The Chernobyl disaster happened on April 26, 1986. The city of Pripyat was evacuated, but animals remained in the area. Over 35 years later, some species have thrived, others have been severely affected, and even new species have been introduced. But how did these animals respond to radiation exposure? What were the effects of living in and around the Chernobyl Exclusion Zone?
Click through the following gallery and learn more about the animals that call Chernobyl home.
Back in 2011, scientist expected to find abnormalities in the wolves around Chernobyl after analyzing the bones of moose the wolves preyed on, which contained high levels of radiation. But it turns out the wolves seemed absolutely fine.
A 2019 study confirmed the lack of internal radiation in the local wolf population. Because the animals travel long distances to hunt, they end up not eating that much contaminated prey. The study also found that the wolves were exposed to higher-than-expected external radiation, but it's unknown if or how it affects the animals.
In 1990 alone, about 400 deformed farm animals were born in the area. Four years after the disaster, animals were being born with several deformities, including malformation of the head and extra limbs.
These deformities also influenced the size of the animals and their color. It is possible that these mutations have occurred in other animals in the area, but the numbers are not documented.
The effects of exposure to high levels of radiation doesn't manifest until years later. A 2007 study found that the rate of thyroid cancer in people living in Ukraine, Belarus, and Russia was 10 times higher than usual, this 10 years after the nuclear accident. Cattle also suffered the consequences.
The effects on cattle manifested as early as five months after the accident. Animals that were within around 6 miles (9.6 km) from the accident site showed signs of thyroid damage.
There was an attempt to exterminate the feral dog population in the area, but an organization called Clean Futures managed to stop it in 2017. Today, the population is under control, sterilized and vaccinated.
The local bird population was also studied following the nuclear accident. A 2011 study looked at the brain size of 550 different birds from 48 species.
The study found that the brains of the birds that were exposed to more radiation levels were about 5% smaller than the average. This effect has also been observed in humans who were exposed to high levels of radiation.
Sometimes the effects of radiation are not visible, but they do affect animals in other ways. Barn swallows in the exclusion zone, for instance, had their fertility affected.
A study found that up to 40% of the sperm of Chernobyl's male barn swallows is defective. Plus, germline mutations were also found. These are a type of mutation that can occur inside the sperm (or egg) and be passed through genes onto the next generation.
Barn swallows and other birds also saw an increase in partial albinism following the Chernobyl accident. Partial albino birds are usually smaller than average, and may have immunodeficiencies.
The number of bugs and spiders decreased in the area following the nuclear accident. A decrease in insect population means there's less food for other species, including birds, fish, and even some mammals.
A 2009 study found that there is a correlation between the level of radiation present in an area and the size of the insect population. It turns out insects are just as vulnerable to radiation as other species.
Pollinators are extremely important. Without them, an estimated 75% of the world's flowers wouldn't bloom and 35% of the world's food crops would not produce food.
The areas close to the Chernobyl disaster saw a decrease in pollinators. A 2020 study looked at the effect of radiation levels in bees. Researchers used similar levels to those affecting the Chernobyl area at the time. The study found that it affected the bees' reproduction, and reduced colony growth.
Researchers found that bank voles in the exclusion zone had high rates of cataracts. And this not only affected vision, but also had an impact in reproduction. Females with cataracts were found to have smaller litters than healthy ones.
While animals living in the exclusion zone were the most affected by the Chernobyl disaster, it is estimated that the radiation spread out across Europe and reached as far as Sweden.
The Greater spotted eagle is yet another endangered species thriving in the area. There are at least 13 pairs of them living in the Chernobyl Exclusion Zone.
Nonetheless, a scientific review conducted in 2016 found that there's a lack of evidence that supports the fact that animals that've been exposed to radiation are, in fact, healthy.
"Numerous organisms have shown an ability to survive and reproduce under low-dose ionizing radiation arising from natural background radiation or from nuclear accidents. In a literature review, we found a total of 17 supposed cases of adaptation, mostly based on common garden experiments with organisms only deriving from typically two or three sampling locations. We only found one experimental study showing evidence of improved resistance to radiation. Finally, we examined studies for the presence of hormesis (i.e. superior fitness at low levels of radiation compared with controls and high levels of radiation), but found no evidence to support its existence. We conclude that rigorous experiments based on extensive sampling from multiple sites are required," reads the review.
