Developing a non-invasive indicator of pinniped health: Neonate behavior and growth in California sea lions (Zalophus californianus)

Assessing the health of wildlife populations is critical to achieving conservation goals; however, proper assessments can be complicated when study sites are difficult to reach or when focal species are sensitive to human disturbance. Condition and growth of offspring may indicate population health...

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Bibliographic Details
Main Authors: D S Green, J K Young, C J Hernández-Camacho, L R Gerber
Format: Article
Language:English
Published: Universidad Autónoma de Baja California 2010-06-01
Series:Ciencias Marinas
Subjects:
Online Access:https://www.cienciasmarinas.com.mx/index.php/cmarinas/article/view/1662
Description
Summary:Assessing the health of wildlife populations is critical to achieving conservation goals; however, proper assessments can be complicated when study sites are difficult to reach or when focal species are sensitive to human disturbance. Condition and growth of offspring may indicate population health, but obtaining such data generally relies on invasive techniques. Here, we examine the extent to which noninvasive observations of neonate behaviors could serve as a proxy for traditional approaches to estimating neonate body condition and growth of a wild pinniped, the California sea lion (Zalophus californianus), in the Gulf of California, Mexico. Generalized linear models and multiple linear regressions were used to examine the effect of sex, breeding island, year, and neonate behaviors (e.g., nursing, active) on body condition and growth rates. We found a strong correlation between individual growth rates and behaviors of male neonates. Males engaged in proportionally more active behaviors had lower growth rates (β = –0.0005), whereas males engaged in proportionally more nursing events had higher growth rates (β = 0.002). There was no relationship between neonate behavior and condition for either sex, nor between behavior and growth rates of female pups. These results provide insight into the possibility of using behavior as an indicator of individual status of males that could facilitate assessments of population status and illustrate the importance of using alternative approaches to measure animal condition for species conservation. 
ISSN:0185-3880
2395-9053