how do birds mate wiki

Dinosaurs and the origin of birdsMain article:

Simplified

Most scientists agree that birds are a specialized subgroup of theropod dinosaurs based on fossil and biological evidence[23]. More precisely, birds are members of the Maniraptora group of theropods, which also includes oviraptorosaurs and dromaeosaurids. [24] The previously distinct line separating birds from non-birds has become hazy as more theropods that are closely related to birds have been found. This uncertainty was increased by findings made in the northeast Chinese province of Liaoning in the 2000s, which showed numerous tiny theropod feathered dinosaurs. [25][26][27].

In modern palaeontology, the general consensus is that the closest relatives of the deinonychosaurs, which include dromaeosaurids and troodontids, are the flying theropods, or avialans. [29] Together, these form a group called Paraves. Certain characteristics of some basal Deinonychosauria members, like the Microraptor, may have allowed them to glide or fly. The most basal deinonychosaurs were very small. This data suggests that the progenitor of all paravians might have been arboreal, skilled at gliding, or both. [30][31] Research indicates that the earliest avialans were omnivores, in contrast to Archaeopteryx and the non-avialan feathered dinosaurs that mostly consumed meat. [32].

One of the earliest transitional fossils discovered, the Late Jurassic Archaeopteryx is well known for supporting the theory of evolution in the late 19th century. The first fossil to exhibit both distinctly classic reptilian traits—teeth, clawed fingers, and a long, lizard-like tail—as well as wings with flight feathers resembling those of contemporary birds was Archaeopteryx. Though it may be closely linked to the true ancestor, it is not thought of as a direct ancestor of birds. [33].

Acoustic signaling edit Song sparrow Japanese bush warbler Purple-crowned fairywrenSee also:

Acoustic signals are one of the most common ways that birds communicate. Many bird species use these signals, which are frequently used to entice mates. Due to sexual selection, several characteristics of bird song, including structure, amplitude, and frequency, have changed over time. [6].

Females of many bird species prefer to sing songs with a large repertoire. [7] One theory for this is that the size of the brain’s song control nucleus (HVC) is positively connected with song repertoire. A large HVC would indicate developmental success. Larger repertoires in song sparrows were associated with larger HVCs, better body condition, and lower heterophil-to-lymphocyte ratios, all of which were indicative of stronger immune systems. This lends credence to the notion that song repertoires are reliable markers of a male song sparrow’s “quality” and that song sparrows with extensive song repertoires are more fit throughout their lives. This adaptation may have direct advantages for the female, like better parental care or territory defense, as well as indirect advantages, like good genes for their progeny. [7].

Compared to mainland populations, the acoustically simple structure of Japanese bush warbler songs is found on islands. [8] In mainland populations, song complexity is correlated with higher levels of sexual selection, suggesting that a more complex song structure is beneficial in a setting where sexual selection is strong. Another illustration can be found in the larger male purple-crowned fairywrens, who sing promotional songs less frequently than their smaller rival male counterparts. Since a healthy body size is a sign of good health, lower frequency calls are an honest way to communicate. A negative relationship between call frequency and body size is supported by evidence from several species within the taxonomic group. [9] Song frequency in rock sparrows is positively correlated with successful reproduction. Female preference is for slower song rates, which are correlated with age. A person’s reproductive status is conveyed by a higher maximum frequency Additionally, there was a positive relationship between the frequency of extra-pair copulation and age. [6].

Numerous socially monogamous bird species have been observed to maintain their calls even after forming pairs. Following breeding, the male zebra finch in one experimental population began to sing more. [10] There is a positive correlation between this increase and the partner’s reproductive investment. The female finches were raised in cages alongside two successive males who produced different numbers of songs. When a female and a male with a high song output were paired, the female laid larger eggs with more orange yolks. This implies that rather than luring additional pairs of females, the relative quantity of song produced by paired zebra finch males may serve to excite the partner. [10].

Reproductive system

Males in the Anseriformes (apart from screamers), the Palaeognathae (apart from the kiwis), and the Galliformes (in primitive forms but fully developed in the Cracidae) all have penises, which are never seen in Neoaves. It is believed that the length is connected to sperm competition [89][90]. [91] Male birds rely on lymphatic fluid rather than blood to achieve an erection. [92] It hides inside the cloacal proctodeum compartment, right inside the vent, when it is not copulating. The sperm storage tubules found in female birds [93] enable sperm to survive long after copulation—up to 100 days in certain species. [94] Sperm from multiple males may compete through this mechanism. The majority of female birds have one ovary and one oviduct, both on the left side of the body[95]. However, some species in at least 16 different bird orders have two ovaries. Even these species, however, tend to have a single oviduct. There have been suggestions that this could be a flight adaptation, but males have two testes, and both sexes’ gonads are known to shrink significantly in size when the breeding season is over. In addition, terrestrial birds and the egg-laying mammal platypus typically have a single ovary. A more plausible explanation is that the egg forms a shell during its passage through the oviduct, taking around a day, so if two eggs were to develop simultaneously, there would be a chance that one would not survive. [95] Parthenogenesis in birds is known to occur, despite its rarity and high rate of abortion. Eggs can be diploid, automictic, and produce male progeny. [98].

An individual’s sex is decided at fertilization in almost all bird species. Nonetheless, a 2007 study asserted that temperature determined sex in Australian brushturkeys, showing that a higher female-to-male sex ratio was produced during incubation at higher temperatures. [101] However, it was subsequently demonstrated that this was untrue. These birds show temperature-dependent sex mortality rather than temperature-dependent sex determination. [102].

FAQ

How do birds mate?

What does a birds cloaca look like?

What do female birds look for in males?

What do you call it when birds mate?