Mama's boy: sex differences in juvenile survival in a highly dimorphic large mammal, the Galapagos sea lion

Kraus C, Mueller B, Meise K, Piedrahita P, Pörschmann U, Trillmich F (2013)
Oecologia 171(4): 893-903.

Journal Article | Published | English

No fulltext has been uploaded

Abstract
In many mammals, early survival differs between the sexes, with males proving the more fragile sex ["Fragile male (FM) hypothesis"], especially in sexually dimorphic species where males are the larger sex. Male-biased allocation (MBA) by females may offset this difference. Here, we evaluate support for the FM and MBA hypotheses using a dataset on Galapagos sea lions (Zalophus wollebaeki). We statistically model sex-specific survival as it depends on body mass and environmental conditions (sea surface temperature, SST, a correlate of marine productivity) at three developmental stages, the perinatal phase (1st month), the main lactation period (1st year), and the weaning period (2nd year). Supporting the FM hypothesis, we found that, early in life (1st month), at equal birth mass, males survived less well than females. During the remainder of the first year of life, male survival was actually less sensitive to harsh environmental conditions than that of females, contradicting the FM hypothesis and supporting the MBA hypothesis. During the second year of life, only male survival suffered with high SSTs as predicted by the FM hypothesis. At each developmental stage, observed survival rates were almost equal for both sexes, suggesting that mothers buffer against the inherent fragility of male offspring through increased allocation, thereby masking the differences in survival prospects between the sexes.
Publishing Year
ISSN
eISSN
PUB-ID

Cite this

Kraus C, Mueller B, Meise K, Piedrahita P, Pörschmann U, Trillmich F. Mama's boy: sex differences in juvenile survival in a highly dimorphic large mammal, the Galapagos sea lion. Oecologia. 2013;171(4):893-903.
Kraus, C., Mueller, B., Meise, K., Piedrahita, P., Pörschmann, U., & Trillmich, F. (2013). Mama's boy: sex differences in juvenile survival in a highly dimorphic large mammal, the Galapagos sea lion. Oecologia, 171(4), 893-903.
Kraus, C., Mueller, B., Meise, K., Piedrahita, P., Pörschmann, U., and Trillmich, F. (2013). Mama's boy: sex differences in juvenile survival in a highly dimorphic large mammal, the Galapagos sea lion. Oecologia 171, 893-903.
Kraus, C., et al., 2013. Mama's boy: sex differences in juvenile survival in a highly dimorphic large mammal, the Galapagos sea lion. Oecologia, 171(4), p 893-903.
C. Kraus, et al., “Mama's boy: sex differences in juvenile survival in a highly dimorphic large mammal, the Galapagos sea lion”, Oecologia, vol. 171, 2013, pp. 893-903.
Kraus, C., Mueller, B., Meise, K., Piedrahita, P., Pörschmann, U., Trillmich, F.: Mama's boy: sex differences in juvenile survival in a highly dimorphic large mammal, the Galapagos sea lion. Oecologia. 171, 893-903 (2013).
Kraus, C., Mueller, B., Meise, Kristine, Piedrahita, Paolo, Pörschmann, Ulrich, and Trillmich, Fritz. “Mama's boy: sex differences in juvenile survival in a highly dimorphic large mammal, the Galapagos sea lion”. Oecologia 171.4 (2013): 893-903.
This data publication is cited in the following publications:
This publication cites the following data publications:

2 Citations in Europe PMC

Data provided by Europe PubMed Central.

Disentangling direct and growth-mediated influences on early survival: a mechanistic approach.
Plard F, Yoccoz NG, Bonenfant C, Klein F, Warnant C, Gaillard JM., J Anim Ecol 84(5), 2015
PMID: 25882771

66 References

Data provided by Europe PubMed Central.


AUTHOR UNKNOWN, 0
Identifying when weather influences life-history traits of grazing herbivores.
Sims M, Elston DA, Larkham A, Nussey DH, Albon SD., J Anim Ecol 76(4), 2007
PMID: 17584382
Is greater female longevity a general finding among animals?
Smith DW., Biol Rev Camb Philos Soc 64(1), 1989
PMID: 2655725
Does genotypic sex have a direct effect on longevity?
Smith DW, Warner HR., Exp. Gerontol. 24(4), 1989
PMID: 2684675

C, J Mammal 80(), 1999

F, Behaviour 114(), 1990

F, Adv Study Behav 25(), 1996

F, 1991
Field metabolic rate of lactating female Galapagos fur seals (Arctocephalus galapagoensis): the influence of offspring age and environment.
Trillmich F, Kooyman GL., Comp. Biochem. Physiol., Part A Mol. Integr. Physiol. 129(4), 2001
PMID: 11440861

F, Oecologia 67(), 1985

F, Behav Ecol Sociobiol 62(), 2008

RL, Am Zool 14(), 1974
Natural selection of parental ability to vary the sex ratio of offspring.
Trivers RL, Willard DE., Science 179(4068), 1973
PMID: 4682135

B, J Anim Ecol 72(), 2003

S, Mar Ecol Prog Ser 363(), 2008

EM, Proc Nutr Soc 35(), 1976

Export

0 Marked Publications

Open Data PUB

Web of Science

View record in Web of Science®

Sources

PMID: 23053230
PubMed | Europe PMC

Search this title in

Google Scholar