810 
THE WILSON JOURNAL OF ORNITHOLOGY • Vol 124, No. 4. December 2012 
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X 2 = 53.77 
P < 0.001 
x 2 = 35-18 
P < 0.001 
X 2 = 2.95 
P = 0.086 
X 2 = 19.04 
P< 0.001 
Both Vacant 
Fern. Saf. 
Fem. Sun. 
Social context 
Male Saf. 
X 2 = 212.75 
P< 0.001 
ma 
Male Sun. 
a female™ Saf" “T* Vilcant IBM v —<•« = «-’>■ 
oSlok 6 (BoTvafamr 11 eXP “' ati ' > " ° f n ° P"*""* All other distributions compared to a'null expect,®" of 
Fig. 2). Females visited the safflower seed feeder 
significantly more often than expected when a male 
was present al the sunflower seed feeder and the 
safflower seed feeder was vacant (y 2 , = 2P 7.5 p 
< 0.001; Fig. 2). 
DISCUSSION 
We investigated how social situations in the 
non-breeding season influence the foraging deci¬ 
sions by free-living male and female Northern 
Cardinals. The birds we observed were not 
individually marked, and it is possible that pre¬ 
existing dominance relationships among a small 
number of individuals could have influenced the 
overall patterns we observed. However, we at¬ 
tempted to minimize the probability of identical 
dyads being observed repeatedly by collecting data 
over a short period of time at five different feeding 
stations, all visited by large numbers of cardinals. 
Both male and female Northern Cardinals preferred 
to visit feeders with sunflower seeds when 
provided with a choice between sunflower and 
safflower seeds when no conspecifics were present. 
This is not surprising considering the higher fat 
content of black-oil sunflower seeds ( 40 %) versus 
safflower seeds (29%) (Foster and Smith 2001), 
Female Northern Cardinals avoided all conspe- 
c.tics when visiting feeders, regardless of which 
feeder they occupied. Females visited the saf¬ 
flower seed feeder significantly more often than 
the sunflower seed feeder when the sunflower 
seed feeder was occupied by another cardinal 
either male or female. Females opted for the 
unoccupied leeder, even if it contained the less- 
preferred lood. Females appeared to be particu¬ 
larly averse to visiting feeders occupied by male 
conspecifics. 
’ -- ■'-wvjv.in WCVU|_UV.-U uy UUItl 
visiting the safflower seed feeder significantly 
more often than the sunflower seed feeder when 
another male occupied the sunflower seed feeder. 
Males preferentially visited feeders occupied by 
leinales. even when these feeders contained the 
Iess-prefened lood. The interactions we observed 
were, almost without exception, brief; the landing 
of a new bird usually resulted in departure of the 
original bird. The motion of the feeding perch upon 
landing ol the second bird may have induced the 
departure of the first, but there seemed to be a 
disinclination to feed side by side. What does a 
male gain by displacing a female from a less- 
preferred food? We could And nothing in the 
literature to explain our observations, and suspect 
male cardinals are conflicted. January is the coldest 
month at our study site, and males begin acting 
territorial as early as February. It seems likely that 
m«lcs may be under selective pressure to initiate 
contact with females before females are willing to 
reciprocate. Consuming a safflower seed for a male 
cardinal with regular access to a feeder containing 
sunflower seeds may he worth the opportunity to 
interact, however briefly, with a female. 
Both female and male Northern Cardinals 
deviated from expected foraging behavior due to 
