Mating Songs of Frogs

Mating Songs of FrogsThe calling or singing of frogs plays an important role in theirreproduction—specifically, in helping individuals find and select mates. Soundhas many advantages as a communication signal. When sounds arebroadcast, the auditory receptors do not need to be in a particular orientationrelative to the sound source in order to receive stimulation. Loud songs,particularly those made by choruses of frogs calling together, can travel longdistances and thus attract distant frogs. Sounds travel around large obstacles.These advantages are not found in the visual modality, where the receivermust be attentive and have its visual receptor orientated in the correct direction.Further, most frogs and toads breed at night, when light levels are low butsounds can be easily localized. We can conclude that auditory signals areused by frogs and toads because they can be effective over long distances atnight.According to paragraph 1, all of the following are mentioned as true of themating calls of frogs EXCEPT:A.They can reach frogs in far-off locationsB.They are not blocked by objects of substantial size.C.They are often combined with non-auditory signals.D.They can be received without the frog’s needing to orient itself towardthe direction of the signal.The author provides information about "the visual modality" in order toA.emphasize that visual information plays a significant part in frogbreedingB.explain why some frogs breed at night, while others breed during thedayC.indicate the resourcefulness with which frogs overcome obstacles insound travel during the breeding processD.argue that auditory signals have advantages over visual signals forfrog reproductionMale frogs do most of the courtship calling. Other male frogs can respond byadding their voices to form a calling chorus. Male frogs can also vocalize toeach other as part of aggressive displays. Aggressive calls can be distinct fromthe advertisement calls used to attract females. Females can respond to malesongs by moving toward the sound source or by selecting certain males asreproductive partners. In some species females also respond to males bycalling: receptive pairs can even perform duets. Predators may also cue in oncalling frogs as potential prey.The word “potential” in the passage is closest in meaning toA.occasionalB.possibleC.easyD.hiddenFrog songs contain several potentially important pieces of information aboutthe calling male. First, sound amplitude can indicate the size of the individualthat is Galling. Since many frogs exhibit indeterminate growth (i.e., they keepgetting bigger as they get older), size is a good predictor of relative age. Inmany species, call amplitude is increased by specialized vocal sacs that canenlarge as the animal grows; thus, older frogs produce louder calls. The male’sage matters to the female because older frogs have successfully surviv...