Heatwave Kills Howler Monkeys in Mexico Amid Neglect

Tabasco, Mexico — Alerts have been reactivated in southeastern Mexico due to extreme temperatures exceeding 40 degrees Celsius, which have already caused the first deaths of howler monkeys (Alouatta palliata) in their natural habitat in the state of Tabasco.

Sources consulted by Excelsior reported that in recent days, at least two adult howler monkeys—a female and a male—were found dead in the municipality of Comalcalco, specifically in the rural communities of Carlos Greene 3rd Section and Oriente 4th Section. The monkeys are believed to have succumbed to dehydration and heatstroke following prolonged drought, severe wildfires, and urban encroachment into the jungle region.

The two carcasses decomposed in the open due to the absence of a real response protocol from federal, state, or municipal authorities, raising concerns about potential public health risks. Witnesses in the affected communities reported that the monkeys were extremely hot to the touch and exhibited signs of disorientation before falling from treetops.

Authorities’ Response and Ongoing Crisis

The Directorate of Environmental Protection and Sustainable Development of the Comalcalco City Council has so far recovered three live monkeys suffering from heatstroke. Of these, two were rehydrated and reintroduced into the same area where they were found, while the third was handed over to the Federal Attorney for Environmental Protection (Profepa) in Tabasco, which has yet to release any information on the case.

This incident echoes last year’s environmental emergency, which began on May 5, 2024, and resulted in the deaths of at least 350 howler monkeys across the states of Tabasco, Chiapas, Veracruz, and Campeche. In Tabasco alone, 286 deaths were documented during the spring of 2024, representing 31% of the endangered species’ population in the Chontalpa region, which includes the municipalities of Centro, Comalcalco, Cunduacán, Jalpa de Méndez, Paraíso, and Cárdenas, according to a study published in the American Journal of Primatology.

Government Negligence and Legal Action

As previously reported, the response from Mexico’s Ministry of Environment and Natural Resources (Semarnat) was delayed by 20 days and deemed inadequate. The former head of the General Directorate of Wildlife (DGVS), María de los Ángeles García Cahuich, was accused of direct responsibility in the deaths of nine orphaned howler monkey infants.

Recently, the Mexican Association of Zoos, Breeders, and Aquariums (AZCARM) filed a complaint against the former Semarnat official with Profepa, demanding an investigation into her “negligent actions” during the crisis, which lasted until June 2024.

Lack of Preparedness in 2025

Despite last year’s tragedy, the inaction of Semarnat and Profepa in 2025 continues to endanger howler monkeys and regional ecosystems. No effective coordination table or rapid-response protocol has been established.

Primatologists and civil society organizations warn that there is still no clear definition of which agency should act first in heatstroke cases, nor are there allocated resources for rescues. Additionally, communication channels and strategies for handling cases with specific budgets—under strict transparency and accountability rules—remain absent.

“Without these basic elements, rescue efforts become improvised, fragmented, and often ineffective. Every minute lost to bureaucracy is a death sentence for these primates. Strategic planning, resource allocation, clear responsibilities, and immediate action are needed to prevent 2025 from repeating the horrors of 2024. The lives of howler monkeys cannot depend on improvisation or good intentions. Omission is no longer ignorance—it is complicity,” experts warned.