At breeding time, If they are on their own they are males
looking for females, if in a clinch and the one on top smaller of
the two then a male and female, if both the same size two males,
one of whom thinks/hopes the other is a male.
Males tend to hang around the pool waiting for females,
females turn up when ready and once they've spawned go elsewhere.
I think my frogs must have read a different book.
The first frogs to appear in my pond are 'always' large well marked
females. These can arrive as early as November/December. They are
therefore 'on their own' for some time before the smaller, more
non-descript males arrive maybe 3 or 4 weeks prior to mating. Both
genders will happily remain 'on their own' until the females are close
to spawning. Then the males start getting fruity, indulging in
amplexus with all and sundry, including themselves.
After spawning, there is a period of 'recuperation' when both sexes
remain and then, I agree, it is usually the females who are first to
leave. I presume that they know there is no more work to be done, and
they leave behind the ever hopeful males.
But, generalisations are always difficult. Last year, I had a big
female still in the pool even after all the tadpoles had hatched. It
would be nice to think of her taking on a guardian role - but for the
fact she was so quick to dive for cover when frightened and I doubt
any frog is equipped to fend off a predator.
....... isn't it a shame that common sense
is not all that common.