But he sought guidance from a counselor, who pointed out that Quinton had made incredible progress in just a few months. He was blooming “like a flower unexpectedly growing in a shady spot,” just where he was. Realizing that he could indeed tackle single parenthood, Mr. Arauz adopted Quinton in 2016. Mr. Arauz changed jobs and the two have moved, but they’re still together at home and at school — he’s now Quinton’s sixth-grade teacher at Forest Lake Education Center in Longwood, Fla.

Mr. Arauz is part of a small but growing trend: single men who adopt. Pinpointing national adoption statistics is difficult, since adoptions occur through a variety of channels including foster care and private agencies and between individuals. According to numbers released in June 2016 from the Adoption and Foster Care Analysis & Reporting System, of the nearly 428,000 children in foster care, 53,549 were adopted with public child welfare agency involvement. In the majority of cases (68 percent), married couples adopt children from foster care, followed by single females (26 percent). Three percent are unmarried couples, and the remaining 3 percent are single males.

Although the percentage is low, Kathy Ledesma, national project director for AdoptUSKids, a project of the Department of Health & Human Services U.S. Children’s Bureau, said it represents a small increase — adoption by single males had been at 2 percent for many years.

Several factors come into play that explain why more single men don’t adopt.

“Historically, white married people adopted. But over the course of several decades, that paradigm has shifted,” says Adam Pertman, president of the Massachusetts-based National Center on Adoption and Permanency and author of “Adoption Nation: How the Adoption Revolution Is Transforming Our Families — and America.” Mr. Pertman cited changing attitudes, prejudices and societal shifts as having an impact on adoption. “Men didn’t perceive themselves as the right single parent and society didn’t perceive them as the right single parent. That is definitely changing,” he said. “It’s not a boom of a change. It’s an incremental one.”

Ms. Ledesma said there was a persistent bias within the child welfare system that children need mothers more than they need fathers, and that somehow children are safer with women than they are with men.

“That is not our experience at AdoptUSKids,” she said. The organization encourages placement professionals to look at prospective adoptive parents on their capacity to parent and to do so with the support of family and friends, and not base approval on a trait such as race, ethnicity, national origin or gender.