Resumen del producto

Pinniped vibrissae provide information on changes in diet at seasonal and annual scales;however, species-specific growth patterns must first be determined in order to interpretthese data. In this study, a simple linear model was used to estimate the growth rate ofvibrissae from adult female California sea lions (Zalophus californianus) from San EstebanIsland in the Gulf of California, Mexico. The d¹⁵N and d¹³C values do not display a markedoscillatory pattern that would permit direct determination of the time period contained ineach vibrissa; thus, time (age) was calculated in two ways: 1) based on the correlationbetween the observed number of peaks (Fourier series) in the d¹⁵N profile and the length ofeach vibrissa, and 2) through direct comparison with the observed number of peaks in thed¹⁵N profile. Cross-correlation confirmed that the two peaks in the d¹⁵N profile reflected thetwo peaks in the chlorophyll-a concentration recorded annually around the island. The meangrowth rate obtained from the correlation was 0.08 ± 0.01 mm d-1, while that calculatedbased on the observed number of peaks was 0.10 ± 0.05 mm d-1. Both are consistent withthe rates reported for adult females of other otariid species (0.07 to 0.11 mm d-1). Vibrissagrowth rates vary by individual, age, sex, and species; moreover, small differences in thegrowth rate can result in significant differences over the time periods represented by the isotopicsignal. Thus, it is important to assess this parameter on a species-by-species basis.

Palabras clave: vibrisas; tasa de crecimiento; Lobo marino de California

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