72 
Broods were marked by injecting variously colored dyes into the eggs. 
This procedure was used very successfully with a hatching success of over 
75 percent. It was found favorable to inject eggs with a double dose of dye right 
at pipping time. Colored broods, especially red and green ones, were exceedingly 
easy to find. Color was visible for at least three weeks and often even up to the 
fourth week after hatching. 
Each pothole on the study area contained one water gauge, an 8-foot 
black spruce pole driven into,the mud. Weekly readings of all the gauges were 
taken to determine rise and fall of water levels. 
Results 
Since a sufficient number of breeding pairs was not marked, the 
conclusions reached regarding size of breeding pair range are all tentative and 
shall not be reported here. However, many observations of unmarked pairs were 
made and it is sufficient to say that size of breeding range varies markedly 
between species. Similarly, variaticns were noted in breeding pair ranges of the 
Same species. This variation appears to depend on the relation of potholes to one 
another, topography of the land, breeding condition of the birds, and a degree of 
intra-species competition. The eggs of 53 nests of various species of waterfowl 
were injected with colored dyes. The colored broods were followed in their daily 
' and seasonal movements and size of brood range was determined for several species. 
In some cases, 1 individual of the brood was trapped and remarked. The following 
chart gives some indication as to the size of brood ranges and number of potholes 
used by the brood. 
Table I - Ranges of Individual Broods of Various Species 
Total Distance Different Age before Original Mortality 
Species Moved (Yards) Potholes Flying size of Hatching 
Involved _ (Days) Brood to Flying 
Canvasback 733 4 62 9 - 2 
- ae 1,796 7 65 8 - 2 
" ut 4,473 8 58 8 0 
Blue-winged teal 770 2 47 12 0 
as “Ue Mm 1,026 5 40 9 - 3 
u u m 1, 467 6 42 . 12 0 
" mn mt 2,252 5 44 11 - 1 
Shoveler 806 3 39 * 12 - 2 
Redhead 1,576 5 66 * 10 - 3 
Pintail 1,100 4 43 8 Zoek 

* Fully-winged but not seen flying. 
Also shown in the above table is time of attainment of flight. This varied 
between broods and between individuals of the same brood. It was exceedingly 
difficult to determine the exact day of first flight, because birds might not attempt 
to fly during periods of observation. 
