Monday, June 29, 2009
Pinyon-Juniper Woodland: Paradise or Purgatory?
Gray Vireo (Vireo vicinior)
“Chu-weet! Che-o! Teedle-e! Chu-u!” The distinct syllables rang out across the pinyon-juniper Woodland (P-J), the song of the Gray Vireo, a New Mexico state-listed as a threatened species. This small, gracefully gray bird has become the New Mexico poster child for one of the most underappreciated but abundant habitats within the state. A recent estimate is that there are 55.6 million acres of pinyon-juniper in the west. It can be rugged country, with steep canyons and hillsides dotted with shrubby trees not much taller than a human. Not much to offer in the way of shade. Often, there’s not much in the way of grasses or shrubs either. Most folks avoid hanging out here. Much of it has been given it over to cows.
More than 70 different bird species breed in the P-J woodland, although you’d be unlikely to see more than 20 to thirty at any one site. These woodlands support the highest proportions of obligate or semi-obligate birds among the forest types in the West. Species that are considered “obligate” are only found nesting in prime habitat condition, birds like the Gray Vireo, which is precisely why there is so much concern about its population trends. Additionally, a high percentage of the total world population of this species breeds in New Mexico, giving our state a high level of responsibility for its well-being.
I’ve been spending a lot of time in P-J country the last couple of years, especially during May and June, when birds are nesting, conducting early morning surveys of all the species present. I’ve grown very fond of this special suite of birds, found nowhere else. The birds of my morning surveys are the very same species that birders worldwide have on their wish list if only they knew where to find them. Actually, it’s not all that hard, once you develop a fondness for all things P-J.
My morning friends range from the spectacularly colored, yellow and black Scott’s Oriole and the laughing call of the Pinyon Jay, to the cute antics of the Juniper Titmouse, all going about their business, just getting by in life. The song of the Black-throated Sparrow greets me at nearly every stop. The Ash-throated Flycatchers are enormously entertaining as they race around chasing each other, oblivious to my presence. The raucous call of the Cassin’s Kingbirds positively make me laugh. And, of course, one could never forget the Northern Mockingbird. He sings the song of all the others, just a few repeats of each and then moves on to another call. He sings all day and all night. If you are camping in P-J country, it seems as if he is singing right into your ear, without pausing for breath, all night long. It was he, along with the pinyon gnats that taught me to sleep in the back of my car. And sometimes, if you are very lucky, you get to hear or see a rarity, like the Gray Vireo.
Mature stands of P-J, with grasses and shrubs in prime condition, and gently sloping hills host the greatest diversity and populations of birds. When there is a nearby water source, the numbers can be simply astounding. One day, I arrived at my designated point to find not one or two, but some 40-50 Pinyon Jays. This site was clearly a Garden of Eden for its residents.
At other location, birds are few and far between, as are the grasses and shrubs. My companions at this site are of the bovine variety, mostly seeking refuge beneath the sparse canopy of the shrubby trees. Water isn’t much in evidence either and the ribs of the cattle show prominently. I wonder how the females will be able to produce enough milk to feed their scrawny offspring. All the emergent edible vegetation seems to have been already eaten. This could be a poster child of another sort, one for poor range management. Most of the birds have flown the coop to better pastures. Even the eagles and hawks are few and far between, for there is little food for their prey, the jackrabbit and cottontail.
We study birds because, much like the canary in the coal mine, they are indicators of biological integrity and ecosystem health and they are quite sensitive to environmental changes. The results of studies like these help land managers, landowners, and others practice best management practices and work toward a system in which multiple uses can co-exist in a beneficial environment.
Our studies have given me the opportunity to really know and understand an unappreciated habitat, and to learn a whole new set of bird songs and habits. It’s a cool place, that P-J, definitely of a different sort! If you’re lucky you might just hear “Chu-weet! Che-o! Teedle-e! Chu-u!”