BIRDS OF SHORE AND SEA 65 



uttered hifrh pleading notes, though the older birds generally ignore them 

 by this time. The adults occasionally remain stationed at nesting sites 

 until fall, even after the young have gone. 



LAND BIRDS 



Point Lobos Reserve lies in what may be termed a Transition Life Zone. 

 To the north is the Boreal and to the south is the Austral zone. Vertebrates 

 typical of both zones are found at Point Lobos, though 60 percent of them 

 belong to Austral species, and only 26 percent to the Boreal. In addition 

 there are some species present — like the Allen hummingbird. Western fly- 

 catcher, violet-green swallow, pigmy nuthatch, and purple finch — about 14 

 percent, which belong specifically to the Transition Zone itself. The last 

 percentage is fairly normal for Transition anywhere ; for this zone is essen- 

 tially merely one of overlap between Austral (or Sonora) and Boreal (in 

 its Canadian division). 



Alien Hummingbird 



The busy Allen hummingbird, flitting rapidly from flower to flower, 

 hovering over a blossom to take the honey, always attracts attention. Of 

 Austral zone origin, the bird is of peculiar interest because, in spite of its 

 great powers of flight individually and its seasonal migrations, it is re- 

 stricted in its breeding to an astonishingly narrow range — to the "fog-belt" 

 of California, from the Oregon line to San Luis Obispo County. Nests have 

 been found beyond these limits but rarely. These hummingbirds are not 

 known to nest farther than 20 miles from the sea. 



The species has no counterpart in the Sierra Nevada ; though it does have 

 in the coast belt north of California. The life zone is thus chiefly Transition. 



Males and females of this species occupy separate types of environment 

 nearly all the time. Grinnell and Linsdale, at the time of their study of 

 Point Lobos, thought some 15 females lived in the area then, but not more 

 than one-third this number of males. 



Santa Cruz Chestnut-backed Chickadee 



The Santa Cruz chestnut-backed chickadee, quite sharply characterized 

 by gray instead of rusty or chestnut-colored sides, is restricted to the 

 narrow, humid, coast belt south from San Francisco interruptedly as 

 far as Cambria, San Luis Obispo County, where, significantly, occurs the 

 southernmost mainland stand of Monterey pines. This bird seems to require 

 the presence of coniferous trees for a suitable environment. Its relative, 

 the mountain chickadee, is found in Monterey County only a few miles 

 in an air line from the Reserve, but the two species are separated on some 

 subtle basis — possibly connected with differing degrees of climatic hu- 

 midity. There is no record of either kind of chickadee in the area of the 

 other. 



When a survey was made in 1935, there were about 50 chestnut-backed 

 chickadees resident within the Reserve. Foraging places for these birds 

 include all of the kinds of trees found here. Nesting begins in March and 



Bird Island, ofF the south shore of the 



Reserve, is a veritable haven of refuge for many of the 



147 species of birds identified in this area 



