Archive for November 7th, 2008

November 7, 2008

Solitary Dolphins in the Lagoon

NASA via Wikimedia / An IRL dolphin in the Banana River

If you ask the average school child what a group of dolphins is called practically all will answer: “pod”.  Its the correct name, to be sure.  Atlantic bottlenose dolphins (Tursiops truncatus), along with many other dolpin species, travel in fluid social groups of various compositions out in the wild.  But I regularly see them travel alone within the Indian River Lagoon.

At first, I thought this was a fluke. (Haha.)  Near Sebastian Inlet on the lagoon side during fall of 2006 and 2007 it was a regular occurrence to see a bottlenose dolphin working shoals of mullet, pinfish, and juvenile sheepshead entirely alone.  While I never photodocumented the dorsal fin patterns of the individuals I saw – which would make accurate identification possible – I noticed such loners frequently enough to wonder if they are perhaps 1) somewhat residential in nature and patrol a given territory and 2) if the repeated sightings were of the same solitary individual. 

My sightings of the Sebastian Inlet individual(s) continued daily to weekly for several months in each autumn season.  Back in February of this year I noticed a single mother and calf pair in the Mosquito Lagoon near Bethune Beach.  And in May and July my notebook boasts sightings of a lone dolphin off the causeway towards Merritt Island National Wildlife Refuge in Titusville. 

This week, I’ve been working within Merritt Island and over the past four days I’ve spotted several bottlenose dolphin.  Of seven total sightings a full six were individual animals noted several hours apart from one another.  While these could be the same individual, if there are multiple animals they didn’t appear to be traveling in a pod.  The seventh sighting consisted of a pair of dolphins; a probable mother and calf judging from the small size of the second dorsal fin that surfaced. 

It really makes me wonder.  Sightings of solitary dolphins have been made before,  but most researchers consider such lonesome behavior rare.  The question is, why do I seem to observe it so often in the lagoon?  While its known that adult males are more likely to exist as pairs or loners, and that group size tends to increase with water depth, it still seems strange to me that in three autumns on the lagoon, I have yet to see more than two dolphins ever traveling together. 

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