REPORT OF THE ORNITHOLOGIST AND MAMMALOGIST. 251 



Have you oljserved from year to year any increase or decrease in the numbers of 

 any kind of bird known to you ? If so, do you attribute stick change to altered 

 conditions in the bud's breeding-grounds V If not, caji you assign a cause V 



Have you observed the increase or dec^rease of one species to alfect the numbers 

 of another s])ecies? If so, can you explain the fact? 



Has any kind disappeared altogctlier, and if so, can you assign a cause for tl)is 

 disap])earance? 



Among the birds which are now common about your station is there any kind 

 that was fonnerly rare or absent ? If so, can you explain the fact? 



Amoni;- tli!> l)ii'd.s which breed regularly in your vicinity have you ever observed 

 an individual wliich Ijj"^ some pei-sonal peculiarity (such as the presence of white or 

 <lark featliers where they do not belong, or by some deformity) could readily be dis- 

 tinguished from others of its kind ? If so, has this bird returned to the same place 

 to nest year after year ? 



In recording arrivals and departures, it is liighly important to distinguish between 

 the movements of irregular stragglers of the advance guard or "van," and of the 

 principal mass or " bulk " of the species. For this purpose observers are requested 

 to note : (1) when the species is first seen ; (3) when it is next seen ; (3) when it be- 

 comes common : (4) when the bulk departs ; (5) when the last individual is seen. 



In addition to the above data, wliich all observers are requested to furnish, the 

 Department particularly desires exact records of every increase and decrease in the 

 numbers of a given species over a given area; for it is only by the knowledge of the 

 daily fluctuations of the same species in the same place that the progress and move- 

 ments of a "flight," or " bird- wave," can be traced. Such data can be contributed 

 by experienced observers only, and in their procm-ement much time must be spent 

 in the field. During the progi-ess of the migratory movement the observer should 

 go over the same gToimd day after day, and, if possible, both early in the morning 

 and late in the afternoon. He should visit wood-lands, thickets of dense under- 

 growth, and open fields, and, if possible, both swamp and upland should faU under 

 his daily sciaitiny. 



The above may be regarded as essential data. There are many other noteworthy 

 details that bear more or less directly upon the complicated problems involved in 

 the study of migration. Among such may be mentioned the bodily condition of the 

 bird (whether fat or lean), the molt, and the period of song. The time of mating, 

 when observed, should always be recorded. 



The Department deskes positive information concerning the food of all birds, and 

 will fvunish, on application, a special circular devoted to this branch of the inquiry. 



(6) Meteorological phenovftenct,. 



Information is desired upon — 



(1) Tlie direction and force of the wind. 



(3) The direction, character, and duration of storms. 



(3) The general conditions of the atmosphere, including rainfall. 



(4) The succession of marked warm and cold waves, including a record of all sud- 

 den changes of temperature. 



(c) Contemjiorary and con'elative phenomena. 



The Department desires that the data under this head be as full and complete as 

 possible, and requests exact information upon — 

 (1) The date at wliich the first toad is seen. 

 (3) The date at which the first frog is heard. 



(3) The date at which the first tree-toad or "peeper" is heard- 



(4) The dates at which certain mammals and reptiles enter upon and emerge from 

 the state of hibernation. 



(5) The dates at which various insects are first seen. 



(6) The dates of the flowering of various plants. 



(7) The dates of the leafing and falling of the leaves of various trees and shrubs. 



(8) The dates of the breaking up and disappearance of ice in rivers and lakes m 

 spring, and of the freeznig over of the same in the fall. 



It must not be supposed, liecause a large amount of information upon a variety of 

 subjects is asked for, that meager or isolated records are not desired. Quite "the 

 contrary is true. Comparatively few of the observers are oriuthologists, or even 

 bud collectors— the gxeat majority being intelligent farmers, ti-adesmen, and light- 

 keepers. Those who know only the commonest birds, such as the Robin, Bluebird, 

 Boboluik, Martin, Humming-bird, and Chimney Swift, can furnish important data, 

 and theii- services are eagerly sought. 



