Paternity in the Australian brush-turkey, Alectura lathami, a megapode bird with uniparental male care

Abstract

Male Australian brush-turkeys, Alectura lathami, provide all parental care by building and tending large incubation mounds. Females visit and lay eggs in the mounds of several males sequentially, but they provide no parental care after laying. Because males and females meet only briefly at mounds to copulate and lay, males have no obvious means of ensuring paternity. I used DNA fingerprinting techniques to determine paternity for 65 brush-turkey chicks. Eighteen chicks (27.7%) did not match the mound-tending male. Some of these paternity exclusions were evidently caused by females switching rapidly from one mound to another, but the majority (23.1% of eggs) appeared to result from females copulating with males other than the one in whose mound they were currently laying. However, the frequency of these copulations (4.5%) was much lower than the estimated frequency with which they fertilized eggs, perhaps because their timing during the ovulatory cycle differed relative to most other copulations. The percentage of eggs excluded in paternity analyses ranged from 20.0% to 43.8% for individual males but did not appear to affect male parental care. Several factors favor male parental care regardless of paternity. Males can accommodate eggs from several females in one mound, which increases the opportunities for additional matings without increasing the cost of parental care. In addition, paternity appears to be unpredictable and hard to assess, and a facultative reduction in care would be difficult without abandoning a mound entirely.