Birth to weaning in 4 days: remarkable growth in the hooded seal, Cystophora cristata
1985; NRC Research Press; Volume: 63; Issue: 12 Linguagem: Inglês
10.1139/z85-424
ISSN1480-3283
AutoresW. Don Bowen, Olav T. Oftedal, Daryl J. Boness,
Tópico(s)Marine Bivalve and Aquaculture Studies
ResumoA brief lactation period with rapid neonatal weight gain may be adaptive for seals breeding on unstable pack ice. We studied the duration of lactation and growth of known-age pups of the hooded seal, Cystophora cristata, on the pack ice off Labrador. Mean body weight of pups increased from 22.0 kg at birth (n = 21) to a maximum of 42.6 kg on day 4 (n = 11) and then declined. On the basis of maternal absence, weight change, gastric contents, and clarity of blood serum, we conclude that pups are weaned 4 days after birth (range, 3–5 days). This is the shortest lactation period known for any mammal. Tagged pups captured on sequential days gained on average 7.1 kg per 24 h from the day after birth to weaning. Maternal effort supported a relative rate of weight gain (145 g∙kg maternal weight −0.75 ∙day −1 ) that is 2.5–6 times that of other phocids. By combining a large birth weight with rapid neonatal weight gain, hooded seals achieve a weaning weight comparable to other phocids in one-third to one-tenth the amount of time after birth.
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