"We like to have all the calves born around the same time," he explains.
But there's far more to this rustic scene than meets the eye: Under a innovative arrangement with his landlords--the Arizona Land Department and the U.S. Bureau of Land Management--Donaldson is helping the Las Cienegas National Conservation Area return to its roots as an abundant, wildlife-rich grassland. In the process, he's also helping to protect several threatened species, from the Southwestern willow flycatcher and Gila topminnow to the lesser long-nosed bat.
A cattleman by trade, with a black hat, sun-beaten cheeks and manure-splattered boots, Donaldson seems an unlikely conservationist. But he's in constant touch with a team of 25 biologists, botanists and even a few enviros. Together, they schedule cattle rotations to keep these sweeping grasslands vibrant. Riparian areas get equal attention: Creek crossings are spare and tightly orchestrated, to avoid damaging banks and disrupting wildlife.
Simply put, Donaldson considers progressive range management the last, best chance of survival for his gasping profession.
"By having this team onboard, I'm able to adjust the management of the ranch, and adjust the bottom line," he says. "I see it as the natural evolution of cattle ranching."
So does Daniel Imhoff, author of the recently published Farming With the Wild: Enhancing Biodiversity on Farms and Ranches (Watershed Media; $29.95). In his beautifully produced book, Imhoff details efforts to integrate nature with farming, rather than obliterate it.
"I think wilderness people really weren't seeing the farmers and ranchers as necessary collaborators," he says, "but they're an increasingly necessary link in the chain of species survival. After all, two-thirds of the land in the lower 48 states is being used for agriculture."
According to the United States Department of Agriculture, agriculture is also the leading contributor to species endangerment in this country. To turn that around, a growing number of farmers and ranchers are blurring the lines between nature and cultivation. Among them is Tubac-area farmer Mark Larkin. Stretching alongside the Santa Cruz River 40 miles south of Tucson, Larkin's organic farm is banked by a canopy of mesquite, cottonwood and willow trees. It's also in the heart of what Imhoff calls the "Pollinator Trail," where researchers have listed up to 1,200 bee species and 25 nectar-feeding birds and bats. To help these animals flourish, Larkin's fields are thickly planted with wildflowers and wild squash--a delicacy for certain bees--winding along the furrows.
Now he's turning to pasture-grazed cattle, which he calls "even more in light with wild farming techniques. Organic vegetable farming really beats up the soil--it involves a lot of plowing to keep down the weeds. As a result, the soil is always getting torn up."
In contrast, properly maintained cattle pastures "are like raising an orchard," Larkin says. "The growth in the fields can remain more permanent. With livestock on pastures, you're also required to pay a lot more attention to natural cycles. The cattle will be rotated, and pasture lands will be great for pollinators."
Larkin's approach marks a convergence of two potent trends, says Imhoff.
"My book started with people arguing for wildlands connectivity. They're saying, 'Look, our core wilderness areas are more and more isolated, and if we are going to maintain species populations and natural migration patterns, we need connectivity between wildlands.' At the same time, you have the organic movement, probably the most dynamic part of the food sector, growing at 10 percent a year."
But that very success is making the industry more globalized--and thus less responsive to local ecosystems.
"You find these huge organic farms that don't conform to surrounding landscapes at a biotic level," Larkin says. "To me, it seemed that these two things really had to come together, if we're talking about sustainability."
That approach is being pushed by several environmental groups, including Defenders of Wildlife.
"Farming with the wild captures the spirit of a new agro-ecology movement that's growing internationally," says Scotty Johnson, a Tucson-based rural outreach coordinator for the group.
Defenders is assisting several projects in the United States and in Mexico; all of them seek to make wildlife protection an incentive to stimulate more wild farming, Johnson says.
"In North Carolina, we work with commodity producers; in Wisconsin, it's potato farmers. In Arizona, Montana and Idaho, we combine our wolf compensation program with rural development to encourage wolf acceptance. We have similar programs for wolves on the Mountain Apache Reservation, and in Mexico, we are working with ranchers to protect the beautiful and elusive jaguar population."
Forty of those ranchers, farmers and groups are the focus of Farming With the Wild.
"My whole approach was to highlight on-the-ground examples of farmers, land trusts, agencies, people starting eco-labels--people who are trying to merge conservation biology with a profitable farm, and see if that inspires others," Imhoff explains.
But for his part, Mac Donaldson doesn't need convincing. Now he's leaning against his truck, as the bulky bulls lumber off across lush rangeland.
"Las Cienegas contains one of the most intact sacaton deltas and riparian areas in the west," he says. "That's good for wildlife, and it's good for ranching."