Tuesday, June 15, 2021

An Interesting Birthing Season in The Making

Stepping Stones

Photos by Bob McConville | Cosmo gave birth to Humboldt in October of 20018. This calf has come a long way, now fishing by mom’s side and full of knowledge to begin life on its own later this year.


 

DOLPHIN EXPLORER LLC IS THE PROPRIETOR OF THE 10,000 ISLAND DOLPHIN STUDY WHICH MONITORS THE ABUNDANCE, TRAVEL RANGE, DISTRIBUTION, ASSOCIATION PATTERNS AND BEHAVIOR OF THE LOCAL BOTTLENOSE DOLPHIN POPULATION. OUR STUDY CONTINUES….

The Dolphin Explorer team members are really excited about the upcoming birthing season for the bottlenose dolphin population this fall…. I mean REALLY excited! 2021 could be the most productive year for new calves that we have ever witnessed! There is plenty of logic and reasoning to support our claim so let’s get right to it.

Born in the fall of 2018, Ariel experienced a fishing line entanglement on his dorsal fin just a few months later. Along with eight other calves approaching three years old this fall, Ariel could be leaving mom Kaya’s side this Summer.

Dolphins are able to give birth anytime of the year but in the north Marco Island area this tends to be in the fall. We’ve tried to understand why but have not yet come to a logical conclusion. Birthing season is different out in the Gulf, on the south end of Marco and even so in Sarasota and on the other coast. Unlike human females, dolphins do not have a constant ovulation cycle and are believed to possess the ability to ovulate spontaneously and may do so between one and six times per year. This ovulation period could last from 20 to 40 days. Here in north Marco, this tends to happen in the fall.

Dolphins will mate all year long but if the female is not ovulating, she will not become pregnant. Females will have multiple male partners throughout the year so there is no family structure of mom, dad, and baby when a new calf is born. The male will not raise a calf with a female. Now, the pregnancy period for a female dolphin is 12 months. Since they conceive primarily in the fall, the calves will be born the following fall.

Back to the fall of 2021 and why our team is excited. Typically, we will see between four and 10 new calves born each fall and surrounding months, with an average being six or seven over the last decade. In the fall of 2018, we had 10 new calves born with nine surviving. This is important because most calves will stay by their mothers’ sides for about three years, but occasionally four years. Add three years of growing, learning, socializing, and feeding next to mom to this 2018 crop of youngsters and that brings us to 2021. Throw in the factor that some of our younger dolphins are maturing and some calves turning four years old, this could lead to a record number of newborns this fall.

Here’s a quick rundown for 2018: Orange gave birth to Swoop, Kaya to Ariel, Cosmo to Humboldt, Chip to Guac, G3 to Muffin, Nadine to Pigeon, Kaycee to Sunshine, Payton to Marvel, Darwina to Ginger and Sintas to Gypsie (Gypsie did not survive). For females Orange, Kaya and Nadine this was their first calf. The mothers of the other six surviving calves are all experienced. Sintas’ calf Gypsie did not survive but Sintas became pregnant within a few months and gave birth to Jimbo in November of 2019.

In addition, young females Skipper and Zipper had been followed often by several of our dominant males last fall so there is a possibility that they may have reached maturity and could give birth to their first offspring this year. There are several other females that are mature and potential new moms as well.

Porkchop did not leave mom Sparky’s company last fall, staying with her for an extra year. Turning four this year, Porkchop could be on its own soon if Sparky is pregnant. Sparky has raised several other youngsters and she is actually the grandmother of Swoop, born in 2018. A few of our grandmothers have given birth in recent years.

One factor that can tip our crew that a female is pregnant is the separation of a youngster from mom’s company. Over the years we have noticed that several of the young have left mom at 32 to 34 months old. Usually, this pattern is an indication that the adult female is pregnant, and the young dolphin has learned what it could from the mother. This has been verified on several occasions. Therefore, the little one is no longer a calf but is considered a “sub-adult”, mature enough to be on its own but not yet physically and sexually mature. They will be fully mature at about seven to 12 years of age. 

Can you feel our excitement yet? Nine calves potentially leaving moms’ sides because the adult might be pregnant, several females reaching maturity, other females that did not give birth in the last few years…this could be a record-breaking birthing season in the north Marco waters!

The Dolphin Explorer survey team will be watching for the “almost” three-year old’s that leave mom over the next few months and we will definitely be on the water VERY often this fall to record as much data as we can about our new calves. How many baby dolphins will we find?

STAY TUNED! Watch for progress on our website dolphin-explorer.com.

I would like to commend our team for their outstanding research and passion to make it a mission to help our guests become educated as well as having fun. Thank you, Hailey, Cathy, Captain Eddie and Captain Jason for sharing your ideals with others! 

Bob is a Naturalist on board the dolphin survey vessel Dolphin Explorer. He is also an owner of Wild Florida Ecotours at Port of the Islands. He is the author of two books and a speaker at area venues and is an award-winning columnist for Coastal Breeze News. Dolphin Explorer recently received Trip Advisor’s Traveler’s Choice Award for 2020, with constant excellent reviews placing them in the top 10-percent of events. Bob loves his wife very much! 

 


 

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