Threats to Frogs

Threat to Frogs: Diseases

Just like us humans, frogs and other amphibians can become sick from diseases. Here are some of the most known diseases for frogs.


Red Leg Syndrome is caused by the capillaries stretching and even bleeding out under the frogs skin.  Untreated, this can lead to the frog’s death. This disease is often found in captive amphibians.  The bacteria Aeromonas hydrophila is one of the most common culprits of getting the amphibian sick but there are other bacteria that can cause red leg syndrome too. 


Ranavirus is responsible for large die offs of frogs, other amphibians, and turtles. Ranavirus is a genus of viruses from the family Iridoviridae. Ranavirus is believed to be found in every state besides maybe Hawaii.  Its found in North America, South America, Europe, Asia, and Australia. One of the easy signs to see of Ranavirus is red skin hemorrhages.

Chytrid Fungus is maybe the worst disease out there. I wrote a full post on it so I’ll just link that here

Threats to Frogs

Threat to Frog: Over-harvesting


One of the driving forces behind the frog extinction crisis is the over-harvest of frogs. Frogs are harvested for a variety of reason: pet trade, food, etc but these can harm the native frog populations. Some frog populations are already too small and removing even a few species could be detrimental to the group.

Besides just removing the frogs from the wild, the trade of frogs and amphibians spread diseases, such as Chytrid Fungus, that kill frogs. The trade is also responsible for some of the invasive species around. One such story is the American Bullfrogs in California. The American Bullfrog isn’t naturally found west of the Rockies but people have brought them over to eat. Sadly, some of the frogs got out and started breeding and took over.

To help stop the problem, you can just not eat frog legs. Also you can try to not import amphibians from other countries and to not get ones that are endangered.



Threats to Frogs

Threat to Frogs: Climate Change

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As the climate around the world changes and warm up, the animals of the world have to deal with the changes around them. The warmer climate is bad news for frogs. Droughts will be more common and frogs need rain and water. Ponds and lakes that frogs use to breed are drying up, leaving the eggs in a bad spot.

Another part of the problem with a warming climate is that Chytrid fungus might become easier to spread. Chytrid Fungus is a disease that affects amphibians. The skin of the frog becomes thick, making it hard for the frog to breath and drink through. The ideal temperature for spreading Chytrid Fungus is apparently 63° and 77°F (17° and 25°C).

Threats to Frogs

Threat to Frogs: Pollution

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When people think of pollution, they usually think about trash in parks or the ocean, but that’s just the tip of the pollution problem. While this type of pollution is a serious problem, it doesn’t affect frogs as much as other types. It is still bad and the plastic can break down and harm frogs.

Frogs have thin skin that allows chemicals and minerals to easily pass into their body. Their eggs don’t have thick, hard shell either and are susceptible as well.

One of the most serious problems for frogs is pesticide runoff from frogs. Various pesticides have been shown to cause harm to frogs. The pesticide Atrazine has been shown to change the sex of frogs, making males produce eggs. Most other pesticides just kill the frog or reduce their immune system. Some frogs have even mutated, adding extra arms and legs.

Besides pesticides, minerals from mining can cause problems for frogs. Aluminium, cadmium, copper, iron, and zinc can all kill frogs. Other minerals such as lead and nickel can mess up frogs too. Also oil spills are bad.

One source of pollution that gets overlooked is light pollution. The light of big cities can screw with the inner workings of frogs. Most frogs are nocturnal and when they see the lights, they still think its day.

Threats to Frogs

Threat to Frogs: Habitat Loss


Habitat loss is the biggest threat to frogs, toads, and wildlife in general around the world. Without a suitable habitat for frogs, they will die out. There are 3 different types of Habitat loss:  habitat destruction, habitat fragmentation, and habitat degradation.

Habitat destruction is where the habitat is completely destroyed, such as plowing down trees for a palm oil plantation. The main reason for habitat destruction is actually agriculture to make room for more crops. Other reasons include mining, urban development, and logging.

Habitat fragmentation is where an animal’s habitat is altered that causes confusion to the animal. Dams in rivers, roads through the forest, and border walls cause this problem. This can cut the population of a species into two isolated populations which reduces diversity.  It also makes it harder for the species to find food.

The last one is habitat degradation where a specific attribute of the habitat is lost. This could be something such as polluting the water in a wetland or over- harvesting a species. The removal of one attribute could damage the whole habitat.

I bought some land to help protect frogs and other species. You can learn more about them here

Threats to Frogs

Threat to Frogs: Chytrid Fungus

Photo by Forrest Brem

Chytrid Fungus has decimated the frog and amphibian world. Chytrid Fungus or Batrachochytrium dendrobatidis, Bd for short, was discovered in 1999 as a fungus that infects the skin of amphibians. The skin of the amphibian becomes thicker which makes it harder for the amphibians to breath and drink through its skin, leading to death.

Chytrid Fungus is scary because it is believed that the majority of the world’s frogs can be infected by it. There are some species of frogs that are resistant to it such as the African Clawed Frog and the American Bull Frog but the majority of frogs aren’t resistant to it. Chytrid Fungus has been spread all over the world through the trade of amphibians for food, experiments, and pets. Also the spores can stick to clothes and shoes and travel with humans.

Chytrid Fungus is treatable. Some conservation groups such as the Hondursas Amphibian Rescue and Conservation Center are bringing in young frogs and treating them for the fungus and releasing them back into the wild.


Threats to Frogs

Threat to Frogs: Invasive Species


Invasive species are a threat to frog populations world wide but what is an invasive species? An invasive species is a non-native species that has a negative impact of the environment. They can be both plants and animals. These introduced species thrive in their new areas since they lack their natural predators and don’t have to compete against organisms that limited their growth in their native environment.

These organisms can be purposely released in the new environment or by accident. Often, these organisms are released into an area to stop a problem, but actually cause even more problems. The Cane Toad was introduced to Australia to reduce insects harming sugar cane crops but the Cane Toad spread and caused harmed to other native species.

These species can out compete the native species for resources, introduce new diseases, and prey on the native species.

There are even invasive frog species that are bad for other frogs. The American Bullfrog is an invasive species around the world. With its large size and appetite, it devours anything that it can fit into its mouth – including other frogs.