So in this weeks missive (conveniently borrowing a few paragraphs from the book), for interesting–if not whimsical–nest materials, I offer this thick mix of thread, fabric scraps, and miscellaneous dress trimmings, that also harbors an added twist tie and some crinkly cellophane from a cigarette package. Gathered from what might have been a dress manufacturer's trash bin, and collected in 1965, this haphazard but ambitious assemblage was built by a female House Finch. That she would have tinkered with these modern materials is no surprise:
In the category of unique building techniques, Common Tailorbirds sometimes pilfer thread, but they put it to use in an entirely different way.
Notorious for loud, metronomic calls that range, depending on their dialect, from annoyingly harsh to melodious, these quick-moving birds are equally famous for a more endearing trait: the talent of “tailoring” live leaves of a shrub together to make a sheltering pouch for their nests. Bending a leaf, or sometimes two, or more, and piercing holes around their edges with their beaks, they insert threads of spiderweb, cocoon silk, plant, or even manmade fibers to hold them in place. They secure these "stitches", as many as two hundred per nest, by fraying the end of the fiber into a rivet-like ball. Tailorbirds living in civilization are famous for brazenly pilfering thread when their human counterparts leave their sewing projects unattended.
Though the male gathers some of the nest materials, the females is the riveter, as well as the mender of monsoon made tears in their leafy shelters.
Loggerhead Shrike, Lanius ludovicianus, Museum of Vertebrate Zoology MVZ 1653 Nest and Eggs United States: California: Inyo County; Laws 19 April 1916 |
But persecution isn’t the reason shrikes are missing where they used to be common. Once just found in prairies, sage deserts, scrub, and southern savannahs, their numbers grew when forests were cleared for horse-powered farms and ranches that included grassy pasture and rangeland for good hunting, and shrubs and hedgerows for nesting. But today’s vast acreages of combine-created agriculture and the incursion of sidewalked suburbs have left little untidy wild in which both Loggerhead Shrikes and their prey can thrive. They are virtually absent from the Northeast, and one subspecies in California, the island-bound San Clemente Shrike, is down to fifty pairs. Pesticide use, predation by foxes, cats and crows, along with over grazing of their habitat by farm animals gone feral have all taken their toll, and their use of roadside fence posts as hunting parapets puts them in the lethal path of traffic.
It is hard to end this entry with any happy note offering what we might do to save these disappearing birds, but I am not alone in my lament at their decline. Here is an article by one of my favorite local nature writers, Joe Eaton, published in the Berkeley Planet.
http://www.berkeleydailyplanet.com/issue/2009-04-02/article/32626?headline=Wild-Neighbors-In-the-Shrike-Zone-Losing-the-Loggerhead-
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