The Critically Endangered western chimpanzee declines by 80

Area of Science:

• Primatology
• Conservation Biology
• Ecology

Background:

• African large mammals face threats from hunting and habitat loss.
• Great apes, like the western chimpanzee (Pan troglodytes verus), are particularly vulnerable due to life history traits.
• These traits include late reproduction, long inter-birth intervals, and low population densities.

Purpose of the Study:

• To assess the population change rate of the western chimpanzee over a 24-year period.
• To quantify the decline in abundance and geographic range of this subspecies.
• To inform conservation strategies and highlight the urgent need for action.

Main Methods:

• Utilized transect nest count data from 20 sites archived in the IUCN SSC A.P.E.S. database.
• Employed Generalized Linear Models to estimate site-specific and global population changes.
• Analyzed data representing 25,000 of the estimated 35,000 remaining western chimpanzees.

Main Results:

• Detected a significant negative population trend at 12 out of 20 study sites.
• Estimated a 6% annual decline in western chimpanzee abundance, totaling 80.2% over the study period (1990-2014).
• Observed a 20% reduction in the subspecies' geographic range.

Conclusions:

• The western chimpanzee population has experienced a drastic decline, leading to its "Critically Endangered" status.
• Threats include poverty, conflict, disease, agriculture, industry, and inadequate law enforcement.
• A call for increased conservation commitment, government engagement, private sector integration, and donor support in West Africa is crucial.