The Mystery of the Blue Yarn

Bro. Juniper told me this morning that our nest builder is a Black-throated Sparrow, and I must admit, a very descriptive name. Then before noon meal as we were observing our flittering sparrow, Bro. Clarence joined us and with his ever present field manual in hand, was totally convinced that our nest builder is a Sage Sparrow, which he informed Bro Juniper is similar to the Black-throated, but, as he referred to his manual, the Sage "has a blackish malar stripe outlining a white stripe below the gray cheek." Being somewhat colorblind, I could only confirm the "blackish" and the "white" stripe, but then Bro. Clarence caught sight of our bird and quickly confirmed his belief with this observation, a singular dark breast spot isolated on a nearly white breast. Hearing this Bro. Juniper thumbed through the field manual and seconded this opinion, noting that the Black-throated is absent the central breast spot. But that left Bro. Clarence with a puzzled look, he said that this nest is most unusual, for desert sparrows normally build nests on the ground or low to the ground in the brush. And here was our sparrow, now with a completed nest (of twigs and grass and bits of feathers and what appears to be some blue yarn), high in the air with a rather commanding view of the monastery courtyard. "Perhaps a bit of reciprocity taking place? Some high-pitched rollicking tinkle in exchange for our morning chants?" With that Bro. Clarence turned and retreated for the chapel, but not before I distinctly heard him muttering, "But where did that blue yard come from?"