ORNITHOLOGY 



151 



As this mountain pass re(|uires a rise 

 of half a mile and as the birds do not feel 

 safe near tiie man with a gun, they must 

 prepare for a steep ascent before they 

 can glide down toward the deep blue of 

 the Pacific. 



Here natm-c comes to their assistance. 

 All eastward of these mountain ranges, 

 that lie generally parallel with the coast, 

 is desert or semi-desert where the sun 

 heats the barren rocks or the parched 

 earth to the satisfaction of even the most 

 exacting horned toad. 



The air coming in contact with these 

 highly heated surfaces ascends and is re- 

 placed by descending currents or by air 

 that pours into this inland basin through 

 many high gaps in the coast range. 



When the winds are not too active 

 these ascending currents rise in great 

 columns, as is evidenced by the whirling 

 of the dust which they gather and carry 

 to great heights. 



\Mien the spreading \'-shaped flock en- 

 counters an ascending air current it at 

 once breaks ranks and each bird for him- 

 self adjusts his wings and begins to circle 

 within a radius that will enable him to 

 avail himself of the rising air. Thus with 

 seldom the flap of a wing the birds often 

 rise until they are scarcely discernible 

 to the unaided vision. 



\\'hen the energy of the ascending cur- 

 rents has reached the limit of useful lift- 

 ing, the flock resumes the businesslike \ 

 form and glides with occasional wing 

 movements down and through the great 

 pass to the distant coast on their way to 

 the land of the melting glacier. 



The writer's many years in Florida per- 

 mitted observations of the ever present 

 buzzard in his lazy soarings. These like 

 those in the desert occurred only when 

 the air was so quiet that the sun's heat 

 from a clear sky could by heating the 

 earth's surface establish the well defined 

 ascending areas of heated air. As the 

 abundant vegetation of Florida prevented 

 the dust from rising to supply visible evi- 

 dence of the ascending current upon 

 which the soaring birds could float, the 

 observer must by watching them assure 

 himself that they limit their ascents 

 to certain areas. Any attempt of a 

 willful bird to pass the limit of its well 

 defined circling was immediately follow- 

 ed by active wing- flapping until it could 

 again find another upthrust of air. 



Remarkable Nest on Water. 



\'.\ FLOYD T. wool), C.\LC..\KV, ALBKRIW, 

 C.\N.\DA. 



The nest is the home of what we call 

 the hell-diver, which I understand is a 

 species of grebe. There were at least 

 three feet of water under the nest. Its 



THE NEST ON WATER. 



support was the dead branches of a small, 

 scrubby willow. The mother bird went 

 only a few feet away and returned to her 

 charges as soon as I splashed my de- 

 parture. I might add that four little 

 hell-divers appeared in due season and 

 lived quite happily in the pond where they 

 were hatched. The picture was taken 

 from the back of my saddle horse. 



In several of our eastern towns and 

 cities house wrens have appeared in 

 the last season or two, where none have 

 been previously observed for ten or fif- 

 teen years, and it is hoped that these 

 friendly little birds may again become 

 common in localities which they for- 

 merly inhabited, being supposed, in 

 many instances, to have been driven off 

 by the English sparrows. The abun- 

 dance of bird houses now being con- 

 structed and placed about, will offer 

 unusual protection and nesting sites, 

 and should do much tow^ard bringing 

 back the wrens. 



