Introduction to Area 1

Randall Wells, whose pioneering research in Sarasota Bay forms the basis of much of what we know about coastal bottlenose dolphins, has described their distribution along the gulf coast of Florida as "a mosaic of slightly overlapping home ranges of different dolphin communities."  Let's see how this model applies to dolphins in our study area.

Each bottlenose dolphin whose dorsal fin appears in our database is a member of one or another of these overlapping communities of resident dolphins.  This post will focus on the community of dolphins whose range falls within Area 1 (marked in yellow on the chart to the right).  We have done relatively few surveys in areas 2 (white), 3 (red), and 4, but Area 1 we have traversed over a thousand times, with surveys occuring during every month of the past five years, a period in which we recorded over 3000 dolphin sightings.  A clear picture of the makeup of this community has emerged.

Any time you draw an arbitrary line through an area as we have done in designating the route we take to conduct area 1 surveys, you are likely to find yourself in the heart of one dolphin's home range, at one extreme of another's and just outside that of a third.  This will be reflected in the frequency with which you encounter any given dolphin while conducting surveys along that arbitrary line.

So, for example, should you query our database, limiting the scope of your inquiry to Area 1 surveys, you are likely to find that Halfway, an adult female, has been encountered 274 times while, in the same period, two other females, KayCee and Crusty were encountered 20 and 17 time respectively.  Disastre, likely an adult male, was encountered only three times in the five years under consideration here.

We are clearly in the heart of Halfway's range.  A smattering of sightings appear near the northern and southern extreme of the Area 1 transect, but the vast majority - 212 - occur between marker #5 at the beginning of the intercoastal waterway between Marco and Naples, around the Isles of Capri Seawall and in Big Marco Pass.

Halfway and her calf Kaya

KayCee's sighting history suggests a different story.  She (and her calf, Slick Joey) have been sighted in the Marco River but never further south in Factory Bay or on the other side of the Jolly Bridge.  Her Area 1 sightings skew further north on the intercoastal.  And she was spotted in the Gordon Pass in Naples during two of the three exploratory trips taken in Area 3.

KayCee and calf, Slick Joey

Just as KayCee's sighting history suggests that the heart of her range lies to the north of the Area 1 transect, Crusty's suggests that hers lies to the south.  She too has been seen in the Big Marco Pass, but in five years and over a thousand surveys she has never been seen in the intercoastal waterway north of Marco Island.  She has, on the other hand, been seen to the south, in Factory Bay.  And, during surveys in Area 2, she has been spotted  three times on the southern end of Marco, in Caxambas Pass.

Crusty and her calf Gracie

As I compile a list of the community of dolphins whose range overlaps with the Area 1 transect, I will include both KayCee and Crusty, based on the frequency of sightings and the number of other dolphins in the community with whom they have associated.

Disastre is another story.  Besides having been seen in Area 1 only three times in five years, Disastre has only associated with 7 other Area 1 dolphins.  Compare this with 65 associates for Halfway, 38 for Crusty and 16 for KayCee.

Disastre

There is a third reason not to consider Disastre as a member of the community of dolphins that inhabit Area 1.  While the heart of KayCee and Crusty's range clearly lies to the north and south of Area 1, their sightings all fall either in the passes (Gordon Pass, Big Marco Pass, and Caxambas Pass) or waters behind barrier islands such as Factory Bay and the Intercoastal waterway.  Disastre, on the other hand, besides his exceedingly infrequent forays into the Big Marco Pass, has been sighted primarily in the near shore waters of the open Gulf.  While this is a subject for another essay, those dolphins seen on Area 2 trips along the coast (or Area 1 trips that dip out into the open Gulf briefly) seem almost never to venture further into the estuary and clearly represent a distinct community.  So, for the purposes of this analysis, Disastre will be considered an Area 2 dolphin and his sightings in Area 1 will be considered to be a sort of incursion.

Finally, before we move on to establish the make-up of this community of Area 1 dolphins, we should consider the example of a dolphin whose range falls just outside of Area 1.  In the same sighting that found KayCee in Gordon Pass in Naples, a dolphin named MissD was observed.  This dolphin has never been sighted in even the northernmost point of Area 1.

MissD with KayCee in Gordon Pass

So, given the judgement calls implied by the preceding examples and recognizing that the home range of individual dolphins (and hence the boundaries of their communities) overlap, following is a list of area 1 dolphins divided by status and, where possible, gender.

