Hello everyone!
In my last post, I explored more on Avitrol and its effect on birds and even non-targeted species. Here, I would like to delve into another pesticide that is known as neonicotinoid.
What is neonicotinoid?
Neonicotinoids are a class of pesticides chemically related to nicotine. The name means “new nicotine-like insecticides” (Texas A&M AgriLife, 2015). They act on certain receptors in the nerve synapse and are known to be much more toxic to invertebrate.
They are the most widely used class of pesticides in the world as they are capable of protecting plants and their seeds from insects resistant to other pesticides (Pennisi, 2019). However, based on a 2-year study by Woodcock et al., 2017, they found that the agricultural use of these common pesticides can hurt both domesticated honey bees and wild bees. This may have been one of the main reasons for the honeybees’ disappearance. Such concerns led to the banning of 3 such compounds in the European Union in 2018. I would like to recommend this short video by PAN Europe for further understanding of how neonicotinoids affect bees.
Besides honeybees, a study by Eng et al., 2019, found that white-crowned sparrows become anorexic after eating neonicotinoid pesticides, causing them to lose weight and delay their southward journeys. This study might also be applicable to other birds as well which could help explain the drastic decline of songbirds in recent decades. Timing is everything for birds when they migrate. Flying too late means that they would miss the peak season for good food, good mate, or even good nest site.
Dozens of white-crowned sparrows were caught by researchers in the southern Ontario province in Canada as the birds migrated. The birds were kept in cages with food and water for 6 hours. About a dozen received low doses of the pesticide, another dozen got a lower dose, and control birds received the same handling but no pesticides. The birds were then released after 6 hours each with a tiny radio transmitter on their back which was used to track them. Within hours, the birds with the highest dose lost an average of 6% of their body weight and17% of their fat stores, which is energy storage for the long flight. Over the 6 hours, birds given the pesticides stopped eating and only took in about 1/3 of food untreated birds ate. In addition, the birds did not recover quickly when released. Half of them stuck around Ontario for 3.5 more days or even longer. This could have significant consequences for survival and reproduction. This delay could have been time needed to get the pesticide out of their body and to start eating and regain lost fat (Eng et al., 2019).
The neonicotinoids pesticides act as an anorexic agent causing mass loss. When consumed at toxic concentration, it directly decreases survival and when ingested in small doses can cause delays that further reduce fitness. This would negatively affect the populations of migratory birds that use these agricultural fields for food.
As we move towards more effective mass production of food supply, with increased usage of pesticides, it can cause such major impacts that we may not realize until they are gone one day. These pesticides can also stay in the environment for a long time making recovery even more difficult for them.
That brings me to the end of this post.
See you guys soon!
References
Eng, M. L., Stutchbury, B. J., & Morrissey, C. A. (2019). A neonicotinoid insecticide reduces fueling and delays migration in songbirds. Science, 365(6458), 1177-1180. doi:10.1126/science.aaw9419
Pennisi, E. (2019, September 12). Common pesticide makes migrating birds anorexic. Retrieved October 28, 2020, from https://www.sciencemag.org/news/2019/09/common-pesticide-makes-migrating-birds-anorexic
Texas A&M AgriLife. (2015, December 29). What is a neonicotinoid? Retrieved October 28, 2020, from https://citybugs.tamu.edu/factsheets/ipm/what-is-a-neonicotinoid/
Woodcock, B. A., Bullock, J. M., Shore, R. F., Heard, M. S., Pereira, M. G., Redhead, J., . . . Pywell, R. F. (2017). Country-specific effects of neonicotinoid pesticides on honey bees and wild bees. Science, 356(6345), 1393-1395. doi:10.1126/science.aaa1190
