| 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 GENETICS 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 CLICK TO READ THE REST OF THE REVIEW! 112 pages, 15 chapters, glossary & more! |
Copyright 2006 Linda S. Rubin
| Multiple Bird Households by Linda S. Rubin |
| Series by 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
