female more effectively. The male can be very vocal when trying to attract a mate,
even croaking underwater. Once he has attracted a female, he climbs on her back
and embraces her in a tight, sometimes suffocating grip called amplexus, which can
last up to two days. He fertilizes the eggs as the female lays them. In recent years, sci-
entists researching the species in the Pyrenees have discovered a behavior known as
“clutch piracy,” in which gangs of males search for newly laid eggs to fertilize them
again. The researchers have found evidence of fertilization from as many as four
males in a single clutch of eggs.
Although huge numbers of eggs are laid, few frogs survive to adulthood. Tadpoles
are preyed upon by both terrestrial and aquatic animals, and adult frogs count grass
snakes, kingfishers, and herons among their many predators. Additionally, many
frogs are caught by humans for the purposes of education, medicine, and science.
Overall, however, this particular species is neither declining nor threatened.
The cover image is from Wood’s Reptiles, Fishes, Insects, &c. The cover font is
Adobe ITC Garamond. The text font is Linotype Birka; the heading font is Adobe
Myriad Condensed; and the code font is LucasFont’s TheSans Mono Condensed.