Table 3.

Ranking of 30 behavioral and physical traits in order of their ability to differentially predict VTA gene expression in the two distinct male groups (Low and High Dopamine) identified using machine learning approaches. The top 5 traits (shaded) predict the two groups with 100% accuracy. Pink indicates the trait or behavior was produced by the female partner. Blue indicates it was produced by the male subject. White indicates that both the male and female contributed.

Ranking	Trait	Details
1	# of courtship behaviors	performed by the female
2	# of nesting behaviors	performed by the female
3	Final nest weight (g)	likely determined by male (see text)
4	# drinking bouts (alone)	performed by the female
5	# of beak wipes	performed by the female
6	# of agonistic behaviors	performed by the female
7	Largest gonad (mm2)	for the male
8	# of approach behaviors	performed by the female
9	# of undirected songs	performed by the male
10	# of calls	performed by the male
11	# of courtship behaviors	performed by the male
12	Weight (g)	for the female
13	# of contact behaviors	performed by the male
14	# of contact behaviors	performed by the female
15	Largest gonad (mm2)	for the female
16	Weight (g)	for the male
17	# of calls	performed by the female
18	Beak hue (upper mandible)	for the female
19	Beak hue (upper mandible)	for the male
20	# autopreen bouts	performed by the female
21	# of synchronous behaviors	performed by both
22	# of nesting behaviors	performed by the male
23	# feeding bouts (alone)	performed by the male
24	# of beakwipes	performed by the male
25	# of approach behaviors	performed by the male
26	# feeding bouts (alone)	performed by the female
27	# of eggs	performed by the female
28	# drinking bouts (alone)	performed by the male
29	# of agonistic behaviors	performed by the male
30	# autopreen bouts	performed by the male