Carolina wrens sing year round and at any point during the daytime, with the exception of performing during the most harsh weather conditions. The birds are also the only species in the family Certhiidae that neither sings in duet nor has their song control regions affect repertoire size. Males alone sing, and have a repertoire of at least twenty different phrase patterns and on average, thirty two. One of these patterns is repeated for several minutes, and although the male’s song can be repeated up to twelve times, the general number of songs range from three to five times in repetition. While singing, the tail of the birds is pointed downward.
Males are capable of increasing their repertoire through song learning, but due to their sedentary nature and territorial defense habits, the song learning must occur within the first three months of life. Geographic barriers affect song repertoire size from male wrens, as one study indicated that distances separated as close as 3 km (1.9 mi) by water barriers can have the same effect as that of a distance of 145 km (90 mi) in the mainland with no barriers.
Northern Mockingbird (Juv.)
Both the male and female of the species reach sexual maturity after one year of life. The breeding season occurs in the spring and early summer. The males arrive before the beginning of the season to establish their territories. The males use a series of courtship displays to attract the females to their sites. They run around the area either to showcase their territory to the females or to pursue the females. The males also engage in flight to showcase their wings. They sing and call as they perform all of these displays. The species can remain monogamous for many years, but incidents of polygyny and bigamy have been reported to occur during a single bird’s lifetime.