Male Acoustic Signals: Poem Recognition And Sexual Selection

Animal vocalisation play important role in individual recognition, kin recognition, species recognition, and sexual selection (Forstmeier et al, 2009). This essay will describe more of the latter one. It is usually very hard to tell what a behaviour or physiological structure evolved to serve as. A commonly used example is the giraffe’s long neck. Since the giraffe has a long neck, it is able to see the predators and reach the leaves. We cannot be sure what the original reason was of evolving a long neck. Maybe just because the giraffe would look silly its head floating in the air and the long neck serves to connect it with the body.
Male acoustic signals have multiple roles in many animal taxa, such as frogs, birds, ungulates, whales and

My hypothesis is that calling behaviour in case of passerines and primates evolved to show competitive ability to conspecifics, hold onto territories, and this can be also attractive to females. In case of reindeer and Tungara frogs it primarily evolved to attract females, by signalling good quality. The case of humpback whales is very complicated, my hypothesis is that the song of the male is primarily addressed to other

These complex structures are called sexy syllables, that are expensive and difficult to produce and this way indicate male quality. Sexy syllables stimulate female nesting and egg laying. Female canaries can vary their investment in egg production depending on male traits that is connected to the attractiveness of his song. Females hearing sexy syllables and complex song lay larger eggs than those whose male do not sing such song. Larger egg indicate larger new-born who has bigger chance to survive and reproduce when adult. Zebra finches (Taeniopygia guttata) also laid heavier eggs when mating with higher quality male with complex song (Leitner et a, 2006). The song of male passerines is learnt in young age from parents and neighbouring birds. If they are not exposed to any birdsong in this critical period, they can still produce song, but this song is over simplified and complex enough to attract any mates or be able to hold on to a territory. If we compare the sonogram of the song of a bird who was not exposed to any song in the critical period with one who was, we can see the elements that are learnt and that are inherited. The complex part of the song, such as sexy syllables are always learnt hence they show the high fitness of the male, who is good in learning a complex song (Doupe et al, 1000). Male zebra finches produce two kind of learned vocalisation while their females produce