Birds and Mammals of Coats Island, N.W.T.

Natal Dispersal in Birds & Mammals

Shivering Thermogenesis in Birds and Mammals

Shivering is the only universal facultative thermogenic mechanism in endothermic vertebrates. Skeletal muscle constitutes a large proportion of body mass and a high scope of metabolic rate, and thus heat production, between resting level and active contraction. Its contractile activity is under rapid and accurate neural control. Together with the inherently low metabolic efficiency of muscle, t...

Cortical computation in mammals and birds.

We humans are particularly proud of our cortices. Our brains are bigger than they should be, given our body size; furthermore, our neocortices constitute a larger fraction of the brain than in all other mammals, and our cortices probably contain more neurons than those of any other species on the planet (1). This cortical expansion is thought to give us our cognitive edge over the rest of the a...

Density-dependent dispersal in birds and mammals

Density-dependent dispersal can be caused by various mechanisms, from competition inducing individuals to emigrate (positive density-dependence) to social crowding effects impeding free movement (negative density-dependence). Various spatial population models have incorporated positively density-dependent dispersal algorithms, and recent theoretical models have explored the conditions for densi...

Sex Allocation Theory for Birds and Mammals

Parents divide their reproductive effort into the production of sons and daughters. Darwin (43) was intrigued by the fact that parents usually split their effort so that approximately equal numbers of sons and daughters are raised. He believed that this male : female ratio had been adjusted by natural selection because he understood that the number of females set a limit on reproductive capacit...