MARSH-WRENS. 91 



tlieir arrival, shows conclusively that temperature alone 

 has almost or quite nothing to do with a bird's move- 

 ments. I know of no one of our birds that cannp^t with- 

 stand a low temperature ; and were the food supply kept 

 up, whether it was hot or cold, the migratory birds in 

 New Jersey would become resident with scarcely an ex- 

 ception ; and when we come to compare the accounts of 

 our birds as recorded by Wilson, seventy years ago, and 

 the habits of these birds as they now are, it is remarkable 

 how variable are certain features which Wilson sets 

 down as governed by fixed rules. 



Evidence of this is, of course, readily obtained by daily 

 observations made throughout the year, and continued 

 for years, in given localities. The results of a single 

 year will have but little bearing upon the regularity or 

 want of it in a bird's movements. The observations of 

 the same person in the same locality must extend over 

 at least a decade before it is safe to arrive at any general 

 conclusions. My own conviction, that summer birds can 

 withstand a winter climate, is based on the fact that I 

 have now a record of nearly thirty instances where sen- 

 sitive summer birds have been slightly injured, and, un- 

 able to undertake a migratory flight, have wisely not at- 

 tempted it, but seeking a sheltered nook for protection 

 against severe storms, have wandered about in search of 

 food in a thoroughly cheerful and contented manner; 

 even singing at times, with much of their springtime 

 earnestness. Such single birds wintering on my hill- 

 side were several cat -birds, a brown thrush, two in- 

 digo birds, several orchard and Baltimore orioles, a sum- 

 mer warbler, and a golden-crowned wagtail. 



