The Effect of Smudging Upon Birds
The Effect of Smudging upon Birds
During California’s recent cold wave, I spent the day of January 25, 1937, observing birds at the mouth of San Gabriel Canyon, some three miles north of Azusa, Los Angeles County. The sun was seldom visible through the dense blanket of smudge which had periodically covered many miles of the near-by citrus groves for the previous week. I mention thfs fact to introduce the cause of such a marked change ln the appearance of the birds throughout, this area.
Those birds most noticeablv blackened were the House Wren. California Thrasher, Audubon Warbler, Willow Goldfinch Golden-crowned Sparrow, Rufous-crowned Sparrow, California Towhee, and Pallid Wren-tit. Some were so heavily covered with smudge that the natural colors could hardly be imagined, while others were only slightly darkened on the chin and forehead. The latter inhabit areas less densely covered, which are not protected by trees or overhanging growth.
Of particular interest was the normal activity of all the species. At least outwardly they showed no evidence of being bothered by such an abnormal environment. A Rufous-crowned Sparrow was singing; others were feeding and flying about in their usual cheerful manner. Evidently the small amount of carbolic acid present in the crude-oil vapor is not enough to be fatally poisonous. When considering the great quantity of seeds and animal matter consumed, it seems unlikely that smudging could have a poisonous effect upon our birds, even should it continue many days. Luckily, that will probably never be necessary.
To give some idea as to how completely saturated the poor little fellows were, I might mention the difficulty I had in even partly restoring specimens to their normal color. Even solutions that normally dissolve grease and oil with ease I found to be of little use. I doubt if the bird itself could be instrumental in restoring its natural color. The spring molt will most likely be the only remedy.
G. Philp
Beverly Hills, California, January 30, 1937
