May, 1907 THE BRERDING BIRDS OF ESCONDIDO 85 



there is a more or less thick growth of willows, in some places forming fine large 

 groves with many large cottonwoods and a few sycamores. This is a bird paradise 

 and much of my hunting and collecting has been done here. At Crescent Valley 

 there are some fine oak groves and the hillsides are still pretty well covered with 

 trees. There are many large cactus patches on the south slopes and the hillsides 

 and small ravines are well filled with sage, grease- wood, sumac and wild lilac. 

 Bernardo boasts of one tule pond, San Pasqual of two, and there are several water 

 holes along the river, which may run well into July, or not at all, according to the 

 season's rains. For two successive years one San Pasqual pond and the Bernardo 

 pond were dry. In 1906 the San Pasqual pond had five feet of water in the tule 

 patch and the river was running until August. The average rainfall here is about 

 fourteen inches. 



The following list comprises all the birds known to have nested in this section 

 and is the result of observations covering some sixteen years. Most of the species 

 given are regular breeders, some very common, others rare but regular, a few casual 

 only. Almost all, however, nest here in such sufficient numbers as to be consid- 

 ered fairly common in consideration of the comparatively limited territory suitable 

 to their requirements. 



In some few instances there has been considerable difference in relative 

 abundance, traceable without doubt to the character of the preceding winter; but in 

 most cases the number of nesting birds remains apparently uniform. In the nest- 

 ing seasons following several very dry winters previous to 1905 one of the com- 

 monest birds along the river in San Pasqual was the willow goldfinch, while the 

 lazAili l^unting was comparatively rare. In the season of 1905, after a winter of 

 more than the average rainfall, the goldfinch was noticeabh^ wanting and in 1906, 

 after a very wet winter, it was hard to find them at all. In 1905 the lazuli bunt- 

 ing was everywhere, as common, almost, as the house finch, but was not at all com- 

 mon in 1906. In 1906, the lawrence goldfinch was more plentiful than I had ever 

 seen it, and the Arkansas goldfinch was nesting in the orchards and willows in 

 great abundance. Previous to 1905, the long-eared owl was a very common bird 

 in the willow groves along the river; but since then they have been noticeably 

 absent, and the nest complements, previously four or five, are largely of three 

 eggs only. These birds were seldom disturbed and it is rather hard to account for 

 their diminished numbers on any other ground than that the wet seasons caused the 

 destruction of the various small mammals on which they so largely feed, causing 

 them to migrate to better hunting grounds. 



I am very well convinced that most of our resident birds produce and bring to 

 maturity two broods in a season, some even more. With the Raptores one brood is 

 a rule unless the first clutch of eggs is taken when a second is always laid. 



The long-eared owl, however, and possibly the burrowing owl will often raise 

 two broods. Of the other birds the California shrike, western mockingbird, 

 mourning dove, house finch, black-chinned hummingbird, and probably the 

 Anthony towhee and western lark sparrow will raise three broods under favorable 

 conditions. The two former species I have known to do so in m_v own orchard, 

 the types of eggs being the same in every case. In the following list the dates 

 given are for the earliest and latest nesting dates, the eggs showing very slight or 

 no traces of incubation unless otherwise stated. 



I am greatly indebted to Messrs. N. K. and B. P. Carpenter for the use of 

 their field and nesting notes which have aided me materially in compiling the list. 



Colymbus nigricollis calif ornicus. American Eared Grebe. A very rare breed- 



