The 71-year-old man cradled a small, juvenile robin in his hand. He fed the bird soggy dog-food pellets with tweezers. The bird was injured badly. But not dead.

“Sssshhh,” he said as he fed the bird.

He’s rehabilitated hundreds—maybe thousands of birds over the last 20 years. About 100 million birds are killed annually in the US by window collisions. They call it a window strike. But when birds collide with windows many of them don’t actually die.

Often, Samaritans take injured birds and mammals to veterinary clinics. And usually, one such cheerful veterinary employee will accept the infirm, say, blue jay, and reply, “Uhhhhh… Thanks?”

Most people don’t ever think about where those birds actually go from there.

Well, they go to places like this.

The older man worked patiently with the robin, with his pet cockatiel riding on his shoulder, pirate-style.

Meantime, his co-volunteer tube fed an injured red squirrel. There are lots of animals in this place. It’s almost a zoo.

The tiny makeshift aviary, about the size of a workshed, contains birds of every kind. Jays, robins, cardinals, finches. There were ducklings in kennels. Cages outside, with furry creatures. Even a homemade duck pond out back.

The older man teaches new volunteers their new trade. He shows younger recruits how to tube feed rabbits. How to massage an opossum’s abdomen to stimulate poop. How to determine when a bird has had enough to eat.

The volunteers become adoptive parents. They do everything.

Sometimes these volunteers spend eight hours out here, in this small, shed-like structure. This tiny volunteer outfit, based in Ohio, rehabilitates and releases nearly 2,000 animals every year.

Which is a huge number for such a small operation, considering that Ohio’s fancy Wildlife Center Hospital only treated 9,000.

It’s a full-time job, the older man says. Some birds require feedings every 15 minutes. Some mammals need to be fed every half hour, even during the night hours.

Not only do these volunteers feed them. They have to change bandages, administer therapy, and pay close attention to monitor progress. Sometimes volunteers go so far as to keep the animals beside them when they sleep.

One volunteer remarks, “Some of these birds coming in, it crushes you to see them. Then, to see it getting stronger and the strength coming back in it, the life coming back… It’s awesome.”

There is nothing, perhaps, more moving than when volunteers release a bird back into the wild. It’s an emotional experience. Some of the volunteers cry privately when the bird flies away. Others feel something deep within themselves. Something they cannot explain.

A reverence for life maybe. A reflection on how short our own time is on earth. And as they watch the creature take flight, you hear a lot of sniffling.

There is usually a moment of rapt silence among them, as volunteers stand staring into the sun.

“He made it,” one volunteer will say, wiping his eyes with his sleeve.

“Yeah,” another will reply softly.

And when the ceremony is finished, the prison guards gently clear their throats and escort each volunteer back to his cell.