Another Tropical Day

Calf at Play 
This is the third day in a row where we have found Jpeg and her new calf in a group. Jpeg’s calf is less than a year old. We can determine approximate time from birth by comparing the size of the calf with the adults. Calves that are only a few weeks old (called neonates) are about ¼ the size of an adult (average adult bottlenose along Florida = 2.5m). They are usually much darker in coloration with lighter colored lines on their sides. These are what we call fetal folds, from when the calf was bent over on its side when in the womb. In addition, very young calves may have bent dorsal fins and flukes (also from being compacted in the womb) and surface very differently from adults and older calves, raising the entire head out of the water when surfacing.

Jpeg and her young calf

Jpeg's calf is less than a year old. Bottlenose dolphin calves greater than a year are >2/3 the size of an adults. This calf (which the interns have named pixel) is full of energy, and spends most of the time we have seen it, playing. Either on its own or with other group members. Yesterday it was playing with another young female (Captain Runaground). Today it played with a calf that was present. Play involves practice chasing fish, rushing through the water at a fast pace around and around other dolphins in the group and leaping around other dolphins. It sort of resembles a young puppy who is trying to get your attention. Calves are usually the member of the group that will approach our boat and circle us, or attempt to bow ride while we work to get pictures of the adults in the group. When near us, they will roll on their side to get a peek of us. They are very curious about everything.

Splitfin 

Splitfin

Splitfin was also noted over the past two days. Animals with split fins have been noted in many dolphin populations. This can occur either through fighting or by getting caught in fishing line. We think that Splitfin likely got this injury through fighting because the tear is jagged. Fishing line injuries can appear straighter (but not always). I am always worried that Splitfin will get in another fight and loose part of the fin, making it difficult to re identify her. But she has remained the same so far for the number of years we have watched her. She has been a mom in the past but does not have a calf at this time.

Blowhole
The blowhole of the dolphin is the nostril. 

This differs from other mammals, who have the nostril very close to the mouth. Many people are not aware that dolphins actually evolved from terrestrial mammals. And in the fossil record, you can see the change over time, where the nostril slowly migrated backwards to the position it is now. This adaptation is a big help for them. With it in this location they  can surface very quickly without stopping movement to breath.

Dress code

While everyone wants to get a tan, working in the sun in the field daily is hard on the skin. For people who make this type of work a career, special care has to be taken to help reduce the chance of skin cancer. We are lucky that there are lots of specialized clothing available now to help, including headgear that allows you to cover your entire face.