It is obvioue in Table 1 that the incrsass in waterfowl this year vas 
rathsr goneral in ths arsa coversd by the transects. Ths only exception to 
the increas¢ was in thea region coversd by transect 4. On an avsrags, howsyer, 
the ducks par square mils on 9 reutas intresssd from 24.4 in 1948 to 35.4 1n 
1949--an inersass of approximately 45 nereent. Tha lowest waterfowl population 
Tecordsd was in ths year 1947. Since that time, ths breeding population Index 
(ducks per square mils} hes increased in almost a straight Lins ralationahip 
(Figure i). 
From 8 management standpoint it is desirable, of course, to obtain infor- 
mation on population trends by sneciss. The valus of information of this typ: 
is obvious in that it is possible to devise management measures for the benefit 
of those species which requirs apscial attention. Tablas 2 summarizss the ocumber 
of ducks sean along ths tranegect routs whith wera identified as to species. 
Tabls 2. --Summation of All Routes [1 through 9} 
*Oomparative Abundancs 
Numbar of Duecka (psresnt of total) 
Speciss 1948 1949 1948 1949 © 
Pintail 1762 2076 — 28.6 | 26,8 
Blus-winged teal 1339 1980 21.7 25.6 
shoveler 627 a14 10,2 10,1 
Mallard Bas 1280 14,9 16.5 
Scaup 217 200 445 2,6 
Baldnats 121 107 a lag 
Gadwall 710 675 11.4 a. 
Redhead ao5 eae L.8 3.3 
Canvas back 111i 123 1.8 1.6 — 
Ruddy 0) P10 i ies) a | 
Green-winged taal rat 25 ate aa 
Unidentified LS L779 -— hed 
Total Beas 9526 
Cook B51 8.2 
Tha data in Tables 2 yeild information aa ta the ralative abundancs of the 
verious specisa. It will bs noted, however, that a larg® number of ducks along 
the transects were not identified. Sines it is logical that ths unidentifiad 
ducke would be present in ths sams apeciess distribution as these that were 
identified, it 18 possible, through the uss of the following formula, to ¢om- 
puts tha number af sach spscias on @ per aquare mils bagia. Ths us¢ of the 
formula ragults in a corraction for ducks not identificad. 
xX - {I} {C) 
N 
ducka por square mile 
total ducks sounted on «all transscta 
comparativs abundances (percant} 
mumber of square miles on all transeote 
ts Ha Pe 
158 
