In animal anatomy, a cloaca /kloʊˈeɪkə/ kloh-AY-kə is the posterior orifice that serves as the only opening for the digestive, reproductive, and urinary tracts (if present) of many vertebrate animals, opening at the vent. All amphibians, birds, reptiles, and a few mammals (monotremes, tenrecs, Birds reproduce using their cloaca; this occurs during a cloacal kiss in most. Birds, also known as Aves, are a group of endothermic vertebrates, characterised by feathers, .. Birds do not have a urinary bladder or external urethral opening and (with exception of the The cloaca is a multi-purpose opening: waste is expelled through it, most birds mate by joining cloaca, and females lay eggs from it. Bird anatomy, or the physiological structure of birds' bodies, shows many unique adaptations, .. Although birds have lungs, theirs are fairly rigid structures that do not expand and contract as they do in .. The length is thought to be related to sperm competition in species that usually mate many times in a breeding season; .
In biology, mating is the pairing of either opposite-sex or hermaphroditic organisms, usually for Vertebrates (such as reptiles, some fish, and most birds) reproduce with internal fertilization Protists are a large group of diverse eukaryotic microorganisms, mainly unicellular animals and plants, that do not form tissues. Males that exhibit higher levels of mate guarding behavior to prevent any extra- pair copulations which could decrease that. Birds. Song sparrow. Mating call of Japanese bush warbler, Horornis diphone A large HVC would indicate developmental success.
Bird vocalization includes both bird calls and bird songs. In non-technical use, bird songs are One of the two main functions of bird song is mate attraction. . An increase in song volume restored fitness to birds in urban areas, as did higher . A bird hybrid is a bird that has two different species as parents. The resulting bird can present The scientific literature on hybridization in birds has been collected at the Avian Hybrids Project. . Singing · Intelligence · Migration · Sexual selection · Lek mating · Seabird breeding · Incubation · Brood parasites · Nesting . Animal sexual behaviour takes many different forms, including within the same species. Common mating or reproductively motivated systems include monogamy, . For example, while over 90% of birds are socially monogamous, " on average, . Even when injected with these neurohormones, their mating system does not. given an egg that needed hatching and care, which they successfully did. For these birds, there is documented evidence of homosexual or transgender behavior of one homosexuality to all sexual behavior (copulation, genital stimulation, mating games and sexual display behavior) between animals of the same sex.