68 

Evidence that little pintail renesting. might be expected was first noted in the 
sex ratio of parts’ of two flocks seen on June 17 and 18 near Eston: 49 drakes: 
87 hens. A third flock of pintails and mallards, the former dominant, was composed 
of 26 drakes and 34 hens. That banding drives in the district between July 19 and 
22 caught a high percentage of pintails ready to fly, but very few Class I and II birds, 
is furth2r indication that first attempts represented a relatively large proportion of 
the successful nests. 
Predators were apparently more common in the area this year, with skunks 
making the greatest gains. Feral cats, weasels, badgers, ground squirrels, hawks, 
crows and magpies were also present. | 
Broods 
By early June of this year pintail-mallard production was on a par with last 
year's early effort -- 78 percent of the 1952 breeding population producing 73 percent 
of the 1952 broods in about the same period: 
Pintail Mallard Others Total Density 
June 10-11, 1953 77 broods 42 broods 5 broods 124 6.1 broods per sq. mi. 
June 3-5 , 1952 132 uv 37 ss 6 m 175 8.3 =" ee 
Class I, June brood sizes this year, however, were down for these two species 
(counts made off transect also included): 
June, 1953: Pintail 5.4 young (112 broods) Mallard 6.4 young (63 broods) 
June, 1952; Pintail 7.4 young ( 93 broods) Mallard 7.9 young (23 broods) 
The reason for this might be twofold: Agricultural operations may have hit at 
a more crucial period with the result that hens affected by them and yet not deserting 
returned to bring off that part of their clutch not destroyed. Also, a higher predator 
population may have taken a higher toll of young as broods made their way across 
country from nests or drying sloughs. The possibility that only part of a set of 
equally developed embryos might be affected by exposure to cold weather may also 
enter into the picture, 
The difficulty of conducting a satisfactory brood census by means of a 1/4-mile 
transect in a district where large water areas predominate in July and August was 
more apparent this year than last. Seventy-seven percent of the July broods recorded 
within the transect were on nine large aréas, partly, and often largely, stretching 
beyond the boundary of the strip. The remaining 23 percent were on 13 small areas 
wholly within the transect. The difficulty arises when broods hatched in May and June 
near small sloughs in the transect move in July and August to larger areas (many 
more than half a mile across), which have also attracted broods hatched near small 
early season ponds outside the transect. Loafing bars, cover and open water are 
foundin and out of the transect on these key areas and with so few of them in the late 
summer there is little chance of all the variables evening out on one coverage if, 
indeed, they would ever do so, Because of the dense cover and the size of these 
sloughs it is difficult to get accurate data on them at any time. As indicated above, 
sloughs within the transect were more numerous during the first half of June, 1953 
than in 1952. By mid-July of this year, however, there were fewer water areas 
than in mid-August of last year. 
