Vol. 21, No. 12 
Page 3 
Responses of Prairie Chickens to Habitat Manipulation 
4fl\' 
R* L* Westemeier, 
D. R. Vance 
aw. 
4 ^ 
a?e S basic parameters wUh^h^Trmll^IX^ pe , rcenta 9 e hatchabi I i ty of egg 
chickens. AI though these tu a“ Id or ZT.Th ■?£*'•' ° f prairia 
has provided some insight on these aspects fir 16 Mill l 9 ' 3 ' 67 ’ our nest st ^y 
for which r^rs; 
chicken eggs at Bogota Mngl^f lom ^toMMes ^Thrilll ' 68 = ,utc ^ es of Prairie 
r?n^r tc ^??r t £i ^'.v 971 to ' 3; ' in 9e???.r; 0 r 
Stable Y for% W-yeor perfodf ,Uet “ t,ons » tha ° var *" ***" clutch size was 
The mean number of fertile enns fr,r 109 , 
in 1974 to 12.4 in I 970 and averaged 11 1 1 h^i C,Utches ranged from 9.6 
clutch size, the number of fertile enn /1 , h '. 6 years * As was the case for 
fertility of 2,259 prairie rhi i,p " P ** C utch a PP ea red to be stable. The 
percent in 1*5 aldMerlgeS“pS^ntMII thMM' L° ' 9&9 t0 97 ‘° 
fertile eggs also appeared stable ' 6 yearS ’ The P er «ntage of 
hatchabintyVevLf a what°may h be n cause for^oncern 6 "^^ 1 " C,UtCh and percenta 9 e 
eqqs per clutrh fnr 910 1 I u ' or concern * The mean number of hatched 
averaged “or thl Vj^r ? $ IhMiVhM.?: 9 1974 “ "l 7 in ' 97 ° -d 
ranged from only 82.3 percent in 1074 3 a 2l',!' ty ° f 2 ’ 497 prairie chicken eggs 
in 1965. Graphic p lslltluln If m 82-6 Percent in 1978 t0 '» 0.0 P«rc2t 
percentage hatehlbi mT^Ts° de f?lM^ mean ™ mber ° f h *^* d *99* and 
at Bogota. 7 def,mte do ""ward trends over the 16-year period 
per clItlh^aird^IuIinT'^Irr^ytatlit^ ^ 
such factors as population density a1 V f th ® data seems to ru,e out 
tamination may merit investing- u nsit y, and weather. Pesticide con- 
s«a --airthat 
of predation during the last 6 years u/ii-h at f hab111 ty- t Als o, the high levels 
conceivably result in lowered her h s*i- 9 her concomitant renesting could 
hatchabi I i ty may be a r“ioI ol'a '‘I'/ 0 ” 1 ° f a "; the trend i n 1owe r 
Of prairie chickens at Bogota; we hope Tt*if not?**'° Variati ° n in the P 0 Pn'ation 
