It's just a genetic marker abbreviation that people use to name the base color of the bird. The E locus is the main locus for the color pattern of the bird. What comes after the E, like +, wh, b, etc. is the way you designate the pattern variations. Most Delawares are supposed to be partridge based or eb.
The E-locus alleles:
E Often called 'extended black', 'nigrum' or 'self black'. Extends black, changes red to black, red inhibitor.
ER Birchen. Resembles extended black, E, but with non-black breaks on head and hackle. Body is black with some stippling (flecks/dots) of other color. Used as red inhibitor in Leghorn.
eb Partridge (brown). Sometimes represented as ep, females have non-salmon breast with stippling. Males are wild-type.
eWh Dominant wheaten. Female body varies from light salmon to wheat color, some black may be present. Males are wild-type.
e+ Wild-type. Female: breast is salmon brown and devoid of stippling, body is black and brown in stippled pattern. Males: black breast and abdomen; non-black hackle, saddle and wings.
es Speckled. Resembles eb but with less pronounced stippling. Males are wild-type.
ey Recessive wheaten. Female: resembles dominant wheaten with more coarse black stippling on breast and back. Males are wild type.
ebc Buttercup allele. Resembles the eb phenotype.
from "Chicken Genes of Common Interest."
For more info, you can go here:
http://home.ezweb.com.au/~kazballea/genetics/theory.html#gen_theory_intro
The E-locus alleles:
E Often called 'extended black', 'nigrum' or 'self black'. Extends black, changes red to black, red inhibitor.
ER Birchen. Resembles extended black, E, but with non-black breaks on head and hackle. Body is black with some stippling (flecks/dots) of other color. Used as red inhibitor in Leghorn.
eb Partridge (brown). Sometimes represented as ep, females have non-salmon breast with stippling. Males are wild-type.
eWh Dominant wheaten. Female body varies from light salmon to wheat color, some black may be present. Males are wild-type.
e+ Wild-type. Female: breast is salmon brown and devoid of stippling, body is black and brown in stippled pattern. Males: black breast and abdomen; non-black hackle, saddle and wings.
es Speckled. Resembles eb but with less pronounced stippling. Males are wild-type.
ey Recessive wheaten. Female: resembles dominant wheaten with more coarse black stippling on breast and back. Males are wild type.
ebc Buttercup allele. Resembles the eb phenotype.
from "Chicken Genes of Common Interest."
For more info, you can go here:
http://home.ezweb.com.au/~kazballea/genetics/theory.html#gen_theory_intro
