Nest Building is an Indicator of Parental Quality in the Monogamous Neotropical Buff-Breasted Wren (Thryothorus Leucotis)

Abstract

AbstractIn species with long-term partnerships, optimal mate preferences may differ from actual mate choice, and pair displays that advertise individual quality may be expected. We examined the relationship between nest-building and nestling-provisioning effort in Neotropical Buff-breasted Wrens (Thryothorus leucotis) to determine whether male or female expenditure during nest construction was used as an indicator of subsequent parental ability. Buff-breasted Wrens build two nest types: breeding nests used for raising offspring, and “dormitory“ nests built year-round and used by pairs for roosting overnight. The building effort of males was greater than that of their mates for dormitory nests, whereas male and female effort were similar during breeding-nest construction and nestling provisioning. Despite large within-sex variation in building and provisioning efforts, male and female effort within pairs were significantly positively correlated for construction of both nest types and for nestling feeding. Effort expended by males during dormitory-nest construction was positively correlated with nestling-provisioning effort, whereas female building effort was not. No relationship existed between effort in breeding-nest construction and nestling provisioning in either sex. These results suggest that effort in dormitory-nest construction was an indicator of male Buff- breasted Wren parental ability. Females that survived to the year following observation built dormitory nests at a lower rate than those that disappeared, which suggests that nest building may be costly and that by building more than females, males may increase the survival prospects of their partners. Dormitory-nest building by males may play dual roles throughout the year, indicating parental ability and investment in the partnership.La Construcción de Nidos es un Indicador de la Calidad de los Padres en la Especie Neotropical Monógama Thryothorus leucotis