Where the Pilcomayo River runs through the Paraguayan Chaco has become an impossible habitat for wildlife, particularly for the crocodilian caimans whose ecosystem is suffering the worst drought in the past 19 years, partly due to human activities. As a result of the dry spell, which intensified last week, the Pilcomayo is largely a dry, cracked riverbed with sludge deposits where the caimans are dying off for lack of water and of the fish they feed on. Paraguayans have been alarmed these days by the scores of caimans stranded on riverbanks for lack of water, and skeletons of the same species stuck in the mud and dust. However, this is not the first drought to affect the Pilcomayo River, but is rather a phenomenon that occurs every decade, according to the World Wildlife Fund, or WWF. At the same time, human intervention in diverting the river has altered the biological processes of a number of different species that live there, not only caimans but also capybaras and many kinds of fish.



A cattle carcass is pictured on the Agropil ranch as the Pilcomayo river faces its worst drought in almost two decades, in Boqueron, on the border between Paraguay and Argentina, July 3, 2016. (Photo by Jorge Adorno/Reuters)





Alligators are pictured stuck in the mud of the dry Pilcomayo river, which is facing its worst drought in almost two decades, in Boqueron, on the border between Paraguay and Argentina, July 3, 2016. (Photo by Jorge Adorno/Reuters)





Alligators are pictured stuck in the mud of the dry Pilcomayo river, which is facing its worst drought in almost two decades, in Boqueron, on the border between Paraguay and Argentina July 3, 2016. (Photo by Jorge Adorno/Reuters)





Alligators are pictured stuck in the mud of the dry Pilcomayo river, which is facing its worst drought in almost two decades, in Boqueron, on the border between Paraguay and Argentina, July 3, 2016. (Photo by Jorge Adorno/Reuters)





Alligators are pictured stuck in the mud of the dry Pilcomayo river, which is facing its worst drought in almost two decades, in Boqueron, on the border between Paraguay and Argentina, July 3, 2016. (Photo by Jorge Adorno/Reuters)





Dead fish are pictured stuck in the mud of the dry Pilcomayo river, which is facing its worst drought in almost two decades, in Boqueron, on the border between Paraguay and Argentina July 3, 2016. (Photo by Jorge Adorno/Reuters)





Dead fish are pictured stuck in the mud of the dry Pilcomayo river, which is facing its worst drought in almost two decades, in Boqueron, on the border between Paraguay and Argentina July 3, 2016. (Photo by Jorge Adorno/Reuters)





Alligators and capybaras are pictured stuck in the mud of the dry Pilcomayo river, which is facing its worst drought in almost two decades, in Boqueron, on the border between Paraguay and Argentina July 3, 2016. (Photo by Jorge Adorno/Reuters)





An alligator is pictured stuck in the mud of the dry Pilcomayo river, which is facing its worst drought in almost two decades, on the border between Paraguay and Argentina, in Boqueron, July 3, 2016. (Photo by Jorge Adorno/Reuters)





People work to extract water on the Agropil ranch as the Pilcomayo river faces its worst drought in almost two decades, in Boqueron, on the border between Paraguay and Argentina, July 3, 2016. (Photo by Jorge Adorno/Reuters)





Alligators are pictured stuck in the mud of the dry Pilcomayo river, which is facing its worst drought in almost two decades, on the border between Paraguay and Argentina, in Boqueron, July 3, 2016. (Photo by Jorge Adorno/Reuters)





Crows perch on tree branches as alligators are seen stuck in the mud of the dry Pilcomayo river, which is facing its worst drought in almost two decades, in Boqueron, on the border between Paraguay and Argentina July 3, 2016. (Photo by Jorge Adorno/Reuters)





Alligator is pictured stuck in the mud of the dry Pilcomayo river, which is facing its worst drought in almost two decades, on the border between Paraguay and Argentina, in Boqueron, July 3, 2016. (Photo by Jorge Adorno/Reuters)





Alligators and capybaras are pictured stuck in the mud of the dry Pilcomayo river, which is facing its worst drought in almost two decades, on the border between Paraguay and Argentina, in Boqueron, July 3, 2016. (Photo by Jorge Adorno/Reuters)





Alligators and capybaras are pictured stuck in the mud of the dry Pilcomayo river, which is facing its worst drought in almost two decades, on the border between Paraguay and Argentina, in Boqueron, July 3, 2016. (Photo by Jorge Adorno/Reuters)