You know it’s a warm day when even the Horned Larks head for the shade.

In fact, Mark and Farrish and Muggsi and I shivered a bit early in the morning at Arivaca Cienega, but there were no goosebumps for us by lunchtime, when the heat of the day had descended on the high grasslands of southeast Arizona.

For the monolingual out there, that’s 42 degrees Celsius. Surprisingly, and to our relief, it never really felt hot: one of the great advantages of birding is that you can set your own pace–slow–and select your own positions–in the shade–and get home to air conditioning whenever you want–3:00 pm.

We made an early start of it, Farrish and Mark picking me up at 3:30 on a bright, moonlit morning.

We rendezvoused with Muggsi, then headed straight to Arivaca Cienega,  where we were welcomed in the parking lot by displaying Vermilion Flycatchers and lisping Lucy’s Warblers. Ah, Arizona! Summer Tanagers and big, noisy Brown-crested Flycatchers were working the mesquites, and we had a first, not very good view of Varied Bunting before we even set out on the walk.

Blue Grosbeaks and Gray Hawks, Barn Swallows and Common Ground Doves all put on a great show, but the open fields and thickets really belonged to Yellow-breasted Chat. They were never out of hearing, their squawks and honks and rattles and trills coming from every bush; what was truly impressive, though, was how many we saw, perched and in that ludicrous, foot-drooping flight display. Most summers I count myself lucky to see their sky dance two or three times, and yesterday morning we watched at least a dozen times as  a bright-breasted male rose into the air hollering, ballooning back down on stiff wingbeats.

A “cienega” is a marsh, of course, and though there isn’t a lot of standing water, we were still able to find a few wet spots with breeding wetland birds.

Common Yellowthroats and Red-winged Blackbirds shared the marsh with grazing cattle, and we had a single Black-bellied Whistling-Duck pass over. Virginia Rail is an uncommon summer bird here in southeast Arizona; the happy grunting of one was followed by relatively leisurely sightings of two birds on the edge of the cattails.

By the time we were back at the car, we’d developed a new preference for the shade. A few peaceful minutes and a long drink, serenaded by a single Rufous-winged Sparrow, and we were on our way west, through the town of Arivaca and on to an access point along Arivaca Creek.

The dense woods were already fairly quiet, though we did pick up the day’s only Northern Beardless-Tyrannulet and a surprising, surprisingly late, Pacific-slope Flycatcher. The day’s only Zone-tailed Hawk was overhead; two Gray Hawks squealing from the cottonwoods were probably at an invisible nest. We found goodly numbers of Blue Grosbeaks feeding quietly in the leaf litter, probably after the unfortunate fruits of a new insect hatch. We had our best views of Varied Bunting here, too, birds also on the ground, presumably exploiting the same food source as their bigger, commoner congeners.

Buenos Aires is a huge refuge, and the lands it preserves include not just the marshes and riparian corridors around Arivaca, but also vast tracts of good-quality grass north of Sasabe. Sonoran pronghorn still survive here and on a few other grasslands in southeast Arizona, and we were lucky enough to see four of them.

These weird and beautiful grazers are perfectly suited to life on the high, hot grasslands, but not even they can resist the siren call of shade.

We ate our lunch on the cool patio of the visitor center, then birded around the buildings, letting our eyes be drawn again and again to the beautiful skyline of the Baboquivaris across the valley.

The houses and sheds offer shade and water to the local birds, and to many of them, nesting sites, too. A pair of Say’s Phoebes was under the eaves, and Barn Swallows, some with big, nearly fledged chicks, occupied the porch roof.

Every year, it seems, a pair of Hooded Orioles spins a nest inside one of the hanging lights; this year, both parents were busy bringing caterpillars to a nest full of young still too small to be seen–but unmistakably present, to judge by the storm of peeping that broke out each time one of the adults drew near.

The biggest surprise here was a single Warbling Vireo, small-billed and bright-capped, which should by rights have been high in the mountain forests this time of year. It’s hard to know whether this bird was late or early.

Birds were few and distant as we drove back out to the highway, but another pronghorn and the day’s last antelope jackrabbit slowed us down as they posed on the roadside.

This was likely my last visit to BANWR for a long time–and I’m happy to have got to spend it with good friends and good birds.