The Study for Future Families (SFF) recruited men who were partners of pregnant women attending prenatal clinics in Los Angeles CA, Minneapolis MN, Columbia MO, New York City NY and Iowa City IA. Semen samples were collected on site from 763 men (73% White, 15% Hispanic/Latino, 7% Black and 5% Asian or other ethnic group) using strict quality control and well-defined protocols. [. . .] Black men had significantly lower semen volume, sperm concentration and total motile sperm counts than White and Hispanic/Latino men.This is consistent with the other evidence I'm aware of. Lower sperm counts have been noted in Africa, and a study in Rochester, NY, that included a small number of American blacks similarly found:
All sperm parameters were significantly lower in the small subgroup (n = 7) of African-American men compared with other men in this population (p-values for sperm parameters, < 0.001 to 0.016).Also consistent with these results: the only autopsy studies I'm aware of (at least one of which Rushton knew of before he became selectively forgetful) both suggest black men have smaller/lighter testes than white men.