Tanzania’s tree hyraxes survive forest loss by adapting to rocky mountain life

In a remarkable example of wildlife adaptation, Tanzania’s eastern tree hyraxes have successfully transitioned from forest life to rocky mountainsides after losing nearly all their natural habitat. A recent study in the Pare Mountains, near the Kenyan border, reveals how these small, nocturnal mammals have learned to thrive on steep rocky outcrops as centuries of deforestation stripped away their traditional tree homes.

The eastern tree hyrax (Dendrohyrax validus) typically inhabits old-growth evergreen forests across the Eastern Arc Mountains, seeking shelter in large tree cavities during daylight hours. However, the Pare Mountains now retain less than 3% of their original forest cover due to extensive agriculture, mining, and logging activities. Rather than disappearing entirely, these adaptable creatures have made rocky crevices their new refuges.

Conservation biologist Hanna Rosti from the University of Helsinki and her research team documented this adaptation by recording over 700 hours of hyrax calls across 18 sites in the Pare massif. They consistently observed the animals calling from rocky outcrops rather than trees, demonstrating a complete habitat shift. Interestingly, the study also revealed that Pare hyrax vocalizations—including their distinctive “strangled thwack” call—more closely resemble those of populations on Mount Kilimanjaro and Kenya’s Taita Hills than other Tanzanian groups traditionally considered the same species. This vocal evidence suggests these rock-dwelling populations may actually represent a distinct taxonomic group, highlighting how environmental pressures can drive both behavioral and potentially evolutionary changes in wildlife.