14 SECRETS OF ANIMAL LIFE 
sea-leopard, and out of water none that is deadly 
save man. The penguins take no particular notice 
of the killer-whales, but they have a mortal terror 
of the sea-leopards, who sometimes swallow them 
whole. These voracious Pinnipedes often lurk 
below the ledge from which the penguins dive, 
and Dr. Levick gives us a glimpse of another side 
of penguin nature when he tells of the tricks the 
birds play to get one of their number to be the first 
to go into the water. Apart from the sea-leopards, 
man, and one another, the adult penguins live at 
peace, but terrible damage is often done at thaw- 
time by falling boulders and land-slides. Some- 
times, too, crowds of nesting birds are buried in 
snow-drifts which are especially serious when they 
freeze on the surface. But even then the tough 
creatures can survive for many weeks within little 
chambers thawed by the warmth of their bodies, 
and provided with breathing-holes through which 
they thrust their heads. On the whole, the adult 
birds are very safe, but among the eggs and the 
young the mortality is high, for which the voracious 
skuas and the recklessly combative or even vicious 
cocks are largely to blame. 
There is a lighter side to the life of the penguins, 
for they have developed a taste for certain primitive 
games which they play on the sea-ice on their way 
to and from their bathe. There is the diving, in 
which the succession is so rapid “as to have the 
appearance of a lot of shot poured out of a bottle 
into the water’’; there is the “ porpoising,” the 
