Investigating diverse sources of variation in the amount of time Weddell seal ( <i>Leptonychotes weddellii</i> ) pups spend in the water during the lactation period

Field observations suggest that time spent in the water by Weddell seal pups during lactation varies among individuals, which could yield important developmental tradeoffs. We analyzed data from 713 born to 419 different mothers over 9 years evaluate total water, age at first entry, and potential sources of variation using temperature loggers attached rear flipper pups. Pups entered 11–29 days (M = 14.9) 4–204 hr 69.3) 30 age. Age entry was earlier for with higher birth mass above average reproductive experience. Total related maternal identity greater female had mass, intermediate age, skipped reproduction previous year, younger ages. Phenotypic traits explain observed development a key life history behavior seal. Strong individual metabolically costly swimming diving might lead growth, energy stores, survival fitness outcomes.