Hawaiian Monk Seals

An analysis of body size

The Hawaiian monk seal (Monachus schauinslandi) is one of the most endangered marine mammal species. It is also highly studied. There are approximately only 1200 remaining. Although this species is well studied; basic growth patterns of the Hawaiian Monk Seals have not been well documented.

 Earlier research has focused on pup growth through weening. New research conducted by Baker and Johanos (2014) look for evidence of sexual dimorphism (the difference between make and females) in the species and variable growth rates through species range. According to the researchers, they took seal measurements from 1984 – 2011 of seven subpopulations. They excluded any compromised animals (emaciated or wounded) as well as pregnant females. To avoid additional stress, measurements were not taken close to molting season.

You can read the very specifics of methods and results by referring to the full article reference below; “however researchers did not find evidence that length growth patterns differed among male and female monk seals. There were striking differences in growth curves among the various monk seal subpopulations” (Baker & Johanos, 2014, p.264). This is most likely due to variance in environmental conditions determining growth.

Reference:

Baker, J. & Johanos, T., 2014. Body Growth in Hawaiian Monk Seals. Marine Mammal Science. 30(1). 259-271. Online. Available here: http://onlinelibrary.wiley.com/doi/10.1111/mms.12035/pdf

 

Image: http://en.wikipedia.org/wiki/File:Monachus_schauinslandi.jpg