When Frogs mate, the male frog tends to clasp the female underneath in an embrace called amplexus. He literally climbs on her back, reaches his arms around her "waist", either just in front of the hind legs, just behind the front legs, or even around the head. Amplexus can last several days! Usually, it occurs in the water, though some species, like the bufos on the right mate on land or even in trees!
(photo courtesy of Emile Vandecasteele)
While in some cases, complicated courting behavior occurs before mating, many species of frogs are known for attempting to mate with anything that moves which isn't small enough to eat!
Spawn (egg-mass)
While in the amplexus position, the male frog fertilizes the eggs as they get are laid. Frogs tend to lay eggs single eggs in masses, whereas toads usually lay eggs in long chains.
Some frogs leave after this point, but others stick around to watch over the little ones. Some have very unusual ways of caring for their young. You'll learn about some of those later in this tour!.
Egg
Frogs and Toads tend to lay many many eggs because there are many hazards between fertalization and full grown frogness! Those eggs that die tend to turn white or opaque. The lucky ones that actually manage to hatch still start out on a journey of many perils.
Life starts right as the central yolk splits in two. It then divides into four, then eight, etc.- until it looks a bit like a rasberry inside a jello cup. Soon, the embryo starts to look more and more like a tadpole, getting longer and moving about in it's egg.
Usually, about 6-21 days (average!) after being fertilized, the egg will hatch. Most eggs are found in calm or static waters, to prevent getting too rumbled about in infancy!
Some frogs, like the Coast foam-nest treefrog, actually mate in treebranches overlooking static bonds and streams. Their egg masses form large cocoon-like foamy masses. The foam sometimes cakes dry in the sun, protecting the inside