1980] Horton — Stabilimenta of Orb Weaving Spiders 
17 
Table 2. Capture Sequences Exhibited by 8 Blue Jays Given a Choice Among 3 
Crickets and Web Drawings 
Possible 
Capture 
Sequences 
Times 
Observed 
N-P-F 
6 
N-F-P 
3 
P-N-F 
2 
P-F-N 
7 
F-N-P 
7 
F-P-N 
5 
distribution of capture sequences did not differ from random 
(P>0.50), indicating that the blue jays did not discriminate among 
the three web drawings. The web drawings were of course not 
identical to the spider webs. However, the results suggest that the 
birds had no innate preferences among the three web conditions. 
Table 3 shows the observed capture sequences exhibited by six 
experienced birds (i.e., excluding the initial sequence of each bird). Of 
the six birds, four were used twice and two were used three times. The 
results clearly favor rejection of the null hypothesis since the 
probability ofthis oramoreextremedistributionis<0.001 (binomial 
expansion) (Steel and Torrie, 1976). 
The non-web spider was taken first in 13/14 of the cases, 
demonstrating that non-web spiders were preferred over spiders 
within webs. In these cases the birds were left with a choice between a 
complete web and a partial web (one which lacked a stabilimentum). 
Table 3. Capture Sequence Exhibited by Six Experienced Blue Jays Given a 
Choice Among Three Spiders (Abbreviations as in Table 1) 
Possible 
Capture Times 
Sequences Observed 
N-P-F 12 
N-F-P 1 
P-N-F 1 
P-F-N 0 
F-N-P 0 
F-P-N 0 
