1918 x 2606 px | 16,2 x 22,1 cm | 6,4 x 8,7 inches | 300dpi
Altre informazioni:
Questa foto è un'immagine di pubblico dominio, il che significa che il copyright è scaduto o che il titolare del copyright ha rinunciato a tale diritto. Alamy addebita un costo per l'accesso alla copia ad alta risoluzione dell'immagine.
Questa immagine potrebbe avere delle imperfezioni perché è storica o di reportage.
. The effect of altered streamflow on migratory birds of the Yellowstone River Basin, Montana . 47 (8) 40 (2) 84 (11) 80 (8) 35 (6) 12 (2) 60 (3) 0 (0) 0 (0) 8 (1) 0 (0) 20 (2) 6 (1) 0 (0) 8 (1) 0 (0) 64 (29) 20 (9) 11 (5) 5 (2) 1976 Bighorn to Hysham 27 59 (16) 7 (2) 26 (7) 7 (2) Sanders to Forsyth 21 33 (7) 5 (1) 38 (8) 24 (5) Hathaway to Miles City 6 33 (2) 0 (0) 33 (2) 33 (2) Miles City to Sunday Creek 14 36 (5) 0 (0) 57 (8) 7 (1) Sunday Creek to Terry 14 71 (10) 7 (1) 7 (1) 14 (2) Fallon to Glendive 14 64 (9) 0 (0) 7 (1) 29 (4) TOTALS AND MEANS 96 51 (49) 4 (4) 28 (27) 17 (16) NOTE: Nest fates are given first as percentages of study section nests, then (in parentheses) as number of nests. Nests in which eggs were injected with colored dyes were excluded (see page 38 )• The average height of goose nests above water was between 1 and 3 m (table 8), similar to the height above water of goose nests on the upper Snake River as reported by Dimmick (1968). Flooding of goose nests was more pronounced in the upstream study areas in 1975. Figures 6 through 9 show the increase in gage height during the nesting season in 1975 and 1976. More nests in the Bighorn to Hysham and Hathaway to Miles City study sections were flooded than in downstream study sections because gage heights in the upstream sections increased more rapidly. The stage in 1975 substantially increased before the peak of hatching in the upstream sections (figures 6 and 7) and little in those downstream (figures 8 and 9). In 1976, no flooding occurred in any section prior to the hatching peaks. The average distance of goose nests from water was variable between study areas (table 8) and indicative of the nature of the islands surveyed. Nest searches on islands with steep banks and high relief revealed nests close to the edge of the island and close to the water. The average distance from water of goose nests in all study areas in both years was 23.2 m (76.1); distances ranged from .3 to 126 m (1 to 413 ft