Sleeping Giants – Calumma parsonii Brumating

Calumma parsonii is the largest chameleon species of all. Its remarkable size is their advantage and their curse at once: a giant among arboreal reptiles, yet so heavy and slow that the cold season presses on them more than on any smaller forest dweller. When the temperatures fall in the wintertime under a certain threshold, they begin to brumate. They spend several weeks or even months inactive — they overwinter. Their tiny cousins warm their bodies to normal operating temperatures after only brief basking; their small body mass allows rapid heating. But these giants, often above half a kilogram, cannot do so. They choose to "sleep" until the temperatures rise.

While some reports speculated that they brumate high in the canopies, my observations in Vohimana and Anosibe Anala revealed them sleeping at considerably low perch heights: one to three meters high, usually in dense vegetation. They were either fully asleep or simply looking around without moving. Local rangers and forest workers confirmed these observations too.