Mayhew 1953 Experimental Mallard ES4 Egg No. Relative Humidity No. at that R.H. Date Laid Date Set Fertile Date Hatched Water Condition 150 75 47 4/11 4/14 + — 1 151 75 48 4/14 4/14 + — 1 152 75 49 4/12 4/14 + — 2 153 75 50 4/13 4/14 + 5/10 2 154 75 51 4/8 4/14 + 5/10 2 155 85 30 4/9 4/14 + — 1 156 85 31 4/9 4/14 + — 1 157 85 32 4/12 4/14 + — 1 158 85 33 4/10 4/14 + 5/13 2 159 85 34 4/9 4/14 + 5/11 2 160 85 35 4/10 4/14 + — 2 161 85 36 4/16 4/21 + 5/19 1 162 85 37 4/16 4/21 + — 1 163 85 38 4/21 4/21 + — 1 164 85 39 4/15 4/21 + — 2 165 85 40 4/16 4/21 + — 2 166 75 52 4/15 4/21 + — 0 167 75 53 4/18 4/21 + — 0 168 75 54 4/17 4/21 + 5/19 0 169 75 55 4/17 4/21 + — 0 170 75 56 4/18 4/21 + 5/18 0 171 75 57 4/15 4/21 + 5/17 1 172 75 58 4/17 4/21 + — 1 173 75 59 4/15 4/21 + 5/17 1 174 75 60 4/17 4/21 + 5/17 1 175 75 61 4/19 4/21 + 5/17 2 176 75 62 4/19 4/21 + 5/16 2 177 75 63 4/18 4/21 + — 2 178 65 38 4/21 4/21 + 5/18 1 179 65 39 4/19 4/21 + 5/19 1