Endangered Howler Monkey Dies from Screwworm in Mexico

Palenque, Chiapas — The death of a male howler monkey in Palenque, Chiapas, has raised alarms among environmental authorities and specialists after it was confirmed the specimen was a victim of a screwworm infestation. The Secretariat of Environment and Natural Resources (Semarnat) stated that, so far, this is the only documented case in this primate species, which is considered endangered.

Discovery and Diagnosis

According to the Federal Attorney for Environmental Protection (Profepa) and Semarnat, the monkey — approximately five years old — was found by residents in December 2025 after falling from a tree in the jungle area of Palenque. It presented visible lesions on one limb and unusual behavior, leading to its transfer for veterinary evaluation.

Specialists confirmed the animal had a serious infection from screwworm, a pest that causes myiasis by invading open wounds with larvae that destroy living tissue. The lesion showed advanced damage that made recovery impossible.

Semarnat: Isolated Case in Primates

In its official response, Semarnat emphasized this is the only recorded case in a howler monkey and there are no indications of the pest spreading to other primates or similar wildlife. The agency explained that although screwworm primarily affects livestock, isolated cases have been detected in recent months in wild fauna, including birds of prey, deer, and a water buffalo.

Context of the Plague in Mexico

The National Service for Agrifood Health, Safety, and Quality (Senasica) reported that, as of January 2026, there are hundreds of active screwworm cases in 14 states across the country, with the highest incidence in Oaxaca, Veracruz, Yucatán, and Chiapas. Although most correspond to livestock and domestic animals, its presence in wild fauna raises concerns due to its potential ecological impact.