Editing Peafowl (section)

== Breeding and colour variations ==
{{More citations needed|section|find=spalding|date=May 2023}}
[[File:Paon blanc Madère 2008.jpg|thumb|A [[leucistic]] Indian peacock]]
[[File:Pauw, RP-P-2003-219.jpg|thumb|Japanese woodblock print of a white peacock, by [[Ohara Koson]] (小原 古邨), 1925–1936]]
Hybrids between Indian peafowl and Green peafowl are called ''Spaldings'', after the first person to successfully hybridise them, Keith Spalding.{{Citation needed|date=May 2023}} Spaldings with a high-green phenotype do much better in cold temperatures than the cold-intolerant green peafowl while still looking like their green parents. Plumage varies between individual spaldings, with some looking far more like green peafowl and some looking far more like blue peafowl, though most visually carry traits of both.

In addition to the wild-type "blue" colouration, several hundred variations in colour and pattern are recognised as separate morphs of the Indian Blue among peafowl breeders. Pattern variations include solid-wing/black shoulder (the black and brown stripes on the wing are instead one solid colour), pied, white-eye (the ocelli in a male's eye feathers have white spots instead of black), and silver pied (a mostly white bird with small patches of colour). Colour variations include white, purple, Buford bronze, opal, midnight, charcoal, jade, and taupe, as well as the sex-linked colours purple, cameo, peach, and Sonja's Violeta. Additional colour and pattern variations are first approved by the United Peafowl Association to become officially recognised as a morph among breeders. Alternately-coloured peafowl are born differently coloured than wild-type peafowl, and though each colour is recognisable at hatch, their peachick plumage does not necessarily match their adult plumage.

Occasionally, peafowl appear with white plumage. Although [[albinism|albino]] peafowl do exist,{{Citation needed|date=December 2018}} this is quite rare, and almost all white peafowl are not albinos; they have a genetic condition called [[leucism]], which causes pigment cells to fail to migrate from the neural crest during development. Leucistic peafowl can produce pigment but not deposit the pigment to their feathers, resulting in a blue-grey eye colour and the complete lack of colouration in their plumage. Pied peafowl are affected by partial leucism, where only some pigment cells fail to migrate, resulting in birds that have colour but also have patches absent of all colour; they, too, have blue-grey eyes. By contrast, true albino peafowl would have a complete lack of [[melanin]], resulting in irises that look red or pink. Leucistic peachicks are born yellow and become fully white as they mature.

[[File:Black-shouldered Indian Peafowl-Naturalis Biodiversity Center.jpg|thumb|right|Black-shouldered Indian peafowl ''Pavo cristatus'' from private collection of [[Coenraad Jacob Temminck]] (1778–1858), held at [[Naturalis Biodiversity Center]], Leiden, the Netherlands]]

The black-shouldered or [[Japanning|Japanned]] mutation was initially considered as a subspecies of the Indian peafowl (''P. c. nigripennis'') (or even a separate species (''P. nigripennis''))<ref>{{cite journal|author=Sclater PL|year= 1860|title=On the black-shouldered peafowl of Latham (''Pavo nigripennis'')|journal= [[Proc. Zool. Soc. London]]|pages=221–222|url=https://archive.org/stream/lietuvostsrmoksl60liet#page/221/mode/1up}}</ref> and was a topic of some interest during Darwin's time. Others had doubts about its taxonomic status, but the English naturalist and biologist [[Charles Darwin]] (1809–1882) presented firm evidence for it being a variety under domestication, which treatment is now well established and accepted. It being a colour variation rather than a wild species was important for Darwin to prove, as otherwise it could undermine his theory of slow modification by natural selection in the wild.<ref>van Grouw, H. & Dekkers, W. 2023. The taxonomic history of Black-shouldered Peafowl; with Darwin’s help downgraded from species to variation. ''Bulletin of the British Ornithologists' Club'', 143(1): 111–121. https://doi.org/10.25226/bboc.v143i1.2023.a7</ref> It is, however, only a case of genetic variation within the population. In this mutation, the adult male is melanistic with black wings.