(REUTERS) - These animals are among the victims of Venezuela's economic crisis.
Zoo officials say some 50 animals have starved to death in the last six months.
They say the high cost of food has led to chronic shortages. And medicine has not been readily available either, according to union leader Marlene Sifontes who oversees Venezuelan zoos.
"In the Caricuao Zoo, it has been three years without medicine and what has come has been donated by the Nevado Mission [program for animals] and they are overdue," said Marlene Sifontes, union leader for employees of the state parks agency Inparques.
Sifontes says mangos are being fed not only to these monkeys, but also to lions and tigers to make up for reduced rations of meat.
But Paraguana Zoo director Marisabel Santana says the larger animals need more calories.
"The animals are fed depending on the nutritional requirements of their species. But now we are finding it difficult to care for them as we would like to care for them," said director of the Paraguana Zoo, Marisabel Santana.
Like these animals, Venezuelans themselves are skipping meals.
Critics blame failed socialist policies for Venezuela's 2-1/2 year recession.
But President Nicolas Madura says the fault lies with falling oil prices and an "economic" war waged by his opponents.
Meanwhile, the animals are caught in the cross-fire.