Skhinks and magples were found te be the worst predatore, affecting 
waterfowl production in the walley through thelr destruction cf egeée. 
Conceivably this predation may hare been increased py the predatore trailing 
the ohperver to neste. Desertion aleo might have been greater than normal 
due to obeervation, although in no inetance wae there any Indication of 
desertion from this cause. Great care was teker te corer all neste with jown 
and debris after lnepecting the neste, and nc vietble markere were left within 
BO to 30 feet of each nest. Efforts were alee made to avoid conspicaons traile 
to the neats. On several occmeions skunks were obeerved wandering through the 
Rureell Lakes study arca apparently searching for nests. Cne ekunk wae observed 
to fleeh a hen whose neet was unknown to the obeerver. The skunk tomediately 
ttarted crushing the egge.and lapping up their contents. Cne coyote and three 
weasela were aleo obeerred on the study arenas during the nesting season but 
their importance was nerer determined. 
South Platte River Vallev: a Sn ee Se oe 
Study Township - To Sugiai 20 there hawe been 49 broode produced on the study 
towoship, and there are ao indiuectone tf further production this year. The 
OB aquare-ulle area ghowe an awerage of £,9% young per brood and a preducties 
figure of 7,83 per square ollie. 
Mallards are much more numerous thes. the other epecies of ducke in thie 
aren, a2 in other sreae under ebsermation in the State. Of 196 resident ducks 
in the townehip, 9% were coneldered Dree@ere and preduced 49 breeds. This ares 
it thought to hare been sufficiently covered at frequent intervals to hare seen 
and counted all ducke preduced. The entire area was inspected 14 times during 
the breeding season. It seeme conceivable -.12t a sonversion Factor may be 
figured and used for projection to areas with the same feneral characterlatics. 


South Platte Valley: The study area in tne South Platte Valley containe 1,407 
aguare miler. The separation is as follcwe! 
Se ne Sample ., Botal 
Farm Land River Bottom Farm Land River Bettem 
Ht 13 1,182 215 
% Sauple Farm Land ' $,28 
% Sample River Bottom 6,84 
Approximately 55 percent of the farm land samplea is irrigated. I+ hee 
been dirided Lnte five different corer types, and dealt with separately. The 
following table shows resulte found on these corer types, 

Prodaction Young 
Corer type Miles Acres Adults Prosds Fer 
Mile hore 
irrigation canals 15,88 5 4 L.o? 
Secondary irrigation dltches 17.10 1 1 0.206 
Creeka, eeep ar drainage 
ditchee 19.06 ) BR 2.07 
Sloughe 79. 20 a4 “al 1,8) 
Irrigation reserraire eo.e8 ae 15 $.24 

