Callithrix jacchus (Linnaeus, 1758)
手のひらに汗や尿で滑り止め
Sweat and urine on the palm prevent slipping
体長約29cm、尾長約41.5cm。大きさがリスのように小さく、体色も似ていることから「リスザル」と呼ばれます。中南米、ブラジルやコロンビア、フランス領ギアナ、スリナム、ベネズエラ、プエルトリコなどに分布しています。
森林に集団で生息し、木の実や虫、小鳥を食べます。比較的おとなしいサルですが、無理に捕まえたりすると噛み付きます。糞や尿の独特な臭いがあります。尿は手のひらに付けて、さらに足の裏にこすり付けることで、移動の際に木々へ自分の痕跡残すためのマーキングを行います。また同時に枝をしっかり握るための滑り止めの役目もあるようです。
リスザルは手足の手のひらからのみ汗をかくことができます。ですので温度調節機能は限られており、昼行性ですが朝や夕方の涼しい時間帯に行動します。
They live in family groups
They measure approximately 29 cm in body length and 41.5 cm in tail length. They are called “squirrel monkeys” because of their small size and similar body coloring, similar to a squirrel’s. They are found in Central and South America, including Brazil, Colombia, French Guiana, Suriname, Venezuela, and Puerto Rico.
They live in groups in forests, eating nuts, insects, and small birds. They are relatively docile, but will bite if forcibly captured. Their feces and urine have a distinctive odor. They mark their tracks by urinating on the palms of their hands and rubbing it on the soles of their feet. This also appears to provide a non-slip surface for a firm grip on branches.
Squirrel monkeys can only sweat from the palms of their hands and feet. Therefore, their thermoregulation is limited. They are diurnal, but are active in the cooler mornings and evenings.
In a safe zoo with no natural predators, you can sometimes see them taking naps.