The Turtle is a Gold medal diver
With a bit of exercise and healthy lungs, anybody can do what I could do even a few years ago: holding my breath and staying underwater for 2-3 minutes. The lazy South American sloth isn’t a good diver, but should the branch it clings on break off and the animal finds itself under-water, it can indeed hold its breath for 10-15 minutes; it’s simply quite a tough animal. But there is, of course, a limit to the duration anyone can stop breathing and ducks, for instance, can do much better than the average human. They, and other diving vertebrates as well, slow down their heart beats during the under-water period, which allows them to remain without oxygen longer in the submersed condition than in air with a normal heart beat. But while a duck’s dive would rarely exceed 10 minutes, that of the emperor penguin can last for 20 minutes and may take the bird to depths of around 200 m. —>—>
Eavesdropping on serious scientific conversation
When scientists discuss matters related to genitalia or the process of procreation, they do this, of course, in a serious and dignified manner. Witness this conversation by a group of zoologists, overheard in the tearoom of our university during a break between lectures. —>—>
Father’s Milk – a thing of the future?
In an encyclopaedia of 1909, I found the statement that the only mammal in which males are known to regularly supply milk to their offspring was a snowshoe rabbit in the Rocky mountains by the name of Lepus bairdii. Apparently this claim could not be substantiated later on, for the current view is that in spite of the presence of the nipples in many mammalian males, no male is known to normally lactate on a regular basis (but wait!). A combination of oestrogen treatment and nipple stimulation can, however, provoke lactation in male individuals of a wide range of animal species and spontaneous lactation, even in human males, is known. That male and female breast tissues aren’t terribly different is also borne out by the sad, but little known fact, that men, too, can suffer from breast cancer.