About Rhinella proboscidea (Spix, 1824)
Males of Rhinella proboscidea measure 46–54 mm and have smooth skin, while females measure 46–55 mm and have granular skin. The dorsal surface of this toad is reddish or dark brown, and is typically marked with black and brown patches. It has a triangular head with a pointed snout, and a brown to gray belly. This toad is mostly active during the day, and sleeps on small seedlings and shrubs at night. However, it shows nocturnal activity during its breeding period. Its tadpoles are light brown and similar to the tadpoles of the species Rhinella margaritifera. The skin of Rhinella proboscidea is highly toxic, but predation by the snake Xenoxybelis argenteus has still been observed. This species is an explosive breeder that reproduces in shallow pools located off the edge of streams. Toads gather at these locations for two or three days, where they collectively fertilize thousands of eggs. A typical reproductive period runs from March to May, but the timing can vary depending on rainfall. After heavy rain, choruses of up to 100 male Rhinella proboscidea calling for mates have been recorded. Males breed aggressively: they approach any nearby toad and attempt to steal mates from other males that are already in amplexus. These struggles sometimes result in the suffocation of the female. Dead females may be subjected to necrophilia by males. Males use their front and hind limbs to squeeze the sides of the corpse's belly until oocytes are ejected, and then fertilize the ejected oocytes. This behavior was observed in five different males in one study. Researchers have suggested that this necrophilia acts as a reproductive strategy that offsets the fitness cost of the female's death. This would make Rhinella proboscidea the only species known to practice reproductively functional (rather than accidental) necrophilia. Rhinella proboscidea is found in Brazil, Colombia, Ecuador, and Peru. Its natural habitats are subtropical or tropical moist lowland forests and intermittent freshwater marshes. It is threatened by habitat loss, and is common in parts of the Amazon rainforest.