	ADULT FEMALES	18
HALFWAY   *	DARWINA  *	NIBBLES  *
GIZA  *	TRIGGER	AVERY  *
BOOTSTRAP BILL  *	RANGLE  *	SYDNEY  *
SPARKLE  *	TATTOO  *	PATCH’S TWIN   *
SPARKY  *	VICTORIA	CAPTAIN HOOK
TESS  *	KAYCEE  *	PAYTON  *
* currently with calf

	ADULT MALES	21
C.U. JIMMIE	FLAG	SHARKS
SUTILE   *	TUCKER	OSCAR
TRIXIE	BANGLE	MARCO
CAPTAIN JACK	FINCH	SEASTAR
CALAMITY	SCOOP	INTRUDER
AJAX	JINGLE
		CAM
SPIKE	CAPRI
PATCH  *	HATCHET	DESMOND
Spacing indicates strong association indicative of pair bonding		* no longer observed in area 1

	OLDER SUB-ADULTS*	7
MAMAWANE	ROCKY	BUTTON
BATMAN	ELLIE MAY
RAKES	KONA

	YOUNG SUB-ADULTS *	9
SIMON	BABY BLUE	ORANGE
LUCKY CHARM	SEYMOUR	RIPPLE
SINTAS	STELLAR	EL TERRIBLE
* These dolphins are seven years old or younger

	CALVES	16
GUMBO	AUBREY	JING JING
ANGEL	HILTON	DOUBLE DIP
DESTINY	NADINE	SLICK JOEY
STAR	MOCHA	CAMERON
KEEGAN  *	KAYA  *	JAYSON
FLIPPER
* = Young of Year

	DOLPHINS NO LONGER SEEN IN AREA 1	17
PATCH	F. BACON	SUTILE
FARKLE  *	FENDER	PINTA  +
BUTTERMILK  +	GUS   *	HOPPY  +
MR. CLEAN  *	EL TERRIBLE  *	EL DUKE  *
BABY TATTOO   *	SPARK   *	SHERA  ++
NOTCH	RIDGE
*  Clean Fin	+ dead	++ probably dead

So I’ve come up with 70 active dolphins for Area 1, give or take a few whose territories tend to find them more often south or north of Area 1.  For instance KayCee and Slick Joey were included though they spend much of their time in Naples; Yorkshire Lass and David, two other dolphins that show up when we query the database for dolphins that have occurred during Area 1 surveys, were not included as the totality of their sightings suggest they are likely Area 2 dolphins.

By the numbers: 18 Adult females; 19 Adult males; 16 Calves; 16 sub-adults of various ages.

You will want to know how I arrived at these estimates, how for example dolphins came to be categorized as male or female, mature or sub-adult.

Adult females were easy: they have been observed caring for calves at one time or another.  This is fairly easy to determine while observing dolphins.  When dolphins are very young they are kept quite close to the mother and the difference in size is obvious.  Also, the calves’ fins are usually in pretty good shape compared with adults.

The adult male designations were based largely on association patterns and in some cases size: most are now or have been in what looks like male pair bonds.  This is one of the many cases where we are applying insights that the folks at the Sarasota Dolphin Research Institute have gleaned from over forty years of research.  They discovered years ago that male dolphins upon reaching maturity would often form a bond with another male of similar age and that these bonds could endure for decades. *  Oscar and Sharks are a good example of a male pair bond in our area: in five years of surveys and hundreds of sightings, they have rarely been seen apart. The designation of Hatchet and Capri as adult males is perhaps premature, but both, besides having a strong association with each other that may suggest incipient male pair bonding, tend to associate most frequently with adult males, less frequently with the sub-adults in the area.  I imagine them as reproductively mature or on the cusp of maturity, but still too young to be players in the mating game.  I might be exactly wrong.

The designation of dolphins as younger sub-adults was pretty easy as well.  All of these dolphins were still with mum when we first encountered them.  Given that calves stay with their mothers from two to five years on average, we can estimate their age fairly accurately.  This is especially true of the five sub-adults that we have been observing since their birth.

The older sub-adults designation involves the most guesswork.  Unlike the pair bonded males who were almost always with each other and often with one of the adult females, the older sub-adults’ associations were more across the board.  They associate with just about everybody in the population but also a lot with each other, and often in larger groups.  Also, less scientifically, when I ran a query asking which dolphins appeared in the ‘leap’ and ‘play’ categories they all came up with some impressive numbers.  When you add in ‘social’ they really stand out.

I have a high degree of confidence with this description of the area 1 population, but certainly as we expand the range of our surveys into adjacent waters, new information will emerge that will clarify the picture.