Deadly Trap: The Unexpected Threat to Madagascar’s Chameleons

Calumma oshaughnessyi, a Malagasy chameleon species, faces increasing threats from habitat loss, climate change, and invasive species. One such invasive plant, Desmodium uncinatum (Silverleaf Desmodium), has recently been identified as a cause of chameleon mortality in Madagascar's Ranomafana National Park. This plant, introduced for cattle forage, possesses sticky, hooked hairs that can entrap and kill small animals.

Two mortality events of juvenile C. oshaughnessyi were recorded—one in March 2023 and another in March 2024. In both cases, the chameleons were found gripping the plant's stem, unable to free themselves. The trapped individuals likely succumbed to starvation or exposure. Reports from local guides suggest that other small vertebrates, including frogs, may also be affected.

This is the first documented case of chameleon mortality due to D. uncinatum in Madagascar. Given the plant's growth patterns, it may pose a significant risk to chameleon populations, especially near hatching sites. Further research is needed to quantify its ecological impact.

Original article: Nash, M.J. & Adriamihaija, P. (2024): Calumma oshaughnessyi (O'Shaughnessy's chameleon). Mortality. - Herpetological Review 55(3): 439.