Variation in the Introduced English Sparrow

In studying variation in the Galapagos finches, Geospizinae (Lack, in press), it was thought desirable to have some bird of similar size and habits for comparison.Accordingly, the English Sparrow (Passer domesticus domesticus) was selected, since at the same time one could test the interesting evolutionary point of whether or not it had changed significantly since its introduction into the United States.Three measurements were taken: the culmen from the nostril to the tip of the bill, the depth of the closed bill, and the standard wing measurement.Only males ,with black throats were measured.The depth of the bill was not measured in specimens in which the bill would not close properly.The wing was not measured in molting or worn specimens.The table gives the number ' of specimens measured, and the mean and standard deviation for each of these measurements.In deference to standard taxonomic procedure, I also give the maximum and minimum measurements, but in the present investigation they have little significance.The standard deviation is, of course, a much better means of estimating the variability.Acknowledgments.-This study would not have been possible without the large series of Passer domesticus in the Museum of Vertebrate Zoology, Berkeley, assembled through the initiative of the late Dr.Joseph Grinnell.The latter was fully aware of the importance of collecting extensive material of this species, and he seems to have been the only worker to have acted on this.It is particularly unfortunate that more material is not available from the eastern states for the early years when the species was rapidly increasing, and it is to be hoped that material will be collected from areas to which the species has spread only very recently for comparison at some future date when the population has become stabilized.This particularly applies to the southern part of California, where there is some evidence that the species is changing.I have also to thank the following museums for allowing me to measure their specimens: Los Angeles, San Diego, California Academy of Sciences (San Francisco), Museum of Comparative Zoology (Cambridge), United States National Museum (Washington) , University of Michigan, Field Museum (Chicago), and American Museum of Natural History (New York).The majority of the European specimens were in the Rothschild collection now housed with the last-named museum.Localities.-Almost all the English specimens were collected in the southern counties, a very few in the midlands and in the north.Most of the German specimens were collected at Augsburg, Bavaria.The heading "eastern states" includes specimens from New York, Connecticut, Rhode Island, New Jersey, Massachusetts, Pennsylvania, Washington, D. C., Virginia, and Maryland.The specimens from the three last regions were first treated separately, but were grouped with those from the other eastern states when it was found that they showed no significant differences from them in mean or standard deviation.For the "mid-western states" I selected three states from which large series were available, namely, Minnesota, Illinois and Wisconsin."Southern California" includes the counties of Madera, Fresno, Tulare, Inyo, San Bernardino, Ventura, Los Angeles, Orange, Riverside, San Diego and Imperial, and with these are included specimens from Lower California, Mexico.Originally specimens from Lower California, and also specimens from extreme southern California (San Diego, Imperial, Riverside, Orange, and Los Angeles counties) were treated separately, but it was found that they showed no significant differences in mean or standard deviation from each other or from those of the other counties in the southern half of California listed above, so all were