



472 NATURALIST IN CALIFORNIA. 
on several occasions during January. The elevation of the 
river at this point is not over 550 feet, and the whole bottom 
land is inundated nearly every summer. The distance by 
the course of the river from its mouth is 400 miles. 
The fauna of the valley naturally partakes much of the 
Mexican (west slope) character, and has some peculiarities. 
. It is too limited and too liable to inundation for many land 
mammalia to flourish in it, except such as are common to the 
neighboring deserts and mountains. A second species, at 
present known no farther west, is the Leaf-nosed Bat (Ma- 
crotus Californicus) from Fort Yuma. This bat, like the 
birds, is independent of floods, and is probably migratory 
southward in winter, like two species I obtained at Fort 
Mojave—the Pale Bat (Antrozous pallidus), and a small 
species of Vespertilio which did not appear until March 15th, 
though the climate was warm enough for weeks before. 
On walking out with my gun I was struck with surprise 
at the great numbers of Abert’s Finch (Pipilo Abertit) 
frequenting the grove, the flocks flitting before me like dry 
leaves before the wind, their color exactly resembling the 
prevailing hue of the foliage covering the ground, and now 
densely coated with brown dust. It recalled the observation 
I had often made as to the prevalence of this brown hue in 
so many birds of California, of different genera and fami- 
lies, but agreeing in their habit of living in low shrubbery 
which has the same brown and dusty tint for eight or nine 
months of the year. The loud call or alarm note of this 
bird was strikingly different from the notes of its more 
silent cousin near the coast, the P. Suscus (or crissalis), but 
I soon noticed another strange fact, namely, that this note 
was also uttered by two other very distinct birds of dissim- 
ilar habits, the Shining Flycatcher and Gila Woodpecker 
(Centurus uropygidlis), both of which were abundant and 
me feeding together on the berries of the mistletoe, parasitic 
. On almost every tree. These birds were my first specimens, 
. together with the common Grass Finch (Poeecetes grami- 






