The notes contained in this book were taken from March to May, 1889, and from March to July, 1894, at Twin Oaks in southern California. Twin Oaks is the post-office for the scattered ranch-houses in a small valley at the foot of one of the Coast Ranges, thirty-four miles north of San Diego, and twelve miles from the Pacific.

As no collecting was done, there is doubt about the identity of a few species; and their names are left blank or questioned in the list of birds referred to in the text. In cases where the plumage of the two sexes is practically identical, and only slight mention is made of the species, the sexes have sometimes been arbitrarily distinguished in the text.

Several of the articles have appeared before, in somewhat different form, in 'The Auk,' 'The Observer,' and 'Our Animal Friends;' all the others are published here for the first time.

The illustrations are from drawings of birds and nests by Louis Agassiz Fuertes, and from photographs taken in the valley; together with some of eucalyptus-trees from Los Angeles, for the use of which I am indebted to the courtesy of Dr. B. E. Fernow, Chief of the Division of Forestry of the U. S. Department of Agriculture.

In the preparation of the book I have been kindly assisted by Miss Isabel Eaton, and have received from my brother, Dr. C. Hart Merriam, untiring criticism and advice.