 The cane toad is native to the Americas , and its range stretches from the Rio Grande Valley in South Texas to the central Amazon and southeastern Peru . This area encompasses both tropical and semiarid environments . The density of the cane toad is significantly lower within its native distribution than in places where it has been introduced . In South America , the density was recorded to be 20 adults per 100 m ( 109 yd ) of shoreline , 1 to 2 % of the density in Australia . 
