The Chernobyl accident had many immediate harmful effects on plants and animals living within the exclusion zone and beyond. Plants and animals responded differently to the accident depending on the dose of radiation they received and their sensitivity to radiation.
At that time and first few years of the accident, there was an increase in mortality and a decrease in reproduction in animals and plants.
Till today, reports are documented of many genetic mutations and many anomalies in animals and plants within the exclusion area and beyond.
However, over the years, as the radioactivity levels decrease, the biological populations have been recovering from the effects of the accident.
Radiation exposure has caused genetic damage and increased mutation rates in many organisms in the Chernobyl region. Some species have shown high mutation rates, such as the barn swallow, the icterine warbler, and the Eurasian blackcap. Birds and mammals at Chernobyl have cataracts in their eyes and smaller brains. Many of the birds have deformed sperm, and up to 40 percent are sterile.
Tumors are evident on some birds in high radiation areas. So are developmental abnormalities in some plants and insects. Populations of many organisms in highly contaminated regions have shrunk, and all major groups of animals, including birds, butterflies, dragonflies, bees, grasshoppers, spiders, and others are less abundant. Individual organisms exposed to radiation suffer serious harm. Overall, there is a decline in abundance and diversity of birds, and some species are more sensitive to radiation than others.