Animal performance fundamentally influences behaviour, ecology, and evolution. It typically
varies monotonously with size. A notable exception is maximum running speed; the fastest …

Among terrestrial mammals, the largest, the 3 tonne African elephant, is one-million times
heavier than the smallest, the 3 g pygmy shrew. Body mass is the most obvious and …

Speed is the fundamental constraint on animal movement, yet there is no general
consensus on the determinants of maximum speed itself. Here, we provide a general scaling …

The principle of dynamic similarity states that the optimal walking speeds of geometrically
similar animals are independent of size when speed is normalized to the dimensionless …

Movement is integral to animal life, and most animal movement is actuated by the same
engine: striated muscle. Muscle input is typically mediated by skeletal elements, resulting in …

Muscle contraction is the primary source of all animal movement. I show that the maximum
mechanical output of such contractions is determined by a characteristic dimensionless …

The study of allometric and size scaling relationships is well developed in most biological
fields, but lags behind in the area of animal behavior. Part of the reason for this deficit is that …

Larger animals studied during ontogeny, across populations, or across species, usually
have lower mass-specific metabolic rates than smaller animals (hypometric scaling). This …

Despite the neuromechanical complexity and wide diversity of running animals, most run
with a center-of-mass motion that is similar to a simple mass bouncing on a spring. Further …

Relative to body size, smaller animals use more energy to travel a given distance than larger
animals, but the anatomical variable driving this negative allometry remains the subject of …