What If Gone

Species → Common Brown Lemur

Common Brown Lemur

Eulemur fulvus

No precise global figure; decline estimated at 30% over three…
Extinction risk Vulnerable
Seed disperserTropical forestKeystone species
Common Brown Lemur (Eulemur fulvus)
Photo: David Dennis, Wikimedia Commons (CC BY-SA 2.0)

What if it disappeared?

Impact High
Over 25 years, Mayotte

On the island of Mayotte, the introduced brown lemur population fell from 50,000 individuals in 1975 to just 25,000 in 1987 — a decline largely attributed to a devastating 1984 cyclone — before rebounding to 42,000-72,000 by the late 1990s, once that one-off effect had faded.

Documented
Detail

Tarnaud, L. et Simmen, B. (2002). A major increase in the population of brown lemurs on Mayotte since the decline reported in 1987. Oryx, 36(3), 297–300.

This U-shaped trajectory illustrates the difference between a one-off shock — here climatic — and a structural threat: the population recovered once the cyclone's effect faded, but the authors warn that ongoing forest loss and growing human pressure on the island will keep affecting the species with no foreseeable end date.

In Madagascar

What is at stake on mainland Madagascar, where the decline is structural rather than cyclical: as the largest frugivore still present at its study site, the common brown lemur disperses seeds of 70 plant species, 23 of which depend on it entirely — their seeds exceed 10 mm in diameter, too large for any other available animal.

Documented
Detail

Sato, H. (2022). Significance of seed dispersal by the largest frugivore for large-diaspore trees. Scientific Reports, 12, 19086.

The author measures a 58.8% removal rate of the Astrotrichilia asterotricha fruit crop (fruiting in the dry season) and 26.0% of Abrahamia deflexa's (fruiting in the rainy season) by common brown lemurs. In forests where large frugivores have disappeared or declined, seedlings and saplings of large-seeded species occur at much lower density there, and clustered around the parent tree rather than dispersed — an early sign of breaking forest regeneration.

Documentation

Last verified: August 14, 2026