found May 14 te Juma 6, The number of paira at this date wors estimated to ba 
38 par squares mile; broods in the July § to 26 period ware 11.1 per squars mils. 
A comparison of ragular transect figuras with figuras from 120 randomly- 
selgctead study potholes revealed that intsnsivs cerTerags? on study areas produced 
a mora pronounced diffarenes in bresding-psir and brood figuras than in totel 
duck counts. 
Over-water nesting species showsd a marked perfserencs for nesting in ths 
cattall and bulrush-dominant arsas included in ths 120 spscial-study potholas., 
Water levels fluctuated considerably but did not fall below a safe lavel | 
for broods. The value of the mors pormanesnt potholes was realized when 40 ner- 
cent of tha water arsas along ssvyoral transects were dry an July 15. 
Table 1. --Brasding Populations and Production on 12 Transscts [50.4 oq. Mi.) 
Breeding Faira Broods 
Time April Asril 2g May l4 - July July 
Interval 21-25 - May 7 Juns 6 5-26 5-26 
Mellard 434 268 382 156 117 
Pintail 134, 109 113 52 40 
Baldpate 32 65 181 i2 a7 
Gadwall 0 28 112 27 1é 
Shoryeler Li 54 Lo4 | 35 
B-w, teal 6 92 i, 76 195 11S 
G-w. teal an 56 fate! GTA 22 
Canvaeback 131 m3 1436 115 105 
Radhead ‘44 20 164 ad 8) 
Ruddy duck 0 10 43 "9 28 
Lascesr Bcaup tl 18 140 a bo: 1? 
Others 26 22 33 20 Ll 
Total Pairs a39..  #&©|:}8lf  L9l4 822 Total Broods 558 
Pairs 
per sq. mils 16.6 | 16.2 36.0 14.3 Eroods per 
eq. mi. EE ek 
Total Ducks 1659 3139 L372 1i91 
Tucks 
per sq. mils 42.9 62.3 84.7 29.6 
80 
