In the last five years, scientists in Costa Rica have noticed a marked increase in Black Mantled Howler Monkeys — who are turning blonde. Howler Monkeys (called Congos in Spanish), comprise 69% of the primate population of the country. Howlers are renowned for their vocalizations made by adult males, which can be heard more than one kilometer away. They are called “mantled” howler monkeys due to the longish reddish-blonde hairs they have along the sides of their bodies. The rest of their bodies are covered with lush, jet black hair. But now scientists have noticed that these jungle creatures are beginning to change color, at an alarming rate.
Alouatta Palliata (Howler) monkeys are common throughout Central America and northern South America. But only in Costa Rica have scientists discovered that something bizarre is going on. At first, it was just a few spots and patches of yellow hair observed on some Howlers, mostly on their legs and tails. But now scientists have discovered at least 21 Howlers living along the coasts of Costa Rica, who have giant patches of yellow hair, and have even found two wild monkeys who are completely blonde.
What could be going on with these animals? Analysis of the yellow fur of these Howlers reveals that there is a difference in the type of melanin produced by the mutant monkeys. Melanin is the pigment that colors hair and skin in mammals. In Black Mantled Howler Monkeys, the pigment responsible for producing black, gray or brown fur is called eumelanin. But in the mutant monkeys, the melanin switches to pheomelanin, which produces yellow, red, or orange tones instead.
According to Science Alert, “This marks the first time scientists have noticed such a rapid change in the pigmentation of primate fur, or any other mammal for that matter. We are not aware of similar changes in pigmentation of other primates or other groups of animals.”
Scientists are studying these mutant monkeys, but have tentatively concluded that the change is a result of high pesticide use throughout Costa Rica. Pesticides are used to repel bugs from cash crop export foods, including bananas, pineapples, African palm trees, melons and coffee. The pesticides used are mostly sulfur based, but more research is needed to determine if sulfur is the root cause.
What is certain, is that Costa Rica has some of the highest pesticide use in the world, averaging over 25 kilograms (55 pounds) per hectare of cultivated land. China comes in in second place for their pesticide use. Rates for usage of herbicide (weed killer) use in Costa Rica are also quite high in comparison to other developing countries. Scientists have observed that most of the mutant monkeys in Costa Rica reside in forests and jungles surrounding farms using these pesticides.
The use of pesticides is of concern to all Costa Ricans, for its effect on water contamination, crop toxicity, and concerns for the health of farm workers — as well as those, who like the monkeys, live near pesticide treated-crops. Now that Howlers are going blonde, scientists have said it is urgent to look at the causes and effects of this change.
Says Mammalian Biology Journal, “All of that bright fur may look harmless, but the conspicuous colour change could make these monkeys more vulnerable to attack from jaguars and other predators. After all, those poor souls with completely yellow fur stand out like ripe fruit against the dense green jungle.”
Alouatta Palliata (Howler) monkeys are common throughout Central America and northern South America. But only in Costa Rica have scientists discovered that something bizarre is going on. At first, it was just a few spots and patches of yellow hair observed on some Howlers, mostly on their legs and tails. But now scientists have discovered at least 21 Howlers living along the coasts of Costa Rica, who have giant patches of yellow hair, and have even found two wild monkeys who are completely blonde.
What could be going on with these animals? Analysis of the yellow fur of these Howlers reveals that there is a difference in the type of melanin produced by the mutant monkeys. Melanin is the pigment that colors hair and skin in mammals. In Black Mantled Howler Monkeys, the pigment responsible for producing black, gray or brown fur is called eumelanin. But in the mutant monkeys, the melanin switches to pheomelanin, which produces yellow, red, or orange tones instead.
According to Science Alert, “This marks the first time scientists have noticed such a rapid change in the pigmentation of primate fur, or any other mammal for that matter. We are not aware of similar changes in pigmentation of other primates or other groups of animals.”
Scientists are studying these mutant monkeys, but have tentatively concluded that the change is a result of high pesticide use throughout Costa Rica. Pesticides are used to repel bugs from cash crop export foods, including bananas, pineapples, African palm trees, melons and coffee. The pesticides used are mostly sulfur based, but more research is needed to determine if sulfur is the root cause.
What is certain, is that Costa Rica has some of the highest pesticide use in the world, averaging over 25 kilograms (55 pounds) per hectare of cultivated land. China comes in in second place for their pesticide use. Rates for usage of herbicide (weed killer) use in Costa Rica are also quite high in comparison to other developing countries. Scientists have observed that most of the mutant monkeys in Costa Rica reside in forests and jungles surrounding farms using these pesticides.
The use of pesticides is of concern to all Costa Ricans, for its effect on water contamination, crop toxicity, and concerns for the health of farm workers — as well as those, who like the monkeys, live near pesticide treated-crops. Now that Howlers are going blonde, scientists have said it is urgent to look at the causes and effects of this change.
Says Mammalian Biology Journal, “All of that bright fur may look harmless, but the conspicuous colour change could make these monkeys more vulnerable to attack from jaguars and other predators. After all, those poor souls with completely yellow fur stand out like ripe fruit against the dense green jungle.”
