behavior of túngara frogs is long-distance mating call consisting of two distinct call components: ‘whine’ and ‘chuck’. Males produce a call that consists of a whine, and can also add up to seven short chuck sounds to their mating call. A call consisting of both a whine and a chuck is considered a complex call. The chuck portion of the call is produced by vibrations of a fibrous mass suspended near the frog's larynx, with larger masses allowing production of more chucks per whine. Whine is a long, frequency-modulated sound with five harmonics, fundamental frequency sweeping from 900 Hz to 400 Hz, dominant frequency of about 700 Hz, and duration of about 300 ms. Chuck is a short, high amplitude burst of sound with 15 harmonics, fundamental frequency of about 200 Hz, dominant frequency of about 2500 Hz, 90% of its energy above 1500 Hz, and duration of about 45 ms. With these components, male túngara frogs can produce two types of calls: simple call, consisting only of whine, and complex call, consisting of whine immediately followed by up to six or seven chucks. Whine induces female phonotaxis and contributes to species recognition, while chuck increases the call’s attractiveness in mating. The main organ responsible for producing sound in túngara frogs is larynx supported by its fibrous mass hanging from the vocal cords and projecting from the larynx into the bronchi. As the trunk muscles around the lungs contract, the expelled air pushes through the larynx and vibrates the vocal cords/folds and the larynx, producing the sound. Air enters the buccal cavity, passes through the vocal slits, and inflates the vocal sac. The inflation of vocal sac is also known to serve as a visual cue to receivers. Male túngara frogs produce chuck through their fibrous mass, and their fibrous mass is larger than other species and populations that do not produce chuck. Also, surgical excision of the fibrous mass inhibits the production of chuck despite the frog’s attempt to produce complex call. Mate choice Female preferences for calls play a significant role in túngara frog mating. They favor complex calls over simple calls, low frequency chucks over high frequency chucks, and conspecific whine over heterospecific whine. Females prefer the mating call of frogs who produce chucks with lower frequencies. If a female finds a male's call attractive, she will use the call, as well as ripples in the water