Fostering behavior in Hawaiian monk seals: is there a reproductive cost?

摘要: Fostering behavior has been reported in a large number of mammal and bird species although the relative frequency its occurrence most is unknown. A commonly held view that fostering costly to parent(s) engaged it. However, empirical studies are few, measures either cost or benefit even rarer. During study individually marked Hawaiian monk seal mothers pups, observed over course maternal care, I found 87% 30 females fostered pups. Females sequentially an average 2.3 pups (range: 1–5 pups) during approximately 40-day lactation. The median proportion lactation spent was 34% 5%–90%). Confusion aggressive interactions appeared be major antecedent may understandable terms spatial pattern among females. density with relatively low for land-breeding (1.5 per 1000 m2), typical indicated tendency toward dispersion. Yet, movements from water occasionally leave within meter two each other. Several immediate reproductive were obtained, including: length time suckled by size at end suckling, survivorship 1 year age. There no correlation between these individual extent which their fostered, indicating high levels maintained seals because they not selected against.