmful formulations.
Precision Methods and Technology. Precision application of insecticides will eventually pay for the initial investment through increased yields, with the added bonus of protecting pollinators (birds and bees alike). Precision means less insecticide is applied and fewer-insecticide-treated seeds are wasted by sloppy application (hence becoming food for critters).
Bird-Deterrents. Birds get used to just about all of them, so farmers have to use a variety of deterrents, such as dogs, off-site food and shelter, noise-makers, lure crops, and exclusion nets.
Genetically Engineered Crop Varieties: For example, GE corn designed to resist various insects has also been found to significantly reduce wildlife hazard, especially to mammals and fish.
Follow the Manufacturer’s Directions: Some farmers seem to think “more is better” when it comes to insecticides. Not so - check the directions for best practice. Product labels tell how much to use.
Apply insecticides when less collateral damage: avoid applications on windy days. Early evening applications are best, because the birds and bees are less likely to be around.
None of these suggestions are perfect. But perfect is the enemy of much better.
References:
Clark, M., & Tilman, D. (2017). "Comparative analysis of environmental impacts of agricultural production systems, agricultural input efficiency, and food choice" Environmental Research Letters, Vol. 12, No. 6.
Kathage, Jonas et al. “The impact of restrictions on neonicotinoid and fipronil insecticides on pest management in maize, oilseed rape and sunflower in eight European Union regions.” Pest management science vol. 74,1 (2018): 88-99. doi: 10.1002/ps.4715
Perry, E. D. and G. Moschini (2020). "Neonicotinoids in U.S. maize: Insecticide substitution effects and environmental risk." Journal of Environmental Economics and Management 102: 102320. https://doi.org/10.1016/j.jeem.2020.102320
Scott, C. (2019). "The impact of the EU neonicotinoid seed‐dressing ban on oilseed rape production in England." Pest Management Science v. 75(no. 1): pp. 125-133-2019 v.2075 no.2011. https://www.ncbi.nlm.nih.gov/pubmed/30152140