ORIGINAL
BOOK REVIEW
by
Dr. Rainer R.
Erhardt
"Well, there is help on
the horizon and
anyone seriously
interested in color
genetics should take a
look at Linda Rubin's
book:
COCKATIEL
G
ENETICS MADE EASY!
Though this book is
primarily directed to
breeders of cockatiel
mutations, there is
enough information in
thisvolume to teach
anyone the secrets of
dealing with
recessive, sex-linked,
and dominant
mutations..."
ACBM, Vol. 65, No.12
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Copyright 2006 Linda S. Rubin
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The Sex-linked Pearl
Copyright © 2007 LINDA S. RUBIN
CF Genetics Consultant/Panel Judge   
www.CockatielsPlusParrots.com
“All Rights Reserved”




The Pearl cockatiel is a sex-linked recessive mutation that was first
imported into the USA from the Netherlands during the mid/late-1970s.
In those days, we used to advertise strains with heavier yellow
pigment displaying strong yellow pearling as "Golden Pearls." In
contrast, Pearl cockatiels that lacked this yellow carotenoid pigment
resulting in white lacings were termed, "Silver Pearls.” There were also
individuals that carried a partial or incomplete carotenoid wash, which
were a combination of both golden (yellow) and silver (white) pearling
together. Earlier show standards did not distinguish a preference
between any of these forms.



To understand the Pearl mutation, we must first consider color
pigments. The major characteristic of the Pearl mutation is a shortage
of melanin (dark) pigment in the center of individual feathers, which
result in the pearl pattern or pearl markings in the Normal Pearl. The
term "lacewing" (corresponding to the markings of a Lacewing
Budgerigar) that is used primarily overseas, distinguishes Pearls with
elongated lacings from those with lacings that are more circular. The
"scalloped" lacings - also called "thrush chest" pattern - can extend
onto the breast in very heavily marked Pearls. The pearl lacings or
pattern in itself is not an indication of gender.



Because the Pearl mutation affects melanin (e.g., grey) pigments, the
facial mask of the Pearl hen can be much brighter than the mask of
the Normal Grey hen. For example, a Pearl hen’s face may display
more yellow, because the carotenoid (yellow and orange) pigments
are not entirely masked by darker melanin pigment. Similarly, the
orange cheek patches may appear brighter in some Pearl hens
compared to the cheek patches of Normal Grey hens. The tail
feathers of Pearl hens and immature young are primarily yellow, with
under-barring and some dark speckling, accented by a prominent
dark central vane. Flight feathers carry the usual yellow spotting on
the inside of the wing.


Pearl males will develop the yellow facial mask of maturity similar to
their Normal Grey counterparts. Young males begin to lose their pearl
lacings upon the completion of their full adult molt, which occurs
between one to three years of age. At this time, most Pearl males
continue to lose their pearl lacings; however, this loss is gradual and
occurs over several years. Heavily Pearled males, however, can retain
some degree of pearling on their upper chest and shoulders. There
are some aviculturists, however, who are using selective line-breeding
techniques over the generations to produce Pearl males that retain
their markings for life, but such individuals are still rare and would be
pricey. Upon close inspection, adult Pearl males are distinguishable
from Normal Grey males by their variation and intensity of dark grey
melanin pigment acquired upon full maturation.



Show Standards describe Pearls as “Lacings should be extensive,
uniform and well defined, with enough grey for contrast and free from
splotching or defects in pattern. Hens should carry the pearl lacings
over the back, wings, mantle and nape, with a heavier concentration
on the shoulder. Yellow or white flecking on the breast is not unusual
on heavier marked Pearls. Adult Pearl males who retain some degree
of their lacings will be preferred. These lacings should be of a true
pearl design, rather than the light spottings of Normal males in the
ticked class.”
THE SEX-LINKED PEARL
Copyright © 2007 Linda S.Rubin
All Rights Reserved  
c.2007 Nancy J. Mello
Click on image to enlarge
History
Color Pigments
Gender
Show Standards