tf ieee ees et ae a ee SO - 
Meany of ths equatic invertebrates were present in neoticsebly smalisr 
numbsre this year, but thers has never been any indication of food shortage? 
on the nasting grounds, 
Ths Nesting Ssason 
The nesting season of 1949 was sarlisr than that of ths previous year. 
Dates of first broods obsasrved in the two years ars given on Table 3. It will 
be noted that for sach spacias the data of first ohssrved troed in 1949 is 4 
weok to two weeks sarlier than thse corresponding date in 1948. Mallards and 
pintails were the first species seen with young, in seach instance on May 3lat. 
In another paper of this report J. A. Munro gives the astimatess upon 
populations of waterfowl nesting In the Cariboo as obtained by brood counts on 
aamples lakes. It is psttinent to compares the rasults of our trapping operations 
on 11 lakes in the Cariboo and asstern Chileotin banded by us on both years. 
This comparison is mads on Tetl¢ 1. The data revysel a slight declins in ths 
populetion of Barrow'a golden-sye and 4 mors pronounced one in lesser scaup 
and canvasback. On the other hand, thsrs are marked incrasgssa recorded for 
bufflshaad, redhead and, most pronounced cf all, for blus-winged teal and 
baldpats. Compariegon of these fipures with birds and broods observed over a 
somewhat larger aréa makcs us reasonably confidant that in 411 but ons speciss 
thea trends indicated ara reliable. The exception is ths lesser secaup. The 
lakss were banded somewhat earlier in 1949 than in 1948 and many of the scaups 
were still incubating this year, and consequently ware not yet aveilable for 
banding. 
We wish to emphasize? particularly the ineresass in blus-wingsd teal and 
valdpats as this was perticiularly obvious in the field. 
Brood Counts 
Certain writsrs have suggested that there is a recipreesal relationship 
between the avsrags broad sizes and the total population of nesting waterfowl 
in any season; that when nesting is sparss, troods ars largsr. To snable an 
axaminution of this situation on the nesting grounds in British Columbia a 
notes was mada of brood sizes and ages of the young birds in a lares, unselected 
sanple of the broods seen. These figures ars compared for 1948 and 1949 on 
Tables 2. Wany of the speciss ars not represented by a-sufficient-number of 
broods te offsra reliable basis of comparison. But goldsn-sys, lesser scaup, 
buffishead, canvasbsck, redhead, and baldpate are probably comparable for thes 
two yearg. 
If amaller nesting populations do tend to produce lareser brocds it would 
bs expected that those of Barrew's golden-eys and canvasback would be larrer 
in 1949, while baldpats, bufflehsad, and redhead should haves smaller broods 
this yout. Upon sxamination of Tables 2 it will bes seen that. contrary to expecte- 
tion, tha mean brood sizs ion golden-eyse is smeller this year, while that of buffls- 
head and canyasback ares unchanged, and baldpata is, if anything, slightly larger. 
Onty ths redhead lives up to expectation. 
Tt would seem, tharefors, that there are species and conditions wherein 
there is not a compensatory association between population and brood sizes, 
25 
