310 
Auffenberg 
Figure 6. Appeasement display in young monitor approaching carrion where a larger specimen is feeding 
(top right). Head position and raised roach are part of display, but by themselves constitute a stress reac- 
tion (see text). 
tions in the magnitude or qualitative state of 
a behavior). One example is the rate of dis- 
play with respect to population density. As 
another example, the average number of 
stress reactions/hour among individuals of 
1.5 m or less at carrion was 1,6 when aggre- 
gations consisted to 2 to 5 individuals; 2.8 
for aggregations of from 6 to 9; and 4.1 at 
aggregations of more than 10. Similarly, the 
number of tongue flicks vary according to 
aggregation densities around carrion. (X= 
8.2 flicks/minute for aggregations of from 
2 to 5, 12.1 for aggregations of 6 to 9, and 
19.6 for more than 10). Fighting itself prob- 
ably falls into the same category, but the 
differences for the three density classes of the 
present study are statistically insignificant. 
Scaling can also be related to the intensity 
of the communicative cue or display. For ex- 
ample, in the threat display the tail bow and 
open mouth are presented when the displayer 
cannot, or seems unwilling to move. Together 
with other cues they constitute the highest 
level of threat display prior to attack. Tail 
bow and open mouth are not part of the 
stress reaction but enter into a scaled threat 
display ranging from low levels without 
weaponry shown to high levels in which teeth 
and tail are used. On an ascending scale of 
intensity, the first step is probably the simple 
stress reaction, followed by lateral body com- 
pression and back arching. Hissing may occur 
as an additional component at this stage, 
followed by tail movements and finally vary- 
ing degrees of mouth opening (Fig. 8). 
Auditory Communications 
Sounds produced largely by the respiratory 
apparatus are infrequently used by reptiles 
in communicating information to each other 
