Vol. 19 , No. 10 
Page 3 
i 
Ms p ° pses — ^- ckens IS. HSiiiat Manipulation R. L . Westemeier, 
D. R. Vance 
Poor nest success on the sanctuaries at Boaota f nr t-hp 1 , 
TrapD?na r b bUted - t0 destruction b y mammalian predators (MWRL 19(7) '3) ^ 
Trapping by project personnel has had no noticeable effert n L • 
(SS t l , 8( 3 )Toi?i 7):4)> h DeVe, °^ nt "p reda tor-rests tan t'^nest ‘cover St 
(HWRL 18(3).2) offers another possible way to alleviate nest predation if 
on the frequency of strikes ™ each ha^h?^! T ? US ’ he ' 9ht and densit y (based 
with respect to density and success of'pralM?d!l2^«J. ,0n ^ eva,uated 
— :;.r> - *«>••■, »• 
were taken within 2 meters of the nest. * h CaSe > 3 sam P ,es 
In preliminary analyses of the da ta f r ^ipUc ‘ 
are discernible between fields subject to diffe 2 ^' appears that differences 
ii« s,s„'s?rr“ •” ec 
niques, Jasper'county S p rat rte^h tcken ^ Sanctuartest° 1976 management tech " 
Management 
Unmowed 
Mowed 
Rotary mower (weeds) 
Sickle bar (hay) 
Combine (seed) 
Mean 
Maximum 
Height (cm) 
Mean 
Height (cm) 
(all strikes) 
Mean 
Percent 
Occurrence 
(density) 
78.4 
13.0 
12.5 
35.1 
8.9 
13.8 
42.4 
14.1 
7.8 
39.4 
10.7 
16.7 
