Monday, January 25, 2010

The Ecology of Cerro Prieto Vineyard, Part 1 of 4

Ecology? We all know the meaning of that, right? Well, maybe we all have a sense of the definition, but essentially it is the branch of biology dealing with living organisms and their environment. So what, you may ask? Well, how about the common threads between:

-barn owls and great horned owls,

-coyotes, ground squirrels, and gophers,

-mushrooms and the floor of the surrounding forest,

-dead trees and leaves,

-turkey vultures, wild turkeys, and the vineyard,

-clover, vetch, bromes, ryes, and filaree,

-barn owl boxes and gophers

-coyotes and our dogs, Cazadora and Cartucho,

-grape vine prunings and their disposal,

-red tail hawks, gophers and ground squirrels,

-rainwater, steep hillsides, and runoff,

-herbicides, weeds, and prostate cancer,


-to name but a few.

Quite simply, all the above are but a tiny part of the ecology of Cerro Prieto. All living things and their environment are what make the vineyard itself, a living, breathing thing. Most folks see a vineyard and think of grapes. Others see beauty, and yet others see an invasion of beautiful countryside, marred by row upon row of vines, end posts, and miles of shining wire. As they say, beauty is in the eye of the beholder. Ecology deals with how all items above interact with one another, or in some cases, upon one another.

Let's start with the beautiful heart shaped white face of the barn owl, predators of our vineyard's single most troublesome beast: gophers. Why in the world would anyone put gophers on this planet? Obviously they evolved, but I challenge anyone to give me one teeny tiny reason for why they exist. They are extremely destructive, whether they be in barley fields, almond orchards, or vineyards. We spend an inordinate amount of time trapping the little buggers, yet as many as we kill, 3 take his/her place. Right about now we are swamped with gophers, most living deep down in the soil below our vineyard. Yes, some are up top eating, but others are deep down, breeding, reproducing, and awaiting a break in the cold weather so they can come up and start eating anything with roots...and yes, that means grapevines. With all the grasses, filaree, bromes, and clovers, the gophers have their minds on easy pickings at present, so they are leaving the large rooted vines alone...for now. They will feast upon any replants we have done recently, as these all have the small succulent root systems.

So, where do the barn owls come in ? Well, if we can entice a family of barn owls to take up residence in one of our 7 barn owl boxes, we can then have the one worst enemy of gophers living in one of our judiciously placed owl boxes. It helps to know that for a barn owl to inhabit an owl box, the opening must face due north, away from direct sun and also away from prevailing southerly winds...and rain. Additionally, the owl box must not be near any well-travelled road, as people and vehicular noise will drive barn owls away. Once established, barn owls will sit on a perch outside the box and will notice any motion at all in the dead of night. They have spectacular night-time vision, and this is evidenced
by the mounting pile of gopher skeletons (skulls, pelvises, and mandibles are the most common bones found) directly beneath their box homes.
During the daytime the red tailed hawks circle until they see an easy meal pushing dirt up out of their tunnels, and many a hawk feeds on gophers for breakfast, lunch, and dinner. In ecology there are countless issues to consider: are there any predators of the hawks? Not really, unless a red tail gets careless and lets a lucky coyote get too close...but that never happens. What does happen, however, is that we also have 4 families of great horned owls , most of whom roost at or near our house, and their favorite meal is...barn owls. I love to hear the great horned owls hooting late at night, but it is a gut wrenching feeling to go out on gopher patrol next morning and find a freshly killed young barn owl, usually somewhere near our home, flat smack dab in the middle of horned owl country. Last year we lost young barn owls on 2 consecutive days, and both were in easy sight of our house. Our house sits atop our vineyard, so it is a natural site for the huge horned owls to set up shop...not to mention nests.

So, in a sense the barn owls are a wonderful predator to have for the pesky gophers. Yet they also happen to be the preferred food for the bigger, higher on the totem pole, horned owls. It is an odd quirk of nature that the beneficial predator...the barn preyed upon by the king of all owls, the great horned owl. When I first saw those 2 barn owl kills last year, it made me hate the great horned owls, yet I love to see those guys. This is the essence of ecology, though it is just a tiny peek into what ecology is about. Continued in part 2.

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