Professor Spencer says gynandromorphs – animals with both male and female characteristics in a species that usually have separate sexes – are important for our understanding of sex determination and sexual behaviour in birds.
The main groups in which the phenomenon has been recorded include animal species which feature strong sexual dimorphism; most often insects, especially butterflies, crustaceans, spiders, even lizards and rodents.
“This particular example of bilateral gynandromorphy – male one side and female the other – shows that, as in several other species, either side of the bird can be male or female.
“The phenomenon arises from an error during female cell division to produce an egg, followed by double-fertilization by two sperm,” he explains.
Excerpt:
Professor Spencer says gynandromorphs – animals with both male and female characteristics in a species that usually have separate sexes – are important for our understanding of sex determination and sexual behaviour in birds.
The main groups in which the phenomenon has been recorded include animal species which feature strong sexual dimorphism; most often insects, especially butterflies, crustaceans, spiders, even lizards and rodents.
“This particular example of bilateral gynandromorphy – male one side and female the other – shows that, as in several other species, either side of the bird can be male or female.
“The phenomenon arises from an error during female cell division to produce an egg, followed by double-fertilization by two sperm,” he explains.