Editing Songbird (section)

==Song repertoire and courtship==
Sexual selection can be broken down into several different studies regarding different aspects of a bird's song. As a result, songs can vary even within a single species. Many believe that song repertoire and cognition have a direct relationship. However, a study published in 2013 has shown that cognitive abilities may not all be directly related to the song repertoire of a songbird. Specifically, spatial learning is said to have an inverse relationship with song repertoire. So for example, this would be an individual who does not migrate as far as others in the species but has a better song repertoire. This suggests an evolutionary trade-off between possible alleles. With natural selection choosing traits best fit for reproductive success, there could be a trade-off in either direction depending on which trait would produce a higher fitness at that time period.<ref>{{cite journal |doi=10.1098/rsbl.2013.0344 |pmid=23697642 |pmc=3730647 |title=Potential trade-off between vocal ornamentation and spatial ability in a songbird |journal=Biology Letters |volume=9 |issue=4 |pages=20130344 |year=2013 |last1=Sewall |first1=K. B |last2=Soha |first2=J. A |last3=Peters |first3=S |last4=Nowicki |first4=S }}</ref>

[[File:XN_Luscinia_megarhynchos_012.ogg|left|thumb|[[Common nightingale|Nightingale]] song: Because nightingales sing both day and night, it is believed night songs are courtship related and dawn songs are territorial in nature.{{by whom|date=July 2018}}]]
Song repertoire can be attributed to male songbirds as it is one of the main mechanisms of courtship. Song repertoires differ from male individual to male individual and species to species. Some species may typically have large repertoires while others may have significantly smaller ones. [[Mate choice]] in female songbirds is a significant realm of study as song abilities are continuously evolving. Males often sing to assert their dominance over other males in competition for a female, sometimes in lieu of a combative episode, and to arouse the female by announcing a readiness to mate. Though less frequent, females have also been known to sing occasionally a duet with a mate as an affirmation of their partnership. While some will sing their song from a familiar perch, other species common to grasslands will sing a familiar song each time they fly.<ref>{{Cite web|title=Songbird {{!}} bird|url=https://www.britannica.com/animal/songbird|access-date=2020-12-02|website=Encyclopedia Britannica|language=en}}</ref> Currently, there have been numerous studies involving songbird repertoires, unfortunately, there has not yet been a concrete evidence to confirm that every songbird species prefers larger repertoires. A conclusion can be made that it can vary between species on whether a larger repertoire is connected to better fitness. With this conclusion, it can be inferred that evolution via natural selection, or sexual selection, favors the ability to retain larger repertoires for these certain species as it leads to higher reproductive success.<ref name="ByersKroodsma2008"/> During times of courtship, it is said that male songbirds increase their repertoire by mimicking other species songs. The better the mimicking ability, retaining ability, and the quantity of other species mimicked has been proven to have a positive relationship with mating success. Female preferences cause the constant improvement of accuracy and presentation of the copied songs.<ref>{{cite journal |doi=10.1098/rsbl.2007.0234 |pmid=17623632 |pmc=2391182 |title=Female preferences drive the evolution of mimetic accuracy in male sexual displays |journal=Biology Letters |volume=3 |issue=5 |pages=463–6 |year=2007 |last1=Borgia |first1=Gerald |last2=Siani |first2=Jennifer |last3=Coyle |first3=Brian |last4=Patricelli |first4=Gail Lisa |last5=Coleman |first5=Seth William }}</ref> Another theory known as the "song-sharing hypothesis" suggests that females prefer simpler, more homogenous songs that signal a male of familiar territory. As birdsong can be broken into regional dialects through this process of mimicry, the foreign song of a newcomer suggests the lack of territorial possession. This can be costly in the wake of territorial conflicts between disparate songbird populations and may compel a female to prefer a male spouting a familiar song of the area.<ref>{{Cite web|title=The Development of Birdsong {{!}} Learn Science at Scitable|url=https://www.nature.com/scitable/knowledge/library/the-development-of-birdsong-16133266/|access-date=2020-12-02|website=www.nature.com}}</ref>