Not far from Austin, a dirt road winds through patches of bluestem, spiked mesquite, and twisted live oaks on the working Freeman ranch, owned by Texas State University. The ranch is home to an organic garden, a lively head of cattle, and the Texas State Forensic Anthropology Research Facility, or FARF. It is also home to FARF’s ongoing research project on scavenging and decomposition, which is led by two forensic anthropologists.

Another way of saying this is that if you travel for long enough on a dirt road just outside of San Marcos, and if you are able to get through the double security gates, what you will find amid the grasses and trees and occasional longhorn, is a field of human bodies in varying states of decay.

I’m here to ask one of the researchers about vultures. Specifically, I want to understand how the birds are helping law enforcement to develop crime-scene investigation protocols. The researcher gives me a pair of blue, hospital-style booties to slip over my shoes just inside the second gate.

The anthropologists are studying two things: how the Texas sun turns a body into a rusted mummy feeding the switchgrass, and how vultures scavenge those bodies. To learn about the former, the donated cadavers are laid under metal mesh cages. To understand the latter, they are left exposed, tagged wrists crossed, or open, as in savasana—the corpse pose.

Except nothing I see in the open looks reposed. The spines are twisted, the bones scattered. “This young man died in a violent accident,” my guide says as she crouches down to point out signs of vultures, certain cracks and predictable breaks the birds leave behind on the bones. Families donate the bodies of loved ones for a variety of reasons, she says. So the deceased can continue to teach, for example.

My eyes stay wide open and my mouth stays mostly shut as we walk through the grass. I try to think of what I’m seeing as former people, but I can’t. The people have left. All that remains are remains: a countable collection of bones. Shin is connected to leg; leg is connected to hip. I stare at teeth, my notebook full of questions forgotten. I am trying to place birds there, in that mouth, or this eye. But the birds, too, have left. They circle high above us; even their specks have vanished.

The work the researchers and their teams of student volunteers undertake is helping law enforcement in the borderlands solve crimes and identify the dead. That’s why they place donated bodies in the fields, why they work first under the fierce sun, monitoring rates of decay and dispersal, and later in the lab, with toothbrushes and dish soap, scrubbing off stubborn shreds of tendon and cartilage. They need to know how long until the birds come, and how long before they leave, so that a coroner out in the desert has data he can look to when he makes his time-of-death estimate. How long has this body been here? How long has this person been lost?

I remember a story I’d read about butterflies scavenging ammonia salts from carrion. I ask the anthropologist if she’s ever seen butterflies out here. I cannot say the word carrion. Instead, I gesture toward the low cages when I say out here.

“Oh my, yes,” she says. Her voice is soft with a gentle Texas lilt. “In the spring, it’s quite beautiful—all the black-eyed Susans are in bloom and there are butterflies all over . . . It’s a sight.”

For a moment, I forget the talons and curved beaks of vultures. I forget the frenzy of feathers. Instead, I imagine a field of migrating monarchs, green sulfurs, orange-eyed buckeyes, and gilt-edged mourning cloaks. This field becomes their wished-for respite during a long journey. The deliberate opening and closing of all those wings becomes a kind of breath, a last sigh that reaches at once down into the roots of the bluestem and up into the flyway, following the current all the way to Mexico.