THE OOLOGIST 



71 



growth in weight, instinctive habits, 

 and experiments on special senses. 

 Owen, on "A Captive Hermit Thrush," 

 (Auk, Jan. 1897,) gives many valuable 

 hints for the study of young birds. The 

 same observer has reported on the 

 growth of the young Song Sparrow. 



7. Feathers. — Under this head we 

 may study the relative development of 

 the feather tracts, I'ate of growth in 

 wing and tail feathers, and the pheno- 

 mena of moult. A very simple and 

 easy observation to make is the number 

 of feathers cast each day during a moult. 

 Chadbourne, (Auk, XIV, 140,) says; 

 "In the living bird accurate data of the 

 loss before and during the progress of 

 a complete moult are, I believe un- 

 published." A lookout should be kept 

 for albinism, melanism and hybridism. 



8 Variation. — This is a subject with 

 which bnt little has been done. It re- 

 quires a very large series of one species 

 and is best undertaken by those situ- 

 ated where two sub-species overlap, 

 that is, where intermediate forms occur. 



Do not think that I decry the making 

 of a collection. You should have a fair 

 series of each species found in your lo- 

 cality, so that you may recognize any 

 straggler, hybrid or strange plumage. 

 Collect all the specimens you need for 

 working out an uncertain point. If 

 you do not recognize a bird, shoot it. 

 But do not make a collection to show 

 your friends, or to have more than any 

 one else in the town. Make the most 

 of every bird you kill and when you dis- 

 cover something new or unusual, write 

 it up for publication so that others may 

 know the results of your work. 



Some Winter Birds of the Island of 

 Vieques 



BY B S BOWDISH. 



The Island of Vieques lies about 

 fifteen miles off the eastern end of Porto 

 Rico and in general topography much 

 resembles it on a smaller scale. In ex- 



treme length and width it is about 

 twenty-one by nine miles. Some of the 

 hills are still clothed in forest a portion 

 of which exhibits the dense tangle of 

 vine and bush of innumerable species of 

 the tropical forest, also some of the 

 creek bottoms are likewise thickly 

 grown with small growth, but the vir- 

 gin forest, the giant trees of the prim- 

 eval timber are gone forever, a sacrifice 

 to the cupidity and vandalism of Spain. 



In yalley and on hillside in many 

 places acre upon acre of sugar cane 

 waves in the breeze in an uninierrupted 

 expanse Over other like expauses the 

 luxuriant growth of grass furnishes an 

 abundant pasturage for numerous 

 oxen. Small tracts here and there are 

 devoted to gardening. Throughout the 

 open country occasional trees and 

 copses of bushes are scattered. The 

 fences are many of them hedges of the 

 "Spanish bayonet" cactus, and these 

 hedges intergrown thickly with rank 

 grass form havens of retreat for many 

 birds— and also for the Mongoose. 

 This latter and a wood rat, nesting in 

 trees, have undoubtedly efl:ecied the 

 avifauna of the island to a very large 

 extent. Ground nesting birds must 

 have been seriously disturbed by the 

 extreme abundance of the Mongoose 

 which in predacious habits surpasses 

 the ermine or mink. A representative 

 of the Bob-white formerly recorded 

 from the island of Porto Rico seems to 

 be rare now if not quite extinct. 



In presenting this list I would say 

 that it is the result of some three 

 months observation in November and 

 December of '99 and January and Feb- 

 uary of the present year, made under 

 many difficulties and that I was con- 

 stantly hampered by military duties. 



The Gulls and Terns seen were none 

 of them secured hence remained uni- 

 dentified and the same was the case 

 with the majority of the water birds. 

 Consequently the list chiefly represents 

 the more conspicuous winter birds of 



