Nests: In captivity, the male Tangara arthus aurulenta male begins a visual nuptial display by presenting an offering to the female, such as twigs for the nest. The female builds the nest using leaves, twigs, or any other suitable plant material available (Cairpaglini 1971). Outside of captivity, the nests are generally found on mossy limbs and can be burrowed into the moss itself (Isler and Isler 1999). Nest building varies but has been recorded in July, September, and October. Begging juveniles have been documented in May, July, and August (Hilty and Brown 1986). In Ecuador, Greeney and Nunnery (2006) report an observation of nest-building on 28 February and an observation of dependent fledglings for 18 August. In the most detailed published information on nesting behavior, Gelis et al. (2006) record observations at a nest found on 31 March with two newly hatched chicks. The cup nest was about 10 meters above ground in a clump of epiphytes. The two young fledged 11 and 12 days later; thus Gelis et al. (2006) estimate that the nestling period lasts about two weeks.
Clutch Size: One to two eggs are laid at a time (Cairpaglini 1971).
Incubation: Incubation lasts 10-15 days (Cairpaglini 1971).
Parental Care: In captivity, Tangara arthus aurulenta females were observed eating the excreta of the young or throwing it away from the nest. Typically the female fed the young but sometimes the male would help to feed or chase away intruders from the nest (Cairpaglini 1971). In the field, Gelis et al. (2006) also report the removal of faecal sacs early during the nestling period. Young were fed and attended by multiple adults, making this species one of the few tanagers for which cooperative breeding has been documented (Gelis et al. 2006). Of 68 visits to the nest, 20 where made by three adult plumaged birds. These adults vocalized loudly and fed the young both arthropods and fruit.