32 
MEAN NUMBER/ SAMPLE 
20 C/S LONG PULSES 
— -— SHALLOW 
—=— DEEP 
20 C/S SHORT PULSES 
SHALLOW 
=== DEEP 
LF GROANS 
SUNRISE =— ——-— SHALLOW 
ac ae ——-=--= DEEP 
SUNSET 
12 146 18 20 CCen oe 2 4 6 8 1) 2 
HOUR OF SAMPLE 
IP BOP IRG. rao Total number of sounds heard of a 
particular category (20 CVish OMG uaa Sloat meus ers 
and Low Frequency Groans) during all samples of a 
particular time of day, divided by the number of 
aaySe The curves were smoothed arithmetically. 
