Reproduction 65 
Z 2 
4 t 
rc] 
3 
Se 
ie 
o 
ation began, eet complete (Ci jg Ke 
began, set cozplete,(A2 nest s 
began, =p ’ A peo 4 
+3 
42 nest); fourth egg hatched (B2 nest) Lg 
laid (C1 nest); 3 eggs hatehed (B2 nest) Ls 
a) 
+e 
Nest building began (A2 snd C1 nests) [2 
Pe 
ot 
i 
=) 
”“ 
-S 
e 
| <a 
— 
Set complete (4 eggs) Hrs 
Incubation began (3 eggs) -2 
_a 
First egg laid ED 
Sad 
Nest building began (B2 nest) -_ 
z a es 
gs a 
38 coaneet 
~e Pe a 
5 * Poi =) 
2 ? ---flest Bi and Al 
° -~ destroyed by snow Kel 
} * © & ° r) + ° - j) 
T Ls ¥ ’ is ba st 
* 8 eo 3 2 8 = 3 
Fig. 8. Mean and minimum daily temperatures and snow on the 
ground at 8:00 P. M., for April, 1927, at Ithaca, New York, with a 
tabulation of breeding activities of the Prairie Horned Lark 
nth, 
uring the mo 
