EPOW - Ecology Picture of the Week

Hawaiian Monk Seal (Monachus schauinslandi),
Hawaiian name:  'Ilio-holo-i-ka-uaua
Maui, Hawaiian Islands

Explanation:   Showing what appears to be a scar from some altercation is this Hawaiian Monk Seal in repose.  

This is one of the most endangered of all seals.  It is only one of two monk seals existing today, the other living in remote areas of the Mediterranean Sea.  A third monk seal existed in the Caribbean but fell extinct in the 1950s likely due to disturbance and change of its habitat by humans.  The Hawaiian Monk Seal is the oldest living member of the order of pinnipeds, having remained virtually unchanged for over 15 million years. 

I discovered this lone individual hauled out on the remote back side of the island of Maui in Hawaii.  This was an interesting observation, as the current distribution of this species is usually limited to the small and uninhabited northwestern Hawaiian Islands of the Leeward Chain.  Stragglers can be found occasionally on or near the main islands, as I also once observed one in the surf off Big Island.  

Hawaiian Monk Seals are mostly solitary (thus, its "monk" name) and probably never numerous.  Numbers were greatly reduced from hunting in the early 19th century, and later possibly from human disturbance, shark predation, red-tide poisoning, and disease in the mid-20th century.  Numbers began to rise in the 1980s with protection and a recovery program instituted by the National Marine Fisheries Service, but fewer than 1500 seals exist today and populations do not currently seem to be increasing.  It remains a federally-listed endangered species.  

As a consequence of low numbers, Hawaiian Monk Seals today have low genetic variability.  The implication of this is that the species may not be able to adapt to environmental changes.

Information:  
     Kretzmann, M. B., W. G. Gilmartin, A. Meyer, G. P. Zegers, S. R. Fain, B. F. Taylor, and D. P. Costa. 1997. Low genetic variability in the Hawaiian monk seal. Conservation Biology 11(2):482-490.
     Reeves, R. R., B. S. Stewart, and S. Leatherwood. 1992. The Sierra Club Handbook of seals and sirenians. Sierra Club Books, San Francisco, CA. 359 pp.