The rain didn't keep us off the water today...at least until after we collected some data

Like yesterday, we woke to a radar full of greens, yellows and reds over our study area, and had to postpone our start time to later in the day. On many days we play the waiting game, continuing to check the radar till we see a clearing. We got a small window today about 10:00 (usualy leave time is 6:30) and were lucky to find a group of dolphins before another large storm developed that moved quickly on us and forced us off for the rest of the day. Below are some summaries about some of the individuals/behavior we noted. 

Younger members of the population
We followed many known animals today including Blip. 

Blip a young female in the Key West population

We have followed Blip, shown in the photo below, since her birth. Her mother was Poweraide, who we have not seen now for 2 years and may have passed away. Blip does not have many nicks but she attained the ones she has early on and they have not changed much over time. Blip is not old enough yet to reproduce. Bottlenose dolphin females generally do not begin reproducing until around age 12. But she interacts with many of the Key West animals socially. To identify an individual as a female, we either note the presence of a calf next to an animal repeatedly over time (days, months) or we have to get that information from genetic analysis of the skin. This is how we were able to determine Blip’s gender. We previously sampled a sub set of dolphins from the area near Key West, where we collected a small plug of tissue (about the size of a pencil eraser or smaller) which included the skin and blubber. With this small tissue sample, we could determine the gender of each individual and much more (e.g. who they were related to, and even what they had been eating).

Tails everywhere
Today we encountered a group that was socializing a great deal. When dolphins socialize from the surface you can see a great deal of splashing and fast movement, including throwing the tail around in the air. In some of the photos shown below you can see that similar to the dorsal fins, flukes of dolphins also sometimes accumulate nicks.

Dolphin flukes

In large whales, these nicks are used to identify individuals similar to the way we use dorsal fins in bottlenose dolphins. We cannot use the flukes in this way because we rarely see the flukes exposed, and when it does occur, it is usually very fast as a part of frenetic social activity. In large whales, for many species, there is no dorsal fin. And in those that have one this fin is very small. Large whales however have characteristic fluke up dives which are usually slow and pronounced, allowing researchers to capture photos of them and then use them to identify who was present.