Search results
Results From The WOW.Com Content Network
Bird species often demonstrate intersexual selection, perhaps because – due to their lightweight body structures – fights between males may be ineffective or impractical. Therefore, male birds commonly use the following methods to try to seduce the females: Colour: Some species have ornate, diverse, and often colourful feathers.
Many females end up selecting the same male, and many under-performing males are left without copulations. Females mated with top-mating males tend to return to the male the next year and search less. [19] Bower of a great bowerbird. It has been suggested that there is an inverse relationship between bower complexity and the brightness of plumage.
Populations of many birds are often male-skewed and when sexual differences in behavior increase this ratio, populations decline at a more rapid rate. [77] Also not all male dimorphic traits are due to hormones like testosterone, instead they are a naturally occurring part of development, for example plumage. [78]
The long-tailed widowbird (Euplectes progne) is a species of bird in the family Ploceidae. [2] The species are found in Angola, Botswana, the Democratic Republic of the Congo, Kenya, Lesotho, South Africa, Eswatini, and Zambia. [3] The long-tailed widowbird is a medium-sized bird and one of the most common in the territories it inhabits. [4]
Passerines, the "song birds". This is the largest order of birds and contains more than half of all birds. Family Acanthisittidae. Genus Acanthisitta - rifleman; Genus Xenicus - New Zealand wrens; Family Acanthizidae - scrubwrens, thornbills, and gerygones Genus Acanthiza – thornbill; Genus Acanthornis – scrubtit; Genus Aethomyias ...
Cardinal bird. Widespread and abundant, the cherry red birds called Cardinals can be spotted throughout the United States and as far north as southeastern Canada. They are often observed adding a ...
The ZW sex-determination system is a chromosomal system that determines the sex of offspring in birds, some fish and crustaceans such as the giant river prawn, some insects (including butterflies and moths), the schistosome family of flatworms, and some reptiles, e.g. majority of snakes, lacertid lizards and monitors, including Komodo dragons.
Male birds have two Z chromosomes (ZZ), and female birds have a W chromosome and a Z chromosome (WZ). [78] A complex system of disassortative mating with two morphs is involved in the white-throated sparrow Zonotrichia albicollis , where white- and tan-browed morphs of opposite sex pair, making it appear as if four sexes were involved since any ...