Ask Marilyn

We see plenty of mixed-breed dogs and cats. Do mixed-breed birds exist?

—Amy Cabretta, Prosper, Texas Yes, but only a few. All domestic dogs belong to the same species, so various breeds can mate. The same goes for domestic cats. But among birds, about 10,000 species are known, and the vast majority never mates with other species. Even subspecies (for example, at least 19 types of cardinals exist) rarely mate. When birds do mate with a different species, the hybrids often don’t v>Ài Üi ° / iÞ >Þ ` i >Ã yi`} lings or be unable to reproduce as adults, either because they are sterile (like mules and hinnies) or they cannot attract mates.