Parental care Agelaius thilius 4 Sexual size dimorphism 4 Troglodytes 4 Troglodytes aedon 4 Yellow-winged Blackbird 4 parental care 4 parental investment 4 11 oxotestosterone 2 Acoustic cues 2 Androgens 2 Animals 2 Article 2 Aves 2 Behavior, Animal 2 Breeding biology 2 Canada 2 Central America 2 Cichlasoma dimerus 2 Cichlids 2 Feeding rate 2 Fertilization 2 Hirundinidae 2 House wren 2 Humans 2 Information networks 2 Larva 2 Leydig Cells 2 Leydig cell 2 Leydig cells 2