Rhinella proboscidea (Spix, 1824)

Sexual Size & Skin Differences

Males of Rhinella proboscidea measure 46–54 mm and have smooth skin, while females measure 46–55 mm and have granular skin.

Dorsal Coloration

The dorsal surface of this toad is reddish or dark brown, and is typically marked with black and brown patches.

Head & Belly Morphology

It has a triangular head with a pointed snout, and a brown to gray belly.

Normal Activity Pattern

This toad is mostly active during the day, and sleeps on small seedlings and shrubs at night.

Breeding Period Activity Shift

However, it shows nocturnal activity during its breeding period.

Tadpole Appearance

Its tadpoles are light brown and similar to the tadpoles of the species Rhinella margaritifera.

Skin Toxicity & Predation

The skin of Rhinella proboscidea is highly toxic, but predation by the snake Xenoxybelis argenteus has still been observed.

Breeding Habitat Type

This species is an explosive breeder that reproduces in shallow pools located off the edge of streams.

Breeding Aggregation Behavior

Toads gather at these locations for two or three days, where they collectively fertilize thousands of eggs.

Reproductive Period Timing

A typical reproductive period runs from March to May, but the timing can vary depending on rainfall.

Post-Rain Mating Calls

After heavy rain, choruses of up to 100 male Rhinella proboscidea calling for mates have been recorded.

Male Aggressive Breeding Tactics

Males breed aggressively: they approach any nearby toad and attempt to steal mates from other males that are already in amplexus.

Mating Struggle Female Mortality

These struggles sometimes result in the suffocation of the female.

Necrophilia Behavior Observation

Dead females may be subjected to necrophilia by males.

Necrophilia Oocyte Fertilization Process

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.

Necrophilia Study Documentation

This behavior was observed in five different males in one study.

Necrophilia Functional Hypothesis

Researchers have suggested that this necrophilia acts as a reproductive strategy that offsets the fitness cost of the female's death.

Necrophilia Species Uniqueness

This would make Rhinella proboscidea the only species known to practice reproductively functional (rather than accidental) necrophilia.

Geographic Distribution

Rhinella proboscidea is found in Brazil, Colombia, Ecuador, and Peru.

Natural Habitat Types

Its natural habitats are subtropical or tropical moist lowland forests and intermittent freshwater marshes.

Conservation Status & Threats

It is threatened by habitat loss, and is common in parts of the Amazon rainforest.