Table 1. Experimental conditions for each of the eight species of interest. The first four species were homogeneous in population structure, in that all birds had the same probability of calling in each interval, whereas the next four species were heterogeneous. All species except the BAWW had a high singing rate per interval. Total and Singing Population sizes are presented as the probability of singing during the 8-min count. The last two columns summarize the Markovian nature of the singing process and are explained in detail in the text. Species Homogeneous population Singing rate, if sings Total population Singing population Probability sings in 8- min count γ' γ'' HOWA Yes High 100 100 1.0 0.3 0.1 BTNW Yes High 125 100 0.8 0.83 0.45 YTWA Yes High 167 100 0.6 0.9 0.5 BAWW Yes Low/ High 125 100 0.8 0.83 0.45 ACFL No High 50 83 100 1.0 0.6 0.3 0.9 0.1 0.5 SCTA No High 50 83 100 1.0 0.6 0.3 0.9 0.1 0.5 BTBW No High 133 100 empirical na na OVEN No High 127 100 empirical na na