The howler monkey is the loudest land animal on Earth. Its dawn chorus can be heard from three miles away, and across the Amazon basin it is one of the most recognisable sounds in the rainforest. It is also a sound that is going quiet, valley by valley, as habitat shrinks and yellow-fever outbreaks sweep through unvaccinated populations.
The problem
- There are nine recognised species of howler monkey, ranging from southern Mexico to northern Argentina.
- The black-and-gold howler, the brown howler, and the red-handed howler are all listed as Vulnerable or Endangered.
- A male howler's resonating throat sac allows calls to reach 140 decibels — comparable to a jet engine at takeoff.
- Howler monkeys are folivores, eating mostly leaves, and play a crucial role in forest seed dispersal.
What is putting howlers at risk
Three converging pressures: deforestation that fragments their canopy range; periodic yellow-fever outbreaks that can kill entire troops within weeks; and the bushmeat and pet trades, particularly affecting young howlers taken from their mothers in the smaller, gentler red-handed species.
What WARN is preparing to do
Our Peru and Colombia programmes include howler-monkey triage and rehabilitation, partnership with local sanctuaries on troop-level reintroductions, and funding for yellow-fever surveillance in priority forest reserves. None of this happens without supporter funding.
We need your support to make this happen
World Animal Rescue Network is at the launch stage of this work. We do not yet have rescue numbers to share — and that is exactly why your support matters now. Every donation helps us put trained teams on the ground, secure veterinary supplies and equipment, and reach the first animals before they are lost.
Donate today to fund our first deployments, or sponsor an animal to back a specific species through rehabilitation. You can also join the network as a volunteer, fundraiser, or monthly supporter.
