Recent Returns from Trapping and Banding Birds

Physiology of the temperature of birds

“…The first records of the temperature of the bird obtained are, in the case of these experiments, the most significant, as they show the immediate effect of the light and dark periods on the activity of the bird. Although the experimental results are much lower than the control records, the temperature of the bird after being in the dark was in each instance (Figure 26 [2 and 3] ) lower than it was after being in the light (Figure 26 [1 and 4]), although in the second case (Figure 26 [3]) the dark period came at midday, rather than at midnight as in the control (Figure 26 [2]). The three other successful experiments support these results.…”

“…There is a correspondence, however, between the time -Average Daily Rhythm in Body Temperature of an Eastern House Wren (No. 2).…”

“…The first control record obtained (Figure 21 [1]) by means of the indicator potentiometer and a thermocouple down the throat, between 10:16 and 10:56 in the morning, shows the normal tem- between 11 :27 and 12:00 P. M., gives the corresponding control at night (Figure 26 [2]). Then during the next 4 days, conditions were gradually changed until the bird was in the light at night, commencing at about 6:15 P. M., and in the dark during the day, beginning at 7:45 A. M. The normal daily rhythm in air temperature was not interfered with and so does not explain the results obtained.…”

The Role of Environment in the Life of Birds

“…Mention needs only to be made of the importance in this evolution of the habit that many species of birds have of going in groups. Bird-banding operations, carried on now for several years, indicate that, with several species of sparrows and warblers, groups of individuals are formed that migrate together, winter together, and breed in the same general region (Baldwin 1921, Whittle 1923, Fletcher and Whittle 1924, Higgins 1926. Inexperienced birds in these species may be shown the route of migration and appropriate breeding and wintering areas by older members of the group.…”

Measurements of birds

“…II the stretching to which the neck may be subjected; but after a little practice this will not amount to more than one or two millimeters in the smaller birds, an inaccuracy that is, of course, not serious. 2 By some authors the length is measured also to the tips of the shortest feathers of the tail, to show the difference between the lengths of the tail-feathers. This measurement is, of course, not the total length of the bird ; and, furthermore, the difference between the long and short tail-feathers is much more graphically exhibited by measurements of the tail alone.…”