Pygmy White-toothed Shrew

• anatomíaIt is the smallest mammal in the world by body mass, and its heart can beat as fast as 1,500 times a minute.
• It weighs less than a paperclip: 1.8 g on average, which makes it the lightest living mammal on the planet.
• Its heart beats up to 1,511 times a minute, the fastest heart rate of any mammal, 25 times faster than a human's.
• It eats between 1.5 and 2 times its own weight a day, and without food it can starve to death in only two or three hours.
• Its heart beats up to 1,511 times per minute, the highest heart rate ever measured in any warm-blooded animal: around 25 beats per second.
• It has the highest mass-specific metabolic rate of all mammals. At rest it consumes 67 times more oxygen per gram than a person.
• It must eat between 1.5 and 2 times its own weight every day and cannot go more than a few hours without food.
• When food runs short it enters torpor and lets its body temperature fall to 12 °C, and in extreme cases to 6. It comes out of that state by warming itself at almost a degree per minute through muscular shivering and brown fat.
• It hunts prey of almost its own size and prefers those with soft exoskeletons: given the choice, it avoids ants.
• It is the world's smallest mammal by mass, although the bumblebee bat beats it in smallness of skull and in body length.

Skeleton type

Vertebrate - internal bony skeleton (mammal)

Habitat & environment

Open, sunny places of Mediterranean character: olive groves, vineyards, maquis, garrigue and abandoned farmland, as well as open woodland. It shelters in walls or under grass-covered piles of stones, almost always below 1,000 m

Sexual maturity

12 months

Gestation / incubation

27 days

Litter / clutch size

4

Sources consulted: IUCN Red List (e.T90389138A22288134); MITECO - Inventario Español de Especies Terrestres; Proyecto Mammalia; Galán-Puchades et al. 2021, Animals 11(7); MacDonald y Barret 2008, Guía de Campo de los Mamíferos de España y Portugal

Best time: All year round: it is active practically 24 hours a day, alternating spells of torpor with spells of activity